Enhanced mechanical properties in diamond/Cu composites with chromium carbide coating for structural applications

Cr7C3-coated diamond particles are used to improve the interfacial bonding and mechanical properties of diamond/Cu composites, which are prepared by the pressure infiltration technique. The characteristics of Cr7C3 coating were investigated by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results show that a Cr7C3 coating layer between the diamond and Cu matrix greatly improves their interfacial bonding, which in turn helps distribute the external load from matrix to diamonds and enhances Young's modulus and tensile strength of the composites. The measured Young's modulus agrees reasonably well with the predictions by a differential effective-medium (DEM) model.