碳纳米管增强镁基复合材料热残余应力的有限元分析

Finite element analysis of thermal residual stresses in magnesium matrix composite reinforced by carbon nanotubes

为了探寻Ni层厚度对镀镍碳纳米管增强AZ91D镁基复合材料(Ni-CNTs/AZ91D)中热残余应力的影响,在实验基础上,建立不同Ni层厚度时Ni-CNTs/AZ91D复合材料的有限元模型,模拟了Ni-CNTs/AZ91D复合材料中热残余应力的分布。研究发现:在碳纳米管表面镀镍能够明显降低Ni-CNTs/AZ91D复合材料中的热残余应力。Ni-CNTs/AZ91D复合材料中,热残余应力在Ni层厚度为6 nm时最小;Ni层厚度由2 nm增至6 nm时,热残余应力随着Ni层厚度的增加而减小;当Ni层厚度超过6 nm时热残余应力随着Ni层厚度的增加而增大。复合材料中热残余应力的最大值随碳纳米管表面Ni层厚度的增加向Ni层与基体的界面移动。

In order to explore the influence of Ni-coating thickness on the thermal residual stress in AZ91D magnesium matrix composite reinforced with Ni coated carbon nanotubes（Ni-CNTs/AZ91D）,the distribution of the thermal residual stresses in Ni-CNTs/AZ91D composite was simulated by using finite element method（FEM）based on some experiments.The results indicate that plating Ni on CNTs＇surface can greatly reduce the thermal residual stress of Ni-CNTs/AZ91D.For the Ni-CNTs/AZ91D composite materials,the thermal residual stress achieves the minimum at the thickness of Ni-coating is 6 nm.While the thickness of Ni-coating is varying from 2 nm to 6 nm,the thermal residual stress is diminished with the increase of the thickness of Ni-coating.Once the thickness of Ni-coating is larger than 6 nm,the thermal residual stress increases with increasing the thickness of Ni-coating.Moreover,the location of thermal residual stress＇s maximum moves toward the interface of Ni-coating and substrate with increasing of the thickness of Ni-coating.