Foaming of precursor of porous aluminum consisting of dissimilar aluminum alloys by frictional heating during friction stir processing

Abstract

In our previous study, a precursor of porous aluminum consisting of uniform aluminum alloy was foamed by frictional heating during friction stir processing. It was found that the temperature at the tool gradually increased as the tool traversed owing to the heat stored in the steel plate. In this study, a precursor of porous aluminum welding a lower-foaming-temperature ADC12 (Al-Si-Cu) alloy precursor and a higher-foaming-temperature A6061 (Al-MgSi) alloy precursor was foamed during friction stir processing of a steel plate. It was shown that by placing ADC12 in the first-half region of tool traversal and A6061 in the latter half, the precursor can be sufficiently foamed, and porous aluminum consisting of ADC12 and A6061 can be obtained up to the tool traversal speed of 20 mm/min.