Prediction of die wear during hot-extrusion of engine valves

Automotive exhaust valves are conventionally manufactured in North America by an extrusion-forging process. Abrasive and adhesive wear during the valve stem extrusion operation shorten die life markedly under the high-pressure, high-temperature conditions. It is desired to reduce this die wear by developing simulation software to predict wear based on process conditions, and then optimizing the process. This paper describes the procedures and results obtained using a computer modeling method developed at the ERC for Net Shape Manufacturing. Results obtained to date indicate that-accurate abrasive and adhesive wear prediction of steel and ceramic extrusion dies is feasible in cases where plastic deformation is not significant.