Coarsening behavior of γ’ and γ’’ phases in GH4169 superalloy by electric field treatment
来源期刊：International Journal of Minerals Metallurgy and Materials2013年第9期
论文作者：Lei Wang Yao Wang Yang Liu Xiu Song Xu-dong Lü Bei-jiang Zhang
文章页码：861 - 866
摘 要：The coarsening behaviors of γ’ and γ’’ phases in GH4169 alloy aged at 1023 and 1073 K with electric feld treatment（EFT） were investigated by transmission electron microscopy（TEM） and positron annihilation lifetime spectroscopy（PALS）.It is demonstrated that precipitation coarsening occurs,and the growth activation energies of γ’ and γ’’ phases can be decreased to 115.6 and 198.1 kJ·mol-1,respectively,by applying the electric feld.The formation of a large number of vacancies in the matrix is induced by EFT.Due to the occurrence of vacancy migration,the difusion coefcients of Al and Nb atoms are increased to be 1.6-5.0 times larger than those without EFT at 1023 or 1073 K.Furthermore,the formation of vacancy clusters is promoted by EFT,and the increase in strain energy for the coarsening of γ’ and γ’’ phases can be counterbalanced by the formation of vacancy clusters.
Lei Wang1，Yao Wang1，Yang Liu1，Xiu Song1，Xu-dong Lü2，Bei-jiang Zhang2
1. Key Laboratory for Anisotropy and Texture of Materials, Northeastern University2. Department of High-temperature Materials, Central Iron and Steel Research Institute
摘 要：The coarsening behaviors of γ’ and γ’’ phases in GH4169 alloy aged at 1023 and 1073 K with electric feld treatment（EFT） were investigated by transmission electron microscopy（TEM） and positron annihilation lifetime spectroscopy（PALS）.It is demonstrated that precipitation coarsening occurs,and the growth activation energies of γ’ and γ’’ phases can be decreased to 115.6 and 198.1 kJ·mol-1,respectively,by applying the electric feld.The formation of a large number of vacancies in the matrix is induced by EFT.Due to the occurrence of vacancy migration,the difusion coefcients of Al and Nb atoms are increased to be 1.6-5.0 times larger than those without EFT at 1023 or 1073 K.Furthermore,the formation of vacancy clusters is promoted by EFT,and the increase in strain energy for the coarsening of γ’ and γ’’ phases can be counterbalanced by the formation of vacancy clusters.
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