研究了Y2 O3,La2 O3,Nd2 O3等稀土氧化物对Si3N4 陶瓷力学性能和显微组织的影响。添加稀土氧化物的Si3N4 陶瓷可以获得较好的力学性能。添加复合稀土氧化物 (Y2 O3+La2 O3)后 ,断裂韧性达 7 8MPa·m1 2 ,抗弯强度达 962MPa,其性能提高的主要原因是稀土氧化物改善了材料的显微组织 ,提高了 β Si3N4 晶粒的长径比。 The effects of rare earth oxides such as Y2 O3, La2 O3 and Nd2 O3 on the mechanical properties and microstructure of Si3N4 ceramics were studied. Adding rare earth oxide Si3N4 ceramics can get better mechanical properties. The main reason for the increase of fracture toughness is 78MPa · m1 2 and the flexural strength reaches 962MPa after the addition of composite rare earth oxides (Y2 O3 + La2 O3). The main reason for the improvement is that the rare earth oxides improve the microstructure of the material and increase the β The aspect ratio of Si3N4 grains.