激光熔覆纳米SiC增强Ni基合金涂层的组织与高温抗氧化性能

Reinforced Microstructure and High Temperature Oxidation Resistance of Ni-based Alloy Coating by Laser Cladding of SiC Nanometer Powder

目的揭示添加纳米粉体对激光熔覆涂层高温防护性能的影响。方法以NiCoCrAlY合金粉末为熔覆材料，添加纳米SiC粉体，在GH4037合金表面激光熔覆纳米SiC增强Ni基合金涂层．对熔覆层表面及界面区进行显微组织分析，并进行1070℃下的高温抗氧化性实验。结果加入纳米SiC粉体的激光熔覆涂层组织明显细化，界面区未出现明显缺陷，其高温氧化速率远远低于未加纳米粉体的涂层．氧化膜致密，抗剥落能力显著增强。结论添加适量纳米SiC粉体对Ni基合金激光熔覆层的组织具有明显细化作用，对界面区裂纹的产生有一定的抑制作用．使得熔覆层的高温抗氧化性能显薯提高．

Objective To reveal the influence of nanometer powders on the high temperature protection performance of laser cladding. Methods Using NiCoCrA1Y alloy powder as cladding material and with addition of SiC nanometer powders, laser cladding of SiC nanometer powders was conducted on the surface of GH4037 alloy to reinforce the Ni-Based alloy coating. The mierostructure of the cladding layer and the interface region was analyzed, and the high temperature oxidation resistance was tested at 1070 ℃. Results The results showed that the microstructure of laser cladding coating with the addition of SiC nanometer powders was obvi- ously refined, without any obvious flaws in its laser cladding interface region, its high-temperature oxidation rate was much lower than that of the layer without adding nanometer powders, its oxide film was dense and its anti-stripping capability was significantly enhanced. Conclusion The microstructure of the Ni-Based alloy laser cladding was obviously refined by adding appropriate amountof SiC nanometer powders, which could also inhibit crack formation in the interface region. The high temperature oxidation resist ance of the laser cladding was significantly improved.