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Wrought Aluminum Metallurgy

There are a wide variety of wrought aluminum alloys, each developed to provide specific properties. Getting the strength you need in an aluminum alloy requires knowledge of the effects of alloy composition, cold-working, and heat treating on aluminum metallurgy and properties. A good understanding of how aluminum alloys behave and what can be done to modify their properties is critical for being more productive and profitable. The course takes about one hour to complete and consists of one module and a final exam. Also, quizzes and problems give you opportunities to apply the concepts taught.
Technical Paper

Weld Durability Analysis by Equilibrium-Equivalent Structural Stress Approach

Welding has been used extensively in automotive components design due to its flexibility to be applied in manufacturing, high structural strength and low cost. To improve fuel economy and reduce material cost, weight reduction by optimized structural design has been a high priority in auto industry. In the majority of heavy duty vehicle's chassis components design, the ability to predict the mechanical performance of welded joints is the key to success of structural optimization. FEA (finite element analysis) has been used in the industry to analyze welded parts. However, mesh sensitivity and material properties have been major issues due to geometry irregularity, metallurgical degradation of the base material, and inherent residual stress associated with welded joints. An approach, equilibrium-equivalent structural stress method, led by Battelle and through several joint industrial projects (JIP), has been developed.
Technical Paper

Wear of Bearing Materials

Wear characteristics of four bearing materials have been investigated under different sliding conditions. The bearing materials used were CDA 954, CDA 863, CDA 932, and CDA 938. Using a Taber Wear Tester, a cylinder on a flat geometry was used as a tribo contact pair. All bearing materials in the form of a thick cylindrical disk were subjected to combined sliding-rolling motion against a rotating flat disk. The flat disk was either an abrasive disk, or a very soft steel disk, or a hardened steel disk with and without lubrication. Wear was measured as weight loss after several thousand cycles of rotation. Maximum wear of the bearing materials occurred when the counter body was a very soft steel disk. These results together with the wear rate of each bearing material sliding against four different counter bodies are presented. These results are found to be of practical importance in the design and application of journal bearings made of materials used in this investigation.
Technical Paper

Virtual Instrumentation of a Soil Bin for Improved Precision

The existing instrumentation of a soil bin was retrofitted with virtual instrumentation techniques to achieve improved repeatability and more precise measurements. Current-loop sensors were added to the prime mover for improved speed control. Soil preparation operations were instrumented to determine penetrometer forces as a function of soil penetration depth, soil surface smoothness, compaction force, and soil surface elevation. Test hitch-points for agricultural implements were instrumented with wheatstone bridge force transducers. Implement depth was found with ratiometric linear transducers. Distance and speed determinations utilized an optical encoder with a resolution of 3.0 × 10-4 m. Temperature measurements were also recorded with solid state current transducers.
Technical Paper

Vehicle Integration, Gear Material and Heat Treatment Effects on Rear Axle Whining Noise

This paper will focus whining noise on rear axles applied in mid-size trucks. Vehicle integration changes during development affect directly the gear noise perception, in which it may be intensified. Also, gear material and heat treatment choices for the rear axle need to be done carefully, taking into consideration the integration changes and also the driver usage. A lessons learned collection over the diverse aspects of a rear axle whining noise will be the basis of this paper.
Technical Paper

Vacuum Die Casting Technology with True T6 Heat Treating Capability

Outboard Marine Corporation (OMC) developed its own vacuum die casting process to produce true T6 heat treatable aluminum die castings. This process was initiated by OMC Research and developed jointly with OMC Waukegan. The project began 1990 and was put into production in 1992 on the outboard motor lower mount bracket shown in figure 1. OMC is producing vacuum die cast aluminum parts made with 356.0 alloy and T6 heat treated which meet or exceed the strength of similarly alloyed and processed permanent mold or lost foam cast parts. The application of this process is being expanded within the realm of structural outboard motor parts to include other mounting brackets, as well as fuel system components. An automotive die caster is using the technology and equipment provided by OMC to produce leak tight air conditioner compressor housings.
Technical Paper

Using Rapid Prototyping Techniques to Prototype Metal Castings

Several methods have been developed which use rapid prototyping techniques to assist in the creation of prototype metal castings. Methods exist for a number of casting processes such as sand casting, die casting, investment casting, and evaporative pattern casting. In many cases, these methods can reduce both the time and cost required to create prototype castings.
Technical Paper

Using MCAE and Rapid Prototyping for Casting Design

The conceptualization, design, analysis, prototyping, and testing of a steel casting are described. The methods used include 2D CAD, 3D solid modeling, finite element analysis, Solid Ground Curing rapid prototyping, and laboratory prototype testing. The part was successfully delivered to field testing on time. The use of the MCAE techniques provided a more optimal part more quickly than the use of standard CAD techniques would have provided. A minor cost penalty was paid for the prototype pattern versus conventional prototyping.
Technical Paper

Use of Powdered Metal for a Valve Bridge in a 4-Valve Heavy Duty Diesel Engine

A new 12.5 L four-valve heavy duty diesel engine has demonstrated that Powdered Metal (PM) is an effective material alternative to wrought steel for the valve bridge. The valve bridge, an element that spans the pair of intake or exhaust valves, allows a single rocker arm to actuate the pair of valves. The component is subjected to a high number of cycles at a moderately high load and geometry precision is essential for desirable wear characteristics. The PM material selected, MPIF FL4605-120HT, has replaced 8620 steel after making component geometry changes. The PM part has a higher load capacity than the original design with equivalent wear characteristics and offers a 80% cost saving over the original design. This paper presents the geometry changes defined by FEA analysis and component testing performed to verify the change from wrought steel to PM. A required characteristic of this component is moderately high fatigue strength.
Technical Paper

Tribological Evaluation of Silicon Nitride Against Retainer Materials

Sliding wear tests were conducted with silicon nitride (Si3N4) against five retainer materials using different lubricants. The sliding wear tests were conducted with the Torrington Tribology tester at three normal loads and one sliding speed at an ambient lubricant oil temperature and one hour duration. The retainer materials were polyetheretherketone (PEEK) with glass fill, PEEK with carbon graphite/PTFE (polytetrafluoroethylene) fill, machined aluminum with a WS2 coating, machined steel with a silver plating, and machined bronze. The Si3N4 ceramic specimens (both NBD-100 and NBD-200) did not experience any measurable or observable wear. Friction coefficients varied between 0.03 and 0.16 depending upon the retainer material and the lubricant; the lowest values were obtained with the PEEK materials. Large wear scars were generated on the machined bronze, along with high friction coefficients and slip-stick behavior.
Technical Paper

Traction, Compaction, Yield and Operating Cost of Alternative Tire/Traffic Systems

Agricultural tractor work rate depends on tire tractive performance, and crop growth depends on soil degree of compaction. The concept of tire footprint efficiency ratio, based on tire footprint and mean ground pressure studies, is introduced to evaluate tire performance. Effects of mean ground pressure on soil degree of compaction and relative crop yield are presented. A method is proposed to compare various tire mount alternatives, with respect to tractive performance and crop revenue. A sample tire equipment comparison scheme is presented.

Titanium: A Technical Guide, 2nd Ed.

Designed to support the need of engineering, management, and other professionals for information on titanium by providing an overview of the major topics, Titanium: A Technical Guide provides a concise summary of the most useful information required to understanding titanium and its alloys. The author provides a review of the significant features of the metallurgy and application of titanium and its alloys. All technical aspects of the use of titanium are covered, with sufficient metals property data for most users.
Technical Paper

Tillage Practices-Yesterday, Today and Tomorrow

Past tillage practices in the Corn belt were primarily based on the moldboard plow. The chisel plow, disk, and other forms of reduced tillage are now used extensively. The trend toward less tillage has occurred from the desire to reduce costs and to utilize plant residue to control erosion. The trend is hampered by the goal to maintain consistent high yield levels. Yields often decrease due to soil compaction, inadequate weed control, insufficient nutrient incorporation, and other factors. New tillage practices will be tried by farmers but before being widely adopted will be critically evaluated economically and for effects on erosion.
Technical Paper

The Selection of Steel and Heat Treatment for Tractor Gears

This paper discusses steels and heat treatments that have and are being used in John Deere tractors. Some of the development test work is described which led to a given selection in three specific cases. Stress levels and other tractor gear design factors are mentioned.
Technical Paper

The Limitations of Fatigue Testing

Fatigue testing of components is used to validate new product designs as well as changes made to existing designs. On new designs it is common to initially test parts at the design stage (design verification or DV) and then again at the production stage (production verification or PV) to make sure the performance has not changed. On changes to existing designs typically the life of the new part (B) is compared to that of the old part (A). When comparing the fatigue life Weibull analysis is normally used to evaluate the data. The expectation is that the B10 or B50 life of the new part or PV parts should be equal to or better than that of the old parts or the DV parts. However, fatigue testing has a great deal of inherent variability in the resulting life. In this paper the variability of numerous carburized and induction hardened components is examined.
Technical Paper

The Lampson Dynamic Compactor for Effective Soil Compaction and Stabilization

Static soil compaction was used for years, until mechanical tampers, vibrating plates and rollers became popular in the 1960's. With this type equipment, large scale excavation is necessary. Where unstable sub-soil is present, the foundation has to be prepared in lifts (layering) with known soils. Each lift has to be hauled, graded, watered and compacted. Some areas may require as many as 18 lifts, each being 1½ feet thick. Needless to say, this method is not only time-consuming, but costly. With dynamic compaction-the use of a drop weight, some soil conditions can be improved up to a depth of 60 feet. Using a 35 ton drop weight and a lift height of 100 feet, the energy produced is 7,000,000 ft. lbs. Now when we condense that energy into a known area, say 49 square feet, the ground pressure under that weight is 142,857 lbs. per square foot at time of impact.
Technical Paper

The Inter-Relation Between Development, Mass Production and Quality Described on a Practical Example Such as Cast Disc Wheels for Commercial Vehicles

With the product liability for automotive safety parts in mind, the inter-relation between development, manufacture and quality of a cast ductile iron wheel for commercial vehicles is being described. The product quality requirements are derived from the service application condition of the wheel. By definition, the product quality is composed of the design quality and the manufacturing quality. During the development period of the wheel, a very close cooperation between design and manufacturing engineers is imperative. As the physical properties of the nodular iron vary in different parts of the wheel, the wheel-specific material properties are investigated on prototype wheels and serve as base figures for the dimensioning of the product. Investigations prior to mass production are also made regarding dimensional casting tolerances and internal defects.