Ni含量梯度变化的Cu-Ni合金力学性能分子动力学模拟

Molecular Dynamics Simulations on Mechanical Properties of Cu-Ni Alloys with Gradient Distribution of Ni Content

摘要: 应用分子动力学方法模拟Ni成分梯度变化的纳米晶Cu-Ni合金在单向拉伸应变载荷下，合金的力学性能与微观结构变化过程。结果表明，随着Ni含量梯度的增加，Cu-Ni合金的弹性杨氏模量逐渐增加，而且Ni浓度梯度的改变会对合金的屈服强度以及延展性造成一定的影响。垂直于浓度梯度方向拉伸时，屈服阶段过后，合金内部裂纹首先在三叉晶界处产生，然后出现在Ni含量接近50%的区域。Ni浓度梯度非常大时，富Cu区域也较容易产生裂纹。

Abstract: Molecular dynamics (MD) simulations of nanocrystalline Cu-Ni alloys with different gradient dis-tribution of Ni content under uniaxial tensile straining were performed to study their deformation behaviors and mechanical properties. The results indicate that, with the increase of concentration gradient of the Ni, the elasticity young’s modulus of Cu-Ni alloy increases gradually, and the yield strength and ductility of the alloy were impacted by the change of Ni content. When tensile direc-tion perpendicular to the direction of concentration gradient, the cracks appeared in triple junction firstly after yield stage, and then in the area of Ni content close to 50 percent. When concentration gradient of Ni is very high, rich Cu area will crack easily.