Fabrication of Nd:YAG transparent ceramics by non-aqueous gelcasting and vacuum sintering

Abstract

Highly transparent Nd:YAG ceramics were fabricated by non-aqueous gelcasting and vacuum sintering for the first time, using epoxy resin and polyamine curing agent as gelling system. The influences of dispersant, solid loading and the organics of gelling system on the viscosity of suspensions and the stability of suspensions were discussed. The optimized nonaqueous slurry was of 54vol% solid loading, comprising the commercial α-Al2O3, Nd2O3 and Y2O3 powders. The slurry with low viscosity and good fluidity was obtained by using 0.45wt% PEI as dispersant. The homogenous and dense green body was obtained through solidificating the slurry in-situ. The green body after burnout had a relative density of 55.0% with a narrow pore size distribution. The transmittance of the Nd:YAG ceramics sintered at 1775°C for 30h with the thickness of 1.5mm reached 83% at 1064nm. The average grain size of the sample was about 71μm.