Grain refiner for aluminum containing silicon

摘要

Disclosed is an Al-Ti-B master alloy especially designed to grain refine cast aluminum alloys containing silicon. The alloy composition goes contrary to present known art. Present commerical master alloys contain a ratio of Ti to B exceeding 2.2 to promote a mixture of TiB2 and TiAl3 crystals. This invention provides an Al-Ti-B alloy wherein the Ti to B ratio is 1. It contains a preponderance of mixed boride crystals. The optimum composition of the alloy of this invention is Al-3Ti-3B.