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Viewing 1 to 30 of 3723
2011-04-12
Technical Paper
2011-01-0223
Joel Hemanth
This paper describes research on aluminum-based metal matrix hybrid composites reinforced with kaolinite (Al₂SiO₅) and carbon (C) particulates cast using high rate heat transfer technique during solidification by employing metallic, non-metallic and cryogenic end chills. The effect of reinforcement and chilling on strength, hardness and wear behavior are discussed in this paper. It is discovered that cryogenic chilled MMCs with Al₂SiO₅-9 vol. %/C-3 vol. % dispersoid content proved to be the best in enhancing the mechanical and wear properties. A physically based finite element (FE) model for the abrasive wear of the hybrid composite developed is based on the mechanisms associated with sliding wear of ductile aluminum matrix of the composite containing hard Al₂SiO₅ and soft carbon (dry lubricant) reinforcement particles.
2011-04-12
Journal Article
2011-01-0483
Sangwoo Cha, Hoon Chang, Kyung-Woo Lee, Sung-san Cho, Dong-hyeon Hwang
Periodically, engine block-bearing cap structure is subject to the mixed bearing load from combustion and inertia mass of crank. Recently, due to the trend of lightness, cast steel is replaced with aluminum in the material of gasoline engine block. And, the load acting on the main bearing cap is rapidly rising due to the increase of engine power. Therefore, in the development stage, fretting fatigue failures frequently occurred on the block face contacted with the bearing cap. Fretting is a kind of wear which is occurred by micro relative movement. Even though various researches have been made to investigate fretting fatigue failure with FEA approaches, they are not enough to evaluate the phenomenon. In this study, the new CAE method simulating the fretting fatigue failure on the engine block face is developed and the mechanism of the fretting fatigue on the engine block is investigated.
2013-04-08
Technical Paper
2013-01-1018
Laurent Pasquet, Damien Bergès, Philippe DA SILVA, Claire Demarcq
To assess the ability of a material to create filler metal flow and fill the brazing joint areas during the brazing process, we adapted a method which is called aluminum Flow Factor test. The target is to take benefit of this test in order to reach an optimum level of heat exchanger performance from project development steps. This paper studies similar aluminum clad material compositions coming from different suppliers. After brazing process, significant differences were noticed in the filler metal flow results. This study highlighted the impact of brazing peak temperature to create more or less flow of filler metal. The Flow Factor is promoted by the increase of brazing peak temperature. It also showed that regardless the material gage, at a low peak temperature of 591°C, Flow Factor are quite similar around 0,18.
2013-09-24
Technical Paper
2013-01-2350
Matt Kero
The commercial vehicle industry has seen regulations create new requirements over the last few years. Reductions to stopping distance, improvements to vehicle emissions, and the overall need for lighter weight vehicles has caused the commercial vehicle industry to look for new solutions to meet these needs. One such solution is light-weight aluminum metal matrix composite (MMC) brake drums. Aluminum MMC brake drums create the opportunity to reduce weight, lower brake temperatures, improve brake life cycle, and improve brake performance. During the evaluation of these aluminum MMC components it has been seen that existing procedures do not create accurate comparisons for this new material. Current procedures were designed and implemented for cast iron braking solutions. This paper will outline two procedures; FMVSS121 dynamometer burnishing and SAE J2115 wear performance testing, that do not allow direct comparisons from brake system to brake system to be made.
2004-03-08
Technical Paper
2004-01-0182
G. Gottstein, M. Crumbach, M. Goerdeler, L. Neumann, R. Kopp
We report on a novel approach for through-process modeling of anisotropy development during AA5182 sheet production from hot rolling through terminal annealing. For this a thermomechanical process model was coupled to physics based microstructure models for deformation texture (GIA), work hardening (3IVM), and recrystallization texture (StaRT). The model overpredicts the Cube texture during hot rolling but properly predicts the terminal texture after multiple cold rolling with intermediate annealing. This approach can be extended to forming of automative sheet or integrated in crash simulations.
2004-03-08
Technical Paper
2004-01-0181
Philip E. Smith, Dinesh C. Seksaria, Jeffrey M. Shoup
A multi-product aluminum weight balancing trailer hitch assembly consisting of only two parts was designed and tested. The weight of the aluminum hitch was only 15 lb, which is approximately 50% of a comparable steel hitch system.
2004-03-08
Technical Paper
2004-01-0185
Eu-Gene Ng, Mohamed A. Elbestawi, Mihaela Dumitrescu
Advanced manufacturing technology of high silicon aluminium alloys is one of the manufacturing processes in need of new developments to obtain the required improvements for the new generation of vehicles. During ultra high speed machining of aluminium alloys, the optimum machining parameters and tool geometry are controlled by the finished machined workpiece/part surface integrity, burr formation, and part distortion. For the research objectives presented in this paper a dual approach was applied, covering both experimental and theoretical (modeling) work. High speed machining, above 5000 m/min, has been used. From experimental analysis, the most important elements regarding tool life and wear mechanisms are workpiece material microstructure and inhomogenities, non-metallic inclusions, and silicon content.
2004-03-08
Technical Paper
2004-01-0183
Y. Wang, P. K. Mallick
This paper describes the results of dynamic denting experiments conducted on AA5754 and AA6061 alloys. Dynamic denting tests were performed using a drop weight impact machine. The drop height was varied from 38 mm to 914 mm to generate impact velocities ranging from 53.4 m/min to 254 m/min. The dent depth created at different drop heights was related to the input impact energy and peak load observed in the tests. The effects of sheet thickness and yield strength were explored.
2004-03-08
Technical Paper
2004-01-1671
Kazuhiro Hatano, Seiji Hibi, Masahiro Nakamura
From the viewpoint of measures for environmental issues, the amount of solvents in paint for aluminum wheels needs to be minimized. Environmentally friendly powder coatings have been used widely for primer coating and clear coating, but there is no precedent for its use for base coating. This time, we optimized the condition of surface treatment of pigment and hardening behavior of constituent resin in the melting process and succeeded in developing a metallic powder coating for aluminum wheels that fulfills the appearance and the quality requirements of aluminum wheels.
2004-03-08
Technical Paper
2004-01-1669
Mark Simpson, Michel Sudour
As automotive manufacturers continue to look for ways to reduce vehicle weight, aluminum is finding more utility as a body panel component. The substitution of cold-rolled steel and zinc-coated substrates with aluminum has led to new challenges in vehicle pretreatment. As a result, changes to traditional pretreatment chemistries and operating practices are necessary in order to produce an acceptable coating on aluminum body panels. These changes result in increased sludging and other undesirable characteristics. In addition to the chemistry changes, there are also process-related problems to consider. Many existing automotive pretreatment lines simply weren't designed to handle aluminum and its increased demands on filtration and circulation equipment. To retrofit such a system is capital intensive and in addition to requiring a significant amount of downtime, may not be totally effective.
2004-03-08
Technical Paper
2004-01-1025
Zachary Brown, Rathindra DasGupta, Dayne Killingsworth, Mark Musser, Diran Apelian
Semi-solid metal (SSM) casting of aluminum components is currently establishing itself as a viable process for critical applications in the automotive industry. SSM casting processes compete favorably on both cost and performance with other casting techniques including gravity permanent mold (GPM), conventional high pressure die casting (HPDC) and squeeze casting. In this paper the various SSM casting routes in use today are reviewed. The two categories of SSM processes are thixocasting (involves the use of electro-magnetically stirred or grain-refined billets) and rheocasting (slurry produced directly from the liquid phase). The former requires a billet that needs to be reheated and processed, whereas the latter is cast directly from the liquid state. Also described here are new approaches to slurry making. These include the Slurry on Demand (SoD) process from AEMP, the Sub Liquidus Casting (SLCR) process from THT, and Diffusion Solidification.
2004-03-08
Technical Paper
2004-01-1023
Shahrooz Nafisi, Reza Ghomashchi, Jalal Hedjazi, S. M. A. Boutorabi
The effects of Cu-P and Al-Sr master alloys as strong modifiers have been investigated on the microstructure of commercial Al-Si (12-13%Si) alloys. Thermal analysis has been employed to examine the morphological changes of Si particles and identify the optimum concentration of P and Sr to achieve fine and well-distributed eutectic and primary silicon structures. Additions of 0.05% to 0.075% P or Sr have been found to yield the most optimum modification and refining of the structure. The results show that the variation in nucleation temperature of primary phase and the eutectic temperature are the most important parameters.
2004-03-08
Technical Paper
2004-01-1022
H. Mancha-Molinar, H. F. López, A. Silva, K. Still
Alloy A319 is extensively used in the automotive industry. In the as-cast condition the alloy lacks the required strength. A solid solution heat treatment (T4) followed by room temperature quenching improves tensile strength. Accordingly, engine castings in T4 condition are used in the manufacture of automobiles. However, A319 alloy is not thermodynamically stable after solid solution. The matrix is supersaturated with Cu, and a precipitation sequence is expected to occur overtime, which leads to dimensional changes. Alternatively, an aging treatment (T7) can activate the precipitation reactions to achieve dimensional stability in castings. In this work, dilatometric measurements were made during a T7 heat treatment in order to establish the extent of dimensional changes, resulting from the precipitation reactions. In addition, high-resolution electron microscopy was used to follow up the precipitation reactions.
2004-03-08
Technical Paper
2004-01-1021
Rathindra DasGupta, Sumantra DasGupta, Craig Brown
The basic data on the mechanical properties of a casting are frequently obtained from a tensile test, in which a suitable specimen machined from the casting is subjected to increasing axial load until it fractures. The engineering tension test is widely used by casting manufacturers as an acceptance test for customer specifications. However, tensile bars machined from castings often provide undesirable information, thereby leading one to question the part integrity. This paper, therefore, discusses the various factors that affect tensile properties obtained from specimens machined from actual castings.
2004-03-08
Technical Paper
2004-01-1029
Carlos C. Engler-Pinto, John V. Lasecki, James M. Boileau, John E. Allison
The high temperature fatigue behaviors of three cast aluminum alloys used for cylinder head fabrication - 319, A356 and AS7GU - are compared under isothermal fatigue at room temperature and elevated temperatures. The thermo-mechanical fatigue behavior for both out-of-phase and in-phase loading conditions (100-300°C) has also been investigated. It has been observed that all three of these alloys present a very similar behavior under both isothermal and thermo-mechanical low-cycle fatigue. Under high-cycle fatigue, however, the alloys A356 and AS7GU exhibit superior performance.
2004-03-08
Technical Paper
2004-01-1027
John C. Hebeisen, Bruce M. Cox
Hot Isostatic Pressing (HIP) has been routinely used to densify castings for aerospace and medical applications for over 30 years. While HIP is widely known to improve the toughness and fatigue life of castings through the healing of internal porosity, it has been perceived as too expensive for most cast aluminum alloys for automotive applications. Recent developments suggest that the cost effectiveness of certain special HIP processes should be revisited due to reductions in process cost and improvements in throughput. This paper will evaluate the Densal® II process applied to a front aluminum steering knuckle. Two casting processes representing differing levels of relative cost and quality were evaluated. The first was Alcoa's VRC/PRC process, a metal mold process with bottom fill, evacuation before fill and pressurization after fill. This is considered to be a premium quality, but higher cost casting process that is already qualified for this application.
2004-03-08
Technical Paper
2004-01-1028
Hirotaka Kurita, Hiroshi Yamagata, Hiroki Arai, Tamotsu Nakamura
A monolithic aluminum block using a newly developed Al-20%Si alloy was made by a vacuum die-casting process. The bore surface design was a sleeveless type with uniformly dispersed primary-Si crystals around 20μm. The die-casting technology consists of a highly airtight die with two series of evacuation systems. The vacuum level in the die cavity was determined to be as low as 5kPa. The gas content of the block was found to be as low as 5cc/100g Al, which has enabled T6 heat treatment. The die cavity temperature was carefully controlled to generate a fine dispersion of primary-Si crystals. The engine testing has proved that the bore wall temperature is 30 K lower than that of the aluminum block enclosing a press-fitted cast iron liner. The superior cooling performance has decreased the oil consumption value to one half that of the aluminum block enclosing a cast iron liner.
2004-03-08
Technical Paper
2004-01-1019
Stephen J. Mashl, Matthew M. Diem
The temperature range used for HIP processing of cast aluminum parts is also appropriate for solution heat treatment. Integration of these two processes should decrease processing time, energy consumption, and processing cost. In this study, Al-Si-Mg castings were subjected to a combined HIP and T6 heat treatment. The properties and microstructure of these castings were compared to parts processed using conventional methods. Apparent differences in the oxide concentration provided insight into the effect of oxide inclusions on HIP response. Results indicate that fatigue life is increased using an integrated HIP/heat treat process, however, oxide contamination can negate this improvement.
2004-03-08
Technical Paper
2004-01-1020
Yun Xia, John Cincilla, Ernie Mohley
Abstract Casting defects such as gas porosity, shrinkage, poor-fill and blistering are related to the filling pattern and flow control in Al and Mg die-casting. It is not clearly understood how atomized and turbulent flow affects the filling patterns and hence casting defects. Significant improvements in casting quality could be achieved with a better understanding of the basic morphology of atomized and turbulent flow and their relationships to the Reynolds number and J number. This paper will explore the relationship between atomized and turbulent flow in Al and Mg die castings and the relationship of wakes produced by obstacles in the flow path and casting defects.
2004-03-08
Technical Paper
2004-01-1333
Arthur Scafe, Armondo Joaquin
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.
2004-03-08
Technical Paper
2004-01-1328
S. Liu, Y. J. Chao, C. H. Chien
In the friction stir welding (FSW) process, heat is generated by friction between the interfaces between the tool and the workpiece. The amount of heat conducted into the workpiece determines the quality of the weld. In this paper, 37.6 mm (1.48 inch) thick plates made of aluminum alloy 6061-T6 were welded using the FSW process. We report (a) welding parameters such as tool RPM, welding speeds, (b) power and heat input to the welding process, (c) a complete temperature history from 27 thermocouples. Data are reported for one weld with a full-length pin and two welds with a short pin. In conjunction with the measurement, finite element analyses were also performed to study (1) the heat inputs from the tool shoulder as well as from the probe pin, and (2) temperature distribution and history in the workpiece. The analysis results are also compared with the measured data.
2004-03-08
Technical Paper
2004-01-0601
A. Candel, R. Gadow, D. López, M. Buchmann
Actual trends with regard to light weight design in the automotive industry, in order to reduce fuel consumption and pollution emissions as well as improve the engine efficiency lead to the increasing use of light weight engine components. Due to the harsh operation conditions, the aluminum cylinder surface must be reinforced, and new techniques have been developed and applied. A very promising technological alternative is the use of HVOF (high velocity oxygen fuel) deposited internal coatings, showing improved coating quality results compared to APS (atmospheric plasma spray) coatings. Several HVOF (High Velocity Oxygen Fuels) coating processes (with different fuel gases/fluids) were compared and studied, with a complete mechanical characterization and evaluation of the coatings. Also an economical comparison for the different coating systems is shown.
2004-03-08
Technical Paper
2004-01-0628
Mehrdad Zoroufi, Ali Fatemi
A vehicle steering knuckle undergoes time-varying loadings during its service life. Fatigue behavior is, therefore, a key consideration in its design and performance evaluation. This research program aimed to assess fatigue life and compare fatigue performance of steering knuckles made from three materials of different manufacturing processes. These include forged steel, cast aluminum, and cast iron knuckles. In light of the high volume of forged steel vehicle components, the forging process was considered as base for investigation. Monotonic and strain-controlled fatigue tests of specimens machined from the three knuckles were conducted. Static as well as baseline cyclic deformation and fatigue properties were obtained and compared. In addition, a number of load-controlled fatigue component tests were conducted for the forged steel and cast aluminum knuckles. Finite element models of the steering knuckles were also analyzed to obtain stress distributions in each component.
2004-03-08
Technical Paper
2004-01-0742
Zengtao Chen, Michael Worswick, Keith Pilkey, David Lloyd
A so-called damage percolation model is coupled with Gurson-based finite element (FE) approach in order to accommodate the high strain gradients and localized ductile damage. In doing so, void coalescence and final failure are suppressed in Gurson-based FE modeling while a measured second phase particle field is mapped onto the most damaged mesh area so that percolation modeling can be performed to capture ductile fracture in real sheet forming operations. It is revealed that void nucleation within particle clusters dominates ductile fracture in aluminum alloy sheet forming. Coalescence among several particle clusters triggered final failure of materials. A stretch flange forming is simulated with the coupled modeling.
2004-03-08
Technical Paper
2004-01-0792
D. Li, R. Perrin, G. Burger, D. McFarlan, B. Black, R. Logan, R. Williams
It is well known that 4 to 6% silicon spheroidal irons are suitable for use at high temperature. This paper describes solidification behavior, microstructure, mechanical properties, high temperature oxidation, and thermal fatigue of high silicon SiMo cast irons. Cooling curves of cast irons were recorded using a thermal analysis apparatus to correlate with the solidified microstructures. Uniaxial constrained thermal fatigue testing was conducted in which the cycling temperatures were between 500°C and 950°C. Oxidation behavior was studied by measuring the specimen weight and the penetration depth of oxides from laboratory cyclic oxidation testing. The coefficient of thermal expansion and critical temperature of the phase transformation A1 during heating were determined through dilatometry testing.
2004-03-08
Technical Paper
2004-01-0793
Alan P. Druschitz, Dale J. tenPas
The open literature suggests that high strength ductile irons (Q&T or ADI with hardnesses over 250 BHN) in contact with liquids, such as water or motor oil, may show a loss of ductility in the standard tensile test. This study determined the effect of water and various automotive fluids (mineral oil, motor oil, gear oil, brake fluid, power steering fluid and diesel fuel) on the tensile properties of various low and high strength grades of ductile iron (D-4512, N&T, Q&T, Grade 1 ADI and MADITM). The low strength grade of ductile iron (D-4512), the low strength grade of MADI™ and the high strength quenched & tempered ductile iron showed no loss of ductility when in contact with water or automotive liquids but the industry standard high strength grade of ductile iron (Grade 1 ADI) showed significant degradation.
2004-03-08
Technical Paper
2004-01-0794
null, Glen Weber, Tim Dorn, John R. Keough, Tom Schroeder, Tony Thoma, Bruce Boardman, Malcolm Blair
Technical Standards are essential for the expanded use of any engineering material. The Society of Automotive Engineers (SAE) Iron and Steel Castings Committee has been reworking existing, (and issuing new), standards for automotive iron and steel castings. This paper will review the status of the SAE standards for Ductile Iron, Austempered Ductile Iron (ADI), Compacted Graphite Iron (CGI) and high Silicon-Molybdenum (Si-Mo) Ductile Iron, Gray Iron and Steel Castings. The SAE Standards, (and draft standards), will be critically compared to those for ASTM and ISO. Salient differences in the standards will be discussed and implications to design engineers will be addressed. Comparisons to other, competitive materials (and their standards) will be made.
2004-03-08
Technical Paper
2004-01-1775
Xiaoming Chen, Hikmat Mahmood, David A. Wagner, M. Ridha Baccouche
The engine subframe (cradle) is an important contributor to crash energy management in frontal impact for automotive vehicles. Subframe design can enhance vehicle crash performance through energy management. In addition to energy management targets, the subframe must meet stiffness, durability and other vehicle engineering requirements. Various subframe concepts are reviewed. Their design intents and vehicle performance are discussed. A development process of an aluminum subframe is then presented which details the subframe design as an energy absorbing component for frontal impacts. The architecture of the subframe is developed based on overall functionality requirements and package constraints. The geometry of the subframe is first designed to accommodate engine mounts and suspension support locations. The subframe member's shape, orientation, and location are then refined to accommodate the subframe-to-body connection requirements.
2013-01-09
Technical Paper
2013-26-0072
Suresh Babu Muttana, Sajid Mubashir
The automotive industry has to accommodate regulatory norms as well as customer demands in its vehicle design. These include better crash safety, new subsystems (for comfort) and high performance powertrains, all of which lead to increase in vehicle mass. Heavy vehicles consume more fuel and produce more emissions. While there are several ways to increase fuel efficiency (i.e. improving engine and transmission efficiency, reducing aerodynamic drag, and rolling resistance), the most effective means of achieving improved fuel efficiency is by reducing the overall weight of the vehicle. Hence, materials selection plays a significant role in the fuel economy, emissions as well as economics of transportation. If mass of a component is reduced there will be secondary mass reductions in other components, thus resulting in further reduction of final vehicle mass (‘mass decompounding’). The paper highlights potential benefits of using lightweight materials for vehicle body applications.
2014-04-01
Technical Paper
2014-01-0220
Louis Chretien, Adrien Laurino
Abstract The effect of cold-working, i.e. wire drawing, on the corrosion behavior of a 6101 and a 1370 aluminum alloy was investigated in NaCl solutions. For the both alloys, a “grain size - corrosion resistance” was highlighted. The preliminary works performed on Al-Cu welds showed two scales of heterogeneity and two scales of heterogeneity of media which are not considered by the current automotive specifications. Consequently, it seems to be necessary to establish new pertinent specifications to evaluate the new Al solutions.
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