梯度界面对Cu/WC_(P)功能梯度材料力学性能影响

The effect of gradient interface on the mechanical properties of Cu/WC_(P) functionally graded materials

为了研究梯度界面或层状梯度对Cu/WC_(P)功能梯度材料力学性能的影响,采用粉末冶金法制备了WC体积含量分别为3%、6%、9%、12%、15%的Cu/WC_(P)复合材料,利用数字图像相关方法结合拉伸实验研究了WC体积含量对Cu/WC_(P)复合材料拉伸性能的影响,并通过有限元方法模拟了5层Cu/WC_(P)功能梯度材料在沿层向方向拉伸作用下的变形特性及力学行为。拉伸实验结果表明:WC颗粒的掺入明显提高了Cu/WC_(P)复合材料的刚度和强度,但随WC颗粒含量的增加,Cu/WC_(P)复合材料的塑性变形能力明显下降,当应力为214 MPa时,3%WC体积分数Cu/WC_(P)复合材料的应变是15%体积分数Cu/WC_(P)复合材料的25.45倍。有限元分析结果表明:沿层向方向拉伸作用下,5层Cu/WC_(P)功能梯度材料各层内的塑性变形及应变率均呈现出非均匀性,塑性变形及应变率均沿WC含量递减的方向逐渐增大。另外,在梯度界面附近沿WC含量递减方向,梯度界面的存在对塑性应变率的增加有明显的抑制作用。

In order to study the effect of gradient interface or layered gradient on the mechanical properties of Cu/WC_(P)functionally graded materials,Cu/WC_(P)composites with WC volume contents of 3%,6%,9%,12%,and 15%were prepared by powder metallurgy.The effect of WC volume content on the tensile properties of Cu/WC_(P)composites was analyzed by using digital image correlation method combined with tensile experiments,and the deformation characteristics and mechanical behavior of the five-layer Cu/WC_(P)functional gradient material under the tensile action along the layer direction were simulated by finite element method.The tensile experimental results showed that the incorporation of WC particles significantly improved the stiffness and strength of Cu/WC_(P)composites,but the plastic deformation ability of Cu/WC_(P)composites decreased significantly with the increase of WC particle content,and the strain of 3%WC volume fraction Cu/WC_(P)composites was 25.45 times that of 15%WC volume fraction Cu/WC_(P)composites when the stress was 214 MPa.The results of finite element analysis showed that the plastic deformation and strain rate within each layer of the five-layer Cu/WC_(P)functional gradient material presented non-uniformity under the tensile action along the layer direction,and the plastic deformation and strain rate increased gradually in the direction of WC content decrease.In addition,the existence of the gradient interface near the gradient interface along the direction of WC content decrease had a significant inhibitory effect on the increase of plastic strain rate.This study has certain reference for the design of metal-based functional gradient functional materials and their applications.