Tailoring the thermal and mechanical properties of diamond/Cu composites by interface regulation of Cr alloying.

Copper matrix composites reinforced with 60 vol% diamond particles were prepared by pressure infiltration using Cu-Cr alloy with 0.3–1.0 wt% Cr. The x-ray diffraction, scanning electron microscopy, and transmission electron microscopy were conducted to characterize the Diamond/Cu composites interface. The interface structure evolves from the discontinuous point contact to continuous strip carbides depending on the availability of Cr source. With Cr content increasing, the thermal conductivity of the Diamond/Cu-Cr composites increases first and then decreases. The highest thermal conductivity of 696 W/mK was achieved at 0.5 wt% Cr addition, while the highest tensile strength and bending strength of 252 MPa and 523 MPa were achieved at 0.7 wt% Cr addition. By optimizing the interface thermal resistance and interface bonding strength, Diamond/Cu composites with excellent comprehensive properties can be obtained. [Display omitted] • An interface with low thermal resistance and high strength of Diamond/Cu composites is optimized. • The maximum thermal conductivity of 696 W/mK and the maximum bending strength of 523 MPa were achieved. • The Cr 3 C 2 -Cu interface is in atomic-level contact and chemically bonded. [ABSTRACT FROM AUTHOR]