为改善钛合金室温和高温摩擦学性能,分别采用锆-氮离子共渗(Zr+N)与离子渗锆后渗氮(Zr/N)两种工艺在TC4钛合金表面制备锆-氮改性层。利用球盘磨损试验机对比研究了两种Zr-N改性层在室温和600℃高温环境下的摩擦学性能。结果表明,两种工艺制备的Zr-N改性层均由ZrN相组成,Zr/N改性层还包含少量TiN相和较厚的Zr-Ti固溶体,两种等离子表面合金化层均使钛合金表面硬度显著提高。Zr/N改性层比Zr+N离子共渗层表面硬度更高,渗层更深,表面承载能力更强。室温和600℃高温下,Zr/N改性层磨损率比TC4钛合金基材分别降低43倍和21倍;Zr+N共渗改性层磨损率比TC4钛合金基材分别降低24倍和5倍。
Zr-N alloyed layers were fabricated on the surface of Ti6A14V alloy by two kinds of surface alloying processes to improve the wear resistance of Ti alloy at the room and elevated temperature. One process is Zr-diffusing with nitriding simultaneously ( Zr + N) , and the other is nitriding after Zr-diffusing (Zr/N). The tribological property of two kinds of modified surface layers at room temperature and 600 ℃ were investigated with ball-disk tester. The results show that both the Zr-N diffusion layers consist of ZrN phase, and Zr/N layer also contains a small amount of TiN phase and thicker Zr-Ti solid solution. The surface hardness of the tested alloy is significantly increased by both Zr-N alloying layers. The hardness, thickness and surface bearing capacity of Zr/N layer are greater than those of Zr + N layer. Under room temperature and 600℃ , the wear rate of Zr/N layer is reduced by 43 and 21 times than matrix respectively, and the wear rate of Zr + N layer is reduced by 24 and 5 times than matrix respectively.