TiB_2/TiN/WC复合陶瓷刀具材料力学性能及其摩擦磨损性能

为优化WC含量,使TiB_2/TiN/WC具有更好的综合机械性能,研究了TiB_2/TiN/WC中WC含量对的微观结构、力学性能、摩擦磨损性能的影响。结果表明:合适WC含量不仅能细化基体晶粒,还能通过断裂模式转变及晶粒拔出提高TiB_2/TiN/WC复合材料(BNC)力学性能,TiB_2/TiN/20wt.%WC(BNC2)比TiB_2/TiN(BNC0)抗弯强度、断裂韧性、维氏硬度分别提高了27.7%、30.4%、9.0%;随载荷增大,TiB_2/TiN/WC摩擦系数减小,磨损率增长趋势减缓。在50 N下,磨损表面生成的TiO_2、B_2O_3氧化薄膜能提高复合材料减摩耐磨性能,BNC0主要磨损机制为磨粒磨损与粘着磨损,BNC2主要磨损机制为磨粒磨损。

Mechanical Properties and Friction and Wear Performance of TiB_2/TiN/WC Composite Ceramic Tool Materials

To optimize the content of WC for making TiB2/TiN/WC had better synthetical mechanical properties, the influences of different mass friction of WC on microstructure, mechanical properties and the friction-wear perfomances of TiB2/TiN/WC were studied.The results show that the proper content of WC can refine the matrix grains and enhance the mechanical properties of TiB2/TiN/WC composites(BNC)by means of pulling out of grains and changing the fracture mode. Compared with the TiB2/TiN(BNC0),flexural strength, fracture toughness and hardness of the TiB2/TiN/20 wt%WC(BNC2) are increased by27.7%, 30.4%, 9.0%, respectively. The friction coefficient of TiB2/TiN/WC decreased and wear rate growth slowed with increasing applied load. When applied load was 50 N, a layer of TiO2、B2 O3 tribofilm that formed on the BNC worn surface by thermal oxidation, it can improve antifriction and antiwear performance of the composites. The dominant wear mechanisms of BNC0 are abrasion and adhesive wear,the dominant wear mechanism of BNC2 is abrasion wear.