材料期刊网

采用磁控溅射仪制备了一系列不同C含量的TiWCN复合膜.利用XRD,SEM,纳米压痕仪和高温摩擦磨损仪等对TiWCN复合膜的微结构、力学性能和摩擦磨损性能进行了表征.结果表明:TiWCN复合膜由fcc结构的TiWCN相和六方结构的Ti2N相组成;随着C含量增加,薄膜硬度先升高后降低,室温摩擦系数逐渐减小,而磨损率先减小后增大.当C含量为11.25％时,硬度达到最大值,为35.97 GPa;磨损率获得最小值,为1.26×10-5 mm3·N-1·m-1.当C含量为13.68％时,摩擦系数最小,为0.32.当温度低于370℃时,TiWCN复合膜的摩擦系数和磨损率小于TiWN薄膜;当温度超过370℃时,TiWCN复合膜的摩擦系数和磨损率大于TiWN薄膜.C添加到TiWN薄膜中提高了薄膜的力学性能和常温摩擦磨损性能,而薄膜的高温摩擦磨损性能并未得到改善.

Over the past decades,traditional hard transition metal nitride films,such as TiN,have been widely used as machining and metal-forming tools coating materials due to their high hardness and chemical stability.With the rapid development of modem industrial technology,TiN has been unable to meet the requirements of modern industry,nanocomposite films because of its excellent comprehensive performance have attracted more and more scholars' attention.TiWN film as one of the TiN-based films has become a better substitute material.However the room temperature tribologicalproperty of TiWN film is not ideal,which limits its use of performance.According to the published experimental studies,C can well improve the room temperature tribological property because of its self-lubricating performance.However the effects of C content on the hardness of TiWN film is still not clear.The effects of C on mechanical property and the friction and wear property of TiWN film remain to be investigated.A series of TiWCN composite films with various C contents have been synthesized by magnetron sputtering technique.The microstructures,mechanical properties and the friction and wear property were investigated by XRD,SEM,nano-indentation,high temperature ball-on-disc tribo-meter,respectively.The results show that TiWCN composite films consist of fcc structure TiWCN phase and hcp structure Ti2N phase.With the increase of C content,the hardness of TiWCN films increases first and then decreases,the wear rate decreases first and then increases,while the friction coefficient gradually decreases.The maximum hardness of 35.97 GPa and the minimum wear rate value of 1.26× 10 5 mm3· N-1· m-1 are obtained when C content is 11.25％.The minimum friction coefficient of 0.32 is obtained when C content is 13.68％.The friction coefficient and wear rate of TiWCN composite films are lower than that of TiWN films when the temperature is below 370 ℃ ; while the values are higher than that of TiWN films when the temperature exceeds 370 ℃.C added to the TiWN films improves mechanical properties and the room temperature friction and wear properties of the films though does not enhance the high temperature friction and wear properties of the films.