Gas pressure sintering of /9-Si3N4 SHS

��-Si 3N 4 uuitctial prepared by self-propagating high-temperature synthesis from silcon powder and nitrogen w;is studied by gas pressure sintering process. The effects of different amounts of YAG additive and holding time on the properties were investigated. The results show that this ��-Si 3N 4 powder can be sintered to >90% of the theoretical density with high fracture toughness under the sintering conditions of 1.2MP.1 Ar pressure, 1940��C and holding 1 hour.