短切碳纤维Csf含量对TiC基复合陶瓷刀具材料微观组织及力学性能的影响

Effect of Short Carbon Fiber Content on Microstructure and Mechanical Properties of Ti C-based Composite Ceramic Cutting Tool Materials

金属烧结剂选择Ni和Co,增强相选择短切碳纤维C_(sf),采用真空热压烧结技术,在1500°C下制备了短切碳纤维C_(sf)含量不同的TiC基复合陶瓷刀具材料。研究了C_(sf)的含量对TiC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:加入C_(sf)后,复合陶瓷刀具材料断裂方式为穿晶断裂和沿晶断裂方式并存,在C_(sf)含量增加的过程中,TiC基复合陶瓷刀具材料的硬度逐步下降,抗弯强度和断裂韧度先变大后减小;当增加到2wt%C_(sf)时,获得了最佳的力学性能,硬度为14.32±0.16GPa,断裂韧度为8.70±0.15MPa·m^(1/2),抗弯强度为695.63±15.01MPa。

TiC-based composite materials were fabricated using Ni and Co as sintering additive and short carbon fiber as reinforcing phase by vacuum hot-pressing technique at 1500℃. The microstructure and mechanical properties of the composites were investigated. The results showed that when the Csf was added, the fracture mode of TiC-based cermets is an integration of the intergranular fracture and the transgranular fracture, and with the increase of Ca, the hardness decreased, the flexural strength and fracture toughness increased firstly and then decreased. When the Csf content was 2wt%, the materials can obtain optimal mechanical properties. The Vickers hardness, flexural strength and fracture toughness of the composite were 14.32 ±0.16GPa,695.63 ± 15.01MPa and 8.70 ±0.15MPa·m^1/2 ,respectively.