【摘要】 综述了氮化硅及其复相陶瓷超塑性的研究进展论述了Si3N4及Sialon陶瓷的超塑性变形机理、微观特征和断裂特性在Si3N4和Sialon陶瓷的超塑性变形中,α→βSi3N4(β′Sialon)的相变以及βSi3N4(β′Sialon)的长大和晶界玻璃相的析晶引起的纤维强化,将影响Si3N4陶瓷超塑性的流变特性晶界玻璃相的重新分布使Si3N4的变形由牛顿流变向剪切增厚转变变形中的孔洞损伤和裂纹尖端的氧化引起裂纹的扩展,导致Si3N4的延伸率降低更多还原

【Abstract】 The recent developments of superplasticity in silicon nitride ceramics and their composites are reviewed. The deformative mechanism and the microstructural characteristics as well as the fracture behavor are discussed. α to β Si 3N 4 (β′ Sialon) transformation and β′ Si 3N 4 (β′ Sialon) grain growth as well as the devitrification and crystallization of amorphous phase may induce the fiber reinforcing effect, which affects the flow behavior of superplasticity for Si 3N 4 ceramics. The redistribution of grain boundary glass makes Newtonian deformation of Si 3N 4 become shear thickening. The void damage and oxidation inside the cracks during deformation make cracks expand and lead to the decrease of fracture strain.更多还原