强流脉冲电子束作用下TiCN涂层微观结构变化与性能研究

Microstructure and Properties of TiCN Coating Induced by High Current Pulsed Electron Beam

采用化学气相沉积(CVD)技术在硬质合金基体表面制备TiCN涂层,随后利用强流脉冲电子束(HCPEB)对TiCN涂层表面进行辐照处理。通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)等仪器观察了HCPEB辐照前后TiCN涂层的微观结构变化,并对比分析了其显微硬度和耐磨性能。结果表明:HCPEB辐照前后TiCN涂层的相组成保持不变,但相衍射峰的位置发生偏移且有所宽化,表明涂层晶粒细化,同时涂层内部应力状态发生改变;辐照后涂层表面粗大的晶粒消失,涂层变得光滑平整;随着辐照次数的增加,涂层的厚度逐渐减小。显微硬度和摩擦磨损试验结果表明,HCPEB辐照显著增加了TiCN涂层的表面显微硬度,其耐磨性能得到显著提升。涂层表面粗糙颗粒的消除、涂层晶粒细化、高密度晶体缺陷的形成以及涂层内部残余应力的改变是HCPEB辐照TiCN涂层性能改善的主要原因。

The TiCN coating was prepared on the surface of cemented carbide by chemical vapor deposition(CVD)method,and then treated by high current pulsed electron beam(HCPEB).The microstructure of TiCN coating before and after HCPEB irradiation was studied by X-ray diffractometer(XRD)and scanning electron microscope(SEM),and the corresponding microhardness and wear resistance were analyzed.The results show that no new phase was formed after HCPEB irradiation,but the grain of the coating was refined and the stress state in the coating changed.Meanwhile,the original coarse particles disappeared,and the coating surface became flat and smooth.As the increase of irradiation pulses,the thickness of TiCN coating decreased gradually.The results of the performance tests indicated that the microhardness and the wear resistance of TiCN coating were significantly improved after HCPEB irradiation.HCPEB irradiation eliminates the coarse particles on the coating surface,promotes grain refinement,the formation of high-density crystal defects and the change of residual stress,and further improves the properties of TiCN coating.