Browse Topic: Wear

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Comparison of Electronic Chip Detectors and Online Debris Monitoring for Rolling Element Bearing Spall DiagnosticsF-0080-2024-12145/7/2024
Wear debris monitoring and analysis is a common practice for the condition assessment of engine and transmission health. Oil debris monitoring (ODM) and electronic chip detectors (ECD) are two common methods deployed for continuous monitoring of oil wetted component health in-flight. This study evaluates the diagnostic performance of the two sensing technologies within controlled rolling element bearing (REB) fault experiments. Progressive visual inspection of the REB spall progression through failure provided a ground truth against which both systems could be compared. Quantifiable metrics of reliability, diagnostic accuracy, provided maintenance interval were defined to create a framework for condition-based maintenance (CBM) program decision making. In summary, it was found that the ODM sensor system provided earlier fault notice, but more so, vastly outperformed the ECD in reliability and avoidance of false positives.
Mahmoud, Hassan, Rodger, Steve, Oszmian, Adam
Influence of Rotorcraft Gearbox Lubricants on the Relative Adhesive Wear of Rolling Element Bearing Material PairsF-0079-2023-181445/16/2023
Jr., Carl, Sadinski, Robert, Hullenbaugh, Gretchen
Relative Adhesive Wear Performance of Rolling Element Bearings Material PairsF-0078-2022-176025/10/2022
ABSTRACT
Sadinski, Robert, Hager(Jr.),  Carl, Prock,  Dave
Abrasion Resistance Testing - Vehicle Exterior Graphics and Pin StripingJ1847_202101 (Current)1/7/2021
This SAE Recommended Practice applies to the abrasion resistance testing of decorative tapes, graphics, and pin striping. It may also have relevance to certain vehicle labels and plastic wood grain film. The resistance to abrasive damage is judged qualitatively by its effect on the legibility, pattern, and color of the graphic marking. This recommended practice is intended as a guide toward standard practice but may be subject to frequent change to keep pace with experience and technical advances. This should be kept in mind when considering the use of this recommended practice.
Materials, Processes and Parts Council
Experimental Study of Tread Rubber Compound Effects on Tire Performance on Ice02-13-02-00066/16/2020
Mechanical and thermal properties of the rubber compounds of a tire play an important role in the overall performance of the tire when it is in contact with the terrain. Although there are many studies conducted on the properties of the rubber compounds of the tire to improve some of the tire characteristics, such as the wear of the tread, there are a limited number of studies that focused on the performance of the tire when it is in contact with ice. This study is a part of a more comprehensive project looking into the tire-ice performance and modeling. In this study, to understand the effect of different rubber compounds on the tire performance, three identical tires from the same company have been chosen. The tires’ only difference is the material properties of the rubber. Two approaches have been implemented in this study. For the first approach, several tests were conducted for the chosen tires at Terramechanics, Multibody, and Vehicle Systems (TMVS) laboratory at Virginia Tech to compare their performance experimentally. For the second approach, a tire-ice model has been used to compute the height of the water film created at the contact patch. As will be shown in this study, an increase in the height of water film results in a decrease in the friction coefficient, which is one of the most critical parameters for the tire performance. By having this knowledge, the performance of the three tires considered in the study was compared using the developed tire-ice model, based on the values obtained for the height of the water film. It is shown that the results obtained by simulation coincide with the results obtained experimentally. The results from this study show the sensitivity of the magnitude of the tractive force with respect to parameters such as tire temperature, normal load, etc. The results also indicate that the tire with the lowest value of Young’s modulus has the highest traction among all three tires used in this study.
Mousavi, Hoda, Sandu, Corina
Advances in Drilling with PCD (Polycrystalline Diamond)2020-01-00353/10/2020
PCD properties were optimized to drill stacks of CFRP/Ti using an accelerated wear test milling gray cast iron. The optimized PCD was then used to prepare PCD drills. Tests were made to determine the best drilling conditions for the optimized PCD. The results yielded a significant improvement in cycle times as compared to earlier studies using PCD drills. Notched PCD cutting edges were found to eliminate oversizing of the CFRP near the interface of the two materials.
Bunting, Jeremy, Bunting, John
Tool Wear Analysis on Drilling Process of Inconel 718 Superalloy2020-01-00343/10/2020
The Inconel 718 is an alloy based on nickel of high thermal and mechanical resistance, which allows its wide application in the aerospace industry, being generally implemented in aircraft tail cone and engine components. On the other hand, these features become a recurring problem when the machining of this material is performed. For example, in the drilling process of this superalloy, the cutting tools used exhibit excessive wear due to the high temperature and pressure at the cutting edge. However, there are numerous parameters that can influence the cutting tool life, and when analyzed and well defined, determine the types of modifications needed to enable less wear, and consequently an increase of its useful life in service. Given this context and knowing that the study of tool life in the Inconel 718 drilling process is extremely relevant in the aerospace sector, this paper presents a wear study in order to evaluate the behavior of different types of cutting tools used to drill the Inconel 718. It was accomplished by the combination of different cutting parameters to perform the mechanical drilling tests on Inconel 718 sheets, using the Taguchi method as a quality tool for process investigation, and consequently the wear analysis of the cutting tools.
Barros, Pedro Cabegi, Barbosa, Gustavo Franco, Ventura, Carlos Eiji Hirata, Santos, Gustavo Roberto
Acoustic Interactions Change Materials at the Atomic LevelTBMG-357981/1/2020
When exposed to stress and strain, materials can display a wide range of different properties. Using sound waves, scientists have begun to explore fundamental stress behaviors in a crystalline material that could form the basis for quantum information technologies. These technologies involve materials that can encode information in a number of states simultaneously, allowing for more efficient computation.
Analysis of Metal Pick-Up Formation Process within Automotive Brake Pad05-13-01-000311/19/2019
Metal Pick-Up (MPU) is a problematic phenomenon in automotive disc brakes. MPU generally forms as some metal lumps on the surface of the brake pad. If brake pads have MPU, during braking they would cause grooving of the disc rotor, generating brake noise and deteriorating the performance of the brake. The previous literature has so far reported that the source of the MPU is an Fe component from a disc rotor or brake pads. However, only a few of the generation mechanisms of MPU have been proven. We investigate MPU to completely elucidate the mechanism of MPU generation by using different analyses than the previous literature. First, to find out the source of MPU generation, we focus on the chemical reaction of a certain component with wear debris during braking, and some of the verification experiments are conducted under the conditions of simulated friction interface. Second, to clarify the change in the form of the MPU growth process, the crystal structure of MPU is analyzed in detail by using the world’s largest synchrotron radiation facility (SPring-8). The results in this study reveal new facts about the source of MPU generation and the MPU growth process that have so far only been supposed.
Noda, Hirokazu, Takei, Takahiro
Patterns of O-Ring FailuresAIR1707C (Current)11/19/2019
The information presented herein describes the commonly observed patterns of O-ring failure by means of both text and illustration. Possible causes and corrective actions are indicated for alleviating the problem.
AMS CE Elastomers Committee
Tensile and Fatigue Behavior of Shallow Cryogenically Treated EN19 Alloy Steel2019-28-010010/11/2019
Tensile and axial fatigue tests were conducted on shallow cryogenically treated EN19 medium carbon alloy steel to investigate its mechanical behavior. The test samples were conventionally heat treated then oil quenched at room temperature. Followed by the samples were kept for shallow cryogenic treatment to -80°C for 8 hours using liquid nitrogen. Then the samples were tempered in a muffle furnace to relieve the induced residual stresses. Tensile and axial fatigue test were carried out on both treated and non-treated samples to measure its tensile strength and fatigue behavior respectively. Microscopic examination also had done to compare the effect of shallow cryogenic treatment on its microstructure. The results exposed that there is an increase in the tensile strength and reduction in fatigue life of shallow cryogenically treated samples over base metal and improved wear resistance.
Sekar, Loganathan, Raj, Rajendran, Arasan, Tamil
Ceramic Bound Materials: A Suitable Solution for Light Brakes2019-01-21099/15/2019
A ceramic bound matrix has been investigated to be used as a friction material. The materials were produced by means of ceramic technology using frits containing silicates, and ceramic friction modifiers such as tin oxide, zircon, iron oxide, magnesium oxide. Four formulations were tested by means of a tribometer (pin-on-disc tester) using a gray cast iron counterpart. Test section included speeds between 1 and 12 ms-1, and loads between 25 and 400 N. The coefficient of friction of the tested specimens were between 0.7 and 0.4, and exhibited sensitivity to speed at low loads (25 N), while they are quite stables at high loads (400N). The characterization of the tribolayers was carried out by means of scanning electron microscopy. The four developed materials were named A, B, C, and D. They exhibited different wear rates and coefficients of friction. All the materials exhibited sensitivity to speed, while showed a lower sensitivity to load. The coefficient of friction level seems to be suitable for brake applications, oscillating between 0.6 and 0.4, depending on the test section. This kind of materials with further efforts can be possibly useful in future electric vehicles that will not demand large and expensive brakes.
Dante, Roberto C., Cotilli, Edoardo, Conforti, Michael, Cotilli, Mario, Serrano-Posada, José Carlos, Schramm, Tobias, Ostermeyer, Georg-Peter, Dastrù, Marco
Influence of Amount of Phenolic Resin on the Tribological Performance of Environment-Friendly Friction Materials2019-01-21059/15/2019
The binder in friction materials (FMs) plays a very crucial role which binds all the ingredients firmly so that they can function the way they were supposed to do. The type and amount of binder, both are very critical for manipulating the desired performance properties, which mainly include friction and its sensitivity towards operating parameters, wear resistance, counter-face friendliness, noise, vibration etc. Although a lot is reported on the influence of types of resins on tribo-performance of FMs, hardly any paper pertains to paint this on a bigger canvas with more detailed understanding of the amount of resin in FMs on the performance properties. The present study addresses these aspects by developing brake-pads with identical composition but varying in amount (wt. %) of straight phenolic resins (6, 8, 10 and 12) by compensating the difference with barite, a space filler. The ingredients did not contain asbestos, Copper, Zinc, etc. and hence were environment friendly. Tribological performance of the composites was evaluated on a full-scale inertia brake dynamometer following JASO C406 test schedule. With increase in the resin contents, most of the performance properties showed improvement. The performance ranking of pads was done using ‘Multiple Objective Optimizations based on Ratio Analysis (MOORA)’ method based on several conflicting criterions. Worn surface topography of pads was investigated using SEM technique to understand the underlying wear mechanisms.
Kalel, Navnath, Bijwe, Jayashree, Darpe, Ashish
Disc Thickness Variation (DTV) Operational Measurement and Influence on the Overall Vehicle Roughness2019-01-21109/15/2019
The brake disc or rotor design is one of the main concerns in the development of the vehicle brake system. One of the key factors of its drawing and manufacture is related with the thermo-mechanical deformation that can transmit further vibrations to the complete vehicle. This phenomenon, called brake judder or roughness, can appear in both cold and hot brake conditions, the latter being especially affected by the thermal factor. The evolution of the disc shape fluctuation and Disc Thickness Variation (DTV) is usually illustrated before and after a test, reflecting typically the same output. However, the real transient disc behavior during these phases is rarely measured and is difficult to determine. The reality is that most of the time, some unexpected deformations may appear, these being the final root cause of the excitation of judder vibration. During the cold judder, the disc starts at a low temperature and controlled DTV, which corresponds to the disc’s natural shape and is only affected by the wear conditions. On the other hand, hot judder is performed by repeating consecutive snubs, heating up the rotors to a high temperature and assessing the roughness in those ranges. In this case, not only the DTV evolution during the stop is important, but also the change between each snub, according to the temperature increase. All in all, the methods presented in this study become a strong tool for understanding how real and operational measurements are done, and how they can be effective for problem solving activities and useful for validating component design developments.
Ferrer, Bernat
Divergence of Thickness Loss vs. Weight Loss, Friction and Wear Behavior of Heavy Truck Brake Blocks: Development of a New Test Procedure for the Chase Tester2019-01-21079/15/2019
Heavy truck brake blocks are found to swell (or expand) permanently during testing or usage, especially so at high temperatures, thus leading to longer durability as measured by thickness loss, similar to light vehicle disc pads. This swelling phenomenon occurs continuously in the layer adjacent to the friction surface during testing or usage; not a one time event. The thickness loss estimated from the weight loss is always greater than measured thickness loss. Brake block wear does not increase linearly with increasing normal load, and the load-sensitivity of block wear is very much dependent on the products. A new test procedure has been developed for generating friction-vs.-temperature and wear-vs.-temperature data at a constant temperature employing intermittent braking on the Chase Brake Lining Quality Tester (SAE J661) and friction material wear can be compared on equivalent-work basis.
Rathee, Aman, Sharma, Devendra Kumar, Singh, Shivraj, Rhee, Seong Kwan
The Normal-Load and Sliding-Speed Dependence of the Coefficient of Friction, and Wear Particle Generation Contributing to Friction: High-Copper and Copper-Free Formulations2019-01-21319/15/2019
Automotive brakes operate under varying conditions of speed and deceleration. In other words, the friction material is subjected to a wide range of normal loads and sliding speeds. One widely accepted test procedure to evaluate, compare and screen friction materials is the SAE J2522 Brake Effectiveness test, which requires full-size production brakes to be tested on an inertia brake dynamometer. For the current investigation, disc pads of two types of 10 different formulations (5 high-copper and 5 copper-free formulations) were prepared for testing on a front disc brake suitable for a pickup truck of GVW 3,200 kg. Each pad had 2 vertical slots, and one chamfer on the leading edge and also on the trailing edge of the pad. One segment of the test procedure looks at the coefficient of friction (Mu) under different brake line pressures and different sliding speeds to determine its stability or variability. In all cases, the Mu is found to be dependent on the normal load and sliding speed, contrary to the commonly called “Amontons-Coulomb’s Laws of Friction”. According to Wikipedia, Guillaume Amontons (1663 - 1705) observed that the force of friction was directly proportional to the applied load, meaning constant coefficient of friction and that the force of friction was independent of the apparent area of contact, while Charles-Augustin de Coulomb (1736 - 1806) observed that when a piece of metal was slid against wood, the coefficient of friction became very dependent on the normal load and the sliding speed and warned about the limitations of Amontons’ findings. Now one wonders how and when the expression of the so-called “Amontons-Coulomb’s Laws of Friction” surfaced as universal laws. According to analysis of the test data generated in this investigation, the average Mu is found to increase linearly with the increasing total wear rates of the disc and the 2 pads (the inboard and the outboard pads) in the case of copper-containing formulations and also in the case of copper-free formulations: each type of formulation has its own linear relationship. The average Mu is found to consist of 2 parts. One part is dependent on the total wear rates of the disc and the 2 pads while the other part, which is the Mu at zero wear, is independent of the wear rates. Also in this investigation, the disc wear rate is found to be directly proportional to the total wear rate of the 2 pads (the inboard and the outboard). As the pad wear is reported to be best described by a power function of the normal load and the sliding speed, a power function becomes applicable to the disc wear rate as the disc wear rate is proportional to the pad wear rate. So the wear dependent part of the Mu becomes a power function of the normal load and the sliding speed.
Rhee, Seong K., Sriwiboon, Meechai, Tiempan, Nipon, Kaewlob, Kritsana
A Study on the Optimum Reduction of Required Brake Fluid Level for Improvement of the High Speed Continuous Brake Distance2019-01-21219/15/2019
The high speed continuous braking distance assessment is the worst condition for thermal fades. This study was conducted to investigate the relationship between fade characteristic and friction materials & brake fluid amount for improving braking distance. So, we used the dynamometer to measure the friction coefficient, braking distance and required brake fluid amount. Through the measurements, the research was carried out as follows. First of all, we studied the influence of friction coefficient about different shapes (chamfer shape, area of the friction material, number of slots) on the same friction material. Secondly, we knew the effects of braking distance by the shape of the friction material. Through these two studies, the shape of the friction material favorable to the fade characteristics was derived. Finally, we measured the amount of required brake fluid in caliper after 10 consecutive braking cycles through Dynamometer. And then, we measured the amount of compression deformation and uneven wear of the friction material. It was found that the above two factors cause the increase the amount of required brake fluid. Through this study, in order to have strength for the fade characteristic, it is required that continuous management of the friction material and shape of brake pad. This is because the friction coefficient and the high temperature compression deformation of the friction material are determined by its material. Also, it is necessary to robust design the caliper for reducing for uneven wear about the brake pad.
Kim, Junggyu, Kim, Kwang Yun, So, Eue-sub
The Influence of Differential Pad Wear on Low-Frequency and High-Frequency Brake Squeal2019-01-21309/15/2019
The NVH behavior of disc brakes in particular, is in the focus of research since a long time. Measurements at a chassis dynamometer show that brake pad wear has a significant influence on the occurrence of low- and high-frequency squealing [1]. It is suspected that high-frequency squealing is more likely to occur when the wear difference between the inner and outer brake pad is small. In the other case, if the differential wear rate between the inner and outer pads becomes higher, the prevalence of low-frequency squealing increases. In order to examine this hypothesis, this work focuses on a simplified model of a commercial brake system [2]. In a first step, the inner pad’s wear is iteratively increased, while the wear on the outer pad remains unaffected. In a second step, the coefficient of friction at the worn pad is iteratively increased to investigate the influence on the low and high-frequency squealing. With the aid of the Complex Eigenvalue Analysis (CEA), the real part of the eigenvalue is used as a quantification measure in order to investigate the dependence between wear and high and low frequency squealing.
Otto, Johannes, Ostermeyer, Georg-Peter, Rhee, Seong K.
Semi-Empirical Modelling of Erosion Phenomena for Ice Crystal Icing Numerical Simulation2019-01-19676/10/2019
The aim of this work is to develop a semi-empirical model for erosion phenomena under ice crystal condition, which is one of the major phenomena for ice crystal accretion. Such a model would be able to calculate the erosion rate caused by impinging ice crystals on accreted ice layer. This model is based on Finnie [1] and Bitter [2] [3] solid/solid collision theory which assumes that metal erosion due to sand impingement is driven by two phenomena: cutting wear and deformation wear. These two phenomena are strongly dependent on the particle density, velocity and shape, as well as on the surface physical properties such as Young modulus, Poisson ratio, surface yield strength and hardness. Moreover, cutting wear is mostly driven by tangential velocity and is more effective for ductile eroded body, whereas deformation wear is driven by normal velocity and is more effective for brittle eroded body. Several researchers based their erosion modelling on these two phenomena such as Hutchings et al. [4] for deformation erosion, or Huang et al. [5] and Arabnejad et al. [6] for cutting and deformation erosion. The main work of this paper is to develop an erosion model for ice crystal impingement based on these two phenomena, and to show its capability to predict accretion shape by simulating experimental cases from the National Research Council of Canada (NRC). NRC’s Currie et al. ice crystal experiments [7] [8] realized in warm aerodynamic conditions, such as the one encountered in high icing severity areas of a turbofan engine, show accretion severity for a large range of liquid water content to total water content. In order to validate the erosion model based on solid/solid collision, this paper presents the simulation of the lower melting rate experiment. Results show fair agreement with experimental data and allow us to propose pertinent further work.
Charton, Virgile, Trontin, Pierre, Aouizerate, Gilles, Villedieu, Philippe
Modeling of Micro-Perforated Heat Baffle2019-01-15826/5/2019
Classical porous materials are used throughout the automobile with usually good success but there are limitations to their performance in areas where there are adverse environments. An example of this is the transmission tunnel section under the automobile, where there exist high air flow velocities and temperatures which will lead to quick deterioration of the material. Micro-Perforated Heat Baffles (MPHB) are showing success in the heating, ventilating, and air conditioning industry, and therefore there is an effort in applying MPHB extensively in the automotive field. The question with regards to which micro-perforation pattern gives the best performance plus where and how much should be allocated in the automobile still remains. This paper shows how to address these issues by applying Hybrid Statistical Energy Analysis (HSEA) technology. An expression for the Absorption Coefficient (AC) which incorporates the micro-perforation pattern is explained. This equation models the absorption of sound due to friction losses in the holes. Thereafter calculations for flat sample AC are completed and good correlation with experimental data is shown. Flat sample AC is necessary to know but by itself it does not answer the important question whether SPL suppression is being realized on a real car and how this is addressed without building multiple prototypes. Thus, the paper emphasizes the importance of having a HSEA model and how with this model an noise and vibration specialist can run multiple MPHB concepts. This paper shows this capability by applying MPHB to cover the transmission tunnel under the automobile and the calculated SPL under different input modes such as road noise and engine noise.
Teagle-Hernandez, Allen, Ide, Fumihiko, Ichikawa, Shota, Yabe, Kengo, Matsuda, Takehisa
Smart, Soft, Back Orthosis Uses Real-Time Motion DetectionTBMG-346136/1/2019
Back pain is inevitable with constrained posture over a number of hours. Permanent damage such as premature spine wear is not uncommon in people who do not adopt proper ergonomic posture. The same applies to those who frequently lift heavy objects.
Environmental Degradation of TextilesAIR1490C (Current)4/24/2019
Since cargo restraint devices made with textiles should have a predictable service life, there should be data available so that predictions can be made. This document compiles available information on textiles of the types used in air cargo restraint devices and reviews the degradation characteristics of each. Textiles are used primarily in cargo restraint nets on air cargo pallets and nonstructural containers, restraint nets installed in cargo aircraft, and similar applications.
AGE-2 Air Cargo
Wear-Resistant Platinum Gold AlloyTBMG-341724/1/2019
From cellphones to satellites, industry spends millions on traditional gold alloy electrical contact coatings. While gold and other metal alloys have been an industry standard to protect metal components from wear due to metal-on-metal contact, they still experience deterioration over time. Using a novel synthesis approach, Sandia researchers developed an ultra-wear-resistant platinum gold (Pt-Au) alloy that can replace gold alloys for improved durability, longevity, and reduced costs in electronic devices.
Self-Lubrication Improves Standard Braking SystemsTBMG-341164/1/2019
By mixing carbon fibers into polymer-based brakes, researchers designed brakes that are self-lubricating. These new and improved brakes can prevent wear-and-tear and have better frictional properties than brakes currently on the market.
Process for Assessment and Mitigation of Early Wearout of Life-Limited MicrocircuitsARP6338A (Current)2/8/2019
This document is intended for use by designers, reliability engineers, and others associated with the design, production, and support of electronic sub-assemblies, assemblies, and equipment used in AADHP applications to conduct lifetime assessments of microcircuits with the potential for early wearout; and to implement mitigations when required; and by the users of the AADHP equipment to assess those designs and mitigations. This document focuses on the LLM wearout assessment process. It acknowledges that the AADHP system design process also includes related risk mitigation and management; however, this document includes only high-level reference and discussion of those topics, in order to show their relationship to the LLM assessment process.
APMC Avionics Process Management
Tribological Performance of an Engine Mineral Oil Blended with a Vegetable Oil under Approached Long-Term Use Conditions2019-01-00121/15/2019
It has widely reported that tribological performance of engine mineral oils (EMOs) can be improved by blending them with vegetable oils (VOs) in certain concentrations. Nonetheless, bio-oils are more susceptible to oxidation than EMOs by thermal ageing, which could be a drawback when they are used in engines comprising high variations of temperature. In this paper, a comparative analysis of tribological performance of an EMO and a blend made of 80%vol. of EMO and 20%vol. of a VO in fresh and aged conditions is given. The VO selected for the blend was Jatropha oil since various advantages reported in literature. EMO and B20 were thermally aged in laboratory approaching actual oxidation and additives depletion caused in EMO used in a car for 7500 km. The effects of ageing on the oils were evaluated by means of oxidation (PAI value), Zinc dialkyldithiophosphates (ZDDPs) depletion and viscosity. The tribological performance of the oils was determined by measuring the friction coefficients and wear rates generated in samples from engine cylinder liners in a pin-on-disk tester under boundary lubrication conditions. The ageing caused increased viscosity in B20 contrary to EMO that presented a slight decrease. The friction coefficients of B20 were lower than EMO in fresh and aged states. Moreover, the wear rate caused by fresh EMO and B20 were similar; however, ageing caused an increased wear rate by EMO but a decreased rate by B20 meaning that B20 exhibited better tribological performance than EMO under boundary lubrication in fresh and aged conditions.
Farfan-Cabrera, Leonardo Israel, Gallardo, Ezequiel, Gómez-Guarneros, Mario, Hernandez Peña, Andys
Piston Detergency and Anti-Wear Performance of Non-Phosphorus and Non-Ash Engine Oil2019-01-00211/15/2019
The deposition of ash derived from engine oil on the surface of diesel particle filters (DPF) has recently been reported to degrade the performance of the DPF. It is generally known that phosphorus in engine oil is adsorbed on the surface of an automotive exhaust catalyst, reducing the performance of the catalyst. Thus, the amounts of ash and phosphorus in engine oil have been decreased. We have developed a non-phosphorus, non-ash engine oil (NPNA) that does not contain metal-based detergents or zinc dialkyldithiophosphate (ZnDTP). Various engine tests were performed, and we confirmed that under normal running conditions, the NPNA oil had a sufficiently high piston detergency and wear resistance-two important requirements for engine oil-to meet current American and Japanese standards. However, the piston detergency of NPNA required further improvement when engine running conditions were more severe. We performed a hot tube test to evaluate the piston detergency of NPNA at high temperatures and developed additives (ashless detergents) that did not contain ash (metallic elements). We then evaluated the piston detergency and valve train wear prevention of the improved NPNA. The tests were performed using two engines: one manufactured by Caterpillar Inc. and regulated by the guidelines of the American Society for Testing and Materials (ASTM) D6750, and one manufactured by Hino Motors, Ltd. and regulated by the Japanese Automotive Standards Organization (JASO) M354:2015. We confirmed that the improved NPNA possessed excellent piston detergency and provided outstanding valve train wear prevention.
Kasai, Moritsugu, Koshima, Hiroaki, Takashima, Yoriyuki
Are Internal Diesel Injector Deposits (IDID) Mainly Linked to Biofuel Chemical Composition or/and Engine Operation Condition?2019-01-00611/15/2019
The increased use of alternative fuels has been linked to performance deterioration of injectors and engines as a result of internal diesel injector deposits (IDID). The present paper investigates fuel composition impact on injector tendency to blockage. Three main areas were investigated : (1) deposits linked to paraffins and aromatics content; (2) deposits linked to biodiesel composition using fatty acid methyl esters (FAME) and hydrotreated vegetal oil (HVO); and (3) deposits linked to the presence of additives (Dodecenylsuccinic anhydride DDSA, Dodecenyl Succinimid DDSI and Sodium Naphthenate). A deposit formation method was developed for the injection bench in order to discriminate the impact of fuels on system performance in terms of fuel volume injected, injection duration and stability. Three operation conditions were tested to represent low, intermediate and high load. In addition, the influence of soaking time and injector heating temperature was evaluated. The nature of the deposit was studied based on its morphology and chemical composition determined using Scanning Electron Microscopy coupled with Energy Dispersive X-ray (SEM/EDX) Spectroscopy. Deposits were observed for all fuels, even the highly paraffinic biofuel like HVO. Two main results are presented: Firstly, the main impact of fuel soaking period and high load operation on the occurrence of IDID, it was observed that deposit formation can be controlled by the time the fuel remains in contact with the hot metallic surface of the injector; Secondly, the complex correlation between deposit nature and characteristics and the injector’s tendency to blockage, for example, there is no straightforward link between deposit thickness and injector blockage, other parameters seem to be more appropriate to predict injector blockage. These are discussed in more detail in this study.
Alves Fortunato, Maira, Lenglet, Francis, Ben Amara, Arij, Starck, Laurie
Durability Improvement of Cylinder Head in Alternate Fuel Engines2018-32-005510/30/2018
Alternate fuels like LPG and CNG are beneficial in terms of operating cost and emissions as well. They also contribute to reduce CO2 emissions. These gas fuels are known for its problems in engines including wear of parts. Cylinder head valve - seat wear is higher in gas engines. This paper discusses the experimental work on reduction of valve -seat wear in 3 wheeler engine. In the development of new higher power version of the gas engine valve-seat interface wear is observed. Effect of this wear on performance, leak and emissions were studied, qualitative measurements of valve temperatures were studied at different conditions with different fuels. Combustion gas and part temperatures are higher in gas engines. Simulation test cycle is developed for the wear test and various solutions to reduce wear at the valve - seat interface were evaluated. Cost effective solution is implemented with minimum changes in engine.
Thiruvallur Loganathan, Balasubramanian, Elumalai, Duraikkannan, Kumaraswamy, Phaneesh, Lakshminarasimhan, V
Environmental Degradation of Composite MaterialsARP6287 (Current)10/18/2018
In accordance with § 4.11 of AS36100, materials used in the construction of pallets, nets, and containers shall take into account the effects of environmental conditions, such as temperature, humidity, and UV degradation, expected in service. In accordance with (E)TSO-C90, the applicant shall consider environmental degradation due to aging, ultra-violet (UV) exposure, weathering, etc., for any materials used in the construction of pallets, nets, and containers. The purpose of this Aerospace Recommended Practice (ARP) is to provide guidelines for the basic requirements to be considered regarding environmental degradation effects when qualifying composite materials in the design to fulfill the (E)TSO-C90 Minimum Performance Standard. Material qualification is the verifying of a materials attributes and characterizations, which are typically determined through testing. Material variances related to raw materials and manufacturing processes are not part of this Aerospace Recommended Practice (ARP), nor is damage tolerance. However, these variances cannot be neglected, as all variances shall be considered when deciding the test factors for environmental effects.
AGE-2 Air Cargo
Adaptronic Actuator to Minimize the Pins Misalignment on Pin-on-Disc Testers2018-01-189210/5/2018
The Automated Universal Tribotester (AUT) represents a fully automated reduced scale brake dynamometer and was developed by the Institute of Dynamics and Vibrations at TU Braunschweig. The setup is based on the pin-on-disc principle. The downscaled test specimen is brought to contact to the disc, loaded and guided via the load unit, which was specifically designed for this purpose. It is laid out as a combination of parallel and serial leaf springs, facilitating a friction free and horizontal motion. The stiffness in radial and tangential directions are much higher than in normal orientation. If the test specimen has a two-dimensional, flat contact surface, the misalignment of the pin in a Pin-on-Disc setup is a phenomenon that appears even in very stiff and robust Pin-on-Disc testers. The measured friction forces are not sensitive to the tilting movement, but the wear processes that take place in the contact zone are. For investigations of the friction surface, an adaptive adjustment is necessary if no long measurement intervals with constant system preferences are tested. This paper shows the adaptive adjustment and the influence on measurements of friction and wear.
Vogel, Alexander, Ostermeyer, Georg-Peter
Non-Asbestos Organic (NAO) Disc Pad Wear Behavior: Divergence of Thickness Loss and Weight Loss2018-01-186610/5/2018
There is anecdotal evidence that disc pad wear numbers measured in thickness loss and disc pad wear numbers measured in weight loss do not show the same wear trends after wear or performance testing. However, research papers on this topic are difficult to find. Therefore, this investigation was undertaken to study and document this behavior in detail on high-copper, low-copper and no-copper (or copper-free) NAO pads. In all cases, thickness loss measurements are found to be substantially lower than expected from the weight loss data according to the SAE J2522 test schedule. This divergence is caused by pad swelling in the pad layer adjacent to the friction contact surface during brake testing at high temperatures. In addition to formulation changes, disc pad processing conditions such as mixing time and hot molding pressure are found to affect pad swelling. As pad physical properties, especially in the layer adjacent to the friction contact surface, are expected to dynamically change during braking due to the pad swelling, one has to seriously question any attempt to correlate physical properties of unused pads to brake performance and squeal generation. Detailed characterization of the dynamic changes taking place in the pad during testing/usage is recommended to gain better understanding and better prediction of brake performance and squeal.
Sriwiboon, Meechai, Tiempan, Nipon, Kaewlob, Kritsana, Rhee, Seong
Optimization of Slot Disc Shape for Improving Brake Fade Performance2018-01-188310/5/2018
Due to improvements in vehicle powertrain performance, friction material fade performance is becoming an important topic. For this reason, needs for studies to improve thermal characteristics of the brake system is increasing. Methods for improving the fade characteristics have several ways to improve the thermal characteristic of friction materials and increase disc capacity. However, increasing disc capacity(size) have some risk of weight and cost rise, and friction factor improvements in friction material tend to cause other problems, such as increasing squeal wire brush noise and increasing metal pick up on disc surface. Therefore, a slot disc study is needed to overcome the problems discussed previously. Currently, there is few research history for slot disc related to fade and metal pickup improvements. Through this study, I found that the slot disc improved the friction material fade properties, but the application of the slot disc could cause air plane noise and worsen the friction material wear characteristic this study shows that optimizing the number of slots and slot profile and slot direction on disc surface minimizes air plane noise and friction material wear characteristic.
Kim, Hyungjoon, Kim, Yoon Cheol, Seo, Hankyo, Seol, Jaekwang, Yoon, Chul, Kim, Kwang Yun
Modeling Articulated Brake Component Wear to Assist with Routing Decisions2018-01-189010/5/2018
Very few activities the brake engineer engages in can induce as much vexation as trying to find a satisfying routing for the flexible brake components such as hoses, wheel speed sensors, and electric parking brake cables. Ever increasing wheel end content, ever decreasing space, more complex suspensions, and bulkier (but lighter weight) suspension components provide quite the morass through which the components must be routed through. When routing is finalized - and free of any major issues - there frequently remains some combinations of articulation position and component tolerances that allow a light “friendly” touch between components (such as a sensor wire and a surface of a bracket or strut tube), or near misses where clearance exists but raises “what if” questions around what would happen if the tolerances would stack up slightly differently on another vehicle. These conditions are usually evaluated painstakingly by experienced engineers, and either corrected with design changes or accepted if deemed of extremely low risk - but these evaluations are generally subjective. The work presented in this paper introduces an objective assessment based on predicted wear of the component in a contact condition. It is intended to supplement - but not replace - the judgment of experienced and conscientious engineers. Data from customer usage measurements that describe the relative frequency of reaching various steering and suspension travel positions are combined with an energy-based wear model (in turn based on simple measurements of the contact condition) to generate a predicted wear volume. This wear volume is then translated through geometric calculations to a wear depth through the protective outer layer (such as hose outer cover or wire insulation), which can then ultimately be used to project the service life of the component before wear-through of the cover. The model is explained, and then demonstrated through a series of case studies.
Antanaitis, David B.
Lightweight, Wear Resistant, High Thermal Conductivity Metal Matrix Composite Brake Rotors2018-01-187910/5/2018
Aluminum (Al) - silicon carbide (SiC) metal matrix composite (MMC) brake rotors have been investigated for lightweight vehicular applications but have not widely been utilized due to issues with uniformity of distribution of SiC particulates, residual porosity, formation of undesirable phases such as aluminum carbide, and high temperatures incurred during braking that degrade the rotor’s integrity and performance. ATS-MER has overcome these issues with the development of a patented sandwich type structure with wear resistant thin Al-SiC MMC surface layers and a high thermal conductivity aluminum alloy core. Substantial dynamometer and vehicle testing has been performed by a major automobile company with excellent results, including much lower induced temperatures, 96.3 to 99.6% less particulate (dust) generation in comparable testing of cast iron rotors, and almost 10 times the number of maximum cycles possible during testing of cast iron discs. Thus, ATS-MER’s novel Al-SiC MMC brake rotors offer significant environmental benefits of much reduced dust generation and lower CO2 emissions due to lighter weight including unsprung weight, a more comfortable ride, and elimination of the need to replace the rotors over the life of the vehicle. The unique processing technology will be presented along with the current state of development and performance for conventional and electric vehicles.
Bracamonte, Lori, Withers, James, Smith, Thomas
On the Wear Dependence of Low-Frequency and High-Frequency Brake Squeal2018-01-190210/5/2018
The dynamics of disc brakes, and in particular their NVH behavior, have long been the focus of research. Measurements by Rhee et al. show that brake pad wear has a significant influence on the occurrence of low and high frequency squealing [1]. It is suspected that low frequency squealing is more likely to occur when the wear difference between the inner and outer brake pads is high. If the two pads incur comparable wear, however, the prevalence of high frequency squealing increases. In order to investigate this hypothesis, this paper focuses on a simplified model of a commercial brake system. First, the friction force between the inner pad and the disc is iteratively adjusted, while the force between the outer pad and the disc is held constant. In a second step, the inner pad’s wear is iteratively increased, while the wear on the outer pad remains unaffected. With the aid of the Complex Eigenvalue Analysis (CEA), the real part of the eigenvalue is used as a quantification measure in order to investigate the dependence between wear and high and low frequency squealing.
Otto, Johannes, Ostermeyer, Georg, Rhee, Seong
Microscale Superlubricity Improves Electromechanical DevicesTBMG-3307310/1/2018
Superlubricity — the state of ultra-low friction and wear — holds great promise for the reduction of frictional wear in mechanical and automatic devices.
Torsional Fluctuations Consideration while Design of Synchro Rings2018-01-18239/10/2018
In today’s manual transmissions of car, gearshift system requires high performance with particular emphasis on low effort, minimal travel and positive feel. To meet these targets, a high capacity multi cone synchronizers along with higher co-efficient of friction material used for lower gears. The design of synchronizer with these specifications is influenced by torsional fluctuations from engine. Excessive torsional vibrations leads to wobbling of synchro rings within the peripheral clearances with surrounding parts. Wobbling leads to abrasion wear of frictional area of synchro ring causing grating or crashing noise of gears during shifting. This paper presents the optimization of the multiple cone synchronizer design exposed to excessive torsional vibrations and validation of the same on test bench during development stage instead vehicle level validation.
Tawhare, Nitin, Aswale, Dhananjay, Ponkshe, Makarand
Deterioration Characteristic of Catalyzed DPF Applied on Diesel Truck Durable Ageing2018-01-17019/10/2018
In this paper, it was researched the degradation characteristics of catalytic performance of three kinds of DPFs (C1, C2 and C3, with precious metal concentrations being 15, 25 and 35 g/ft3 respectively) after diesel truck aging. It is found out that the crystallinity of three kinds of DPF samples (Used) in full vehicle aging was higher than that of fresh samples (Fresh) and aged samples (Aged) in the laboratory. Compared with Fresh samples, the concentration of Pt atom in precious metal on the surface of Aged and Used samples tends to decrease in most cases. Activities to CO and C3H8 of Aged and Used samples of three kinds of DPFs had all been degraded, and activity degradation showed a substantial correlation with concentration reduction rate of precious metal on the carrier surface. NO2 productivity of Used samples all rose. Crystallinity of DPF samples after full vehicle aging in Inlet, Middle and Outlet areas successively increased. The reduction rate of Pt atom concentration of Inlet samples was higher, followed by that of Outlet layer samples, and that of Middle layer samples was lower. Activities to CO, C3H8 and NO2 of Inlet samples were relatively low, yet the catalytic activity of Middle samples was relatively high. Activity differences were resulted from the differences of thermal degradation due to different thermal loads during aging.
Zhou, Hua, Zhao, Hongwei, Yin, Zenghui, Feng, Qian, Zhou, Maoxiang, Li, Jingyuan, Qin, Kongjian, Li, Mengliang
Super Low Viscosity ATF; AW-22018-01-17569/10/2018
Reducing loss torque in automatic transmissions (ATs) is a key factor in improving fuel economy. A promising approach is to reduce the viscosity of the Automatic Transmission Fluid (ATF) so as to minimize churning loss. Aisin AW and JXTG Nippon Oil & Energy Corporation have developed a super low viscosity ATF, called “AW-2”, which has approximately 50% lower kinematic viscosity at 40 °C compared to the conventional ATF “AW-1”. It is generally understood that if the viscosity of an ATF is too low, it can have a negative impact on the fatigue life of components such as gears and bearings, and possibly lead to increased wear or seizure. AW-2 was designed to solve these problems via the application of two key technologies. The first is a high performance base oil with a low traction coefficient, which translates to low viscosity under high pressure conditions. This decreases the shear resistance between sliding surfaces under elastohydrodynamic lubrication (EHL) conditions, which contributes in improving the fatigue life of bearings and other components. The second is an ester type base oil with high polarity. It was found that the amount of ester base oil used has a major influence on fatigue life. The adsorption of esters onto metal surfaces is thought to improve lubricity in severe lubrication conditions. Durability tests were performed in a wide range of conditions, using gear and bearing components and actual transmission units, and it was confirmed that AW-2 outperforms AW-1, despite its super low viscosity. Furthermore, AW-2 reduced loss torque in the transmission by approximately 10% compared to AW-1.
Masuda, Kohei, Nakao, Hajime, Komatsubara, Hitoshi, Kurosawa, Osamu, Yamada, Katsuhito, Ishikawa, Kazunori, Mori, Atsushi
Spray Parameters of Fuel Blends of Recycled Lubricating Oil and Diesel2018-01-16939/10/2018
The use of alternative fuels consisting of mineral and synthetic waste substances such as recycled lubricating oil blended with diesel is a measure to mitigate the environmental impact of the fossil fuels. However, to inject these fuel blends into contemporary engines without changes to their components, it must maintain or improve the fuel injection characteristics compared to neat diesel, in order to maintain or improve the engine performance. In the present research, the spray parameters of injected fuel, such as length, angle and atomization particle diameter in terms of the Sauter mean diameter (SMD), are modeled depending on the characterization of different concentration of the recycled lubricating oil blended with diesel. It was found that the same nozzle geometry of the injectors can provide an equivalent fuel spray performance for different concentrations of these alternative fuel blends, and that the increase of the recycled lubricating oil in the fuel blend reduced the wear of the needle and nozzle of the injector. The densities and viscosities between each fuel type are very similar and any correction of injection duration or pressure is not required. Due to simple distillation and blending process, alternative and environmentally friendly fuel blends can be obtained to reduce the combustion of fossil diesel and reuse waste pollutant substances as a sustainable and immediately applicable solution for modern engines and fuel injection systems.
Gutierrez, Marcos, Castillo, Andres, Iniguez, Juan, Reyes, Gorky
Aircraft Tire Wear Profile Development and Execution for Laboratory TestingAIR5797A (Current)8/6/2018
This SAE Aerospace Information Report (AIR) describes the current process for performing comparative wear testing on aircraft tires in a laboratory environment. This technique is applicable to both radial and bias tires, and is pertinent for all aircraft tire sizes. This AIR describes a technique based upon “wear” energy. In this technique, side wear energy and drag wear energy are computed as the tire is run through a prescribed test program. The specifics that drive the test setup conditions are discussed in Sections 4 through 7. In general, the technique follows this process: A test profile is developed from measured mechanical property data of the tires under study. Each tire is repeatedly run to the test profile until it is worn to the maximum wear limit (MWL). Several tires, typically 5 to 10, of each tire design are tested. Wear energy is computed for each test cycle and then summed to determine total absorbed wear energy. An index is calculated for each tire design. This is accomplished by dividing the total linear inches of wear at the most worn point into the total wear energy. The indexes are then normalized to provide a comparative wear rate. The described technique is not meant to provide an absolute wear rate or wear index because the technique does not produce results that allow the user to say a tire will last for a specific number of landings. However, it does provide a comparative index. It will make a distinction from one tire design to another by indicating a percentage difference in abrasive wear rate under representative operational conditions. The technique has been demonstrated in a number of test programs and is shown to have an extremely high correlation to field data. Supporting data is included in Section 9.
A-5C Aircraft Tires Committee
Quick Disconnect for High-Pressure Mate/De-MateTBMG-290536/1/2018
NASA Kennedy Space Center seeks partners interested in the commercial application of the Quick Disconnect for High Pressure Mate/De-Mate. Designed at KSC, this technology is intended for use in dusty environments where dust particles can contaminate high-pressure connectors, resulting in wear on connector surfaces and unreliable connections. The Quick Disconnect (QD) utilizes the gas supplied by the umbilical to spray on, entrain, and remove dust from the connector surfaces prior to mating.
Predicting Aging due to Thermal Oxidation and Determining Service Limit for Nylon 66 Fiber in Vehicles Exposed to Actual Weather Conditions2018-01-01124/3/2018
The guarantee of long-term reliability of cars is becoming increasingly important in society. It is extremely important to confirm whether the condition of the accelerated deterioration test (for evaluating long-term reliability) is reasonable with respect to recent use environment conditions. In this paper, we propose how to promote degradation test conditions to guarantee the function of parts (resin materials of interior parts) exposed over a long period of time to a severe temperature environment inside the car. Heat-resisting grade nylon 66 fiber (hereinafter referred to as H-PA 66), which is a constituent material of parts requiring long-term reliability, was used as a specific resin material. High-temperature accelerated deterioration test of H-PA 66 fiber was carried out to obtain the time (hereinafter referred to as 90% strength time,) during which the tensile strength retention rate decreased to 90%. The relationship between this high temperature accelerated deterioration temperature and 90% intensity time could be expressed by the Arrhenius equation. The acceleration rate of deterioration was determined from the Arrhenius plot of this equation. At the same time, we propose DOE (Design of Engineering) graph which can judge deterioration by expressing accelerated deterioration temperature on the vertical axis and accelerated deterioration time on the horizontal axis. We predicted deterioration after 15 years from the temperature history of the actual environment obtained by the exposure test. Moreover, reasonable promotion deterioration condition without excess or deficiency in the case of 15 year guarantee was sought. The DOE graph (capable of expressing the relationship between the actual use environment and accelerated deterioration test condition) improves the accuracy and reliability of the accelerated deterioration condition.
Fukuda, Takeru, Kai, Takeshi, Nakada, Masayuki, Miyano, Yasushi, TAJIMA, Yusuke
Microwave-Based Test Method for Computer ChipsTBMG-281411/1/2018
A new approach was developed that overcomes the limitation of conventional chip-testing methods on 3D chips, which include many thin horizontal “floors” connected to one another by vertical pathways called through-substrate vias (TSVs). TSVs help 3D chips do three essential things: speed up, shrink down, and cool off. By allowing elements on different floors to communicate with each other, signals no longer need to travel all the way across a comparatively sprawling 2D chip, meaning calculations go faster and electrons heat up far less conducting material as they move.
Effect of Normal Load and Temperature on the Evolution of Topology of Friction Materials2017-36-014111/7/2017
The friction materials of the drum and disk brakes correspond to one of the most complex materials applied to automotive industry, however, little is known about how this type of material reacts under wear conditions. The aim of this work is to understand the effects of loads and temperatures on the topology of brake's friction materials under wear regime. For this, brake friction material specimens were subjected to wear tests on which procedure was based on the SAE J661 standard. The tests consisted on a sequence of braking and cooling intervals, where friction material specimens were pushed against a rotating drum with controlled velocity. Different test temperatures and normal loads were set. From these tests, the mass loss of each specimen was measured. In order to understand the topological aspects of the materials tested, an optical microscope and confocal microscope were used. The variation of the surface characteristics during the wear process on each specimen was analyzed using quantitative metallography technique and the influences of normal load and temperature on the topology evolution were studied.
Terra, Caroline da Silva, Suetti, André Lima, Travaglia, Carlos Abílio Passos, Silva, Ladário da, Lopes, Luiz Carlos Rolim
Effect of Metallurgy on the Formation of Tribofilms and Wear Prevention2017-01-235710/8/2017
Different mechanical components in a vehicle can be made from different steel alloys with various surface treatments or coatings. Lubricant technology is needed to prevent wear and control friction on all of these different surfaces. Phosphorus compounds are the key additives that are used to control wear and they do this by forming tribofilms on surfaces. It has been shown that different operating conditions (pressures and sliding conditions) can influence the formation of tribofilms formed by different anti-wear additives. The effect of surface metallurgy and morphology on tribofilm formation is described in this paper. Our results show that additive technology can form proper tribofilms on various surfaces and the right combination of additives can be found for current and future surfaces.
Devlin, Mark, Guevremont, Jeffrey, Hewette, Chip, Ingram, Marc, Pollard, Grant, Wyatt, William
Enhanced Anti-Wear Performance Induced by Innovative Base Oil in Low Viscosity Engine Oil2017-01-234310/8/2017
The oil and additive industry is challenged to meet future automotive legislations aimed at reducing worldwide CO2 emissions levels. The most efficient solution used to date has been to decrease oil viscosity leading to the introduction of new SAE grades. However this solution may soon reach its limit due to potential issues related to wear with lower engine oil viscosities. In this paper, an innovative solution is proposed that combines the use of a new tailor-made polyalkylene glycol (PAG) with specific anti-wear additives. Valvetrain wear measurements using radionuclide technique demonstrates the robustness of this solution. The wear performance was also confirmed in Sequence IVA test. An extensive tribological evaluation (film formation, wear and tribofilm surface analysis) of the interactions between the base oil and the anti-wear additives lead us to propose an underlying mechanism that can explain this performance benefit.
Champagne, Nicolas, Obrecht, Nicolas, Gangopadhyay, Arup, Zdrodowski, Rob, Liu, Z
New Generation Fuel Efficient Engine Oils with Superior Viscometrics2017-01-234910/8/2017
Automobile OEMs are looking for improving fuel economy[1,2] of their vehicles by reducing weight, rolling resistance and improving engine and transmission efficiency apart from the aerodynamic design. Fuel economy may be improved by using appropriate low viscosity [3] and use of friction reducers (FRs)[4,5] in the engine oils. The concept of high viscosity index [6] is being used for achieving right viscosity at required operating temperatures. In this paper performance properties of High Viscosity Index engine oils have been compared with conventional VI engine oils. Efforts have been made to check the key differentiation in oil properties w.r.t. low temperature fluidity, high temperature high shear viscosity/deposits, friction behavior, oxidation performance in bench tribological /engine/chassis dyno tests which finally lead to oil performance assessment. Three candidates of SAE 0W-30 grade oil with ACEA C2/API SN credentials have been chosen using various viscosity modifiers. Impact of viscosity modifiers on cranking, pumping, high temperature high shear viscosity and Kurt Orbahn after shear viscosity have been studied. Bench tests such as SRV/MTM, Four Ball WSD, PDSC, JIS K2514 and TEOST tests are also included in the study. Selected candidates have been evaluated in Seq IV(Wear test) and in an equivalent test to Seq IIIG(High Temp Oxidation) engine test benches. Effect of FRs on fuel economy performance of best candidate has been studied in chassis dyno test on actual vehicle. Results show that Moly as friction modifier in gasoline engine oils has significant effect in reducing deposits, may be due to some synergy with additive package and base oil used. Work also shows that high viscosity index and use of FRs have significant contribution on fuel economy performance. The authors have plan to use this concept in further study of low viscosity engine oils.
Seth, Sarita, Maloth, Swamy, Kumar, Prashant, Tyagi, Bhuvenesh, Kumar, Lokesh, Mahapatra, Rajendra, Garg, Sarita, Saxena, Deepak, Suresh, R, Ramakumar, SSV
Real World Fleet Test to Determine the Impact of Lower Viscosity Engine Oils from Heavy-Duty CNG and Diesel Buses. Part II: Oil Performance2017-01-235110/8/2017
Low viscosity engine oils are considered a feasible solution for improving fuel economy in internal combustion engines (ICE). So, the aim of this study was to verify experimentally the performance of low viscosity engine oils regarding their degradation process and possible related engine wear, since the use of low viscosity engine oils could imply higher degradation rates and/or unwanted wear performance. Potential higher wear could result in a reduction in life cycle for the ICE, and higher degradation rates would be translated in a reduction of the oil drain period, both of them non-desired effects. In addition, currently limited data are available regarding “real-world” performance of low viscosity engine oils in a real service fleet. In this particular case, there were included out-of-the European Automobile Manufacturers' Association (ACEA) oil specifications in terms of HTHS dynamic viscosity, where low viscosity was considered (3.0 mPa·s), making this test highly interesting for industry. On this test, 49 buses were monitored using a deep and extensive oil analysis program, comprising two engine technologies (Diesel and CNG), four engine types and three different lubricants, two of them low viscosity engine oils and other two as a reference baseline, during an oil drain period of 30000 km, taking between 5 to 10 samples per bus. For every sample, a broad list of thermo-physical and chemical properties were measured, and specially engine wear was quantified using ICP-OES, in order to detect abnormal wear patterns in the engine. Results indicate that oil performance and wear effects do not show abnormal patterns due to use of low viscosity engine oils, even some parameters obtain a better performance because of higher quality formulation.
Tormos, Bernardo, Miró, Guillermo, Ramirez, Leonardo, Pérez, Tomás
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