The mechanism of spontaneous infiltration of Al–Si alloy into SiC preform in air

Abstract

Rapid, spontaneous infiltration can be achieved by dipping a SiC preform that contains pyrolyzed carbon into an Al–Si alloy bath in an open air environment. The mechanism for infiltration is investigated in the present work by studying the effects of several relevant parameters on the infiltration process. Experimental results have shown that the requirements for rapid spontaneous infiltration are an infiltration temperature higher than 1400 °C, the presence of a pyrolyzed carbon, and the presence of SiC particle in the preforms. The concentration of Si in the alloy does not have significant influence on the infiltration rate, but it strongly affects the resulting microstructures in the infiltrated composites.