Investigation on the Freeze Casting Porous Al2O3 Ceramic Bodies Infiltrated with Nb-Ti-Al-Cr Alloy by Pressureless Infiltration

Abstract

This paper adopted freeze casting method to prepare porous Al2O3 ceramic bodies with different volume percentage and interconnected pore channels as the preform. The porous Al2O3 ceramic bodies were pressureless infiltrated with Nb-35Ti-20Al-10Cr alloy (atom percentage, at%) by using electromagnetic induction furnace. The results indicated that there is a well wettability between Nb-35Ti-20Al-10Cr melt and porous Al2O3 ceramic body. And it would be possible to infiltrate Nb-35Ti-20Al-10Cr melt into porous Al2O3 ceramic body through pressureless infiltration. The microstructure observation for the Nb-35Ti-20Al-10Cr/Al2O3 composites demonstrated that it was still retained the layer structure characteristics of the preform. The Nb-35Ti-20Al-10Cr melt was filled into the interconnected pore channels existed in the porous Al2O3 ceramic bodies and the Nb, Ti, Al, Cr alloy elements diffused into the reinforced Al2O3 particles during pressureless infiltration.