NiAl(Si)/Al 2O 3 co-continuous composites by double reactive metal penetration into silica preforms

Abstract

NiAl(Si)/Al 2O 3 composites with co-continuous structure were prepared by a double reactive metal penetration technique. Silica preforms were in a first step immersed in an Al bath, obtaining an Al(Si)/Al 2O 3 composite, then a reactive penetration of Ni was performed, bringing to the substitution of Al with NiAl. The obtained composites present both phases continuous, and the whole process is a near-net-shape one. Various tests were performed, showing that the composites present high hardness and melting point and good modulus.