YAG对TiCN陶瓷刀具材料力学性能及烧结工艺的影响

Effect of YAG on Mechanical Properties and Process of TiCN Ceramic Tool

以钇铝石榴石（YAG）为添加相,采用热压烧结法制备YAG–TiCN复合陶瓷。研究了不同YAG添加量对复合陶瓷的物相、显微结构、力学性能的影响。结果表明：热压烧结过程中TiCN和YAG不发生反应;YAG第二相明显改善了TiCN的烧结性能,并有助于提高YAG–TiCN复合陶瓷的硬度、抗弯强度和断裂韧性;YAG含量在10%（质量分数）时复合陶瓷的致密度达到99.3%,并且Vickers硬度、断裂韧性、抗弯强度均达到最高,分别为：20.48 GPa、7.27 MPa·m^1/2、570.36 MPa,远远超过TiCN单相陶瓷的致密度以及力学性能：88.04%、9.33 GPa、5 MPa·m^1/2、204.45 MPa。YAG作为添加相可显著提高TiCN等难烧结陶瓷的致密度和力学性能。

YAG-TiCN composite ceramics were prepared via hot pressed sintering when yttrium aluminium garnet （YAG） was added. The effect of YAG amount on the phase composition, microstructure, and mechanical properties of the composite ceramic was investigated. The results show that no reaction between YAG and TiCN occurs during the hot pressing sintering process. The secondary phase YAG can improve the sintering performance of TiCN as well as the hardness, the flexure strength and fracture toughness of YAG-TiCN composite ceramic. The YAG-TiCN composite ceramic has the optimum mechanical performance at YAG addition of 10%. The Vickers hardness, fracture toughness, flexure strength of composite ceramics containing 10% YAG are 20.48 GPa, 7.27 MPa·m^1/2, and 570.36 MPa, respectively, which are greater than those of pure TiCN ceramics （i.e., 9.33 GPa, 5.5 MPa·m^1/2, and 204.45 MPa）. The addition of YAG can markedly improve the density and mechanical properties of ceramics with poor sinterability, such as TiCN, etc.