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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

Development of High Fatigue Strength Valve Spring Using Control of White Layer by Nitriding

2009-11-03
2009-32-0082
For the requirements of high power output, lightweight and improved fuel consumption of motorcycles to respond to global environmental needs, high fatigue strength to cope with high stress is becoming more important than ever for valve springs. To satisfy such needs, a new alloy steel that softens less in tempering (1),(2) and nitriding that increases surface hardness of valve springs has been developed using oil-tempered silicone-chrome steel wire as the base material. Also, with regards to shot-peening to create compression residual stress on the surface, studies are being performed for multi-stage and high-hardness peening. The research reported in this paper is aimed at an increase of internal hardness after nitriding while maintaining the cold-coiling-ability by adding elements that reduce softening from tempering while reducing non-dissolved carbide in the material.
Technical Paper

Endurance Testing and FE Analysis of Four Wheeler Automobile Stabilizer Bar

2009-01-21
2009-26-0066
Durability of automobile stabiliser bar is assessed in the present study. Finite element analysis of the stabiliser bar is performed based on the experimental observations. Fatigue analysis is performed under cyclic loading. Fatigue analysis is performed for maximum cyclic loading conditions. Improvement is the fatigue life of stabilizer bar is analysed by shot peening. Special purpose machine is used to simulate the fatigue life of stabilizer bar. Commercial software ABAQUS is used for numerical simulation. Computational fatigue simulation software, fe-safe is used for the fatigue analysis to predict the fatigue life (number of cycles for crack initiation) and crack site location. Predicted results were compared with that of the physical test results for validation.
Technical Paper

Weight Reduction Using Massive Carbide Free Thin Walled Ductile Iron Produced via Lost Foam Casting

2011-04-12
2011-01-0426
Significant research has been conducted with the goal of obtaining thin walled ductile iron for use in lighter weight designs. A review is made of the past efforts to achieve thin walled ductile iron. Most past efforts resorted to costly processes or non-standard production practices. Lost Foam Casting (LFC) is an alternate foundry process which used in conjunction with standard melt shop practices results in a massive carbide free structure when used with thin section size. Chemistry, hardness tests, microstructures, and design improvements of a case study are reviewed.
Technical Paper

Corrosion Performance of “Green” Finishes on Zinc Die Castings

2011-04-12
2011-01-1085
Many new surface finishes have been proposed for zinc die casting. In many cases these are intended to replace the traditional processes of solvent-based painting, electroplating and hexavalent chromium. Twenty new coatings were offered by suppliers and were subjected to cyclic corrosion testing (CCT). A wide variation in results was seen, suggesting the need for further development in come cases. However, several of the new environmentally friendly finishes are of interest for current application.
Technical Paper

A New High Fluidity Zinc Die Cast Alloy

2011-04-12
2011-01-1086
A new high fluidity zinc die cast alloy was developed at Teck Metals' Product Technology Centre. This hot chamber die cast alloy is based on the commonly used ZAMAK alloys but possesses up to 40% better fluidity. Industrial trials and evaluations have confirmed the excellent fluidity of the alloy as well as the easy use and adoption of the alloy. Tests have shown the alloy has comparable physical, mechanical and corrosion properties as Alloy 3 and 7. The alloy is best suited to be used for casting parts with section thickness less than 0.45 mm. It can also be used for casting parts that are difficult to fill or have high surface finish requirement.
Technical Paper

EZAC™ - A Novel High Strength, Creep Resistant, Hot Chamber Zinc Die Casting Alloy

2011-04-12
2011-01-1084
Progress in recent alloy development work has resulted in the commercialization of a high strength, creep resistant, hot chamber zinc based die casting alloy. The work was based upon earlier research conducted under the sponsorship of the Department of Energy Cast Materials Consortium (CMC). Refinement of alloy chemistry produced significant improvements in tensile strength, hardness and creep performance. Because the composition of this new alloy is near that of the Aluminum/Copper/Zinc ternary eutectic, the low melting temperature enables the alloy to be cast in a hot chamber die casting machine without excessive wear of shot end components typically experienced with other high-copper zinc die casting alloys contents such as ACuZinc 5.
Journal Article

Improving the Relationship between Processing and Properties of Zinc Die Casting: Developments in Creep and Ageing Correlations

2011-04-12
2011-01-1082
Most creep studies are conducted to determine steady state creep rate and time to failure. However, the priority for the designer is to predict the amount of total creep, being the sum of primary and secondary creep elongations, for a given service life under given loads and temperatures, for example 0.5% elongation after 3000h. An assessment of total creep behavior of industrially important zinc alloys has been conducted, and correlation/prediction curves produced. Another important property, related to creep, is stability after ageing, both for unloaded and also loaded castings. Recently developed relationships between natural and artificial ageing, and the correlation of mechanical property changes for different periods of artificial ageing with natural ageing will be presented.
Technical Paper

Steel Produced by the Lost Foam Casting Method

2011-04-12
2011-01-1090
Despite the embrace of aluminum and other nonferrous materials, steel is still a widely used material in the vehicle industry. However, it is not produced in the vehicle industry by the lost foam casting (LFC) method despite the tremendous potential benefits. These include the elimination of machining due to tolerances equal to investment casting and part consolidation which allows for the elimination of components and joining technologies. Both of these are financially and operationally beneficial by allowing for the creation of a leaner supply chain. With proper lost foam casting technology adjustments to compensate for the higher melting point of steel, there appear to be no degradation in cast steel as compared to when cast by green sand or resin bonded sand (no -bake) methods. In fact the opposite is true as the LFC benefits of improved surface roughness and dimensionality are maintained.
Technical Paper

Mechanical Property Behaviour of Rheocast 319 Alloys with and without Iron Additions

2011-04-12
2011-01-1089
Cast aluminum-silicon alloys have witnessed a notable increase in use in the automotive and transport industry. The ability of these alloys to be easily cast into complex shapes coupled with a favorable strength-to-weight ratio has given them an edge over cast irons. One particular area of casting which has received further and further attention is the area of semi-solid casting, where an alloy casting is prepared as slurry with flow properties that resemble both solid and liquid. In the present work, the effects of iron additions on the mechanical properties of a 319 semi-solid alloy were studied. This alloy was prepared using the SEED process, as developed by Rio Tinto Alcan in collaboration with the Aluminum Technology Centre of NRC Canada. The SEED (Swirled Enthalpy Equilibration Device) process is a novel rheocasting method which yields a semi-solid slurry from the mechanical stirring and cooling of the molten aluminum.
Technical Paper

Recent Developments in Impact, Flexural and Fatigue Data for Zinc Die Casting Anti-Theft Applications

2011-04-12
2011-01-1088
Alloy 3, Alloy 5, ACuZinc 5, and ZA-8 were tested at five temperatures between −40 C and room temperature to determine impact properties. Izod impact energy data was obtained in accordance with ASTM D256. Unlike ASTM E23, these samples were tested with a milled notch in order to compare with plastic samples. In addition, flexural data was obtained for design use. Fatigue stress-life (S-N) curves and fatigue limits of die cast zinc Alloy 2, Alloy 3, Alloy 5, ACuZinc 5, and ZA-8 were determined using the rotating bend test. Fatigue limits for Alloy 3, Alloy 5, and ACuZinc 5 appeared to be higher and the fatigue limit for ZA-8 appeared to be lower than the values reported in the literature. The improvement in properties for Alloy 3, Alloy 5 and ACuZinc 5 is related to the presence of the die cast skin.
Technical Paper

Zinc Die Castings for Automotive Applications

2011-04-12
2011-01-1087
Zinc die casting products and metal casting processes continue to evolve for the benefit of end users. Through cooperative global research programs continuous improvements are still being made to the broad range of excellent mechanical properties, easy castability and the wide choice of finishes available for zinc die castings. Recent advances will be highlighted with case histories specific to automotive applications.
Technical Paper

Studies on Edge Strain Hardening Produced by Trimming Operations

2013-04-08
2013-01-1774
Advanced high strength steels (AHSS) are widely used in the automotive industry for various applications especially for structural and safety parts. One of the concerns for AHSS in stamping operations is edge fracture originating from sheared blanked edges. This type of failure cannot be predicted by computer simulations using the conventional forming limit as the failure criterion. The reason for this is that edge damage produced by the blanking operation is not incorporated into the computer models to properly simulate the material edge formability. This study presents a method to evaluate edge damage in terms of the residual stress at the sheared edge produced by the blanking operation. The method uses the level and distribution of edge strain hardening (ESH) through the material thickness as an index to characterize the edge damage caused by the shearing operation.
Technical Paper

A Development of the High-toughness Nitriding to Reduce Heat Treatment Distortion of AT Annulus Gear

2013-04-08
2013-01-1769
In terms of reducing the gear noise of automatic transmission, improvement of heat treatment distortion of the annulus gear is very important, because annulus gear is very sensitive heat treatment due to thin walled ring-like shape. Nitriding is very effective method to meet the both requirements for heat treatment distortion and durability of the annulus gear, as compared with conventional carburizing. However, conventional nitriding has problems to be applied for annulus gear, such as brittleness of compound layer and low adhesion strength between compound layer and matrix. In this research, we developed the high toughness nitriding and greatly improved the problems as mentioned above, by controlling gas pressure and temperature.
Technical Paper

Enhancement of Cu with Addition of CNT for its Electro Thermal Properties Using Electro Plating Techniques

2013-01-09
2013-26-0075
As we all know the price of Cu alloy keep on increasing trend and in few products like motors, generators and power electronics. Cu price plays a vital role in determining the cost. Particularly in power electronics products for the hybrid electric vehicles the electrical/thermal conductivity property of Cu alloy needs to be enhanced since of high voltage requirement within a small space. Many research activities are ongoing to enhance the properties of Cu metal by addition of various alloys compositions. In addition to that the extra-ordinary properties of Carbon Nanotube (CNT) in Metal Matrix Composite (MMC) were main focus for science and technology. Few successful attempts have been made for Copper-Carbon nanotube (Cu-CNT) composites by powder metallurgy techniques, also it was reported the issues on the detoriation of the CNT's properties due to mechanical working.
Technical Paper

Sheet Metal Performance: Hot Stamping and Hydroforming Process Contributions for INOVAR Auto Program

2013-10-07
2013-36-0227
INOVAR-Auto program is a Brazilian government program to encourage innovation and improvement of the productive chain that aims stimulating investments in domestic auto industry providing tax benefits. However, to qualify for the incentive applicants the OEM's must meet several requirements and attend some vehicle performance targets. The body in white is an item that's directly linked to performance in terms of energy efficiency, so it's necessary lighter and stiffer bodies development comparing with the current ones. There is a lot of manufacturing process which may be applied in BIW construction, however some are more competitive considering present Brazilian automotive scenario. Considering this point, this paper will address two important forming processes that will be crucial to mass reduction and stiffness improvement in BIW: hydroforming and hot stamping. These process has a substantial utilization in USA and Europe, although are poorly used and exploited in Brazil.
Technical Paper

Development of Production Techniques for Aerospace Titanium Alloys

2013-10-07
2013-36-0370
Titanium alloys parts are ideally suited for advanced aerospace systems because of their unique combination of high specific strength and superior resistance to many corrosive environments, in addition to excellent composite compatibility. Despite these features, use of titanium alloys in engines and airframes is limited by cost. Therefore, the improvement of processing techniques for titanium alloys production became a trend of the modern metallurgic technology. This work presents results of the microstructural development of Ti-6Al-2Sn-4Zr-2Mo alloy produced by arc melting and powder metallurgy processes. This alloy has important applications in aerospace area, in sections exposed to high temperatures. Samples of this alloy were characterized by SEM (scanning electron microscopy), XRD (X-ray diffraction), Vickers microhardness measurements and density.
Journal Article

Residual Stress Mapping along the Cylinder Bores of Al Alloy Engine Blocks Subjected to Production Solution Heat Treatment Schedule

2014-04-01
2014-01-0837
The development of an optimized heat treatment schedule, with the aim of maximizing strength and relieving tensile residual stress, is important to prevent in-service cylinder distortion in Al alloy engine blocks containing cast-in gray iron liners. However, to effectively optimize the engine block heat treatment schedule, the current solutionizing parameters must be analyzed and compared to the as-cast condition to establish a baseline for residual stress relief. In this study, neutron diffraction was carried out to measure the residual stress along the aluminum cylinder bridge following solution heat treatment. The stresses were measured in the hoop, radial and axial orientations and compared to a previous measured as-cast (TSR) engine block. The results suggest that solution heat treatment using the current production parameters partially relieved tensile residual stress in the Al cylinder bridge, with stress relief being more effective near the bottom of the cylinder.
Technical Paper

Improvement of Powder Metallurgy Gears for Engines and Transmissions

2013-10-15
2013-32-9102
This paper presents the progress in Powder Metallurgy (PM) Gears, including examples of how to combine the disciplines of materials-, design- and process technology to push the limits towards increased performance, reduced weight, energy consumption and total manufacturing cost. Advancements in materials and manufacturing technology for PM gears will be presented as well as the result from simulations and reverse engineering work on existing automotive transmissions. The results from this work show that the amount and type of load on the individual gears in auto transmissions are very different and this gives room for optimized selection of material and manufacturing process.
Technical Paper

Advances in Numerical Investigation of Immersion Quenching at Different Pool Temperatures

2013-10-07
2013-36-0369
This paper outlines an improved computational methodology to simulate the immersion quenching heat transfer characteristics. Main applicability of the presented method lays in virtual experimental investigation of the heat treatment of cast aluminum parts, above all cylinder heads of internal combustion engines. The boiling phase change process between the heated part and a sub-cooled liquid domain is handled by using the Eulerian multi-fluid modeling approach, which is implemented within the commercial Computational Fluid Dynamics (CFD) code AVL FIRE®. Solid and liquid domains are treated simultaneously. While for the fluid domain mass, momentum and energy equations are solved in the context of multi-fluid modeling approach, only the energy equation is solved to predict the thermal field in the solid region. For the presented quenching simulation, the solid and fluid parts are contained in a single domain.
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