Susan E. Hartfield-Wünsch

Bench Wear Testing of Common Gasoline Engine Cylinder Bore Surface/Piston Ring Combinations

In this study, two bench wear tests, the Cameron-Plint modified lest (C-P) and the Electro-Mechanical test (LS9), have been used to evaluate common internal combustion engine cylinder bore surface/piston ring pairs. Bore, materials tested include cast iron, 390 aluminum, and Nikasil. Piston rings tested include chromium-plated, plasma-sprayed molybdenum, and gas-nitrided stainless steel. Both the C-P and LS9 bench wear tests showed the same general trends. Gas-nitrided stainless steel rings provide the lowest overall ring wear and the lowest cast iron bore wear. 390 bore wear is higher than that of cast iron or Nikasil. Chromium-plated or gas-nitrided stainless steel rings provide the best balance of ring and bore wear against 390 aluminum, while molybdenum rings against 390 produce the worst combined wear. Differences in wear rates for 390 aluminum are related to variations in temperature and lubrication rate between the two testers. Bore wear measurement accuracy is quantified and an improved measuremen...

Comparing Laser Welding Technologies with Friction Stir Welding for Production of Aluminum Tailor-Welded Blanks

A comparison of welding techniques was performed to determine the most effective method for producing aluminum tailor-welded blanks for high volume automotive applications. Aluminum sheet was joined with an emphasis on post weld formability, surface quality and weld speed. Comparative results from several laser based welding techniques along with friction stir welding are presented. The results of this study demonstrate a quantitative comparison of weld methodologies in preparing tailor-welded aluminum stampings for high volume production in the automotive industry. Evaluation of nearly a dozen welding variations ultimately led to down selecting a single process based on post-weld quality and performance.

Aluminum Tailor-Welded Blanks for High Volume Automotive Applications

Design of Experiment based approach is used to systematically investigate relationships between 8 different welding factors and resulting weld properties including strength, elongation and formability in 1.2mm-2mm thick friction stir welding of AA5182-O for TWB application. The factors that result in most significant effects are elucidated. The interactions between several key factors like plunge depth, tool tilt, pin feature and pin length on the overall weld quality is discussed. Appropriate levels of factors that lead to excellent weld properties are also identified.

Benchmark 2 - Springback of a draw / re-draw panel: Part C: Benchmark analysis

Benchmark analysis is summarized for DP600 and AA 5182-O. Nine simulation results submitted for this benchmark study are compared to the physical measurement results. The details on the codes, friction parameters, mesh technology, CPU, and material models are also summarized at the end of this report with the participant information details.