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Technical Paper

Next Generation Formed-In-Place Gasket (FIPG) Liquid Sealant for Automotive Intake Manifold Application

2009-04-20
2009-01-0996
Intake manifold is a part of an engine that supplies fuel/air mixture to the cylinder heads. Recently, silicone FIPG has been used for the two part design of the intake manifold. It is known that a small, but significant, amount of gasoline fuel can penetrate through silicone FIPG layer due to the flexible nature of the siloxane backbone. Since gasoline permeation is becoming more important because of more severe regulations, it is found that a new polyacrylate based FIPG dramatically reduces the gasoline fuel permeation. This study compares this new technology, polyacrylate FIPG sealant with silicone FIPG sealant used today for vehicle powertrain gasketing applications. Adhesion investigation on both aluminum and magnesium alloys, and oil resistance are also discussed in this study.
Technical Paper

Influence of Environmental Temperature on the Fatigue Strength of Type 3 Compressed-Hydrogen Tanks

2009-04-20
2009-01-1011
The environmental temperature where vehicles are used varies significantly by region and season, so this study investigated the influence of environmental temperature on the fatigue life of compressed hydrogen tanks for vehicles (Type 3). Pressure-cycle tests with varying environmental temperature were conducted on tanks until the tank was failed. Results indicated that fatigue life decreased in low-temperature environments and improved in high-temperature environments. We investigated the cause of such results using the strains inside and outside the tank and other indexes and found that the effect of autofrettage varied as environmental temperature changed, due to the difference between the thermal expansion rate of CFRP and that of aluminum alloy. Thus, we concluded that fatigue life changed according to changes in environmental temperature.
Technical Paper

A Study of Lead-free Al-Zn-Si Alloy Bearing with Overlay for Recent Automotive Engines

2009-04-20
2009-01-1054
Recently, a lead-free Al-Sn-Si alloy bearing with metallic overlay has started to be used for a portion of automotive engines. This bearing has good anti-seizure and excellent running-in properties, and is an environmentally friendly alternative to the current copper-lead alloy with lead based overlay in accordance with the ELV regulation for the removal of lead from bearings. But automotive engines have been required to exhibit higher performance in order to enhance their commercial power, which tends to require the engine bearing to perform under higher temperature due to higher specific load on the bearing and higher rotational speed of the crankshaft. It is clear that the current lead-free aluminum alloy bearing is not satisfactory with respect to fatigue strength in some cases, and requires higher strength under the higher temperature conditions.
Journal Article

Development of High Strength Mg Alloys

2009-04-20
2009-01-0788
Mg96Zn2Y2 cast alloy is composed of an α-Mg phase, Mg12ZnY phase and Mg3Zn3Y2 phase. The coarse dendritic Mg grains have transformed into small cellular Mg grains with the addition of an increasing amount of Zr. Furthermore, increasing the cooling rate led to the precipitation of the fine Mg3Zn3Y2 phase and the Mg12ZnY phase forming a net-like structure. We found that this alloy has mechanical properties equivalent to those of commercial aluminum alloys with good tensile and fatigue properties at temperatures above 473 K.
Technical Paper

Optimization of Casting Parameters on an Improved AA6061 Aluminum Alloy for Semi-Solid Die Casting

2010-04-12
2010-01-0225
A study was conducted to assess the performance and castability of a new AA6061 aluminum alloy variant specially designed for semi-solid pressure die casting. The AA6061 alloy has very desirable mechanical properties for the fabrication of automotive parts. However, it has limited castability due to its low silicon content. It is not well suited for shape casting processes which are, for their part, very interesting in terms of production costs for complex-shaped automotive components. In an effort to meet automotive industry requirements, new AA6061 alloy variants have been developed by Rio Tinto Alcan researchers over the past years, aiming to improve the castability of the alloy while maintaining its desirable mechanical properties, by increasing its die-filling capacity, decreasing its hot tearing tendency. The study described herein is an example of how the performance of a single variant was assessed in terms of castability. The full study was conducted on six separate variants.
Technical Paper

Effects of Cellular Shear Bands on Interaction between a Non-pneumatic Tire and Sand

2010-04-12
2010-01-0376
To facilitate the design of a non-pneumatic tire for NASA's new Moon mission, the authors used the Finite Element Method (FEM) to investigate the interaction between soil and non-pneumatic tire made of different cellular shear bands. Cellular shear bands, made of an aluminum alloy (AL7075-T6), are designed to have the same effective shear modulus of 6.5E+6 Pa, which is the shear modulus of an elastomer. The Lebanon sand of New Hampshire is used in the model. This sand has a complete set of material properties in the literature and Drucker-Prager/Cap plasticity constitutive law with hardening is employed to model the sand. The tires are treated as deformable bodies, and the authors used the penalty contact algorithm to model the tangential behavior of the contact. The friction between tire and sand is considered by using Coulomb's law. Numerical results show deformation of sand and tire.
Technical Paper

New Generation Oil Pan Modules

2009-04-20
2009-01-0346
An oil pan may be a simple auto component with an uncomplicated function. Nevertheless, it is vital for the proper operation of engine parts. This component is usually made of thin sheet steel or cast alloy, although there are also high-performance oil pans that are made from billet aluminum or magnesium alloy [1]. Nowadays Automobile part manufacturers are manufacturing new generation plastic oil pans to reduce weight and manufacturing cost with same performance as of metal pan. This Reduction is beneficial in making car lighter and cheaper. This report talks about Computational Fluid Dynamics (CFD) Analysis for plastic oil pans in comparison with sheet metal oil pans. Along with this, oil pan design improvements/optimizations based on CFD Analysis Results are also discussed.
Technical Paper

Development of Cast-Forged Knuckle using High Strength Aluminum Alloy

2011-04-12
2011-01-0537
Aluminum steering knuckles are widely employed for weight reduction and improvement of ride & handling performance. In this study, a high strength aluminum alloy for cast-forged knuckle was designed to achieve higher mechanical properties than those of the conventional foundry alloy. Using this alloy, high strength knuckles were manufactured and performed test of mechanical properties, suspension module strength and durability. The strength and the elongation of the developed knuckle were increased by 20% and 40%, respectively, as compared with the conventional alloy. Also this knuckle passed the static strength and durability test of the front suspension module.
Technical Paper

Thermal Characterization of Air-Cooled Aluminum Die-Cast Cylinder Blocks with Various Cast Iron and Aluminum Liners

2011-04-12
2011-01-0316
In most air-cooled engines, aluminum cylinder blocks are lined with cast iron, which enjoys a higher wear resistance than aluminum. Recently, rather than a turned periphery, an increasing number of cast iron liners have employed as-cast periphery with projections, so the liner better adheres to the aluminum cylinder block, and improves heat transfer. This study attempts to maximize heat transfer while minimizing cylinder weight, by comparing four liners: (1) a cast iron liner with higher projections on its periphery, (2) a cast iron liner with lower projections, (3) a cast iron liner with lower projections, and aluminum-silicon coated on its periphery by thermal spraying, and (4) a high-silicon aluminum alloy liner with aluminum-silicon coated by thermal spraying. These four experimental liners were fitted in a die-cast low-silicon aluminum-alloy cylinder block, to investigate their joint and cooling characteristics.
Technical Paper

Forming Limit Curves for the AA5083 Alloy under Quick Plastic Forming Conditions

2011-04-12
2011-01-0235
Forming Limit Curves (FLCs) were developed for the 5083 aluminum alloy at conditions simulating high temperature processes such as superplastic and quick plastic forming. Sheet samples were formed at 450 °C and at a constant strain rate of 5x10-3 s-1, by free bulging into a set of elliptical die inserts with different aspect ratios. Friction-independent formability diagrams, which distinguish between the safe and unsafe deformation zones, were constructed. Although the formability diagrams were confined to the biaxial strain region (right side quadrant of an FLD), the elliptical die insert methodology provides formability maps under conditions where traditional mechanical stretching techniques are limited.
Technical Paper

Study on EP Energy-Saving Vehicle

2008-06-23
2008-01-1775
The price of fossil fuels and the increasing inexorable energy crisis have become vital issues for everyone. Tongji University EconoPower Racing Team was established to participate in the “Honda EconoPower Cup” annually. Every contestant in the competition must finish a certain distance in the fixed time, with the gasoline supplied by the committee. After that the committee will measure the fuel consumption of every team and calculate the distance per liter fuel (the farther the better) to determine the champion. In order to enhance the EP vehicle's achievement we've made some improvements, such as framework, body, engine's optimization and so on. In this passage we mainly state some details of our research approaches in framework, steering, transmission, shape and driving strategy. The main technologies were: friction reduction, lightweight, enhancement of power train efficiency, tire selection and driving strategy.
Technical Paper

Research on Pb-free Electroless Ni Plating for Pistons of General-purpose Engines

2009-11-03
2009-32-0065
Ni-P-B plating applied to the piston of a general-purpose engine with an aluminum alloy cylinder contains some thousands ppm of Pb, which is used as the treating liquid stabilizer, in its plating. But, Pb is considered an environmental hazardous and it is necessary to reduce its amount in the plating. Our previous researches, however, reveal that Pb plays a major role in wear and seizure resistance. In order to obtain the sliding properties equivalent to Ni-P-B plating that contains Pb, therefore, it is necessary to review the composition of Ni-P-B plating. In this research, therefore, we specifically focus on the plating hardness of Ni-2%P plating subject to the temperature environment in which the piston operates, and discuss whether the same sliding effects as that of the Pb containing Ni-P-B plating is obtainable by restraining the hardness decrease.
Technical Paper

The Potential for use of Heat Treated Aluminum High Pressure Die-Castings in Engine Applications

2008-09-09
2008-32-0058
Aluminum alloys used for most high pressure die-castings manufactured worldwide are based on the Al-Si-Cu-(Fe) system, examples being the alloys (AA)380, (JIS) ADC10, (JIS) ADC12, and EN-AC-AlSi8Cu3(Fe). These alloys are used for a wide range of applications including engines and drivetrains for which they are usually heat treated to a stabilized T5 temper. Such a treatment does not, however, provide a significant improvement to the as-cast mechanical properties. The reason why conventionally produced HPDC components are not heat treated to the higher strength T6 or T7 tempers is that a standard solution treatment cycle (e.g. 8h at 540°C) causes internal pores to expand resulting in unacceptable surface blistering and dimensional instability. Recently a modified heat treatment regime has been developed which avoids these problems and allows large improvements (e.g. around 100%) to be achieved in some tensile properties. Fatigue resistance and thermal conductivity are also improved.
Journal Article

Dissimilar Joining of Aluminum Alloy and Steel by Resistance Spot Welding

2009-04-20
2009-01-0034
This study concerns a dissimilar materials joining technique for aluminum (Al) alloys and steel for the purpose of reducing the vehicle body weight. The tough oxide layer on the Al alloy surface and the ability to control the Fe-Al intermetallic compound (IMC) thickness are issues that have so far complicated the joining of Al alloys and steel. Removing the oxide layer has required a high heat input, resulting in the formation of a thick Fe-Al IMC layer at the joint interface, making it impossible to obtain satisfactory joint strength. To avoid that problem, we propose a unique joining concept that removes the oxide layer at low temperature by using the eutectic reaction between Al in the Al alloy and zinc (Zn) in the coating on galvanized steel (GI) and galvannealed steel (GA). This makes it possible to form a thin, uniform Fe-Al IMC layer at the joint interface. Welded joints of dissimilar materials require anticorrosion performance against electrochemical corrosion.
Technical Paper

Dissimilar Metal Joining of Aluminum Alloys and Steel in the Spot Welding by using Advanced Hot-dip Aluminized Steel Sheet

2009-04-20
2009-01-0035
Nisshin Steel and Kobe Steel have developed a spot welding technique capable of obtaining high joint strength in joining the dissimilar metals of an aluminum alloy and steel by using an advanced hot-dip aluminized steel sheet (advanced HDAS) supplied by Nisshin Steel. This report reveals the results of investigating the spot welding properties in joining dissimilar metals of the advanced HDAS and aluminum alloy. Furthermore, this report presents the results of investigating the long-term durability of the dissimilar metal joint material electrocoated under the accelerated corrosion test.
Technical Paper

Friction Bit Joining of Dissimilar Material Combinations of High Strength Steel DP 980 and Al Alloy AA 5754

2009-04-20
2009-01-0031
A new spot joining technology relying on a consumable joining bit has been developed and evaluated on dual phase (DP) 980 steel and a dissimilar combination of aluminum alloy 5754-O and DP 980. This new process, called friction bit joining (FBJ), uses a consumable bit to create a solid-state joint in sheet materials by the action of cutting and frictional bonding. A series of experiments were done in which different welding parameters were employed and lap shear tension testing was carried out to evaluate performance. The best lap shear values averaged 6.5 kN.
Technical Paper

Effects of Thickness Combinations on Joint Properties and Process Windows in Ultrasonic Metal Welding

2009-04-20
2009-01-0027
A single transducer wedge-reed ultrasonic welder has been used to make welds, in the non-age hardening aluminum alloy AA5754. A range of thickness combinations, varying from 1.2 mm to 2.5 mm, have been ultrasonically welded. A matrix of process parameters (input energy, impedance matching setting, tip clamp pressure and power) have been used to achieve high strength joints. Samples were welded in standard configuration for a tensile lap-shear test, which has been used to determine failure strength and type of failure. Optical microscopy has been used to reveal the bonding mechanisms. Variations in strength and failure mode have been related to changing process parameters and material thickness. It has been observed that stacking sequence has little effect on overall strength. Optimization of process parameters rather than the stack-up sequence has been shown to give the largest gains in joint strength.
Technical Paper

Fatigue of Spot Friction Welded Joints of Mg-Mg, Al-Al and Al-Mg Alloys

2009-04-20
2009-01-0024
Spot friction welding shows advantages over resistance spot welding for joining light alloys for automotive applications. In this research, fatigue behaviors of spot friction welded joints in lap shear specimens of AM-60 magnesium alloy and AA 5754 aluminum alloy were investigated. Static and fatigue tests were conducted with Mg-Mg, Al-Al and Al-Mg specimens. Fatigue S-N curves were obtained for all these specimens using load-controlled fatigue tests. Finite element analysis was conducted to investigate the stress distribution and the location of maximum stresses in spot friction welded joints in Mg-Mg specimens.
Journal Article

Visualization of Material Flow in a Refill Friction Stir Spot Welding Process Using Marker Materials

2010-04-12
2010-01-0971
Friction Stir Spot Welding (FSSW) is a relatively new solid state joining technology that has the potential to be a replacement for single point joining processes like Resistance Spot Welding and rivet technology in certain applications. Since the material flow around the pin plays an important role in determining the quality of the weld, understanding how the material moves is important to optimize process parameters and to validate the results of numerical simulations of the process. In this paper, an experimental study aimed at visualizing the material flow during the plunge phase of refill FSSW of an aluminum alloy is presented. Different marker materials were placed at a certain depth from the plate surface and metallographic samples in three mutually perpendicular directions were prepared and examined to identify the final location of the marker material after the plunge of the pin.
Technical Paper

Aluminum Alloy for Automotive Cable - A perspective on emerging cars applications

2010-10-06
2010-36-0177
The automotive industry is constantly searching for technological improvements to assure car maker's requirements based on the following criteria: reliability, quality and economic impact. The efforts for light weighting in automobile wiring harness had increased significantly by the 1970s, when meteoric rises in copper prices metal market propitiated the aluminum and its alloys approach as a substitute material in the electrical and electronic field. During almost fifteen years, solid aluminum wire and Copper Clad Aluminum (CCA) had been applied to General Motors Corporation cars for primary and battery cables, respectively. After this implementation the copper prices came down and became more interesting. Nowadays, the aluminum wiring harness and battery cable may become an important alternative to provide mass reduction and fulfill environmental compliance requirements helping to reduce fuel consumption and CO2 emission.
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