Browse Topic: Iron

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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
Iron Nanorobots Destroy Cancer CellsTBMG-362383/1/2020
Drug-coated iron nanowires that can be guided to the site of a tumor using an external magnetic field before activating a three-step cancer-killing mechanism could provide an effective option for cancer therapy.
Design Treatment for Advanced Metals Enables Easier MachiningTBMG-358021/1/2020
Exotic and advanced metals are used in aircraft, orthopedic components, medical instruments, cars, solar panels, military equipment, and other applications. They are referred to as advanced or exotic because they are more difficult to find and more costly to use in manufacturing.
Ultra-Thin Layers of Rust Generate Electricity from Flowing WaterTBMG-3572212/1/2019
Research shows that thin films of rust (iron oxide) can generate electricity when saltwater flows over them. These films represent an entirely new way of generating electricity and could be used to develop new forms of sustainable power production.
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
Brake Rotor Corrosion and Friction Cleaning Effect on Vehicle Judder Performance2019-01-21159/15/2019
Brake disc corrosion has emerged as an important field of study within the automotive industry due to the wide range of lining materials that are currently used worldwide, and their inherent rust-cleaning properties. The presence of oxide layers irregularly deposited on the cast iron disc surfaces usually leads to a forced, braking-induced vibration that can reach the driver’s position as a pronounced annoyance. Hence, the friction material composition directly impacts on the judder performance during the early corrosion-removal stage. This study incorporates both dynamometer and vehicle tests into the definition of a predictive methodology that allows corrosion-induced vibrations to be investigated at both system and vehicle levels. The oxide film is artificially generated by means of a salt spray chamber under steady-state climate conditions in order to guarantee a repetitive and robust procedure. The vibration response of the system is objectively evaluated in the form of caliper accelerations and pressure (BPV) / torque (BTV) oscillations throughout a reduced rust-removal test sequence composed of 30 snubs; basic spectral and order analyses are conducted with the gathered data. Furthermore, vehicle-based results are correlated with the subjective ratings that an expert driver gives to the different vibrations perceived at chassis level. The in-service roughness of the oxide layer, on the other hand, is indirectly monitored by using a couple of non-contacting capacitive sensors that measure the variation in disc thickness (DTV). Ultimately, this paper is intended to characterize the inherent corrosion-cleaning capability of different friction materials -paying special attention to the presence of copper-, as well as revealing their impact on the vehicle judder subsequently induced during the actual removal of the oxide layers.
Molina Montasell, Narcís, Ferrer, Bernat
3D-Printed Soft Mesh RobotsTBMG-351559/1/2019
Researchers have created 3D-printed flexible mesh structures that can be controlled with applied magnetic fields while floating on water. The structures can grab small objects and carry water droplets, giving them the potential to be useful as soft robots that mimic creatures living on water surfaces or that can serve as tissue scaffolds for cell cultures.
Optimized Requirements Verification for Flexible Drive ShaftsF-0075-2019-145455/13/2019
An optimized design, fabrication and testing solution is presented for flexible drive systems. A single piece welded drive shaft as well as a system consisting of sub and supercritical shafts, couplings and bearing hangers (for Tail Drive System in Helicopters and Interconnect Drive Systems in Tiltrotors) are included. This solution facilitates the qualification for flight of the drive shaft in airframes with reduced iron bird and expensive flight testing on the airframe. This solution also provides opportunities for improvements during the prototype phase such that potential deficiencies are identified and corrected before the drive shaft is put into service. An important part of the testing is accelerated testing, not in terms of operational life, but in terms of reliability. Theoretical Life of a flexible drive shaft is 'infinite' by design. 2.0
King, Michael, Schaefer, Joyel, Iyer, Raghu
Iron-Nickel Alloy Strip 49Fe - 5.3Cr - 42Ni - 2.5Ti - 0.55Al Solution Heat TreatedAMS5221F (Historical)1/10/2019
This specification covers an iron-nickel alloy in the form of strip 0.020 to 0.250 inch (0.51 to 6.35 mm) inclusive, in thickness (see 8.8).
AMS F Corrosion Heat Resistant Alloys Committee
Physical and Virtual Simulation of Lightweight Brake Drum Design for Heavy Duty Commercial Vehicles Using Alternate Material Technologies2018-01-189710/5/2018
Brake drum in commercial vehicles is very important aggregate contributing towards major weight in brake system module. The main function of brake drum is to dissipate kinetic energy of vehicle into thermal energy, as a results in braking operation major load comes on brake drum. Hence this is very critical component for vehicle safety and stability [1]. Objective of this paper is to increase the pay load, which is utmost important parameter for commercial vehicle end customers. To achieve the light weighing target, alternate materials such as Spheroidal graphite iron (SGI) has been evaluated for development of brake drum. Many critical parameters in terms of reliability, safety and durability, thickness of hub, wheel loading, heat generation on drum, manufacturing and assembly process are taken into consideration. The sensitivity of these parameters is studied for optimum design, could be chosen complying each other’s values. Digital thermal performance evaluated in house, fine-tuned and verified by correlating with test data available for existing cast iron design and then applied for new design with alternate materials. In two different designs around 10 Kgs weight saving per brake drum has been achieved as compared to conventional grey cast iron brake drum. Considering the most demanding 10x2 haulage platform in current commercial market approximately 100 Kgs payload increment for fleet owners was achieved, which will result in end customer profitability.
Kandreegula, Suresh Kumar, Deshmukh, Himanshu, Prasad, Shivdayal, Paroche, Sonu, Anil Shah, Ashesh
The Factors Governing Corrosion Stiction of Brake Friction Materials to a Gray Cast Iron Disc2018-01-189910/5/2018
Corrosion stiction at the contact interface between a brake friction material and a gray iron disc under the parking brake condition was investigated by evaluating the possible parameters that affect the shear force to detach the corroded interface. Using production brake friction materials, comprising non-steel and low-steel types, corrosion tests were carried out by pressing the brake pad onto the gray iron disc using a clamp at various conditions. Results showed that the shear force to detach the corroded interface tended to increase with applied pressure and corrosion time. On the other hand, porosity, acidity, and hydrophobicity of the friction material did not show a reliable correlation to the stiction force. The poor correlation of the stiction force with the friction material properties indicated that the stiction force was not determined by a single factor but governed by multiple parameters including surface contact areas and inhomogeneity of the ingredients. Microscopic observation of the detached disc surface showed adhered fragments that were removed from the friction material surface, thus shedding light on the possible estimation of the stiction force from the disc area covered by the friction materials. The scattered small areas without corrosion on the gray iron surface, which were well matched with hollow areas on the friction material surface, supported the importance of the contact area information in understanding the poor correlation between the stiction force and of the friction material properties.
Gweon, Jaehyun, Shin, Sanghee, Jang, Ho, Lee, Wangyu, Kim, Dooyeon, Lee, Keeyang
A Study of the Disc Scoring Generation Principle and Reduction (II)2018-01-189110/5/2018
In the latest paper [10], we presented our work based on experiments studying MPU (Metal Pick Up) of the pad and scoring(scratching) of the disc. The main component of MPU was iron “Fe”. If the roughness of the disc was small, the content of iron “Fe” was increased and the segregation of that was decreased especially in initial condition. In this study, we extended our study based on the results by adding some additional factors such as the location of the roughness of the disc, the coefficients brake pad friction, and disc slots. We made various discs of different roughness boundaries and slots, and pads of pad friction coefficients; and conducted two types of tests for whether a slot is present or not with the other same conditions to confirm the impact of the scoring. We find and believe that our experimental data should serve a useful guideline for reducing MPU of the pad and scoring of the disc.
Jeong, ByeongUk, Ryu, Hyoung Tae, Kim, Chang Jin, Jung, Kwang Ki, Lee, Hyunkyoung
Iron-Nickel Alloy, Bars, Forgings, and Rings 42Fe - 37.5Ni - 14Co - 4.8 (Cb + Ta)(Nb + Ta) - 1.6Ti Solution Heat Treated, Short-Time Precipitation Hardenable Multiple Melted, High Temperature, Low ExpansionAMS5893C (Historical)8/16/2018
This specification covers an iron-nickel alloy in the form of bars, forgings, flash-welded rings, and stock for forging, flash-welded rings, or heading.
AMS F Corrosion Heat Resistant Alloys Committee
Multi-Attribute, System-Level Design Process for Automotive Powertrain Electric Drives: An Integrated Approach08-07-02-00076/5/2018
This article presents an electric drive powertrain design and virtual integration methodology in the context of electric vehicle systems. In the first stage, using the Model-Based System Engineering paradigm, the electric vehicle performance requirements are translated into electric drive target specifications using a system-level vehicle model. Subsequently, a functional electric drive subsystem-level model is developed based on magnetic co-energy and iron losses data obtained from a reference electric machine design. The functional electric drive model is scaled in order to meet the requested specifications, and it is coupled with different 1D (i.e. lumped-parameter) multi-physics sub-models that are later integrated into the electric vehicle system-level model. At the electric drive level the torque ripple and Noise, Vibration and Harshness characteristics are analyzed. At the vehicle level the energy consumption, thermal behavior, and mechanical performances are determined with reduced computational time. The proposed approach allows for early assessment of multiple attributes and enables designers to make decisions supported by accurate system-level simulations.
Ciceo, Sebastian, Faria, Cassio T., Gyselinck, Johan, Martis, Claudia
Response of Austempering Heat Treatment on Microstructure and Mechanical Property in Different Zones of As-Welded Ductile Iron (DI)05-11-02-00165/8/2018
Sound ductile iron (DI) welded joints were performed using developed coated electrode and optimized welding parameters including post weld heat treatment (PWHT). Weldments consisting of weld metal, partially melted zone (PMZ), heat affected zone (HAZ) and base metal were austenitized at 900 °C for 2 hour and austempered at 300 °C and 350 °C for three different holding time (1.5 hour, 2 hour and 2.5 hour). In as-weld condition, microstructures of weld metal and PMZ show ledeburitic carbide and alloyed pearlite, but differ with their amount. Whereas microstructure of HAZ shows pearlite with some ledeburitic carbide and base metal shows only ferrite. However, in spite of the significant variation in microstructures at different zones of weldment in as-weld condition, all the zones show similar microstructure of base metal such as bainitic ferrite along with some retained austenite after austempering heat treatment, indicating the response of heat treatment from different zones like base metal. However, the microstructure of each zone of weldment varies in shape, size and amount with changing the austempering temperature and holding time. In general, microstructure at 300 °C reveals needle shaped bainitic ferrite with lower amount of retained austenite; whereas at 350 °C microstructure shows feathery shaped bainitic ferrite with higher amount of retained austenite. After austempering weld metal shows lowest hardness followed by PMZ, HAZ and base metal, which is just opposite to as-welded condition, irrespective of austempering temperature and holding time. All the transverse tensile test weld samples austempered at 300 °C and 350 °C for 2 hour holding time, failed from the base metal indicating 100% joint efficiency.
Sarkar, Tapan, Pal, Tapan Kumar
An Integrated Approach to Constitutive Modeling and Life Prediction for Automotive Materials2018-01-12134/3/2018
An integrated approach of constitutive modeling and life prediction is presented through introduction of the integrated creep-fatigue theory (ICFT). The ICFT is formulated based on participating deformation and damage mechanisms, which not only describes the cyclic deformation behavior but also the life and fracture mode. Automotive exhaust system materials such as ductile cast iron and austenitic cast steel are used as example materials for demonstration in good agreement with experimental results and metallurgical examinations. This enlightens the understanding of the roles each mechanism plays in low-cycle fatigue (LCF) and thermomechanical (TMF) processes, thus helping material and component design specifically targeting the most damaging mechanism(s) encountered in service.
Wu, Xijia
Modelling of Electrode Erosion for Prediction of Spark Plug Lifetime2018-01-01754/3/2018
A high-fidelity arc plasma simulation tool has been developed that can model arc physics coupled with electrode erosion. The arc physics is modelled using an equilibrium, resistive magneto-hydrodynamic (MHD) model. Solid electrodes are modelled using an immersed boundary method that allows for the electrodes to deform dynamically without modifying the original mesh or the underlying governing equations. First, a partial validation of the arc physics is performed by comparing arc stretch in cross-flow with experimental results across a 1.1 mm spark gap. Subsequently, the ability to model arc physics in a coupled manner with ablating electrodes is demonstrated in 2D using a 0.7 mm electrode gap with iron electrodes. The objective of this work is to illustrate modeling of coupled arc physics with eroding electrodes; a capability that will be extended for the realistic prediction of spark plug lifetimes in future work.
Breden, Douglas P., Karpatne, Anand, Raja, Laxminarayan
Automotive Compacted Graphite Iron CastingsJ1887_201802 (Current)2/15/2018
This SAE Standard covers the mechanical and physical requirements for Compacted Graphite Iron (CGI) castings used in automotive and allied industries. Requirements in this document include: a Tensile Strength b Yield Strength c Elongation d Graphite Morphology
Metals Technical Committee
Tech Briefs April 201818AERP022/1/2018
Multi-Domain Command and Control (MDC2) Changing the Face of Modern Warfare Loop Thermosyphons Gravity-Driven Two-Phase Cooling for the 21st Century CompactPCI Serial Space A New Embedded System Specification Takes on Extreme Environments Plain Bearings for Aerospace Applications Additive Manufacturing Materials for RF Components NASA CubeSats: Pushing the Boundaries of Technology Content Addressable Memory (CAM) Technologies for Big Data and Intelligent Electronics Enabled By Magneto-Electric Ternary CAM New associative memory approach based on the propagation of spikes provides ultra-low energy search operations. Natural DNA-Based Nonvolatile Resistive Switching Memory Reliable memory devices can be realized within a single macromolecule based on natural DNA. A Mechanistic Analysis of Oxygen Vacancy Driven Conductive Filament Formation in Resistive Random Access Memory Metal/NiO/Metal Structures Study could lead to more efficient electrically switchable resistive random access memory devices. pH-Dependent Spin State Population and 19F NMR Chemical Shift Via Remote Ligand Protonation in An Iron(II) Complex An FeII complex that features a pH-dependent spin state population demonstrates potential as a 19F chemical shift-based pH sensor.
Elevated Temperature Properties of Cast IronsJ125_201801 (Current)1/9/2018
The purpose of this SAE Information Report is to provide automotive engineers and designers with a concise statement of the basic characteristics of cast iron under elevated temperature conditions. As such, the report concentrates on general statements regarding these properties with limited illustrative data, anticipating that those who may be interested in more detail will want to use the bibliography provided at the conclusion of the report.
Metals Technical Committee
Controlling Soft Robots Using Magnetic FieldsTBMG-281911/1/2018
A fundamental advance in controlling soft robots involves using magnetic fields to remotely manipulate microparticle chains embedded in soft robotic devices. Several devices have been developed that make use of the new technique. Possible applications for these devices range from remotely triggered pumps for drug delivery, to the development of remotely deployable structures.
Using Sunlight to Activate the Flow of Electrical Current in a New MaterialTBMG-275369/1/2017
Mined to make the first compass needles, the mineral magnetite is also made by migratory birds and other animals to allow them to sense north and south, and thus navigate in cloudy or dark atmospheric conditions or under water. Researchers have compositionally modified magnetite to capture visible sunlight and convert this light energy into electrical current. This current may be useful to drive the decomposition of water into hydrogen and oxygen. The team generated this material by replacing one third of the iron atoms with chromium atoms.
Omnidirectional Mobile Robot with Two Moving PartsTBMG-270356/1/2017
SIMbot is an updated version of the ballbot, an elegantly simple robot whose tall, thin body moves on top of a sphere slightly smaller than a bowling ball. SIMbot features a motor with just one moving part: the ball. The other active moving part of the robot is the body itself.
Corrosion-Resistant Steel Parts: Sampling, Inspection and Testing for Surface PassivationAMSSTD753B (Current)4/4/2017
This standard describes general and detailed methods of sampling and testing for surface passivity of corrosion-resistant steel parts. These tests may also be useful to determine if there is a need for passivation.
AMS F Corrosion Heat Resistant Alloys Committee
Fatigue Assessment of Nodular Cast Iron with Material Imperfections2017-01-03443/28/2017
For the design of thick-walled nodular cast iron components, fatigue assessment, especially in the context of local imperfections in the material, is a challenging task. Not only the cyclic material behavior of the sound baseline material, but also the cyclic behavior of materials with imperfections, such as shrinkages, dross and chunky graphite, needs to be considered during the design process of cast iron components. In addition to this, new materials, such as solid solution strengthened alloys, offer new possibilities in lightweight design, but need to be assessed concerning their fatigue strength and elastic-plastic material behavior. If a safe and reproducible fatigue assessment for any component cannot be performed and a secure usage is therefore not given, the cast components are generally rejected, leading to a loss of additional material, energy and money for recasting the component. In this context, four nodular cast iron materials are compared with reference to their cyclic material and fatigue behavior as well as their potential for a lightweight design, based on stress- and strain-controlled tests both for sound and defective material. However, to develop an optimal and individual fatigue design method for cast components with local material imperfections present, the component’s local fatigue strength needs to be combined with information from non-destructive testing (NDT), since a removal of specimens is generally not possible. For this purpose, as an example, a method is described that uses information from ultrasonic and X-ray analysis as well as the given fatigue strength of the baseline material to conduct a fatigue assessment of local shrinkages in nodular cast iron components. The method is based on the reproducible measurement of the local density by NDT and its correlation with the local fatigue notch factor, enabling a safe and local assessment of the allowable fatigue strength when shrinkages are present.
Bleicher, Christoph, wagener, Rainer, Kaufmann, Heinz, Melz, Tobias
Lifetime Assessment of Cylinder Heads for Efficient Heavy Duty Engines Part II: Component-Level Application of Advanced Models for Thermomechanical Fatigue Life Prediction of Lamellar Graphite Cast Iron GJL250 and Vermicular Graphite Cast Iron GJV450 Cylinder Heads2017-01-03463/28/2017
A complete thermomechanical fatigue (TMF) life prediction methodology is developed for predicting the TMF life of cast iron cylinder heads for efficient heavy duty internal combustion engines. The methodology uses transient temperature fields as thermal loads for the non-linear structural finite-element analysis (FEA). To obtain reliable stress and strain histories in the FEA for cast iron materials, a time and temperature dependent plasticity model which accounts for viscous effects, non-linear kinematic hardening and tension-compression asymmetry is required. For this purpose a unified elasto-viscoplastic Chaboche model coupled with damage is developed and implemented as a user material model (USERMAT) in the general purpose FEA program ANSYS. In addition, the mechanism-based DTMF model for TMF life prediction developed in Part I of the paper is extended to three-dimensional stress states under transient non-proportional loading conditions. The material properties of the plasticity model are determined for lamellar graphite cast iron GJL250 and vermicular graphite cast iron GJV450 from isothermal and non-isothermal uniaxial tests. The methodology is applied to obtain a TMF life prediction on two cast iron cylinder heads for heavy duty diesel engine applications made from both cast iron materials. It is shown that the life predictions using the developed methodology correlate very well with observed lives from two bench tests in terms of location as well as number of cycles to failure.
Hazime, Radwan, Seifert, Thomas, Kessens, Jeremy, Ju, Frank
Lifetime Assessment of Cylinder Heads for Efficient Heavy Duty Engines Part I: A Discussion on Thermomechanical and High-Cycle Fatigue as Well as Thermophysical Properties of Lamellar Graphite Cast Iron GJL250 and Vermicular Graphite Cast Iron GJV4502017-01-03493/28/2017
Cast iron materials are used as materials for cylinder heads for heavy duty internal combustion engines. These components must withstand severe cyclic mechanical and thermal loads throughout their service life. While high-cycle fatigue (HCF) is dominant for the material in the water jacket region, the combination of thermal transients with mechanical load cycles results in thermomechanical fatigue (TMF) of the material in the fire deck region, even including superimposed TMF and HCF loads. Increasing the efficiency of the engines directly leads to increasing combustion pressure and temperature and, thus, lower safety margins for the currently used cast iron materials or alternatively the need for superior cast iron materials. In this paper (Part I), the TMF properties of the lamellar graphite cast iron GJL250 and the vermicular graphite cast iron GJV450 are characterized in uniaxial tests and a mechanism-based model for TMF life prediction is developed for both materials. The model can be used to estimate the fatigue life of components by means of finite-element calculations (Part II of the paper) and supports engineers in finding the appropriate material and design. Furthermore, the effect of the elastic, plastic and creep properties of the materials on the fatigue life can be evaluated with the model. However, for a material selection also the thermophysical properties, controlling to a high level the thermal stresses in the component, must be considered. Hence, the need for integral concepts for material characterization and selection from a multitude of existing and soon-to-be developed cast iron materials is discussed.
Seifert, Thomas, von Hartrott, Philipp, Boss, Kristopher, Wynthein, Paul
Development of High Efficiency Rectifier with MOSFET in “eSC Alternator”2017-01-12283/28/2017
Alternator, which supplies electric energy to a battery and electrical loads when it is rotated by engine via belt, is one of key components to improve vehicle fuel efficiency. We have reduced rectification loss from AC to DC with a MOSFET instead of a rectifier diode. It is important to turn on the MOSFET and off during a rectification period, called synchronous control, to avoid a current flow in the reverse direction from the battery. We turn it off so as to remain a certain conduction period through a body diode of the MOSFET before the rectification end. It is controlled by making a feedback process to coincide with an internal target conduction period based on the rotational speed of the alternator. We reduced a voltage surge risk at turn-off by changing the feedback gain depending on the sign of the time difference between the measured period and the target. In addition to reducing the rectification loss, reducing copper loss with low resistance coil winding and iron loss with magnetic steel contributed to improve the alternator efficiency by 10%. As a result, we achieved 2.6g/km CO2 reduction in a petrol-fuelled vehicle calculated by a guideline with a reference to [1].
Nakanishi, Masaya
The Development of Direct Drive Motors for Solar Cars2017-01-12323/28/2017
Solar car races are held worldwide, aiming to promote vehicles that help reduce environmental loads on the roads. In order to gain superiority in solar car racing, it is essential to develop a high efficiency brushless direct drive motor that optimizes the energy use to the fullest and allows high speed driving when needed. To achieve these goals, two development approaches of solar car motors are proposed: the high efficiency motor which improves electrical characteristics and significantly reduces energy loss; and the variable field magnet motor that offers instant speed boost for a temporary period of time for overtaking opponents. We have developed a high efficiency motor through the application of an amorphous core and laminated magnets. Instead of the standard method of the W-EDM (Wire-Electric Discharge Machining) for amorphous cores, we utilized water jet cutting, through which we succeeded in achieving insulation between laminated cores. In general, a sheet of magnet is used in each slot and its dimension is determined according to the lamination height of the core. In this project, multiple magnet segments shorter in the direction of the shaft are stacked vertically to achieve the desired height, which successfully resulted in the reduction of iron loss. The application of these methods led to the achievement of motor efficiency exceeding 98%. For the instant speed increase, we have developed the optimized design configuration for a variable field magnet module that can change T-N characteristics, utilizing our unique method for varying the effective magnetic flux. The result shows that our variable field magnet motor achieved a 1.57 times higher rotational speed than conventional types. The proposed technologies can contribute to the efficient use of energy in solar car applications, promoting the development of novel solar car systems.
Yamazakii, Tsubasa, Uchiyama, Hidekazu, Nakazawa, Kazuaki, Isomura, Tsubasa, Ogata, Hisashi
Development of Aluminum Composite Automotive Brake Rotors2016-01-19379/18/2016
Aluminum metal matrix composite brake rotors with a selective ceramic function reinforcement gradient (FRG) have been developed for automotive applications. This paper will highlight the design, manufacturing, and testing of the rotors. Weight saving of an aluminum composite rotor in comparison to an industry standard cast iron rotor is 50-60%. With this material change comes design considerations to manage rotor temperature, rotor surface integrity, and friction. Manufacturing methods to meet these design constraints were needed to develop a viable high performance aluminum composite rotor. High pressure squeeze casting with soluble coring techniques were developed to incorporate the selective FRG MMC rotors. Dynamometer testing was performed, concentrating on brake friction and temperature to evaluate the macro and micro interfaces in the rotors. The rotors’ testing results indicate that a functional reinforced aluminum metal matrix composite rotor is viable option for front and rear brake applications in the automotive and commercial trucking market.
Erva, Taylor, Loukus, Adam, Luskin, Luke
Fine-Tuning of Rotor Gray Iron Material for Optimal Brake Performance2016-01-19429/18/2016
Developing a brake system with high overall customer satisfaction rating is a constant challenge for OEMs as well as their brake suppliers. Brake system performance is directly linked to the engagement between the rotors and pads. The materials for the rotors and pads play a key role in the nature of the engagement. Therefore, to meet the performance targets, it is critical to have a good understanding of the brake rotor materials and their impacts. Gray iron is the most widely used brake rotor material in the industry owing to its superior thermal handling capacity, damping characteristics, and wear and cost advantages. G30 per ASTM A48 is generally specified for most brake rotors with minimum tensile strength of 200 MPa and Brinell hardness of 187∼241. G20 is also widely used for brake rotors, especially for brake smoothness and optimal lining life. This study has found that variations in gray iron material can considerably affect brake fiction coupling behaviors and hence the overall brake performance. Rotors that meet both physical property and chemical composition requirements in general can deliver very different brake performance due to variations in rotor friction surface characteristic and microstructure of rotor material. The suitability of microstructure and control of friction surface characteristics are the most important aspects for gray iron material in dictating overall rotor performance.
Chen, Sarah, Hoxie, Steve
The Multiobjective Optimal Design Problems and their Pareto Optimal Fronts for Li-Ion Battery Cells2016-01-11994/5/2016
This paper begins with a baseline multi-objective optimization problem for the lithium-ion battery cell. Maximizing the energy per unit separator area and minimizing the mass per unit separator area are considered as the objectives when the thickness and the porosity of the positive electrode are chosen as design variables in the baseline problem. By employing a reaction zone model of a Graphite/Iron Phosphate Lithium-ion Cell and the Genetic Algorithm, it is shown the shape of the Pareto optimal front for the formulated optimization takes a convex form. The identified shape of the Pareto optimal front is expected to guide Design of Experiments (DOE) and product design. Compared with the conventional studies whose optimizations are based on a single objective of maximizing the specific energy, the proposed multi-objective optimization approach offers more flexibility to the product designers when trade-off between conflicting objectives is required. The solutions of the multi-objective optimization include multiple alternatives which may lead to more energy per unit separator area but result in larger weight or vice versa. These alternatives enable the product designers to choose the most appropriate design that best fits the characteristics of the application. Three design cases are employed to illustrate the wide applicability of the developed Pareto optimal front to common design problems in industry. Different objectives are adopted in the three cases to represent different appropriate applications for the cell to be designed, but all the three cases can be solved with the solutions for the baseline multi-objective problem.
Hong, Yao, Lee, Cheol W.
A Novel Equivalent Circuit Model for Lithium-ion Battery with Complex Electrical Element Parameters2016-01-11974/5/2016
An equivalent circuit model for lithium-ion battery including capacitor and inductor with complex parameters is proposed. The imaginary part of the complex-valued capacitor expresses diffusion processes instead of constant phase element, which leads to a higher computational efficiency by removing the exponential variant calculation. The inductor with the complex parameter, the imaginary part accounting for the frequency-dependent magnetic hysteresis loss of battery current collectors and cables, can accurately regenerate the impedance characteristics at high frequencies with various linear slope angles to the real axis in a Nyquist plot. The fitted electrochemical impedance spectrum of a lithium iron phosphate/graphite battery with this proposed model is compared to the measured data. The maximum relative error of the impedance magnitude is 4.94% at the frequencies between 0.01 Hz and 10 kHz. The electrical component parameters of the proposed equivalent circuit model are calculated and analyzed.
Wu, Zhengbin, Weng, Rongcheng, Zhang, Zhiqun, Li, Juan
Tribological Properties of Engine Lubricant With Nano-Copper Oxide as an Additive2016-01-04874/5/2016
Anti-wear additives are mostly required to improve lubricant properties and hence tribological performance. Addition of nanoparticles to lubricant oils reduces friction and thus enhances the lubrication characteristics. The mechanism of friction reduction in friction could be justified by more than one method. In this work, copper oxide nano-material was added to the engine lubricant oil Mobil 1 SAE15W-40SF with 0.1% wt. concentration. Two new engines were used and operated for 1000 hours, where nanolubricant was added to one of them and regular lubricant was used in the other. Twelve samples were taken periodically from each engine. ASTM-D6595 spectrometry standard was used in order to measure the wear particles in the taken oil samples. Further investigation was done by doing more tests to some of the oil samples using Laser Net Fines Analyzer. Results showed an improvement in the friction properties through a reduction in wear rates in the case of using nano-additives. Basically a wear reduction is found for aluminum, iron and chromium wear particles by 48%, 11.5% and 42%, respectively. Also, an average reduction in amount of specific wear particle was found by 39%, 36% and 60% for cutting wear, severe sliding wear and fatigue wear, respectively. A relevant decrease in engine temperature is found as well.
Akl, Sayed Y., Abdel-Rehim, Ahmed A., Khafagy, Esraa A.
Alternative Technology for Platinum Group Metals in Automobile Exhaust Gas Catalysts2016-01-09304/5/2016
This paper describes a new catalyst powder has been developed that provides cleaner exhaust emissions and reduces the consumption of precious metals. In recent years, precious metal usage has been increasing due to the tightening of emission regulations and the increase in automobile production worldwide. Minimizing the use of precious metals in exhaust catalysts is crucial not only for reducing the cost of vehicles but also for effective utilization of scarce resources. Iron is one of the alternative material candidates for precious metals. It was found that the Iron catalyst was activated by iron becoming the low oxidation state while iron oxide and cerium oxide synchronized in a nanostructure interface. A catalyst with improved iron support technology that enables better contact between highly dispersed particles of iron and ceria was found to exhibit higher exhaust gas cleansing performance than precious metal catalysts even after aging.
Hanaki, Yasunari, Fujimoto, Misaki, Itou, Junji
Investigation into Mixed and Hydrodynamic Frictions of PEO Coatings and Cast Iron2016-01-04914/5/2016
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 (COF) vs surface roughness (Ra: 0.2 - 0.8 μm) and sliding speeds (up to 6.07 m/s) were particularly studied. The results show that the COF significantly decreased with the increase of sliding speeds, and a smoother coating surface generally exhibited a lower COF and a steeper descent rate of the COF. While such observations seem true for both PEO coatings and the cast iron sample, the polished PEO coatings can have a lower COF than cast iron. The study indicates that the Al-Si alloy with PEO coatings could be further explored as a feasible solution to reduce the weight and improve the fuel efficiency of an Al engine.
Wang, Guang, Nie, Xueyuan, Tjong, Jimi
Development of Trivalent Chromium Passivation for Zn Platng with High Corrosion Resistance after Heating2016-01-05424/5/2016
Trivalent chromium passivation is used after zinc plating for enhancing corrosion resistance of parts. In the passivating process, the amount of dissolved metal ions (for example zinc and iron) in the passivation solution increases the longer the solution is used. This results in a reduced corrosion resistance at elevated temperatures. Adding a top coat after this process improves the corrosion resistance but has an increased cost. To combat this, we strove to clarify the mechanism of decreased corrosion resistance and to develop a trivalent chromium passivation with a higher corrosion resistance at elevated temperatures. At first, we found that in parts produced from an older solution, the passivation layer has cracks which are not seen in parts from a fresh/new solution. These cracks grow when heated at temperatures over 120 degrees Celsius. Next we researched the reason for cracks to occur and found that the main difference between an old and new solution’s layer is the amount metal deposits in it. These metal ions deposit into the passivation as hydroxides, and the larger the quantity in this layer the more the layer contracts by heating, meaning the newer the solution the less the layer contracts. So, we investigated developing a new solution to improve the corrosion resistance after heating through the reduction of metal ion deposits in the passivation layer. We achieved this reduction by adding organic carboxylic acid to chelate the dissolved metal ions. The carboxylic acid prevents excess depositing of these ions in the passivation layer. Using this developed solution, cracks disappeared and the corrosion resistance after heating was improved.
Kawaguchi, Hiroshi, Funatsumaru, Osamu, Sugawara, Hiroyoshi, Sumiya, Hiroshi, Iwade, Takanobu, Yamamoto, Tomitaka, Koike, Takashi, Kashio, Ryuta
AGS511 Ballast Weights. (Grey Cast Iron)AGS511-2 (Current)12/3/2015
No scope available.
Engine and Airframe Technical Standards Committee (TSC)
Closer Look at Gray Iron Rotor Material to Understand Metal Pickup and Brake Noise Tendency2015-01-26839/27/2015
Developing a quiet brake system has been a constant task for OEMs as well as their brake suppliers. As a major component in the brake system, the rotor plays a significant role in brake noise performance. Owning to the cost and damping property advantages, gray iron is still the most widely used material for brake rotor application. When pads/rotor coupling is examined to address noise issues, however, most efforts have been on pads and insulators. Rotor specifications are rather general and the component is typically accepted based on grades defined by mechanical property minimum (mostly in G3000 SAE J431). Nevertheless, we have found that gray iron within a grade can have wide microstructure variations, and the deviation (especially on the rotor friction surface) can critically affect the noise propensity in addition to friction output performance and wear characteristics. In this work, the impact of brake disc material on brake noise and output performance is investigated. More specified microstructure descriptions are recommended.
Chen, Sarah, Hoxie, Steve
A Study on Emission of Airborne Wear Particles from Car Brake Friction Pairs2015-01-26659/27/2015
The emission of airborne wear particles from friction material / cast iron pairs used in car brakes was investigated, paying special attention to the influence of temperature. Five low-metallic materials and one non-asbestos organic material were tested using a pin-on-disc machine. The machine was placed in a sealed chamber to allow airborne particle collection. The concentration and size distribution of 0.0056 to 10 μm particles were obtained by a fast mobility particle sizer and an optical particle sizer. The temperature was measured by a thermocouple installed in the disc. The experiments show that as the temperature increases from 100 to 300 °C the emission of ultrafine particles intensifies while that of coarse particles decreases. There is a critical temperature at which the ultrafine particle emission rate rises stepwise by 4 to 6 orders of magnitude. For the friction pairs investigated, the critical temperature was found to be between 165 and 190 °C. Below the critical temperature, fine particles outnumber coarse and ultrafine particles, although coarse particles make up the bulk of the particulate matter mass. The friction pairs differ in the ultrafine particle emission rate by 1 to 2 orders of magnitude. Above the critical temperature, ultrafine particles constitute almost 100% of the total particle number and their relative mass contribution can exceed 50%. Analysis of the particle size distributions revealed peaks at 0.19-0.29, 0.9 and 1.7 μm. Above the critical temperature, one more peak appears in the ultrafine particle range at 0.011-0.034 μm.
Alemani, Mattia, Nosko, Oleksii, Metinoz, Ibrahim, Olofsson, Ulf
Promaxon® D in NAO Non Steel Disc Pad Formulations: the Importance in the Third Body Layer and its Effect on Brake Noise2015-01-26789/27/2015
Friction performance is the result of the interaction between rotor and friction material surfaces. Kinetic energy has to be transformed into heat, plastic deformations, chemical reactions and wear debris. The later generates the formation of the so-called third body layer and its initiation, growth and degradation will generate the actual friction coefficient and vibrations behavior. Some raw materials seem to promote third body layer formation more than others. The composition of plateaus usually contains iron oxide, copper, carbon, silicon and calcium. Since copper free materials are under development, the importance of understanding the third body layer formation has become bigger. Promaxon® D is widely used in NAO non steel formulations. It is a calcium silicate with a special morphology that influences friction material at two levels: the macro -bulk- scale and the micro -surface- scale. Bulk effect is related to the volume and porosity degree of the friction material. This affects the elastic modulus and vibration adsorption. The micrometric effect is related to the third body layer. When Promaxon® D is combined properly with an anchoring material (i.e. a fibre) it can promote the initiation and stabilization of the third body layer. As a result friction coefficient stabilization and wear will be improved. Wear is also directly related to noise as proposed by Lee et al [15]. This paper deals with the understanding of the importance of calcium silicate morphology for the bulk properties and in the third body layer formation. It demonstrates how the raw materials morphology, regardless of its chemical composition, plays an important role at macro and micro level in NAO non steel materials.
Santamaria Razo, Diego Adolfo, Decrock, Johan, Opsommer, Ann, Fabré, Maarten, Persoon, Fernao
Categorization and Properties of SAE Cold Rolled Strip SteelsJ2392_201504 (Historical)4/28/2015
This SAE recommended practice defines and establishes tolerances and attributes of cold rolled strip steels. Differences between cold rolled strip and cold rolled sheet products are discussed so that process designers can make informed material selection decisions.
Metals Technical Committee
Effect of Temperature Cycle on Thermomechanical Fatigue Life of a High Silicon Molybdenum Ductile Cast Iron2015-01-05574/14/2015
High silicon molybdenum (HiSiMo) ductile cast iron (DCI) is commonly used for high temperature engine components, such as exhaust manifolds, which are also subjected to severe thermal cycles during vehicle operation. It is imperative to understand the thermomechanical fatigue (TMF) behavior of HiSiMo DCI to accurately predict the durability of high temperature engine components. In this paper, the effect of the minimum temperature of a TMF cycle on TMF life and failure behavior is investigated. Tensile and low cycle fatigue data are first presented for temperatures up to 800°C. Next, TMF data are presented for maximum temperatures of 800°C and minimum cycle temperatures ranging from 300 to 600°C. The data show that decreasing the minimum temperature has a detrimental effect on TMF life. The Smith-Watson-Topper parameter applied at the maximum temperature of the TMF cycle is found to correlate well with out-of-phase (OP) TMF life for all tested minimum temperatures. Fractography and energy dispersive spectroscopy (EDS) are then performed on the tested specimens to determine the difference in failure mechanism as the minimum cycle temperature changes. Based on these observations, it appears that the segregation of magnesium to the grain boundary which occurs near 400°C in HiSiMo DCI influences TMF failure behavior when the TMF temperature cycle passes through 400°C.
Avery, Katherine, Pan, Jwo, Engler-Pinto, Carlos
Thermal-Mechanical Fatigue Analysis of Diesel Engine Cylinder Head Based on Fluid-Structure Interaction2015-01-05584/14/2015
With a focus on a heavy diesel engine, complete set of multi-field coupling methodology aimed at analyzing and optimizing for fatigue-strength of cylinder head is proposed. A detailed model of the engine consisting of both the coolant galleries and the surrounding metal components is employed in both fluid-dynamic and structural analyses to accurately mimic the influence of the thermo-mechanical load on the cylinder head and block structural reliability. This model carries out several simulating experiments like 3-dimensional CFD of in-cylinder combustion and engine cooling jacket, simulation of cylinder head temperature field which use fluid-structure interaction, stress and strain analysis under thermal-mechanical coupling conditions and high cycle fatigue analysis. In order to assess a proper CFD setup useful for the optimization, the experimentally measured temperature distribution within the engine head is compared to the CFD forecasts. The analysis shows that computed temperatures were consistent with experimental measurements, and the danger region predicts through calculation matches the crack in actual experiment. In addition, the simulation analyzes two optimization schemes for problems of original head. The results show that the stress at the crack decreased from 245MPa to 230MPa after increased wall thickness, and the stress drop significantly after changed the cylinder material from gray iron to compacted graphite iron. Either increasing the wall thickness or replacing the material solved the crack failure obvious.
Cheng, Xiaobei, Wang, Xin, Ming, Yang, Hongfei, Zhang, Gao, Ran
Simulation of Thermomechanical Fatigue of Ductile Cast Iron and Lifetime Calculation2015-01-05524/14/2015
In this paper, both standard and constrained thermomechanical fatigue (TMF) tests were conducted on a high silicon ductile cast iron (DCI). The standard TMF tests were conducted with independent control of mechanical strain, out-of-phase (OP) and in-phase (IP) strain, and temperature in the range from 300 to 800°C. The constrained TMF tests were conducted with various constraint ratios of 100%, 70%, 60% and 50% at the temperature ranges of 160 to 600°C and 160 to 700°C. Based on a material model as calibrated with low-cycle fatigue (LCF) data of DCI, finite element analyses (FEA) of the above TMF tests were carried out with Abaqus. A damage mechanism-based lifetime model was integrated into a C++ API code to post-process the Abaqus output results. Simulation predictions show good agreement with experiments for stress-strain responses and lifetime under different TMF conditions.
Liu, Xiaoyang, Quan, Guangchun, Wu, Xijia, Zhang, Zhong, Sloss, Clayton
Effect of Current and SOC on Round-Trip Energy Efficiency of a Lithium-Iron Phosphate (LiFePO4) Battery Pack2015-01-11864/14/2015
While equivalent circuit modeling is an effective way to model the performance of automotive Li-ion batteries, in some applications it is more convenient to refer to round-trip energy efficiency. Energy efficiency of either cells or full packs is seldom documented by manufacturers in enough detail to provide an accurate impression of this metric over a range of operating conditions. The energy efficiency of a full battery pack may also be subject to more variables than would be represented by extrapolating results obtained from a single cell, and can be more demanding to measure in an accurate and consistent manner. Roundtrip energy efficiency of a 22.8-kWh A123 Li-ion (Lithium Iron Phosphate, LiFePO4) battery pack was measured by applying a fixed quantity of charge and discharge current between 0.2C and 2C rates and at SOCs between 10% and 90% at an average temperature of 23°C.
Safoutin, Michael, Cherry, Jeff, McDonald, Joseph, Lee, SoDuk
Surface Effect of a PEO Coating on Friction at Different Sliding Velocities2015-01-06874/14/2015
In order to reduce the weight of an automotive engine, an aluminum (Al) alloy engine block with cast iron liner has been successfully used to replace the gray cast iron engine. For newly emerging Al linerless engine in which the low surface hardness of the aluminum alloy has to be overcome, a few surface processing technologies are used to protect the surface of cylinders. Among them, plasma transferred wire arc (PTWA) thermal spraying coating is becoming popular. Plasma electrolytic oxidation (PEO) coating is also proposed for increasing the wear resistance of aluminum alloy and reducing the friction between the cylinder and piston. In this work, a PEO coating with a thickness of ∼20 μm was prepared, and a high speed pin-on-disc tribometer was used to study the tribological behavior of the coating at oil lubricant conditions. Different surface roughness of the coating and a large range of the sliding speeds were employed for the tests. The coefficient of friction (COF) vs surface roughness and sliding speed were particularly studied. The results show that the COF significantly decreased with the increase of sliding speed, and a smoother coating surface had a lower COF.
Wang, Guang, Nie, Xueyuan, Tjong, Jimi
Corrosion Aspects Regarding the Use of Martensitic Stainless Steels in Automotive Chassis Parts2015-01-13474/14/2015
In order to meet new environmental regulations (i.e. mass of CO2 rejected in the atmosphere per km), car manufacturers are looking for new solutions to lighten chassis and structural parts in cars. High strength steels formed by hot stamping have proved to be good candidates for achieving better in-use performances together with a lighter structure. In particular, the martensitic stainless steel MaX fulfils the industrial targets for chassis parts in terms of mechanical and fatigue properties. For instance, from a cold formed baseline made of 600 MPa carbon steel, a 50 % mass reduction can be expected with a hot stamped suspension arm made of MaX and included a new clamshell design. However, those parts are often made of a complex assembly of different materials (high strength steels, aluminium and cast iron among others) which are subjected to aggressive environments in service. Therefore galvanic corrosion of those complex assemblies has to be evaluated. Galvanic coupling measurements have been made on MaX / Cast iron, MaX / Aluminium and Cast iron / Aluminium assemblies using the Zero Resistance Ammeter (ZRA) technique. Results reveal that the galvanic current of the Aluminium / Cast iron couple is higher than the galvanic current of the Aluminium / MaX couple and Cast iron / MaX couple. These results are discussed in terms of cathodic currents and polarisation resistances of metals showing that the anodic dissolution rate is higher in the case of the Aluminium / Cast iron couple compared to the Cast iron / MaX and Aluminium / MaX couples. In this regard, the MaX material shows better performances than Aluminium, a result which goes against predictions that are made based on the electro-chemical potential differences of MaX and Aluminium compared to Cast iron. The importance of these findings regarding the open circuit potential difference used for the choice of materials in the automotive industry is discussed and a new criterion for material assessment is proposed.
Ruel, Fiona, Santacreu, Pierre-Olivier, Saedlou, Saghi, Badinier, Guillaume, Herbelin, Jean
Effect of Surface Roughness and Lubrication on Scuffing for Austempered Ductile Iron (ADI)2015-01-06834/14/2015
This paper describes the scuffing tests performed to understand the effect of surface roughness and lubrication on scuffing behavior for austempered ductile iron (ADI) material. As the scuffing tendency is increased, metal-to-metal interaction between contacting surfaces is increased. Lubrication between sliding surfaces becomes the boundary or mixed lubrication condition. Oil film breakdown leads to scuffing failure with the critical load. Hence, the role of surface roughness and lubrication becomes prominent in scuffing study. There are some studies in which the influence of the surface roughness and lubrication on scuffing was evaluated. However, no comprehensive scuffing study has been found in the literature regarding the effect of surface roughness and lubrication on scuffing behavior of ADI material. The current research took into account the inferences of surface roughness and lubrication on scuffing for ADI. The effect of various surface roughness values and two types of lubricants were evaluated based on the experimental data using ball-on-disc rig to better understand scuffing behavior affected by surface roughness and lubricants.
Han, Jiman, Zou, Qian, Barber, Gary, Sun, Xichen
Fatigue Behavior of Cast Iron Including Mean Stress Effects2015-01-05444/14/2015
With improvements in casting technology, cast iron can be an alternative to steel in some applications due to its similar strength. One objective of this study was to analyze cast iron data obtained from the literature and evaluate predictive correlations between its tensile, microstructural, and fatigue properties. Reasonably good correlation of tensile strength and yield strength were found with hardness. However, fatigue strength could not be correlated with hardness or tensile properties. Another objective of this study was to evaluate tensile and compressive means stress effects on fatigue behavior of 120-90-02 ductile cast iron experimentally, as well as analytically by using predictive models. Mean stress levels were chosen such that R ratios in load-controlled tests were −7, −3, −1, 0, 1/3, 0.5, and 0.75. Modified Goodman, Smith-Watson-Topper, FKM and the Fatemi-Socie mean stress parameters were used to account for the mean stress effect on fatigue life. Constant life diagrams were also constructed to evaluate predictive capabilities of these mean stress models for applications in design.
Meyer, Nicholas, Fatemi, Ali, McCutcheon, Steven, Havard, Brian, Fairchilds, William
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