Integrated Laser Additive Manufacturing of α-Al2O3 Nanoparticle-Seeded β/γ' Ni-Al Intermetallic Alloy with Enhanced High-Temperature Oxidation Performance

作者：He, Xun; Shu, Xiaoyong; Zhou, Ziyi; Yang, Shouhua; You, Limei; Peng, Xiao^*

来源：Materials, 2023, 16(22): 7205.

DOI：10.3390/ma16227205

• oxidation
• laser deposition
• intermetallic compounds
• aluminum oxide
• surface modification

The oxidation of beta-NiAl at high temperatures leads to the preferential formation of metastable alumina, such as theta-Al2O3, which exhibits a significantly faster growth rate compared to stable alpha-Al2O3. However, our recent research has shown that through the use of the surface-dispersing nanoparticles (NPs) of metal oxides with a hexagonal closed pack (hcp), such as alpha-Al2O3, the thermal growth of alpha-Al2O3 can be facilitated. The present study employed laser additive manufacturing (LAM) to develop an integrated alpha-Al2O3 NPs surface-seeded two-phase intermetallic alloy comprising brittle beta-NiAl and tougher gamma'-Ni3Al, which demonstrated better comprehensive mechanical properties. It was found that seeding the alpha-Al2O3 NPs promoted the early stage growth of alpha-Al2O3 on both beta and gamma' phases during oxidation in air at 1000 degrees C. This led to a decrease in the oxidation rate but an enhancement in adhesion of the formed alumina scale in comparison to the naked beta/gamma' two-phase alloy. The reasons for this result were interpreted.

• 单位
  北京航空航天大学; 南昌航空大学