Noble Casting of Hypereutectic Al-Si-X Alloy and Its Application as an Automobile Part Requiring High Young's Modulus

摘要

Hypereutectic Al-Si-X (X; minor elements) alloys are produced by spray forming and extrusion for the usage as a light-weight propeller shaft for passenger cars, which requires materials having high specific Young's modulus, high ductility, and high strength. The Young's modulus of the hypereutectic Al-Si-X alloy can be increased by adding higher contents of Si, however, the Si particle as a reinforcement is known to have low strength, which degrades the mechanical properties of the Al-Si-X alloys. Therefore a noble casting process of spray forming is adopted in order to produce a fine-microstructured/high-strength hypereutectic Al-Si-X materials. In this study, the Young's modulus and mechanical properties of the hypereutectic Al-Si-X alloy are tailored by varying the Si contents, matrix alloy systems, heat treatment conditions, and spray forming & extrusion parameters, and then the feasibility of the materials for the usage as a the rotating propeller shaft is estimated.