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The Multi Material Lightweight Vehicle (MMLV) developed by Magna International and Ford Motor Company is a result of a US Department of Energy project DE-EE0005574. The project demonstrates the lightweighting potential of a five passenger sedan, while maintaining vehicle performance and occupant safety. Prototype vehicles were manufactured and limited full vehicle testing was conducted. The Mach-I vehicle design, comprised of commercially available materials and production processes, achieved a 364kg (23.5%) full vehicle mass reduction, enabling the application of a 1.0-liter three-cylinder engine resulting in a significant environmental benefit and fuel reduction. This paper reviews the mass reduction and structural performance of aluminum, magnesium, and steel components for a lightweight multi material door design for a C/D segment passenger vehicle. Stiffness, durability, and crash requirements are assessed.

The pneumatic air brake system for heavy commercial trucks is composed by a large number of components, aiming its proper work and compliance with rigorous criteria of vehicular safety. One of those components, present along the whole vehicle, is the air brake tube, ducts which feed valves and reservoirs with compressed air, carrying signals for acting or releasing the brake system. In 2011, due to a lack of butadiene in a global scale, the manufacturing of these tubes was compromised; as this is an important raw material present on the polymer used so far, PA12. This article introduces the methodology of selecting, developing and validating in vehicle an alternative polymer for this application. For this purpose, acceptance criteria have been established through global material specifications, as well as bench tests and vehicular validation requirements.

Finite element analysis (FEA) predictions of magnesium beams are compared to load versus displacement test measurements. The beams are made from AM60B die castings, AM30 extrusions and AZ31 sheet. The sheet and die cast beams are built up from two top hat sections joined with toughened epoxy adhesive and structural rivets. LS-DYNA material model MAT_124 predicts the magnesium behavior over a range of strain rates and accommodates different responses in tension and compression. Material test results and FEA experience set the strain to failure limits in the FEA predictions. The boundary conditions in the FEA models closely mimic the loading and constraint conditions in the component testing. Results from quasi-static four-point bend, quasi-static axial compression and high-speed axial compression tests of magnesium beams show the beam's behavior over a range of loadings and test rates. The magnesium beams exhibit significant material cracking and splitting in all the tests.

Magnesium alloy extrusions offer potentially more mass saving compared to magnesium castings. One of the tasks in the United States Automotive Materials Partnership (USAMP) ?Magnesium Front End Research and Development? (MFERD) project is to evaluate magnesium extrusion alloys AM30, AZ31 and AZ61 for automotive body applications. Solid and hollow sections were made by lowcost direct extrusion process. Mechanical properties in tension and compression were tested in extrusion, transverse and 45 degree directions. The tensile properties of the extrusion alloys in the extrusion direction are generally higher than those of conventional die cast alloys. However, significant tension-compression asymmetry and plastic anisotropy need to be understood and captured in the component design.

Magnesium alloys are the lightest structural metal and recently attention has been focused on using them for structural automotive components. Fatigue and durability studies are essential in the design of these load-bearing components. In 2006, a large multinational research effort, Magnesium Front End Research & Development (MFERD), was launched involving researchers from Canada, China and the US. The MFERD project is intended to investigate the applicability of Mg alloys as lightweight materials for automotive body structures. The participating institutions in fatigue and durability studies were the University of Waterloo and Ryerson University from Canada, Institute of Metal Research (IMR) from China, and Mississippi State University, Westmorland, General Motors Corporation, Ford Motor Company and Chrysler Group LLC from the United States.

A task group within the SAE Automotive Corrosion and Protection (ACAP) Committee continues to pursue the goal of establishing a standard test method for in-laboratory cosmetic corrosion evaluations of finished aluminum auto body panels. The program is a cooperative effort with OEM, supplier, and consultant participation and is supported in part by USAMP (AMD 309) and the U.S. Department of Energy. Numerous laboratory corrosion test environments have been used to evaluate the performance of painted aluminum closure panels, but correlations between laboratory test results and in-service performance have not been established. The primary objective of this project is to identify an accelerated laboratory test method that correlates with in-service performance. In this paper the type, extent, and chemical nature of cosmetic corrosion observed in the on-vehicle exposures are compared with those from some of the commonly used laboratory tests

Creep-resistant magnesium alloys for automotive powertrain applications offer significant potential for vehicle weight reduction. In this study permanent mold casting, microstructure and creep behavior have been investigated for a series of ternary magnesium alloys (Mg-4Al-4X (X: Ca, Ce, La, Sr) wt%) and AXJ530 (Mg-5Al-3Ca-0.15Sr, wt%). A permanent mold was instrumented with twelve thermocouples and mold temperature was monitored during the casting process. Average mold temperature increased from 200°C to 400°C during a typical alloy casting series (fifteen to twenty castings). The cast microstructure for all alloys consists of primary α-Mg globular phase surrounded by eutectic structure which is composed of intermetallic(s) and α-Mg magnesium phases. The primary cell size of the AXJ530 increased from 18 to 24 μm with increasing mold temperature and a similar trend is expected for all alloys.

This paper describes a new concept for a Ford F-150 light truck Front End Support Assembly (FESA) based on a one-piece die cast structural magnesium component. This new FESA reduces the number of parts and therefore the complexity of manufacturing and assembly, it integrates a multi-piece weldment assembly into a die cast part, and it considerably decreases mass compared to its steel counterpart. The design also reduces FESA cost. Major design criteria included corrosion protection, crashworthiness assessments, Noise Vibration Harshness (NVH) performance, durability and Ford assembly plant constraints. Die casting requirements included feasibility for large volume production, coating strategy and assembly constraints. The resulting design used the flexibility present in a magnesium die-casting that would not be possible using conventional steel stampings and assembly techniques.

This study is a life-cycle assessment (LCA) comparing two types of a powertrain structural component: one made of diecast primary aluminum and another hypothetical part made of semi-solid injection molded primary magnesium (Thixomolded®). The LCA provides an indication of the potential environmental burdens throughout the life-cycles of both parts, ranging from raw material acquisition to product end-of-life. Preliminary results show high sensitivity to selection of primary vs. secondary metals, and to the SF6 emission factor used in the model. Opportunities exist for reducing energy consumption using secondary instead of primary metals for both parts, although the use of such is influenced by market supply and demand

Improvement of engine fuel efficiency through the use of low friction engine oils is a major task in engine lubrication research. This friction reduction can be achieved by improving the rheological characteristics and elastohydrodynamic (EHD) properties of engine oils, and by controlling boundary chemical interactions between oil-based additives and lubricated components in the engine. In order to achieve minimal frictional power loss under all lubrication regimes, engine tribological systems must be designed to effectively use advanced lubricant technology, material and surface modifications. This paper presents results of cooperative research addressing opportunities for minimizing friction through extension of hydrodynamic lubrication regime in lubricated components using various formulation approaches. A set of experimental oils has been evaluated using laboratory test rigs that simulate hydrodynamic, EHD, mixed and boundary lubrication.

The effect of temperature and preload on the bolt load retention (BLR) behavior of AZ91D and AE42 magnesium die castings was investigated. The results were compared to those of 380 aluminum die castings. Test temperatures from 125 to 175°C and preloads from 7 to 28 kN were investigated. The loss of preload for AZ91D was more sensitive to temperature than that observed for AE42, especially at low preloads. In general, retained bolt-load was lowest in AZ91D. All test assemblies were preloaded at room temperature and load levels increased when the assemblies reached test temperature. The load-increase was dependent on the preload level, test temperature, alloy, and results from thermal expansion mismatch between the steel bolt and the magnesium alloy components, mitigated by the onset of primary creep. Thermal exposure (aging) of AZ91D at 150°C improved BLR behavior.

Painting is the most difficult, the most costly, and the most polluting step in manufacturing vehicles. When low weathering performance paints are used, the results are dissatisfied customers, and huge warranty costs. It would obviously be wise to fully characterize the weathering performance of new coatings systems before they are used. Unfortunately this is not always practical. Coating formulations are changing rapidly in the States to comply with solvent emission regulations, the introduction of plastic substrates, and customer tastes. There is rarely enough time to wait ten years for outdoors exposure tests to reveal the "true" weathering performance of coatings before marketing vehicles. As a result, accelerated tests are often used to guide decisions. However, the results of such tests can be misleading because the harsh exposure conditions used can distort the chemistry of degradation.

A method was adapted to measure the adhesion strength of polyurethane, semi-flexible foams to thermoplastic substrates. This method (lap-joint shear) was used to determine the effect of six (6) variables upon adhesion. These variables were: 1.) the type of substrate material, 2.) the type of polyurethane foam, 3.) the weight percentage of water in the polyurethane formulation (the degree to which the foam is blown and the chemical constituents), 4.) the chemical index of the polyurethane (the ratio of isocyanate to polyol resin), 5.) the surface roughness of the substrate, and 6.) the temperature of the polyurethane materials. Five (5) typical automotive interior thermoplastic substrates were studied: 1.) Polypropylene with preblended glass, 2.) Polycarbonate/ABS, 3.) PPO/HIPS with preblended glass, 4.) SMA with in-house dry blended glass, and 5.) SMA with preblended glass.

The presence of a foreign substance on or within a polymer often affects the mechanical, chemical and thermal properties of the material. The change in strength and rigidity of a polymer resulting from the plasticizing action of a sorbed chemical or due to the withdrawal of an added plasticizer by the leaching operation can seriously affect the useful life of the material. In the real engineering world, incompatible chemicals and lubricants get onto various plastic components unexpectedly through design, manufacturing processes, customers services and repairs. This paper presents a number of case-studies which illustrate how undesirable chemicals found on plastic parts can affect product performance and cause damage to the parts.

Erosion damage to automotive car bodies caused by stones and small sand particles and road debris significantly affects the appearance of paint. Painted engineering plastics as well as precoated sheet steel are affected by erosion phenomenon. Erosion of painted plastic substrates results in cosmetic concerns while that on metal substrates results in cosmetic to perforation corrosion. This work describes a laboratory simulation of erosion of painted plastic substrates by small particles on various paint and substrate types. Gloss loss was used to quantitatively evaluate erosion of painted surfaces. Wear behavior of painted plastic substrates to slag sand impact was evaluated as a function of several variables including paint type (one-component melamine crosslinked (1K) vs. two-component isocyanate crosslinked (2K)), thermal history, and coating modulus. The effect of slag sand type (particle size and chemical composition) was studied.

A vehicle system to monitor the actual condition of engine oil in service would provide the customer with the opportunity to utilize the full useful life of the oil and would minimize problems which can occur when oils remain in the engine too long and are excessively degraded and/or contaminated. This paper describes limitations of some systems which have been proposed, outlines the requirements and potential difficulties related to development of sensors designed to monitor changes in chemical properties of the oil, and describes laboratory and vehicle evaluations of a candidate sensor.

Field inspection of 41 vehicles equipped with magnesium clutch housings or transfer cases was carried out after service in Nova Scotia or Prince Edward Island for periods up to five years. This area is reported to be the most severe location in North America for salt-induced corrosion of automobiles. The die cast magnesium components were unpainted, but basic measures were taken to control galvanic corrosion. The clutch housings had the longest history, with production spanning the years 1982-1987. The general surface corrosion of these housings was negligible, notably less than that of die cast aluminum 380 or carbon steel components on the same vehicle. Slight galvanic corrosion of exposed bolt bosses was observed, induced by the plated bolt. Some galvanic action was noted at the face-to-face junction between the magnesium clutch housings and aluminum 380 transmission cases. This was not sufficiently advanced to indicate a threat to component function.

Speciation of sulfurous acid, sulfuric acid and ammonium sulfate collected from the aerosol phase on a Fluoropore filter has been readily accomplished using techniques of chemical ionization mass spectrometry combined with thermal separation. Thermal separation of ammonium hydrogen sulfate from ammonium sulfate was not possible. Spectral separation of these species by selective ionization is proposed. Analysis of sulfate aerosols collected from ambient air and catalyzed vehicle emissions is described. It was found that sulfuric acid aerosol was rapidly converted to ammonium sulfate or ammonium hydrogen sulfate in the presence of ambient concentrations of ammonia. Ambient samples collected in the Detroit metropolitan area have been found to contain only trace quantities of sulfuric aicd. Sulfate samples collected from a dilution tube into which catalyzed vehicle exhaust was injected were found to contain significant quantities of ammonium sulfate in addition to sulfuric acid.

Pyrolytic gas chromatography (PGC) has been applied to the characterization of the organic constituents of brake linings. The test involves the pyrolysis of a sample followed by the instrumental separation and sensing of the products of decomposition. A study of experimental variables, such as pyrolysis temperature, has allowed the selection of conditions which yield excellent reproducibility and sensitivity. The preferred test conditions, which have been incorporated in Ford's brake lining quality control specifications, result in a relatively rapid, meaningful test for constancy of composition.

Three techniques for the measurement of the oxides of nitrogen in automotive exhaust were evaluated. These included a “nitrous fume” analyzer, a gaseous NO2 colorimeter, and a movable mass spectrometer. All data obtained were compared to data from currently accepted wet chemical methods, the phenoldisulfonic acid and the “modified” Saltzman. Of the techniques evaluated, the mass spectrometer analysis of NO has been found to be the most useful for the study of nitrogen oxides in engine exhaust. The high cost of wet chemical analysis has indicated a need for an improved and continuous analytical method. The mass spectrometer approach measures NO within seconds of its discharge, thus minimizing any reactions prior to measurement.