在钛合金(TC4)表面利用大功率半导体激光器制备镍钛表面改性层, 采用扫描电子显微镜、X射线能谱仪、X射线衍射仪、显微硬度计、摩擦磨损试验机及汽蚀装置分别分析了镍钛表面涂层的组织形貌、相结构与成分、硬度分布、耐磨损性能及抗汽蚀性能。研究结果表明, 采用合适的保护措施和激光处理工艺参数, 可获得与基体具有良好冶金结合的金属间化合物改性层; 激光合金化涂层主要由NiTi2、Al3Ti0.8V0.2组成, 与此同时镍钛合金涂层可将TC4基体的耐磨性提高8 倍, 抗汽蚀性能提高2.7 倍。

Ni-Ti alloying layer was prepared by a high power diode laser (HPDL) on the substrate of titanium alloy(TC4). The microstructure morphologies, phase structure, composition and hardness distribution, wear property, cavitation erosion resistance of the coating were studied by the scanning electronic microscopy (SEM), Energy Dispersive Spectrdmeter (EDS), X-ray diffraction (XRD), microhardness tester, friction-abrasion testing machine and the test device for cavitation respectively. The results show that, an excellent metallurgical bonding between the intermetallic compound layer and the substrates can be obtained by the proper protective measures and laser processing parameters; the phase compositions of laser alloying coating mainly are NiTi2, Al3Ti0.8V0.2. The wear resistance of laser alloying layer increase 8 times than that of the substrate, and the cavitation resistance is 2.7 times that of the substrate.