放电等离子烧结无黏结相Ti(C,N)基金属陶瓷的组织与性能

Microstructure and properties of bindeless Ti(C,N)-based cermets prepared by spark plasma sintering

以Ti(C,N)粉末为原料,采用放电等离子烧结法制备无黏结相Ti(C,N)金属陶瓷,对材料的显微组织、力学性能和摩擦磨损性能进行分析和测试。研究烧结温度、碳黑添加量w(碳黑)和WC、Mo2C与TaC等碳化物的添加对无黏结相Ti(C,N)基金属陶瓷致密度和力学性能的影响;另外还将合金元素预固溶于Ti(C,N)粉末中合成(Ti,W,Mo,Ta)(C,N)固溶体粉末,以此为原料制备无黏结相Ti(C,N)基金属陶瓷。结果表明,随烧结温度升高,Ti(C,N)基金属陶瓷的致密度与力学性能提高;随炭黑添加量w(C)增加,金属陶瓷的密度与性能先升高后降低。在Ti(C,N)粉末中加入WC、Mo2C和TaC等碳化物,或用(Ti,W,Mo,Ta)(C,N)固溶体粉末为原料制备无黏结相Ti(C,N)基金属陶瓷后,材料的氧含量均明显降低,致密度和力学性能大幅提升,并具有较低的摩擦因数和良好的耐磨性能。其中,以(Ti,W,Mo,Ta)(C,N)固溶体粉末为原料制备的无黏结相Ti(C,N)基金属陶瓷,硬度(HV30)为19.9 GPa,横向断裂强度和断裂韧性分别为1280 MPa和7.8 MPa·m1/2。

The binderless Ti(C,N)-based cermets were fabricated by spark plasma sintering using Ti(C,N)powder as raw materials.The microstructure,mechanical properties,wear resistance of the materials were studied.Effects of sintering temperature,carbon black addition,carbides additives and solid solution raw powders on the relative density and mechanical properties were investigated.Furthermore,the(Ti,W,Mo,Ta)(C,N)solid solution powder fabricated by the dissolving of other alloying elements in the lattice of Ti(C,N)was also used to prepare the binderless cermets.The experimental results show that the relative density and mechanical properties of binderless cermets increase with increasing sintering temperature.With increasing carbon black content,the relative density and mechanical properties increase firstly and then decrease.After adding WC,Mo2C and TaC carbides into Ti(C,N)powder,or using(Ti,W,Mo,Ta)(C,N)solid solution powder as raw materials,the oxygen content of Ti(C,N)-based cermets with bindeless phase is obviously reduced.The density and mechanical properties of the materials are greatly improved,and the friction coefficient and wear resistance of the materials are lower.The binderless Ti(C,N)-based cermet prepared by(Ti,W,Mo,Ta)(C,N)solid solution powders exhibits hardness(HV30)of 19.9 GPa,transverse rupture strength of 1030 MPa and fracture toughness of 7.8 MPa·m1/2.