Experimental Study on the Effect of Gradient Interface on the Mechanical Properties of Cu/WCP Functionally Gradient Materials Using Digital Image Correlation Technique

In order to investigate the effect of gradient interface on the mechanical properties of Cu/WC_P functional gradient materials, digital image correlation technique was used to analyze the mechanical characteristics of laminated Cu/WC_P functional gradient material under tension load in the layer direction. In this paper, the deformation information of the specimens is obtained by the digital image correlation method. In order to obtain high-precision measurement results, speckle patterns with small spots and uniform distribution are prepared on the specimen surface by using small sample speckle preparation technology. The tensile experimental results showed that the incorporation of WC particles significantly improved the stiffness and strength of Cu/WC_P composites. Meanwhile, the plastic strain and plastic strain rate are non-uniform in each layer of the five-layer Cu/WC_P functional gradient material under the tension load along the layer direction. The plastic strain and plastic strain rate in each layer gradually increase along with the decreasing direction of WC content. It is found, from the analysis of experimental results, the existence of the gradient interface has an obvious inhibitory effect on the increase in plastic strain rate along the decreasing direction of WC content, and the specimen fracture location also has a certain relationship with the plastic strain rate, which reflects the important influence of the gradient interface on the mechanical properties of Cu/WC_P functional gradient materials.