Fabrication of beta-Si3N4 whiskers from a GPSed-RBSN sponge using 6Y(2)O(3)-2MgO additives

Abstract

In this study, beta-Si3N4 whiskers with a diameter of 0.05-1.5 mu m and length of about 70 mu m were successfully fabricated using a gas pressure sintered (GPSed)-reaction boned silicon nitride (RBSN) process at 1550 degrees C for 9 h. The beta-Si3N4 whiskers grew on the frame and filled fully in the pores of the GPSed-RBSN sponge. 6Y(2)O(3)-2MgO additives played a significant role in the growth of beta-Si3N4 whiskers and alpha-Si3N4 whiskers, while alpha-Si3N4 whiskers, which were grown inside the RBSN sponge through the vapor solid mechanism, had a diameter ranging from 50 to 100 nm and length of about 80 mu m. (C) 2010 Elsevier Ltd and Techna Group S.r.l. All rights reserved.