激光熔覆纳米Al2O3颗粒增强Ni基合金涂层界面组织和高温热腐蚀性能

Interface Microstructure and High Temperature Corrosion of Nano-Al2O3 Particle Reinforced Ni-based Alloy Powder Laser Cladding

目的研究纳米颗粒对Ni基合金涂层抗热腐蚀性能的影响。方法采用压片预置式激光熔覆工艺，制备了纳米Al2O3颗粒增强的NiCoCrAlY合金涂层．对熔覆层界面区组织及裂纹进行了显微分析，进行了1000℃高温熔盐热腐蚀性能试验。结果加入纳米Al2O3颗粒的激光熔覆涂层界面区未出现明显缺陷，其热腐蚀失重速率远远低于未加纳米颗粒的涂层，腐蚀表面未出现严重的隆起和剥落，腐蚀层深度小。结论添加适量纳米Al2O3颗粒对NiCoCrAlY合金激光熔覆层界面区裂纹的形成有一定的抑制作用．可使熔覆层的抗高温热腐蚀性能明显提高。

Objective In order to study the effects of nanoparticles on the hot corrosion resistance of Ni-based al- loys cladding. Methods Nano-A12 03 particles reinforced NiCoCrA1Y alloy cladding was prepared using the tabletting preset laser cladding process. The microstrueture and interface cracks of cladding layer were analyzed, and high tem- perature corrosion was performed in the 1000 ℃ molten salt. Results The results showed that the laser cladding in- terface region prepared with addition of AlE03 particles did not show obvious flaws, compared to the layer prepared without addition of nanoparticles, its hot corrosion weight loss rate was much lower, its corrosion surface did not show serious uplift and flake, and its corrosion depth was low. Conclusion Addition of appropriate amount of nano-A12 0a particles had an inhibitory effect on the formation of cracks in the NiCoCrA1Y alloy laser cladding interface region. And the high temperature corrosion resistance of the laser cladding layer was significantly improved.