氮化硅陶瓷冲蚀磨损特性研究

Erosive Wear and Fracture Toughness of Silicon Nitride Ceramics

对Ｓｉ３Ｎ４陶瓷进行冲蚀磨损和断裂韧性测定，对磨损表面和断口进行扫描电镜观察。结果表明：压痕断裂是热压烧结Ｓｉ３Ｎ４产生冲蚀的控制机制；Ｓｉ３Ｎ４的冲蚀率ＥＶ与断裂韧性ＫＩＣ有强烈的依赖关系，随ＫＩＣ的增高冲蚀抗力迅速增高，即ＥＶ∝ＫＩＣ＾ｎ，ｎ值变动于－７．０￣－４．４之间；依磨粒硬度ＨＥ和Ｓｉ３Ｎ４硬度Ｈ的比值和ＫＩＣ的大小可以评价Ｓｉ３Ｎ４陶瓷的抗冲蚀特性；

The erosive wear and fracture toughness of silicon nitride ceramics have been investigated. The main results are as follows:1. The control erosive wear mechanism of hot pressed silicon nitride ceramics is indentation-fracture.2. There are intensive relationship between erosive rate Ev and fracture toughness KIC of silicon nitride ceramics, i, e Ev ∞ KICn, the valur of n changed from -7. 0 to -4. 4.3. The erosion resistance of silicon nitride ceramics can be evaluated by fracture toughness and the ratio of erodent hardness HE and ceramic hardness H.