Influence of heat treatment on microstructure of laser powder deposited Ni20Al30Fe intermetallic alloy Available to Purchase

Ni20Al30Fe intermetallic alloy was synthesized by laser powder deposition. Heat treatment experiments on the synthesized layer were conducted at different heat temperature and time to investigate the microstructure evolution. The results indicate that laser deposited Ni20Al30Fe intermetallic alloy consists of β phase and a few γ phase particles. The sizes of the crystal grains are within 30-50µm. After heat treatment at 650°C and 850°C, more γ phase precipitates in particle-shape and strip-shape within the crystal grains or along the crystal boundaries. With the increase of heat temperature and isothermal holding time, the sizes and amount of the γ phase increase. At the same time, the sub-crystal grains combine and grow, the sub-crystal boundaries disappear. The precipitation of the γ phase is favorable to the improvement of ductility of the Ni20Al30Fe intermetallic alloy. After heat treatment at 1050°C, recrystallization of the crystal grains occurs, which results in the refinement of the microstructure.