Effect of Orientation on Stress-Rupture Property and Related Deformation Microstructure of a Ni-Base Re-containing Single-Crystal Superalloy at 900 ℃
来源期刊：Acta Metallurgica Sinica2021年第5期
论文作者：Guang-Lei Wang Jin-Lai Liu Ji-De Liu Yi-Zhou Zhou Xu-Dong Sun Hai-Feng Zhang Xiao-Feng Sun
摘 要：Stress-rupture properties of a Ni-base Re-containing single-crystal superalloy with three orientations have been tested under 900 ℃/445 MPa. An obvious anisotropy of stress-rupture property is attributed to orientation reliant deformation microstructure. The good strength in [001] orientation is attributed to the rapid multiplication of dislocations active in horizontal channels and later γ’ cutting via dislocations pair coupled with anti-phase boundary. The microtwin formation largely limits the strength and plasticity as a result of the continuous shearing across γ/γ’ microstructure by {111} 112 slip activated in [011] orientation. The property in [111] orientation results mainly from the lateral cross-slip movements of the screw dislocations within connected matrix channels as well as the precipitate shearing by coplanar dislocations. Microcracks all initially originate from the interdendritic micropores in three orientations. The critical temperature of stress-rupture anisotropy could be increased by a high level of refractory solutes especially Re.
Guang-Lei Wang1,2，Jin-Lai Liu2，Ji-De Liu2，Yi-Zhou Zhou2，Xu-Dong Sun1，Hai-Feng Zhang1,2，Xiao-Feng Sun2
1. School of Materials Science and Engineering,Northeastern University2. Institute of Metal Research, Chinese Academy of Sciences
摘 要：Stress-rupture properties of a Ni-base Re-containing single-crystal superalloy with three orientations have been tested under 900 ℃/445 MPa. An obvious anisotropy of stress-rupture property is attributed to orientation reliant deformation microstructure. The good strength in [001] orientation is attributed to the rapid multiplication of dislocations active in horizontal channels and later γ’ cutting via dislocations pair coupled with anti-phase boundary. The microtwin formation largely limits the strength and plasticity as a result of the continuous shearing across γ/γ’ microstructure by {111} 112 slip activated in [011] orientation. The property in [111] orientation results mainly from the lateral cross-slip movements of the screw dislocations within connected matrix channels as well as the precipitate shearing by coplanar dislocations. Microcracks all initially originate from the interdendritic micropores in three orientations. The critical temperature of stress-rupture anisotropy could be increased by a high level of refractory solutes especially Re.
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