Manufacture of aluminum automotive piston by semi-solid forming with a statistical approach

摘要

In these days, manufacturing of many products related to automobile and airplane industry by semi-solid forming is increasing according to environmental and economical point of view. It is very important to find effects of forming variables on final products in semi-solid forming. Since the process parameters, in other words, forming variables in semi-solid forging have relatively high sensitivity on the quality of final product, the statistical methodology is reasonably adopted for optimization of the process parameters. In order to find the effects, however, many researchers and industrial technicians have depended upon too many types of experiments that require too much efforts and time. In the present study, a statistical approach in semi-solid forging process has been adopted to improve experimental efficiency, which means prediction of optimal forming condition from minimum numbers of experiments. Forming variables such as initial solid fraction, die temperature, and compression holding time were considered for manufacturing aluminum engine piston by semi-solid forging. Hardness and microstructure were inspected so that optimal forming condition was found by a statistical approach. In addition, experiment to make aluminum engine piston was performed under the optimal condition found by the statistical approach.