激光熔覆Ti基NiAlSi合金涂层的组织及高温抗氧化性能研究

通过激光熔覆工艺在Ti4合金表面生成了NiAlSi涂层，分析了涂层物相组成、显微组织结构及在860℃时的抗氧化性能。研究结果表明:Ti4合金和涂层的结合部位形成了熔合线，可以推断涂层和钛合金之间形成了良好的冶金结合状态，且在涂层的底部区域形成了众多的柱状晶，涂层中包含了Ti₅Si₃与Al₃Ni₂两种主要成分。涂层的耐高温氧化性能优于钛合金，经过40 h的高温氧化处理后，粉末涂层的质量增加值是2.19 mg·cm-2，比Ti4合金的耐高温氧化性能提高了12倍左右。在860℃下进行40 h氧化处理，涂层与氧化膜之间保持紧密结合状态，未看到有脱落情况出现，氧化膜的主要成分是Al₂O₃。

Study on microstructures and high temperature oxidation resistance of Ti-based NiAlSi alloy by laser cladding

The NiAlSi coating on Ti4 alloy surface was generated by laser cladding, the phase composition, microstructures, and oxidation resistance at 860 of the Ti℃ -based NiAlSi alloy were analyzed. The results show that, the fusion line is present at the interface of Ti4 ally and coating, which can be deduced that there is a good metallurgical combination between titanium alloy and coating. The numerous columnar crystals are formed in the coating bottom, and the major components of coating are composed of Ti₅Si₃ and Al₃Ni₂. The coating has higher oxidation resistance than titanium alloy. After high-temperature oxidation treatment for 40 h, the mass increase of coating is 2.19 mg·cm-2, which is about 12 times higher than that of Ti4 alloy. After the oxidation treatment for 40 h at 860℃, the combination between coating and oxide film remains tied closely without peeling, and the main component of oxide film is Al₂O₃.