Effect of the Amount of Gases on the Foaming Efficiency of Porous Aluminum Using Die Castings Fabricated by Friction Stir Processing

摘要

Porous aluminum was fabricated by friction stir processing using the gases intrinsically contained in aluminum alloy die castings without the use of a blowing agent. The effect of the amount of gases contained in the die castings on the foaming efficiency was investigated. Although the expansion efficiency of each type of gas was not clear, the total amount of gases was sufficient to obtain high porosity. A porosity of approximately 60 pct was obtained with highly spherical and fine pores.