First-Principles Study of the Influence of Lattice Misfit on the Behavior and the Ductility Effect of Hafnium in Ni-Ni3Al System
来源期刊：Acta Metallurgica Sinica2014年第1期
论文作者：Yuxi Wu Jia Guo Jieshan Hou Wanglin Zhang Renzhong Huang Xianguo Liu Xiufang Ma Qianfeng Zhang
文章页码：87 - 94
摘 要：Two Ni/Ni3Al-interface-contained cluster models with/without lattice misfit are studied by first-principles method to clarify the debates about the segregation behaviors of Hafnium（Hf） and explore the influence of lattice misfit on the ductility effect of Hf.It is found that though Hf prefers to substitute Al rather than Ni in Ni3Al phase within most of the investigated misfit range,its stronger preferring to Ni phase than Ni3Al phase makes it impossible to go into Ni3Al phase to occupy Al site in Ni-Ni3Al alloys.Bond order analysis in Hf-free case shows that lattice misfit has different effects on the Griffith work of interfacial cleavage 2γint/E and the maximum theoretical shear stress τmax of Ni and Ni3Al,contributing to the existence of anomalous strength-temperature phenomena in Ni3Al alloys.However,the addition of Hf will make the2γint/E(or τmax) of both Ni3Al and Ni decrease（or increase） with lattice misfit,indicating that the addition of Hf may make the anomalous strength-temperature relationship in Ni3Al region disappear locally.
Yuxi Wu1，Jia Guo1，Jieshan Hou2，Wanglin Zhang1，Renzhong Huang3，Xianguo Liu4，Xiufang Ma1，Qianfeng Zhang1
1. Institute of Molecular Engineering and Applied Chemistry,Anhui University of Technology2. Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences3. College of Physics Science and Technology,Shenyang Normal University,Huanghe Street 2534. School of Materials Science and Engineering,Anhui University of Technology
摘 要：Two Ni/Ni3Al-interface-contained cluster models with/without lattice misfit are studied by first-principles method to clarify the debates about the segregation behaviors of Hafnium（Hf） and explore the influence of lattice misfit on the ductility effect of Hf.It is found that though Hf prefers to substitute Al rather than Ni in Ni3Al phase within most of the investigated misfit range,its stronger preferring to Ni phase than Ni3Al phase makes it impossible to go into Ni3Al phase to occupy Al site in Ni-Ni3Al alloys.Bond order analysis in Hf-free case shows that lattice misfit has different effects on the Griffith work of interfacial cleavage 2γint/E and the maximum theoretical shear stress τmax of Ni and Ni3Al,contributing to the existence of anomalous strength-temperature phenomena in Ni3Al alloys.However,the addition of Hf will make the2γint/E(or τmax) of both Ni3Al and Ni decrease（or increase） with lattice misfit,indicating that the addition of Hf may make the anomalous strength-temperature relationship in Ni3Al region disappear locally.
关键词：
