A study on manufacturing of aluminum automotive piston by thixoforging

Abstract

The manufacture of many products related to the automobile and airplane industries by semi-solid forming is nowadays increasing from environmental and economical points of view. Especially in the automobile industry, to upgrade engine capability and reduce engine weight, the aluminum engine piston has already been developed by researchers and industrial technicians. Currently, forming methods to manufacture engine piston are casting, squeeze casting and hot forging. These methods, however, include several casting defects and need post machining as well. In this study, aluminum engine piston will be manufactured by thixoforging according to forming variables. In addition, it is very important to find the effects of forming variables on the final product by thixoforging. In order to determine the effects, however, researchers and industrial technicians have depended upon many experimental trials. In this study, a statistical approach for thixoforging has been adopted to improve experimental efficiency. Forming variables such as initial solid fraction, die temperature, and compression holding time were considered for manufacturing aluminum engine piston by thixoforging. Hardness and microstructure characterization were carried out so that the optimal forming condition could be found by the statistical approach. The experiment to make aluminum engine piston was performed under the optimal condition found by the statistical approach.