激光沉积镍钛涂层组织与摩擦学性能研究

Microstructure and tribological properties of laser deposited NiTi coatings

为了改善钛合金零件的耐磨性能,利用激光沉积技术在基体材料TC4上制备了NiTi合金涂层,通过优化工艺获得无裂纹、无气孔、且呈冶金结合的涂层。使用光学显微镜(OM)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)等技术手段对涂层的组织结构进行分析,对涂层的硬度、耐磨性等性能进行测试。结果表明:涂层的主要组织由树枝晶和等轴晶组成,涂层主要由NiTi(B2)奥氏体母相组成,基体和涂层两种材料的硬度相差不大,NiTi涂层的摩擦系数与磨损失重均低于TC4基体。在TC4基体上制备NiTi涂层可以显著改善摩擦磨损性能。

In order to improve the wear resistance of titanium alloy parts,NiTi alloy coating was prepared on the matrix material TC4 by laser deposition technology,and a crack-free,porosity-free and metallurgical coating was obtained by optimizing the process.The microstructure of the coating was analyzed by optical microscope(OM),scanning electron microscope(SEM),X-ray diffractometer(XRD)and other technical means,and the hardness,wear resistance and other properties of the the coating were tested.The results show that the main structure of the coating is composed of dendrite and equiaaxial crystal,and the coating is mainly composed of NiTi(B2)austenite parent phase.There is little difference in hardness between the matrix and the coating,and the friction coefficient and wear weight loss of the NiTi coating are lower than those of the TC4 substrate.The preparation of NiTi coating on TC4 matrix can significantly improve the friction and wear properties.