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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NiAlT(i 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。
The Ni-based self-fluxing alloy powder was used to add a certain amount of Al and Ti mixed powder. The Al8Cr5 / NiAlTi composite coating was prepared on the surface of TC4 alloy of dual-phase (α + β) titanium alloy by laser combustion synthesis. The microstructure of the composite coating was analyzed by means of scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The microhardness of the coating was measured by microhardness tester and air resistance furnace respectively. Under the composite coating at high temperature oxidation resistance. The results show that the composite coating mainly consists of NiAlT (i Ni0.35Al0.30Ti0.35) matrix phase and Al8Cr5 acicular reinforcing phase. The average microhardness of the coating cross section is 777 HV0.2, about 3.1 times that of the TC4 titanium alloy substrate (250 HV0.2). The relative oxidation resistance test of the composite coating shows that the Al8Cr5 / ℃ and 800 ℃ were significantly higher than the TC4 substrate samples, respectively, about 3.75 times and TC4 substrate 4.30 times.