不同孪晶界间距对截角八面体Pt力学性能的影响

Effect of Different Twin Boundary Spacing on the Mechanical Properties of Truncated Octahedral Pt

摘要: 本文通过分子动力学方法，研究了不同孪晶界间距对10 nm和20 nm截角八面体构型Pt晶粒的强化作用。本文研究了0.67 nm、1.55 nm、2.43 nm、3.31 nm、4.19 nm孪晶界间距在10 nm和20 nm晶粒拉伸过程中的力学性能和变形机制。研究结果表明，在10 nm晶粒和20 nm晶粒中均存在一个最优孪晶界间距，分别为1.55 nm和2.43 nm，拥有最好的力学性能，同时发现在临界孪晶界前后会产生变形机制的转化，位错由沿着孪晶界滑移转变为垂直孪晶界生长。本文通过分子动力学方法，研究了不同孪晶界间距对10 nm和20 nm截角八面体构型Pt晶粒的强化作用。本文研究了0.67 nm、1.55 nm、2.43 nm、3.31 nm、4.19 nm孪晶界间距在10 nm和20 nm晶粒拉伸过程中的力学性能和变形机制。研究结果表明，在10 nm晶粒和20 nm晶粒中均存在一个最优孪晶界间距，分别为1.55 nm和2.43 nm，拥有最好的力学性能，同时发现在临界孪晶界前后会产生变形机制的转化，位错由沿着孪晶界滑移转变为垂直孪晶界生长。

Abstract: In this paper, molecular dynamics method is used to study the strengthening effect of different twin boundary spacing on 10 nm and 20 nm truncated octahedral Pt grains. This paper studies the mechanical properties and deformation mechanisms of the 0.67 nm, 1.55 nm, 2.43 nm, 3.31 nm, 4.19 nm twin boundary spacing during the 10 nm and 20 nm grain stretching process. The research results show that there is an optimal twin boundary spacing in both 10 nm grains and 20 nm grains, 1.55 nm and 2.43 nm, respectively, which have the best mechanical properties. At the same time, it is found that deformation mechanisms occur before and after the critical twin boundaries. The dislocation is transformed from sliding along the twin boundary to vertical twin boundary growth.