Fabrication and microstructure of Cu(Al)-diamond composites reinforced with Cr3C2 and Al2O3 synthesized in-situ

Cu-diamond composites (CDCS) possess great potential in thermal management materials. However, they face critical scientific challenges, including weak interfacial bonding and poor high-temperature performance of the Cu matrix. To improve the bonding at the Cu-diamond interface and to construct a structure of ceramic-reinforced matrix, this study employed Cr2AlC and Cu-coated diamond powders as the raw materials to prepare the composites sintered at 970 °C via vacuum hot-press sintering. Cu(Al)-diamond composites co-reinforced with Cr3C2 and Al2O3 (CDCSCA) were successfully fabricated. Microstructure results obtained by XRD, SEM, and EDS indicate that Cr2AlC decomposes within the composites during sintering to form Cr3C2 and promotes the formation of Al2O3, which together act as ceramic phases embedded in the Cu(Al) matrix to improve its high-temperature performance. In addition, Cr2AlC promotes the formation of a Cr3C2 interfacial layer at the Cu(Al) matrix-diamond interface, thereby improving the interfacial bonding.