Ni含量对TiB_2基复合陶瓷刀具材料微观组织及力学性能的影响

Effects of Ni Content on Microstructure and Mechanical Properties of TiB_2-based Composite Ceramic Cutting Tool Materials

以作Ni为金属烧结剂,采用真空热压烧结技术,在1650℃下制备了含Ni量不同的Ti B_2基复合陶瓷刀具材料。研究了Ni含量对Ti B_2基复合陶瓷刀具材料微观组织和力学性能的影响,结果表明:随着Ni含量的增加,Ti B_2基复合陶瓷刀具材料微观组织中的缺陷先减少后增多,抗弯强度、断裂韧度和硬度也随着先增大后减小;当Ni含量为8wt%时,微观组织的缺陷少、力学性能良好,此时的相对密度为(99.3±0.3)%,抗弯强度为(952.3±86.2)MPa,断裂韧度为(7.3±0.3)MPa·m^(1/2),硬度为(22.4±0.6)GPa。

TiB2-based composite tool materials were fabricated by using Ni as sintering additive by vacuum hot-pressing technique at 1650 ℃. The microstructure and mechanical properties of the composite were investigated＇. The results show that the defects in the microstructure and the mechanical properties of the TiB2-based ceramic cutting tool materials increases firstly, and then decreases with the increase of Ni content. When the Ni content is 8wt%, the materials can obtain good microstructure and optimal mechanical properties. The relative density, the flexural strength, fracture toughness and Vickers hardness of the composite is （99.3±0.3）%, （952.3±86.2）MPa, （7.3±0.3）MPa.m1/2 and （22.4±0.6）GPa, respectively, when the Ni content is 8wt%.