中文摘要：

对原位TiN／O′-sialon纳米复相陶瓷（NTS）和采用“二步法”制备的TiN／O′-sialon复相陶瓷（TS）的常温导电性能进行了对比研究，并对材料TS进行了放电加工。研究结果表明，初始原料中20％（质量分数）和25％（质量分数）左右的TiO2加入量是决定材料NTS和TS中TiN能否形成导电网络的最低TiO2加入量，该导电临界值同基相O′-sialon与导电相TiN的颗粒尺寸比有关，此时相应材料的电阻率为1.6×10^-2和1.8×10^-2Ω·cm，满足放电加工的需要。烧结温度升高，两种材料的电阻率略有降低。随放电加工速度的增加，材料TS加工表面粗糙度明显增加。

英文摘要：

Room-temperature electrical conductivity property of in-situ TiN/O′-sialon nano multiphase ceramics （NTS） and TiN/O′-sialon multiphase ceramics （TS） fabricated by two steps method was investigated compara- tively. TiN/O′-sialon multiphase ceramics （TS） were machined by electrical discharge machining. The results show that the minimum amount of TiO2 in initial raw materials is about 20wt% and 25wt% respectively for the formation of electroconductive network in the in-situ TiN/O′-sialon nano multiphase ceramics （NTS） and TiN/ O′-sialon multiphase ceramics （TS）. The critical values of electrical conductivity are as function of the particle size ratio between O′-sialon and TiN. The electrical resistivity of such two multiphase cera0mics is 1.6 ×10^-2 and 1.8×10^-2Ω·cm respectively, which is available for electrical discharge machining. With the increase of sintering temperature, room-temperature electrical resistivity decreases. Surface roughness increase significantly with the increase of speed of the electrical discharge machining.