Re对Ni和Ni3Al 结构稳定性影响的分子动力学模拟研究

应用分子动力学方法模拟研究了Re在Ni和Ni3Al中的分布及其对材料微结构的影响.研究发现,Re的添加量影响Ni和Ni3Al晶体中空位的产生,但Re在Ni中对体系结构的破坏程度小于其在Ni3Al中占据Ni位时的程度.在Ni中,Re添加量较少且增大空位比时,其结构依然能保持稳定;随着Re数目的增多,空位比的增大,其影响逐渐变得明显.Re在Ni3Al中占据Ni,Re含量或空位比较小时,结构皆会出现局部不稳定.随着Re添加量的增多,结构的破坏程度加剧.然而Re占据Ni3Al中的Al位时其结构并未发生明显的变化,直至Re的添加量大至1%和空位比增至1%～1.5%时体系中才出现局部不稳定.相比而言,Re置换Al比置换Ni时对体系结构的影响较弱,在Ni3Al中Re占据Al位比占据Ni位更稳定.

Effect of Re on the Structure Stability of Ni and Ni3Al: A Molecular Dynamics Study

Molecular dynamic simulation was used to study the distribution of Re atoms in Ni and Ni3Al and its effect on the microstructure of Ni and Ni3Al.It was found that the content of Re markedly affected the formation of vacancies both in bulk Ni and Ni3Al.Doping Re at the Ni site, the damage on the Ni bulk was weaker than that on Ni3Al.The structures were stable when the content of Re was small in Ni.The damage became obvious when the content of Re increased.When doping Re at the Ni site in Ni3Al, the effect was more obvious.However, the damage on the Ni3Al bulk was very weak when Re atoms occupied the Al sites in Ni3Al.The effect became obvious as the content of Re was 1.0 % and the ratio of vacancy to atoms was about 1.0 %.Re atoms preferred the Al sites to the Ni sites in Ni3Al, and the damage of Re occupying the Al sites in Ni3Al was weaker than that occupying the Ni sites in Ni3Al.