等离子辉光TiN复合渗镀层结构与性能的研究

Study on Structure and Property of TiN Multi-permeating coatings Prepared by Plasma Discharge Technique

利用等离子渗金属技术、尖端放电、空心阴极效应和反应气相沉积技术,在碳钢表面形成具有扩散层和沉积层的新型复合渗镀TiN沉积层+TiN析出相+Ti扩散层,并与等离子渗镀TiN/Ti层以及在碳钢基体表面直接用PVD法沉积TiN薄膜的表面形貌、结构、耐蚀性进行了检测和分析。结果表明:等离子渗镀的复合渗镀TiN/Ti层表面为均匀起伏的胞状物,Ti和N原子由表层呈梯度沿基体向内分布,属于冶金扩散层;用等离子渗金属技术等形成的复合渗镀TiN沉积层+TiN析出相+Ti扩散层,其表面形貌是为均匀、致密、细小的组织,平均硬度达到2500HV0.1左右,渗镀层厚度达十几微米,TiN层择优取向为(200)晶面;而PVD法直接沉积TiN薄膜厚度较薄,晶粒以不规则形式分布在基体上。在0.5mol/L H2SO4溶液中腐蚀性能表明,复合渗镀TiN沉积层+TiN析出相+Ti扩散层的耐蚀性较好。

The TiN multi-permeating coatings consist of deposition layer and diffusion layer. They were successfully synthesized onto carbon steel by a new compound process, mainly the process contains plasma discharge, tip discharge, hollow-cathode effect and reactive sputtering. The phase constitution of the coatings and growth orientation of the crystallites were investigated through X-ray diffraction analysis. The corrosion resistance of the TiN multi-permeating coatings was performed in 0.5 moL/L H2SO4 corrosion media by means of an electrochemical potentiodynamic polarization. The results show that the surface of TiN multi-permeating coatings is pure TiN phase and the strongest diffraction apex is on the (200) crystal face that is of obvious preferred orientation. The TiN multi-permeating coatings are uniform and compact. The content of the atoms Ti and N gradually decreased with the increasing distance from the surface to the core. The adhesion belongs to metallurgical bonding with matrix without desquamating phenomenon. The surface hardness is about 2500HV0.1. Its thickness is more than 10 μm. The corrosion resistance of the TiN multi-permeating coatings proves excellent, and no clear corrosion pit is found on the surface of the coatings.