碳化硅、氧化锆增韧氧化铝复相陶瓷的研究

A Study of SiC(w), ZrO_2 Toughened Al_2O_3 Matrix Multiphase Ceramics

在纳米氧铝粉中加入碳化硅晶须和纳米氧化铝粉，通过烧结得到细晶的氧化铝基复相陶瓷，达到了提高氧化铝陶瓷断裂韧性的目的．研究了Ｎａｎｏ－Ａｌ２Ｏ３／ＳｉＣ（ｗ）、ＺｒＯ２复相陶瓷的烧结温度、晶粒尺寸、ＳｉＣ（ｗ）含量等对细晶Ａｌ２Ｏ３基复相陶瓷材料断裂韧性的影响．采用纳米Ａｌ２Ｏ３粉，可使烧结温度大幅度下降，在１６００℃即可得到致密的细晶陶瓷材料．ＳｉＣ（ｗ）质量分数ｗ为１８％时可以得到较高的断裂韧性值，ＫＩＣ＝６．９６ＭＰａ·ｍ１／２．晶须增韧的机理仍然是晶须的拔出和断裂．加入ＺｒＯ２后，利用ＺｒＯ２的相变增韧的效果，可以使Ａｌ２Ｏ３基陶瓷材料的断裂韧性进一步提高．

In order to improve the fracture toughness of the alumina ceramic, SiCwhisker and Nano-ZrO2 were added in Nano-Al2O3 powder.Through sintering Al2O3 matrix multiphase ceramics were obtained. The effect of sintering temperature, grain-size and components on fracture toughness are studied. It is found that Nano-Al2O3 powder can greatly lower the sintering temperature. Dense fine-grain Al2O3 matrix multiphase ceramics can be obtainal at 1600℃, when the mass percentage of SiC(w) is 18%, the fracture toughness of sintered body is the the, KIC=6.96 MPa·m1/2. The mechanism of toughening are mainly pull and fracture of SiC(w).Addition of ZrO2 makes the fracture toughness of Al2O3 matrix ceramics to increase further by phase transformation toughening of ZrO2.