Microstructure Evolution of Primary γ′ Phase in Ni3Al-Based Superalloy
来源期刊：Acta Metallurgica Sinica2020年第12期
论文作者：Xin He Jianbo Zhang Yuanyi Peng Jingan Li Jian Ding Chang Liu Xingchuan Xia Xueguang Chen Yongchang Liu
摘 要：In this work, water cooling, air cooling（AC） and furnace cooling（FC） were applied to investigate the effect of cooling rate on microstructure evolution of primary γ′ in a newly designed Ni3Al-based alloy. The results showed that nucleation rate of primary γ′ increased with increasing cooling rate. In addition, higher cooling rate shortened growth period of primaryγ′, which made its morphology close to the initial precipitated γ′. For AC and FC specimens, due to the lower cooling rate,primary γ′ possessed longer growth period and its morphology was mainly due to the evolution of lattice misfit between γand primary γ′. Meanwhile, growth of primary γ′ depended on lattice misfit distribution between its corner and edge area.Moreover, primary γ′ morphologies of sphere, cube and concave cube with tip corners were illustrated by considering interaction between elemental diffusion and elastic strain energy.
Xin He1，Jianbo Zhang1，Yuanyi Peng1，Jingan Li1，Jian Ding1，Chang Liu1，Xingchuan Xia1,2，Xueguang Chen1，Yongchang Liu2
1. School of Material Science and Engineering ,Hebei University of Technology2. School of Material Science and Engineering ,Tianjin University
摘 要：In this work, water cooling, air cooling（AC） and furnace cooling（FC） were applied to investigate the effect of cooling rate on microstructure evolution of primary γ′ in a newly designed Ni3Al-based alloy. The results showed that nucleation rate of primary γ′ increased with increasing cooling rate. In addition, higher cooling rate shortened growth period of primaryγ′, which made its morphology close to the initial precipitated γ′. For AC and FC specimens, due to the lower cooling rate,primary γ′ possessed longer growth period and its morphology was mainly due to the evolution of lattice misfit between γand primary γ′. Meanwhile, growth of primary γ′ depended on lattice misfit distribution between its corner and edge area.Moreover, primary γ′ morphologies of sphere, cube and concave cube with tip corners were illustrated by considering interaction between elemental diffusion and elastic strain energy.
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