Browse Topic: Tribology

Items (225)

Schey’s Tribology in Metalworking: Friction, Lubrication, and Wear

B-ASM-05702/28/2024

Schey’s Tribology in Metalworking—Friction, Lubrication, and Wear is an update to the seminal text Tribology in Metalworking by John Schey, originally published by ASM International in 1983. The 1983 first edition served as a recognized essential resource for researchers in the fields of manufacturing tribology and metal forming for many decades. This 2023 update preserves the essential information in that first edition but provides a thorough update, including a description of the significant advances in tribological research and detailed information for every metal forming process.

Tutorial: Building the Bridge Testing Measurement and Tribology

1335210/12/2022

Different ingredients of the friction material have different effects on its tribological behavior, some of them conflicting and interfering among themselves (abrasives can increase performance, but also reduce lining life and cause overheating�). This tutorial will try to explain some of the features of dyno/vehicle tests that can be affected by friction materials, and what on the contrary is typically out of the scope of its characterization, and more pertinent to caliper, rotor or system functionalities. The goal is to give the audience an overview of how �chemists�, compounders, look at brake testing, and what they can learn when working on new developments. Outline: � Introduction (classes of raw materials, with their main effect & drawbacks to determine the main tribological effects: Friction level, wear, noise, thermals�) � A formulation approach to Design. Overview of design considerations based on the most relevant tests: how are formulators looking at these tests, to define

Schandelmeier, Brandie

Wear and Friction of PTFE and PEEK Coated Cast Iron Piston Ring

2022-01-038003/29/2022

In engine 30% of the total energy is lost due to the friction between piston ring and cylinder liner due to their constant rubbing motion. A piston that reciprocates at high speeds has piston rings that constantly scrape against the wall leading to high frictional losses within the engine. The engine has to work against this resistance to provide the required power, and hence it will consume more fuel. For this reason, material used for these components is more crucial. Reduction of surface friction between moving parts in order to increase overall efficiency can be achieved by suitable coating. The most commonly used piston rings are coated with chromium layers that are electroplated which is being replaced by chrome plating. Low coefficient of friction (COF) and high wear resistance can be achieved by self-lubricating coating of PTFE and PEEK polymer-based composite coatings. Experimental results showed that the PEEK and PTFE coating performed better in terms of friction and wear

Rajendran, R.

Influence of the chemical composition on the generation of cracks in brake discs

2021-36-042302/10/2022

Thermoelastic instabilities in the contact of brake friction material cause hotbands and hotspots on the surface of brake disc. These phenomena generate thermal stresses that result in generation of cracks, which limit the lifetime of the discs. In the present work, the influence of the chemical composition of brake discs on the thermoelastic behavior of the system and on the lifetime of the discs was investigated. The experimental evaluation was carried out in an inertial dynamometer using the SAE J3080 standard procedure applied on a brake system. Two discs (namely A and B) with different chemical compositions were subjected to the tests. The brake pad composition was kept fixed. The thermoelastic effects on the inner surface of the disc were observed by contact (thermocouple) and noncontact measurement techniques (thermography), as well as through photographic images of the disc’s surfaces. Disc A showed negligible amount of Nb while disc B exhibited 0.360%. Besides, disc B

Flores, Roberto, Ferreira, Ney Francisco, Neiss, Patric Daniel, Barros, Liu Yesukai, Poletto, Jean Carlos, Buneder, Diogo, Lorandi, Natalia Pagnoncelli, Pavlak, Rafael Paini, Fidler, Genesis Guilherme, Lopes, Carlos Henrique Raposo

Chemistry of the Brake Emissions: Influence of the Test Cycle

2021-01-130010/11/2021

The reliable chemical characterization of non-exhaust emissions generated by brakes is of fundamental importance in order to provide correct information for source apportionment studies as well as for their toxicological and environmental assessment. Nowadays, the best option to obtain samples of PM10 emissions composed only by material worn from the tribological interface, i.e. the braking disc (BD) and the friction material (FM) rubbing surfaces, is to sample them on suitable collection filters at a dedicated dyno-bench, during a standard braking test cycle. In particular, the use of enclosed dyno-bench is necessary for excluding other spurious contributions from the environment, while defined test cycles are necessary to simulate standard driving conditions. Nevertheless, different braking cycles are usually characterized by different overall temperature profiles or energy parameters, which in the end have significant influence on the wear and the oxidation of the materials involved

Mancini, Alessandro, Tsyupa, Bozhena, Pin, Sonia, Bandiera, Marco, Bertasi, Federico, Federici, Matteo, Bonfanti, Andrea, Perricone, Guido, Gigli, Lara, Bolzacchini, Ezio

A Molecular Dynamics Study of Tribological Properties of Silicon Carbide as a Metal-Free Friction Material

2021-01-128410/11/2021

Friction materials containing metal ingredients used in the automotive industry can cause unfavorable environmental impacts. Existing laws and regulations require heavy metals in brake pads to be phased out of production. Substitutions for metals in friction materials, however, may introduce operational safety issue and other unforeseen problems. In the current study, a molecular dynamics model based on LAMMPS has been developed to study the effect of material composition, density, and geometric configurations on the tribological, mechanical, and thermal properties of silicon carbide under various contact conditions at the atomic level. Simulations which incorporate interfacial contact between surface asperities were performed to predict the elastic modulus, thermal conductivity, wear rate, and coefficient of friction. The resulting predicted properties may help enhance the performance of engineered metal-free friction materials against thermal-mechanical failures. The following

Zhang, Yizhan, LeNeave, Cortney, Yi, Yun-Bo

Effect of Single Layer Thin Film Thermal Barrier Coatings on Mechanical, Thermal and Tribological Characterization of Cast Iron (GJL 300)

2021-28-028510/01/2021

Thermal Barrier Coatings (TBCs) are one of the most promising technologies for reducing heat dissipation through the combustion chamber in internal combustion engines. In this paper, Gadolinium Zirconate (GZ) was chosen as coating material and prepared using a solid-state synthesis process. Cast iron (GJL 300) was selected as substrate, which is predominantly used as the cylinder head material, and GZ was deposited using Electron Beam Physical Vapor Deposition Technique (EB-PVD). The mechanical, thermal, and tribological properties were evaluated as per the ASTM standards. Improved hardness and wear resistance is noted on coated substrates. The thermal conductivity and Coefficient of Thermal Expansion (CTE) of the coated substrates were decreased by 2.43% and 6.15% respectively when compared to uncoated substrates. Hence, it is confirmed that thin-film TBCs will also be helpful in retaining some heat inside the combustion chamber of IC engines.

Velusamy, Raja, Swaminathan, Mangudi Rangaswamy, Periyana Pillai, Hariharan, Annamalai, Suresh Babu, Ganapathy, Sakthinathan, Sathishkumar, Dhanalakshmi, Annamalai, Kumarasamy, Venkat, Natarajan, Radhakrishnan PhD, Vignesh, Kumaran, Naveen Kumar, Sharma, Gnanaeshwar

Enhancement in Tribological Properties of Squeeze Casted A356 Alloy with Post Processing Techniques through Heat Treatment and Heat Treated cum Shot Peening Approach

2021-28-026510/01/2021

Primary objective of this research work is to study the effect of heat treatment and heat treated cum shot peening processes on the tribological properties of squeeze casted A356 Alloy. The proposed alloy has wide range of applications in automobile industries due to its appreciable mechanical and tribological properties. Squeeze casting is an efficient economic and promising processing route for fabricating aluminum alloy with improved properties and pore free structure. Further the properties can be improvised through post processing technique like heat treatment and heat treated cum shot peening approach and also residual stresses are removed as a result of heat treatment process. So, this research work aims to investigate the effect of post processing approach on the tribological properties of squeeze casted A356 alloy. A wear and friction characteristics of the prepared samples were tested using pin-on-disc tribometer apparatus under dry sliding condition of load 10, 20, 30 and

A, Sathishkumar, R, Soundararajan, Ganapathy, Sakthivel, Kalidasan, Reshvanth

Tribological evaluation of organic frictional composites filled with various nano- solid lubricants

2021-28-025910/01/2021

Incorporation of organic fibers originate from plants in polymer composite is not new as they provide eco-friendly lighter composite and it have gained attention over a period of time because of the specific applications. The augmenting demanded by automotive sectors for wear and frictional areas where the conservation of energy is concerned is expected one with the addition of nano – solid lubricants. Our aim is to highlight the possibility of organic basalt fiber reinforced polymer composites along with three possible combination of nano – solid lubricants like graphite/graphene/ molybdenum disulfide was chosen and to fabricate tribo-materials through hot press technique. The outcome of the tribological tests (by varying load and sliding velocity) indicates that the responses of these three organic fiber based polymer composites have been effectively modified by nano-solid lubricants leading to significant enhancement as tribo materials is highlighted in higher level of load and

R, Soundararajan, Javid Firnas, Sait, Naveen raj, Nandakumar, pradeep s, sabapathy

Evolution of A356 with flyash composites on metallurgical mechanical and tribological behaviour under dry and wet conditions

2021-28-027210/01/2021

Among all metal matrix composites, A356 is the most applicable matrix due to its low density and exhibits nominal strength with soft nature. This proposed study is concerned with examination of mechanical and tribological behaviour of virgin A356 alloy and A356 reinforcement with 10wt.% power plant waste flyash particles composites were processed by liquid metallurgy stir casting technique. The fabricated composites expose enhanced higher hardness and compare the virgin A356 alloy due to presents of flyash particles in the matrix. The wear and friction behaviour of casted samples was tested in pin on disk tribometer apparatus under dry and wet sliding environment at the presence of lubricant (SAE 80W-90) by varying sliding load of 10N-40N and sliding velocity of 1-3 m/s respectively. Wear rate increase with the increasing load and sliding velocity. The usage of lubricant tends to decrease the wear rate by reducing the friction when compared to dry sliding method. This was ascribed due

R, Soundararajan, A, Sathishkumar, Kalaiarasan, Kaviyarasan, Kumar K, Sathish

Tribological Behavior of Thermal and Mechanical Composite Reinforced Sisal Characteristics and Influence SiC Filling Material

2021-28-027710/01/2021

In order to investigate the possible use of normal capital, we have tried by hand to manufacture sisal fibre polymer composites. Natural fibre composites are reusable, low-cost and biodegradable. Simple source, lesser compactness, superior basic property, lower quality, acceptable physical and mechanical properties, non acidic in environment, make them a good-looking biological substitute for glass, carbon or other artificial fibres. The outcome of SiC on the physical and mechanical properties of organic sisal composite materials is studied in this work. The composite was manufactured with and without SiC, mixing natural sisal fibre with polyester as a reinforcement medium. The investigational results showed that the tensile force of the mixture with 12 % SiC was 2.52 times better than that of the composite devoid of SiC. The collision strength of the 12% SiC merged is 1.72 times higher than that of the SiC pure polyester composite. The physical properties deliberate include thermal

RAJU, GANESAMOORTHY, NATARAJAN, Balaji, Chakaravarthy, Ezilarasan, Samikannu, Poovaragan, R, Soundararajan

Sensitivity Analysis of the Geometrical Dimensions of the Crankpin Bearing on the Tribological Property of an Engine

03-15-03-001809/21/2021

Under high-speed working conditions of an engine, the lubrication and tribological performance (LTP) of the crankpin bearing (CB) are strongly influenced by the oil film pressure (p) and asperity contact in the mixed lubrication regime (MLR) of CB, while these parameters mainly depend on the CB’s geometrical dimensions including the bearing radius (r b), bearing width (B), surface roughness (σ), gap between crankpin and bearing (c), and crankpin speed (ω). To analyze the sensitivity of the dynamic parameters of the r b, B, σ, c, and ω on the CB’s LTP, a hybrid model of the piston-rod-crank dynamic and CB lubrication is proposed to establish the dynamic equations of the CB. An algorithm program written in MATLAB software is then applied to solve the dynamic equations. The effect of the dynamic parameters of the r b, B, σ, c, and ω on the CB’s LTP is simulated and evaluated via the indexes of the p, asperity contact force, friction force, and friction coefficient. The research results

Xu, Shaoyong, Nguyen, Vanliem, Wang, Xiangjie, Zhou, Huaxiang

Investigation of Distribution and Structure of Surface Textures on Improving Tribological Properties of an Engine

03-15-03-001909/17/2021

The elastic hydrodynamic lubrication (EHL) region of the crankpin bearing (CB) not only creates the high friction force due to the solid asperity contact but also reduces the CB’s lubrication effectiveness. To improve the CB’s tribological properties, the partial textures (PT) designed on the EHL region are proposed. Based on a new hydrodynamic approach combined between the CB’s lubrication model and the slider-crank-mechanism (SCM) dynamics model, the distribution density of spherical dimples (SDs) and different structures of the SDs, circular-cylindrical dimples (CCDs), square-cylindrical dimples (SCDs), and wedge-shaped dimples (WSDs) are then simulated and assessed for their effectiveness on improving CB’s tribological properties, respectively. The oil film pressure (p), friction force (F f), and friction coefficient (μ) of the CB are selected as the evaluation indexes. Research results show that the SDs of the PT designed on the EHL region has better performance than the SDs of

Hua, Wenlin, Nguyen, Vanliem, Qiang, Jiao Ren

Assessment of Tribological Characteristics of Low-Sulfur and Ultralow-Sulfur Diesel under Practical Load and Temperature Scenarios

03-15-01-000206/10/2021

The lubricating properties of diesel are an imperative aspect for the optimal functioning of fuel injection components. Regulatory standards followed by refineries utilize accelerated wear testing methodologies. These tests provide indicative results for judging the lubricity but are not conclusive for determining wear in functional applications attributed to higher loads and other environmental factors. In the course of this article, a tribological evaluation was carried out on Low-Sulfur Diesel (LSD) and Ultralow Sulfur Diesel (ULSD) by utilizing modified test parameters incorporating higher loads and a more extensive gradient of temperature on High-Frequency Reciprocating Rig (HFRR) tribotester. The variance in the resultant coefficient of friction (COF) and wear scar concerning the change in parameters was observed as well as a comparative analysis was drawn between both test fuels. Further to analyze the impact of temperature on the tribological behavior of diesel, a ramp test was

Anil, P. M., Patra, Arka, Thangaraja, J., Samuel, Olusegun D., Abbas, Muhammad Mujtaba

A Comparative Study On-Dynamometer Performance Evaluation of Fly Ash Containing Non Ferrous Organic and Low-Metallic Disc Brake Pads for Passenger Vehicles and Thereby Promoting a Very Cheap Inorganic Filler Available in Abundance

2020-01-161310/05/2020

A number of functional and non- functional fillers are invariably used for friction material composites. In recent years disposal of fly ash has been a big challenge due to low availability of damping sites. Current work investigates the characterization of Low -metallic and Organic composites made with fly ash with variable concentrations and evaluated for braking performance (SAE J2522) & wear (SAE J2707) on a brake inertia dynamometer. Composites have been characterized for their physical, thermal, mechanical and tribological performance. Low-metal based composites (LMBC) have shown better thermal resistance than non-ferrous organic formulation based composites (NFOC). Mechanical properties such as hardness, shear strength and compressibility have been found to be similar for both the composites. NFOC composites have shown better wear resistance while acquiring slightly lower coefficient of friction values. Load-speed sensitivity of the composites has been further investigated to

Tomar, Bharat Singh, Ali, Sharafat, Ellis, Keith, Choudhary, Yogesh

Controlling the Performance of Copper-Free Brake-Pads by Varying Size of Graphite Particles

2020-01-160410/05/2020

Graphite plays a crucial role in friction materials, since it has good thermal conductivity, lubricity and act as a friction modifier. The right type, amount, shape, and size of the particles control the performance of the brake-pads. The theme of the study was investigating the influence of size of graphite particles (having all other specifications identical) on performance properties of brake-pads containing graphite particles in the average size of 60 μm, 120 μm, 200 μm and 400 μm. Physical, mechanical and chemical characterization of the developed brake-pads was done. The tribological performance was studied using a full- scale inertia brake dynamometer following a Japanese automobile testing standard (JASO C406). Tribo-performance in terms of fade resistance, friction stability and wear resistance were observed best for smaller graphite particles. It was concluded that smaller size serves best for achieving best performance properties barring compressibility.

Singh, Sandeep, Kalel, Navnath, Darpe, Ashish, Gilardi, Raffaele, Bijwe, Jayashree

Influence of Increasing Amount of Attapulgite on the Performance Properties of Cu-Free Brake-Pads

2020-01-160110/05/2020

Copper is almost inevitable functional filler in the brake-material and efforts to replace it are continuing since it is now known as a hazard to the aquatic life. It is always desirable to search for ingredients for Cu-free brake-pads, which will be beneficial for friction-related properties and especially fade resistance. Attapulgite, is a mineral which was proven to be an excellent substitute for asbestos in brake-pads long back. However, hardly anything in details is reported on its exact role in controlling tribo-properties of friction materials (FMs). It was of interest, if it can be helpful in enhancing the performance of Cu-free FMs. Hence, in this work a series of brake-pads (five types) was formulated and developed with increasing amount of attapulgite (0, 5, 10 and 15 wt. %) by compensating with inert barite particles in Cu-free FMs. The parent composition was fixed and instead of Cu powder, 10 wt.% stainless steel powder was used. One more type of pads was also developed

Bhatt, Bhaskar, Kalel, Navnath, Abdel-Latif, May, Bijwe, Jayashree

The Tribological Behavior of the DLC-Coated Engine Surfaces Lubricated with Oils with Nanoadditives

2020-01-215909/15/2020

Nowadays, it is commonly strived to achieve the highest efficiency of internal combustion engines and the longest possible inter-repair millage conditioned by low wear of engine components. This needs the reduction of the friction and wear intensity for the mating surfaces of engine components. This is commonly achieved by using the right oil, its additives and coating the surface with protective layers. Various nanoparticles, such as TiO2, ZrO2, CuO can be added to the base oil to change lubricating properties and creating so-called nano-oils. Parallelly, mating engine surfaces are often covered with very thin DLC coatings. Lubrication of DLC-coated surfaces with nano-oil can create both positive and negative synergy effects. The goal of the present review is to recognize the state-of-art in terms of existing types of DLC coatings and techniques for their application, types of nanoparticles dispersible in engine oils and the tendency to create a synergistic effect in contact zones.

Jozwiak, Piotr, Siczek, Krzysztof, Batory, Damian

Optimizing the Piston/Bore Tribology: The Role of Surface Specifications, Ring Pack, and Lubricant

2020-01-216709/15/2020

The present study looks into different possibilities for tribological optimization of the piston/bore system in heavy duty diesel engines. Both component rig tests and numerical simulations are used to understand the roles of surface specifications, ring pack, and lubricant in the piston/bore tribology. Run-in dynamics, friction, wear and combustion chamber sealing are considered. The performance of cylinder liners produced using a conventional plateau honing technology and a novel mechanochemical surface finishing process - ANS Triboconditioning® - is compared and the importance of in-design “pairing” of low-viscosity motor oils with the ring pack and the cylinder bore characteristics in order to achieve maximum improvement in fuel economy without sacrificing the endurance highlighted. A special emphasis is made on studying morphological changes in the cylinder bore surface during the honing, run-in and Triboconditioning® processes. It is demonstrated that the Triboconditioning

Zhmud, Boris, Tomanik, Eduardo, Grabon, Wieslaw, Schorr, Dietmar, Brodmann, Boris

Lubricants for Oxygen Use

AIR4071A (Current)07/14/2020

This SAE Aerospace Information Report (AIR) describes two classes of lubricants which, when properly applied, can be used in oxygen systems and components.

A-10 Aircraft Oxygen Equipment Committee

The Influence of the Content and Nature of the Dispersive Filler at the Formation of Coatings for Protection of the Equipment of River and Sea Transport

05-13-01-000601/23/2020

To protect ship equipment of river and sea transport, it is suggested to use polymeric protective coatings based on epoxy diane oligomer ED-20, polyethylene polyamine (PEPA) curing agent and filler, which is a departure from industrial production. Thus the purpose of the work is analysis of major dependency of the properties on the content of fillers that allowed to revealed the critical filler content (furnace black) in composites to form a protective coating with the required set of characteristics. The infrared (IR) spectral analysis was used to investigate the presence of bonds on the surface of particles of the PM-75 furnace black, which allows us to assess the degree of cross-linking of the polymer. The influence of the content of dispersed furnace black on the physicomechanical and thermophysical properties and the structure of the protective coating is investigated. For the formation of the coating with increased adhesive properties, the optimum content of the additive is q

Sapronov, Oleksandr, Buketov, Andriy, Sapronova, Anna, Sotsenko, Vitalii, Brailo, Mykola, Yakushchenko, Serhii, Maruschak, Pavlo, Smetankin, Serhii, Kulinich, Andriy, Kulinich, Viacheslav, Poberezhna, Liubov

Tensile and Fatigue Behavior of Shallow Cryogenically Treated EN19 Alloy Steel

2019-28-010010/11/2019

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

Mechanical and Corrosion Behaviour of Al 7075 Composite Reinforced with TiC and Al ₂ O ₃ Particles

2019-28-009410/11/2019

Various research regarding new types of fabrication and modifications of Aluminium alloy to improve the existing properties are going on. The wide range application of aluminium alloy is in aerospace and Automobile Industries. The demand for this material improved by mechanical properties with little to zero increment in weight. The current work is based on the fabrication of hybrid aluminium metal matrix composites with the addition of TiC (Titanium Carbide) and Al2O3 (Aluminium Oxide) reinforcement particle using stir casting technique. Three types of hybrid composite samples were prepared based on the weight percentage 5% Al2O3+0% TiC (sample-1), 8% Al2O3 + 12% TiC (sample-2), 20% Al2O3+15% TiC (sample-3). The objective of the study is to analyze the mechanical and corrosion properties of the hybrid composite with the influence of the reinforcement and varying the weight fraction of the particles. Overall, It is observed that a gradual increase in the hardness value in sample-1(83

Jaiswal, Subham, Rajamurugan, Govindasamy, Krishnasamy, Prabu, Shaswat, Yashwardhan, Kaushik, Mishra

Influence of Amount of Phenolic Resin on the Tribological Performance of Environment-Friendly Friction Materials

2019-01-210509/15/2019

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

Kalel, Navnath, Bijwe, Jayashree, Darpe, Ashish

Understanding the Stick Slip Behavior of Plastics and Target Setting: An OEM Perspective

2019-01-146506/05/2019

Automotive OEMs are aggressively using different materials for interiors due to value proposition and variety of options available for customers in market. Excessive usage of different grade plastics with zero gap philosophy can cause stick slip effect leading to squeak noise. Even though systems and subsystems are designed using best practices of structural design and manufacturing tolerances, extreme environmental conditions can induce contacts leading to squeak noise. Appropriate selection of interface material pairs can minimize the possibilities of squeak conditions. Stick-slip behavior of different plastics is discussed in the present study, along with critical parameters during material compatibility testing in a tribological test stand. Friction coefficient of different material pairs for a defined normal load and sliding velocity are analyzed for patterns to recognize squeaks versus time. An OEM perspective is presented with focus on material selection using objective metrics

Somasundharam, Sundaralingam, Kumar, Amit, Mohammed, Riyazuddin, Raghavendran, Prasath

Screening of Potential Biomass-Derived Streams as Fuel Blendstocks for Mixing Controlled Compression Ignition Combustion

2019-01-057004/02/2019

Mixing controlled compression ignition, i.e., diesel engines are efficient and are likely to continue to be the primary means for movement of goods for many years. Low-net-carbon biofuels have the potential to significantly reduce the carbon footprint of diesel combustion and could have advantageous properties for combustion, such as high cetane number and reduced engine-out particle and NOx emissions. We developed a list of over 400 potential biomass-derived diesel blendstocks and populated a database with the properties and characteristics of these materials. Fuel properties were determined by measurement, model prediction, or literature review. Screening criteria were developed to determine if a blendstock met the basic requirements for handling in the diesel distribution system and use as a blend with conventional diesel. Criteria included cetane number ≥40, flashpoint ≥52°C, and boiling point or T90 ≤338°C. Blendstocks needed to be soluble in diesel fuel, have a toxicity no worse

Fioroni, Gina, Fouts, Lisa, Luecke, Jon, Vardon, Derek, Huq, Nabila, Christensen, Earl, Huo, Xiangchen, Alleman, Teresa, McCormick, Robert, Kass, Michael, Polikarpov, Evgueni, Kukkadapu, Goutham, Whitesides, Russell A.

Wear-Resistant Platinum Gold Alloy

TBMG-3417204/01/2019

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.

Tribological Performance of an Engine Mineral Oil Blended with a Vegetable Oil under Approached Long-Term Use Conditions

2019-01-001201/15/2019

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

Farfan-Cabrera, Leonardo Israel, Gallardo, Ezequiel, Gómez-Guarneros, Mario, Hernandez Peña, Andys

Gearset Synchronization Modeling of a Heavy Commercial Vehicle Transmission and Correlation with Objective Measurements of Gear Shift Quality

2019-01-003101/15/2019

For manual transmissions, including the automated types, reduced shifting effort and easy of gear set engagements in a short period of time without rattles and shakes are major requirements for the shift quality evaluations. Performance of the synchronizer mechanisms depends highly on the design, material and arrangement of the transmission synchronization components; thus, the synchronization process is a mechanical and tribological process which is influenced by numerous design parameters of the synchronizers, constraints and properties of the lubricated contacts. In this study, a detailed multi-body-dynamics model for a HCV (Heavy Commercial Vehicle) transmission gearset is presented; various synchronization simulations are performed and the results are compared with the objective shift quality measurements. The developed model yields total synchronization and engagement time based on the applied gear shifting effort. The translational and rotational movements are calculated using

Özpınar, İlker, Akalin, Ozgen

System Identification Method for Brake Particle Emission Measurements of Passenger Car Disc Brakes on a Dynamometer

2018-01-188410/05/2018

Besides particulate emissions from engine exhausts, which are already regulated by emission standards, passenger car disc brakes are a source of particulate matter. With the current car fleet it is estimated that up to 21% of the total traffic related PM10 emissions in urban environments originate from brake wear and reduction of brake dust emissions is subject of current research. For the purpose of reducing brake dust emissions by choosing low-emission operating points of the disc brake, the knowledge of the emission behavior depending on brake pressure, wheel speed, temperature and friction history is of interest. According to the current state of research, theoretical white box modeling of the emission behavior is complicated due to the complexity of tribological contact between pad and disc. Thus experimental black box modeling is supposed to describe emission behavior. In order to minimize the influence of disturbances and therefore to improve prediction accuracy of such

Niemann, Hartmut, Winner, Hermann, Asbach, Christof, Kaminski, Heinz, Zessinger, Marco

Boundary Layer Dynamics and Sound Generation

2018-01-190010/05/2018

In recent years, characteristic structures in the boundary layer of high-load contacts such as brakes have been reported, which substantially influence the dynamics of the tribological contact. Usually, local assumptions concerning the friction behavior of these patches are used to reach global conclusions about the brake system. Several numerical methods (e.g. Cellular Automata) have been developed which employ such assumptions. The validation of these methods through measurement data tends to be laborious and costly. Sprag-Slip elements are friction elements that are exclusively subjected to static friction, never undergoing sliding friction. Implementing such elements on a mesoscopic scale, it is possible to generate global descriptions of macroscopic stick and slip friction phenomena. Locally, these Sprag-Slip elements are similar to the patch structures in the tribological boundary layer of brakes. The Sprag-Slip elements are suitable for describing the basic physics in the

Recke, Bastian, Ostermeyer, Georg

Microscale Superlubricity Improves Electromechanical Devices

TBMG-3307310/01/2018

Superlubricity — the state of ultra-low friction and wear — holds great promise for the reduction of frictional wear in mechanical and automatic devices.

Development of friction coefficient controller for E-coat (KTL)

2018-36-020009/03/2018

Global competitiveness increase in the past decades has been a crucial factor for the technological advance and industrial automotive development. Possibility of reducing costs, concentrate knowledge and increase in manufacturing efficiency has lead to development of global automotive platforms. In this scenario, the supply chain needs for adaptations that allow evolution at the same fastness imposed by original equipment manufacturer (OEM). Such demands reflect directly on the fasters market requiring lighter and stronger products. Stronger products are obtained by increasing corrosion resistance and lowering friction coefficient, in order to increase the clamp load and, consequently, reduce the weight without reducing performance. However, increasing corrosion resistance causes, generally, an increase in friction coefficient and, consequently, a decrease in clamp load. To minimize such effects, the surface coating industry has been developing, over the years, friction controllers

Egêa, Renan Barranqueiro, Primolini, Alexandre, Maia, Bruno Inácio da

Plain Bearing Selection for Landing Gear Applications

AIR1594D (Current)04/18/2018

This document is intended to give advisory information for the selection of plain bearings and bearing materials most suitable for aircraft landing gear applications. Information included herein was derived from bearing tests and service experience/reports. Airframe/landing gear manufacturers, commercial airlines, the U.S. Air Force and Naval Air Systems Command provided input for the document. Information is given on bearing installation methods and fits that have given satisfactory performance and service life. Base metal corrosion is a major cause of problems in bearing installations for landing gears. Therefore, methods of corrosion prevention are discussed. Effort is directed toward minimizing maintenance and maximizing life expectancy of landing gear bearings. Lubricated and self-lubricating bearings are also discussed. There are wide ranges of bearing load and motion requirements for applications in aircraft landing gears. For this reason, it is the responsibility of the

A-5B Gears, Struts and Couplings Committee

Sliding Wear and Friction Studies of Disc/ Pad Materials

2018-01-084004/03/2018

Brake disc provides friction force with minimum weight loss on application of brake. The pad material only experiences more wear and friction. Disc and pad materials are selected to give a stable and high coefficient of friction (0.25-0.40). COF is directly proportional to braking force generated and inversely proportional to the stopping distance. The aim of the study is to identify a new material for replacement of pad material in practice. In this study, wear, hardness and friction properties of E glass fiber with epoxy resin and cashew friction dust composite are studied and compared with brake pad material in practice. The hardness was measured using shore hardness tester. The wear and friction was measured using the pin on disc wear testing machine. The pad material was made as pin with cast iron as the disc material for wear studies. The wear studies were conducted for various load conditions and sliding velocities. It was observed that the wear rate increases with increasing

Rajendran, R., N, Ravikumar, S, Madhan Kumar, Tamilarasan, T.R

Study on Frictional Behavior of AA 6XXX with Three Lube Conditions in Sheet Metal Forming

2018-01-081004/03/2018

Light-weighting vehicles cause an increase in Aluminum Alloy stamping processes in the Automotive Industry. Surface finish and lubricants of aluminum alloy (AA) sheet play an important role in the deep drawing processes as they can affect the friction condition between the die and the sheet. This paper aims to develop a reliable and practical laboratory test method to experimentally investigate the influence of surface finish, lubricant conditions, draw-bead clearances and pulling speed on the frictional sliding behavior of AA 6XXX sheet metal. A new double-beads draw-bead-simulator (DBS) system was used to conduct the simulated test to determine the frictional behavior of an aluminium alloy with three surface lubricant conditions: mill finish (MF) with oil lube, electric discharge texture (EDT) finish with oil lube and mill finish (MF) with dry lube (DL). The experimental results could be utilized to distinguish the frictional performance of the three different sheets aforementioned

Xu, Wan, Gao, Xinya, Zhang, Boyang, Yang, Lianxiang, Du, Changqing, Zhou, Dajun, Rawya, Bazzi, Szymanski, Michael

New Generation Fuel Efficient Engine Oils with Superior Viscometrics

2017-01-234910/08/2017

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

Seth, Sarita, Maloth, Swamy, Kumar, Prashant, Tyagi, Bhuvenesh, Kumar, Lokesh, Mahapatra, Rajendra, Garg, Sarita, Saxena, Deepak, Suresh, R, Ramakumar, SSV

Evaluation of the Stability and Ignition Quality of Diesel-Biodiesel-Butanol Blends

2017-01-232010/08/2017

FAME is the most common renewable component of conventional automotive diesel. Despite the advantages, biodiesel is more susceptible to oxidative deterioration and due to its chemical composition as well as its higher affinity to water, is considered to be a favorable substrate for microorganisms. On the other hand, apart from biodiesel, alcohols are considered to be promising substitutes to conventional diesel fuel because they can offer higher oxygen concentration leading to better combustion characteristics and lower exhaust emissions. More specifically, n-butanol is a renewable alcohol demonstrating better blending capabilities and properties when it is added to diesel fuel, as its composition is closer to conventional fuel, when compared ethanol to for example. Taking into consideration the alleged disinfectant properties of alcohols, it would be interesting to examine also the microbial stability of blends containing n-butanol in various concentrations. Based on the

Dodos, George S., Tsesmeli, Chrysovalanti E., Zahos-Siagos, Iraklis, Tyrovola, Theodora, Karonis, Dimitrios, Zannikos, Fanourios

Enhanced Anti-Wear Performance Induced by Innovative Base Oil in Low Viscosity Engine Oil

2017-01-234310/08/2017

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

Self-Healing, Self-Lubricating Tribofilm

TBMG-2769710/01/2017

Tribologists have developed a diamond-like film that is generated by the heat and pressure of an automotive engine. The ultra-durable, self-lubricating tribofilm — a film that forms between moving surfaces — can be made to develop self-healing, diamondlike carbon (DLC) tribofilms. The film generates itself by breaking down the molecules of the lubricating oil, and can regenerate the tribofilm as it is worn away.

Discrete Surface Dynamics: Distributed Sprag Slip Elements in Brakes

2017-01-253109/17/2017

In recent years, characteristic structures in the boundary layer of high-load contacts such as brakes have been reported, which have an important impact on the dynamics of the tribological contact. Usually, local assumptions concerning the friction of these patches are used to reach global conclusions about the brake system. Several numerical methods (e.g. Cellular Automata) have been developed which make use of such assumptions. The validation of these methods through measured data tends to be laborious and costly. Sprag-Slip elements are friction elements which are typically considered to exclusively undergo static friction. Such elements have been sporadically utilized towards describing friction in brake applications. In this paper, many locally distributed Sprag-Slip elements are used to model the global dynamics of braking friction. The results show good agreement with the measured characteristics of brakes. This approach offers new possibilities for the description of global

Ostermeyer, Georg Peter, Recke, Bastian

Studies on Friction Mechanism of NAO Brake-Pads Containing Potassium Titanate Powder as a Theme Ingredient

05-11-01-000609/17/2017

Potassium titanate (KT) fibers/whiskers are used as a functional filler for partial replacement of asbestos in NAO friction materials (FMs). Based on little information reported in open literature; its exact role is not well defined since some papers claim it as the booster for resistance to fade (FR), or wear (WR) and sometimes as damper for friction fluctuations. Interestingly, KT fibers and whiskers (but not powder) are proved as carcinogens by the International Agency for Research on Cancer (IARC). However, hardly any efforts are reported on exploration of influence of KT powder and its optimum amount in NAO FMs (realistic composites) in the literature. Hence a series of five realistic multi-ingredient compositions in the form of brake-pads with similar parent composition but varying in the content of KT powder from 0 to 15 wt% (in the steps of 3) were developed. These composites were characterized for physical, mechanical, chemical and tribological performance. Composites were

Mahale, Vishal, Bijwe, Jayashree, Sinha, Sujeet

Performance and Use of Polymer Plan Bearings in Transmission Design Web Seminar RePlay

PD331710ON07/11/2017

As part of a broad transmission design philosophy, the understanding and application of tribological systems is critical. The number of interacting surfaces within a modern automotive transmission continues to increase, while the demands on the system continue to press the limits of traditional technologies. The understanding of each surface interaction within the greater system becomes increasingly important as each component is asked to do more to benefit the overall system. This short course will present the tribological performance of polymeric plain bearings as related to transmission applications. It will deal with the various wear and damage mechanisms that can occur with a polymer bearing in transmissions. The damage mechanisms discussed will include adhesion, abrasion, fatigue and erosion. A brief discussion of relevant lubrication states, boundary lubrication and fluid film formation, will also be included. The course will also address specific mechanical design issues

Interference between Tin Sulfides, Graphite and Novolak Oxidation

05-11-01-000903/07/2017

Tin sulfides (SnS and SnS2), represent a safer and greener alternative to other metal sulfides such as copper sulfides, and MoS2 etc. Their behavior is usually associated to that of solid lubricants such as graphite. A mixture of tin sulfides, with the 65 wt% of SnS2, has been characterized by scanning electron microscopy and by thermal gravimetric analysis (TGA). In order to investigate the effect of tin sulfides upon two crucial friction material ingredients, two mixtures were prepared: the former was made by mixing tin sulfides with a natural flake graphite and the latter was made mixing tin sulfides with a straight novolak. They were analyzed by TGA and differential thermal analysis (DTA) in both nitrogen and air. Some interferences were detected between tin sulfides and graphite in air. However, the oxidation of tin sulfides was concomitant with that of the novolak so that the resin onset decomposition-oxidation was considerably shifted to higher temperatures allowing the resin to

Dante, Roberto, Sliepcevich, Andrea, Andreoni, Marco, Cotilli, Mario

Durability Improvement of Engine Valves and Interfacing Systems

2016-32-002011/08/2016

Development of small air cooled motorcycles is ever challenging due to combination of customer expectation, regulatory requirements and cost factors. Achieving higher performance, emission standards means higher engine and parts operating temperature. Under these changes meeting durability targets at reasonable cost needs good understanding of material, surface treatment and tribological aspects. In this paper some of the surface and process improvements done to reduce wear in engine valves and interface systems is discussed in detail. Design of engine valves shall ensure meeting thermal, mechanical strength requirements, wear and durability targets. Surface treatments, coating, surface finish and also use of special materials in tip, valve stem, seat ensures higher durability; low wear in valve and interfacing parts. During new engine development process verification tests, wear observed in valve stem- guide, valve tip- screw interface. Effect of various design parameters are studied

Thiruvallur Loganathan, Balasubramanian, Narasimhan, Srivenkata Subramani, Varadha Iyengar, Lakshminarasimhan, Sandur, Ajith Kumar, Vediappan, Sudhagar

Comparative Small Engine Testing Using Hybrid Composite Cylinder Liners

2016-32-002211/08/2016

Cylinder liners exert a major influence on engine performance, reliability, durability and maintenance. Various combinations of nonmetallic reinforcements and coatings have been used to improve the tribological performance of sleeves or surfaces used in compressors and internal combustion engines in four stroke, two stroke and rotary configurations. In this paper we report the use of a hybrid composite containing silicon carbide and graphite in an aluminum alloy matrix to improve the performance of various small engines and compressors. Material properties of the base material, as well as comparative dynamometer testing, are presented.

Weiss, David, Beno, Simon, Jordan, Chris, Rohatgi, Pradeep

Alkali-Activated Inorganic Based Brake Pads: Realization and Performances of Alternative Friction Materials for a Concrete Industrial Application

2016-01-191309/18/2016

Organic brake pads for automotive can be defined as brake linings with bonding matrix constituted of high-temperature thermosetting resins. Bonded together inside the polymeric binder are a mix of components (e.g. abrasives, lubricants, reinforcements, fillers, modifiers…), each playing a distinctive role in determining the tribology and friction activity of the final friction material. The herein reported work presents inorganic “alkali-activated”-based materials suitable for the production of alternative brake linings (i.e. brake pads), by means of an unconventional low-temperature wet process. Exploiting the hydraulic activity of specific components when exposed to an alkaline environment, such peculiar inorganic materials are capable of coming to a complete hardening without the need of traditional high-temperature energivorous procedures. The main advantages of these materials resides in: the decreased embodied energy of the employed raw materials, the reduction of process costs

Sanguineti, Alessandro, Tosi, Federico, Bonfanti, Andrea, Rampinelli, Flavio

Efficiency and Durability Predictions of High Performance Racing Transmissions

2016-01-185206/15/2016

Efficiency and durability are key areas of research and development in modern racing drivetrains. Stringent regulations necessitate the need for components capable of operating under highly loaded conditions whilst being efficient and reliable. Downsizing, increasing the power-to-weight ratio and modification of gear teeth geometry to reduce friction are some of the actions undertaken to achieve these objectives. These approaches can however result in reduced structural integrity and component durability. Achieving a balance between system reliability and optimal efficiency requires detailed integrated multidisciplinary analyses, with the consideration of system dynamics, contact mechanics/tribology and stress analysis/structural integrity. This paper presents an analytical model to predict quasi-static contact power losses in lubricated spur gear sets operating under the Elastohydrodynamic regime of lubrication. Tooth Contact Analysis (TCA) is used to predict variations in contact

Fatourehchi, Ehsan, Elisaus, Vishak, Mohammadpour, Mahdi, Theodossiades, Stephanos, Rahnejat, Homer

A Study of Reliability Evaluation of Main Bearings for Multicylinder Diesel Engines

2016-01-049404/05/2016

In recent years, although experiment technologies on real engines and simulation technologies has been improved rapidly, the tribology contributing factors have not been quantitatively well evaluated to reveal critical lubrication failure mechanisms. In this study the oil film thickness of the main bearings in multicylinder diesel engines was measured, and the data was analyzed using response surface methodology, which is a statistical analysis methods used to quantitatively derive the factors affecting oil film thickness and the extent of their contribution. We found that the factor with the strongest effect on minimum oil film thickness is oil pressure. Lastly, as a verification test, bearing wear on the main bearings was compared under various oil pressure conditions. Clear differences in bearing wear were identified.

Sadatomi, Masashi, Ito, Hiroaki

Investigation into Mixed and Hydrodynamic Frictions of PEO Coatings and Cast Iron

2016-01-049104/05/2016

A linerless aluminum (Al) engine block has potential to reduce the weight of an automotive engine and improve the fuel economy. However, the Al cylinder surface of an aluminum engine block is not usually strong enough to withstand the sliding wear against piston rings. A few surface processing technologies are used to protect the surface of cylinders. Among them, a thermal spraying coating, such as plasma transferred wire arc (PTWA) is already popular. Plasma electrolytic oxidation (PEO) coating is also proposed for increasing the wear resistance of aluminum-silicon (Al-Si) alloys and reducing the friction between the cylinder and piston. In this work, two different PEO coatings with a thickness of around 23 μm were prepared on an Al-Si alloy A356, and a high speed pin-on-disc tribometer was used to study the tribological behavior of the coatings at oil lubricant conditions. A cast iron sample was also used to do similar tribological tests for comparison. The coefficient of friction

Wang, Guang, Nie, Xueyuan, Tjong, Jimi

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