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High-strength aluminum alloys such as 7075 can be formed using advanced manufacturing methods such as hot stamping. Hot stamping utilizes an elevated temperature blank and the high pressure stamping contact of the forming die to simultaneously quench and form the sheet. However, changes in the thermal history induced by hot stamping may increase this alloy’s stress corrosion cracking (SCC) susceptibility, a common corrosion concern of 7000 series alloys. This work applied the breaking load method for SCC evaluation of hot stamped AA7075-T6 B-pillar panels that had been artificially aged by two different artificial aging practices (one-step and two-step). The breaking load strength of the specimens provided quantitative data that was used to compare the effects of tensile load, duration, alloy, and heat treatment on SCC behavior.

The Composite Hybrid Automotive Suspension System Innovative Structures (CHASSIS) is a project to develop structural commercial vehicle suspension components in high volume utilising hybrid materials and joining techniques to offer a viable lightweight production alternative to steel. Three components are in scope for the project:- Front Subframe Front Lower Control Arm (FLCA) Rear Deadbeam Axle

Fuel economy and federal safety regulations are driving automotive companies to use Dual Phase and other Advanced High Strength Steels (AHSS) in vehicle body structures. Joining and assembly plays a crucial role in the selection of these steels. Specifications are available for the resistance spot welding (RSW) of lower strength sheet steels, covering many aspects of the welding process from the stabilization procedure to endurance testing. Currently, specifications in the automotive industry for RSW with AHSS are limited. It is well known that welding of a thickness ratio greater than 1:2 poses a challenge. To utilize thinner gauge AHSS panels on body-in-white, welding schedules to join the thin to thick sheet steel stack-up are needed. Most of the existing published work was conducted on uncoated sheets and welded to the same thickness.

Bolted joint separation occurs when components of a joint are no longer capable of maintaining a clamp load. The clamp load of a joint is the resultant of various factors such as the strength of joining components, geometry, and the surface condition of the joined parts. The fastener installation torque is a very critical parameter that contributes towards achieving the desired clamping force at the joint during the assembly process. Thread rolling screws are increasingly being used in many automotive structural applications. The thread rolling screws are easy to install, are self aligning, and offer a torque prevailing feature with improved vibration resistance when mated with a un-threaded nut. This combination results in a robust joint and low field costs. They also offer increased joint strength by work hardening the mating nut interface.

The automotive industry is in constant pursuit of alternative materials and processes to address the ever changing needs of their customer and the environment. This paper presents findings from a study using a laser hybrid process (laser with MIG) to join aluminum-silicon coated boron steel (USIBOR). In this report the influence of heat from the laser hybrid welding process and its effect on the coated boron steel is discussed. In order to understand the affect from laser hybrid joining process, bead on plate experiments were conducted using 1.0 mm, 1.6 mm and 2.0 mm thick coupons. Further, two lap joint configurations were also investigated using the 1.6 mm and 2.0 mm thick coupons. Based on the test results, a significant reduction in tensile strength was observed at the Heat Affected Zone (HAZ).

Typical automotive joints are lap, coach, butt and miter joints. In tubular joining applications, a coach joint is common when one tube is joined to another tube without the use of brackets. Various fusion joining processes are popular in joining coach joints. Common fusion joining processes are Gas Metal Arc Welding (GMAW), Laser and Laser Hybrid, and Gas Tungsten arc welding (GTAW). In this study, fusion welded 2.0 mm uncoated DP780 steel coach joints were investigated. Laser, Gas metal arc welding (GMAW), and laser hybrid (Laser + GMAW) welding processes were selected. Metallurgical properties of the DP780 fusion welds were evaluated using optical microscopy. Static and fatigue tests were conducted on these joints for all three joining processes. It was found that joint fit-up, type of welding process, and process parameters, especially travel speed, have significant impact on static and fatigue performance of the coach joints in this study.

There is continued demand for cost and weight reduction as well as for improved process control in the production of P/M planetary carriers. After a brief review of sinter brazing as the primary process for the joining of P/M carrier components, capacitor discharge (CD) welding is introduced as a promising alternative. The processing of carriers by CD welding is described and the possibilities of advanced process control offered by this technology are reviewed. Subsequently, the micro-structure and mechanical properties of CD welded carriers are analyzed. Actual application validation data for ultimate and torsional fatigue as well as ultimate axial loading are presented for a two piece carrier produced from a P/M body and a stamped sheet metal spider as launched in the Ford Motor Company 5R55 transmission. Finally the processes of sinter-brazing and CD welding are compared, specifically the mechanical performance and manufacturing costs.

The use of Friction Stir Welding (FSW) is a robust process to use in the assembly of aluminum automotive components. The advantages include: minimal distortion, higher tensile strength, lower costs and improved weld capability than other joining processes. Though a simple process, there are key parameters that must be carefully selected to optimize the weld. This paper will focus on the use of FSW to assemble extrusions into automotive components.

The International Lubricant Standardization and Approval Committee (ILSAC) ATF subcommittee members have compared the two oxidation bench test methods, Aluminum Beaker Oxidation Test (ABOT) and Indiana Stirring Oxidation Stability Test (ISOT), using a number of factory-fill and service-fill ATFs obtained in Japan and in the US. In many cases, the ATFs were more severely oxidized after the ABOT procedure than after the same duration of the ISOT procedure. The relative severity of these two tests was influenced by the composition of the ATFs. The bench test oxidation data were compared with the transmission and the vehicle oxidation test data.

Piston wetting can be isolated from the other sources of HC emissions from DISI engines by operating the engine predominantly on a gaseous fuel and using an injector probe to impact a small amount of liquid fuel on the piston top. This results in a marked increase in HC emissions. In a previous study, we used a variety of pure liquid hydrocarbon fuels to examine the influence of fuel volatility and structure on the HC emissions due to piston wetting. It was shown that the HC emissions correspond to the Leidenfrost effect: fuels with very low boiling points yield high HCs and those with a boiling point near or above the piston temperature produce much lower HCs. All of these prior tests of fuel effects were performed at a single operating condition: the Ford World Wide Mapping Point (WWMP). In the present study, the effects of load and engine speed are examined.

The history behind Polymer Class “A” Body Panels for automotive applications is very interesting. The driving factors behind these applications have not changed significantly over the past sixty years. Foremost among these factors is the need for corrosion and dent resistance. Beginning with Saturn in 1990, interest in polymer body panels grew and continues to grow up to the present day, with every new global application. Today, consumers and economic factors drive the industry trend towards plastic body panels. These include increased customization and fuel economy on the consumer side. Economic factors such as lower unit build quantities, reduced vehicle mass, investment cost, and tooling lead times influence material choice for industry. The highest possible performance, and fuel economy, at the lowest price have always been a goal.

Residual stresses in metals are caused by a number of processes such as inhomogeneous deformation, phase changes and temperature gradients. This investigation focuses on the residual stresses caused by plastic deformation of automotive metals. Such stresses are responsible for part springback and shape distortion in many manufacturing and assembly processes. Tensile residual stresses may lead to stress cracking and, in some alloys, to stress corrosion cracking which may ultimately lead to premature product failure. The residual stress potential of metals can be evaluated by using the Split Ring Test Method. The test can be used to evaluate the effect of materials on residual stresses in cup drawing. Drawn cups are used because they produce large amounts of residual stresses and, therefore, increase measurement accuracy and reduce experimental error. A closed form analytical solution is used to estimate residual stresses in split rings taken from sections cut from the drawn cups.

The relationship between engine oil formulations and catalyst performance was investigated by comparatively testing five engine oils. In addition to one baseline production oil with a calcium plus magnesium detergent system, the remaining four oils were specifically formulated with different additive combinations including: one worst case with no detergent and production level zinc dialkyldithiophosphate (ZDTP), one with calcium-only detergent and two best cases with zero phosphorus. Emissions performance, phosphorus loss from the engine oil, phosphorus-capture on the catalyst and engine wear were evaluated after accumulating 100,000 miles of taxi service in twenty vehicles. The intent of this comparative study was to identify relative trends.

General corrosion protection of sheet materials such as steel used in automobile construction has reached a high level of performance, due primarily to the incorporation of mill-applied treatments such as electrogalvanizing, galvannealing and other coil-coating processes developed over the last half century. While such treatments have greatly extended the corrosion resistance of steel and its various body constructs, attention is now focused on aspects of the manufacturing process wherein these intended protections are compromised by such features as weldments, joins, cut edges and extreme metal deformations such as hems. A novel metal deposition process, based on high-velocity impact fusion of solid metal particles, has been used to extend the corrosion resistance of base steel and pre-galvanized sheet, by selectively placing highly controlled depositions of zinc and other sacrificial materials in close proximity to critical manufacturing details.

An obliquely incident X-ray radiography was developed to measure the greatest depths, orientations and locations of corrosion pits in automobile metallic plates. This technique can also be used on-site for components in use. The corrosion depth profile and the greatest depth can be calculated with the established relations. A 3-D rotational microscope and surface profiler were utilized to evaluate the sensitivities and accuracies of the technique for aluminum and steel plates, respectively.

A simple and rapid immersion type corrosion test has been successfully developed that discriminates corrosion performance in condensers from various suppliers and with differing manufacturing processes. The goal is to develop a test specification that will be included in the Ford corrosion specification for condensers so that condensers received from various suppliers may be evaluated rapidly for their relative corrosion performance to each other. Sections from condensers from Supplier A (tube is silfluxed), Supplier B (tube is zinc arc sprayed), and Supplier C (bare folded tube with no zinc for corrosion protection) were tested in 2% v/v hydrochloric acid for 16, 24 and 48 hours. The results showed that in terms of corrosion performance, zinc arc sprayed Supplier B condenser performed the worst while Supplier C condenser performed the best with Supplier A in between. It was also observed that the fins, and fin-to-tube joints were first to corrode followed by the tube in all cases.

Corrosion failures of aluminum air conditioner evaporator cores have been reported in regions where the climate is relatively warm and humid. Microbiologically-influenced corrosion [MIC] has been implicated in these failures. Application of surface-treatment chemicals may inhibit microbiological (bacterial) growth and/or attachment, thereby reducing the potential for MIC. In this study, two laboratory methods were developed to evaluate selected surface-treatment chemicals for their ability to inhibit bacterial growth and reduce bacterial attachment to treated surfaces. Using the developed methods, two controlled-atmosphere brazed aluminum core materials and three surface-treatment chemicals were evaluated. Neither of the untreated core materials was found to inhibit the growth of the bacteria tested.

Spot weld is the primary joining method to assemble the automotive body structure. In any crash events some separation of spot-welds can be expected. However, if this happens in critical areas of the vehicle it can potentially affect the integrity of the structure. It will be beneficial to identify such issues through CAE simulation before prototypes are built and tested. This paper reports a spot weld modeling methodology to characterize spot weld separation and its application in full vehicle crash simulation. A generalized two-node spring element with 6 DOF at each node is used to model the spot weld. Separation of spot welds is modeled using three alternative rupture criteria defined in terms of peak force, displacement and energy. Component level crash tests are conducted using VIA sled at various impact speeds to determine mean crush load and identify possible separation of welds.

A number of metallic oxidation catalyst substrates with advanced internal structures have emerged in the past few years. In an aftertreatment application, these structures improve gas mixing by increasing turbulence within the substrate's matrix. Modeling results show these advanced structures, under some operating conditions, can be correlated to reductions in catalyst substrate volume and precious metal 1,2. Three structured metallics were compared to a baseline ceramic substrate in a designed experiment to understand the effect of advanced metallic substrates on diesel oxidation catalyst (DOC) sizing and performance. The results showed that smaller metallic DOCs coated with up to 30% less precious metal (PM) catalyst performed on par or better than the baseline ceramic DOC in terms of hydrocarbon conversion, heat-up, and pressure drop.

MIG (Metal Inert Gas or Gas Metal Arc welding) and spot welding are the most common way of joining steel components in automotive body, and frame structures. The main design benefits of MIG welding are however the ability to join the parts with single side access and the reduction or elimination of flanges. Different finite element based methodologies exist for predicting the durability of welds. These methodologies are being used in the automotive industry to resolve potential and current durability issues in spot and MIG welded steel components and also to reduce expensive testing practices. However, the analysis results highly depend on the finite element modeling and the accuracy of weld data. This paper briefly describes some of the lessons learned while applying the weld life prediction technology for MIG and spot welds in automotive steel structural components.