Notice of Retraction: A research on fabrication of aluminum foam precursor using semi-solid melt

Abstract

This paper described a novel method to fabricate aluminum foam precursor. High viscosity character of semi-solid melt as well as stirring technique were used in this method, the blowing agents were homogeneously distributed without adding thicken additions, aluminum foam precursor embedded with distributed blowing agents were fabricated directly and efficiently through this method. This paper investigated the effects of main parameters in the fabricating process such as solid phase fraction, stirring speed, stirring time and stirring blade angle. And it was proved that when solid fraction was lower than 30%, the distribution effects would increase with stirring time and speed. The great amounts of aluminum solid-phases in the semi-solid melt would not lead to more nucleation and harmful initial gas bubbles. The growing behavior of initial gas bubbles in semi-solid melt was closely related to the melt temperature and cluster size of blowing agents. Lower temperature and smaller size of blowing agent cluster were the key factors to better precursors. The distribution behavior would be affected by the melt viscosity and stirring speed. The useful lag in melt transportation would perform greater with increase of the viscosity and would be weaken when the stirring speed was too high.