Ti-6Al-4V基體上氮電弧熔化法制備TiN層的組織及性能

采用直流氮電弧熔化方法在鈦合金(Ti-6Al-4V)基體上原位制備了TiN表面層。采用掃描電子顯微鏡、X射線衍射和顯微硬度儀等分析測試手段對TiN表面層的組織、硬度及摩擦磨損性能等進行了分析。探討了電弧電流對TiN層組織及性能的影響。結果表明:通過氮電弧熔化法制備的TiN層組織為樹枝晶,氮化層中樹枝晶的含量隨著深度的增加而減少,表面層與基體為冶金結合;隨著電弧電流由60A增加到100A,所制備的TiN表面層中樹枝晶的含量增加,表面層的硬度及耐磨性能都提高;當電弧電流為100A時,所制備的TiN表面層的最高硬度可達到1885HV,約為基體硬度的5倍,抗磨損性能也顯著提高。

TiN layers prepared by nitrogen arc melting technique on Ti-6Al-4V substrate

Direct current ( DC) nitrogen arc melting technique is presented,which allows for in-situ preparing TiN layers on Ti-6Al-4V substrate. The microstructures,hardness and wear properties of the TiN layers were investigated by scanning electron microscopy,X-ray diffraction and microhardness testing instrument. The effects of arc current on microstructure and properties of TiN layers were discussed. The TiN layer is mainly composed of TiN dendrites and the content of the TiN dendrites gradually decreased. The TiN layer has a good metallurgical bonding with substrate. With an increase of arc current from 60 A to 100 A,the amount of TiN dendrites increased,and the layer hardness and wear resistance enhanced. At the condition of 100 A,the TiN layer highest hardness reached 1885 HV which is about 5 times that of substrate. At the same time,the wear resistance of TiN layer was significantly increased.