选用Ni基自熔性合金粉末添加一定量的Al和Ti元素混合粉末, 采用激光燃烧合成技术在双相(α＋β)钛合金TC4合金表面制备了Al8Cr5/NiAlTi复合涂层。借助扫描电子显微镜(SEM)和X射线衍射仪(XRD)分析了复合涂层的截面显微组织结构, 运用显微硬度计和空气电阻炉分别测试了涂层截面的显微硬度分布和不同温度下复合涂层的高温抗氧化性能。结果表明, 复合涂层主要由NiAlTi(Ni0.35Al0.30Ti0.35)基体相和Al8Cr5针状增强相组成。涂层截面平均显微硬度值为777 HV0.2, 约为TC4钛合金基材的3.1 倍(250 HV0.2); 复合涂层相对耐氧化性测试结果表明, Al8Cr5/NiAlTi复合涂层在600 ℃和800 ℃下的相对耐氧化性值均明显高于TC4基材试样, 分别约为TC4基材的3.75倍和4.30 倍。

Al8Cr5/NiAlTi composite coating was prepared on TC4 titanium alloy surface by laser combustion synthesis processing with Ni-based self-fluxing alloy powder, aluminum powder and titanium powder. The microstructure of composite coating cross section was analyzed by X- ray diffraction and scanning electrical microscopy. The results showed that the composite coating is mainly composed of Ni0.35Al0.30Ti0.35 matrix phase and Al8Cr5 reinforced phase. The micro-hardness of coating cross section and high temperature oxidation resistance was characterized by micro-hardness tester and air resistance furnace. The results illustrated that the average micro-hardness value of composite coating is about 777 HV0.2, and 3.1 times the value of TC4 alloy. The relative oxidation resistance of coating is 3.75 and 4.30 times the value of TC4 substrate alloy at 600 ℃ and 800 ℃, respectively.