Microstructure and thermal conductivity of Cu–B/diamond composites

Abstract

This article considers the potential of boron as matrix-alloying element and gives perspectives about which content of boron is favorable to maximize the interfacial bonding and thermal conductivity of copper/diamond composites. The thermal conductivity of Cu–B/diamond composites is investigated both experimentally and theoretically. The thermal conductivity measurements show that the optimum boron content at 0.8 wt% has provided highest thermal conductivity of 538 W/mK, increases 190% compared to that of copper/diamond composite without boron addition. Theoretical models are used to understand the underlying thermal conductivity enhancement mechanisms of matrix alloying. It is found that the Hasselman–Johnson model combined with a modified Debye model considering the carbide thermal resistance can provide a satisfactory agreement to the experimental data.

High thermal conductivity through interfacial layer optimization in diamond particles dispersed Zr-alloyed Cu matrix composites

“…As shown in Fig. 3b, this value is extraordinarily high among the thermal conductivities reported for Cu/diamond composites so far [6,[13][14][15][16][17][18]20,25,28,29,31,32,[36][37][38][39][40][41]. The high thermal conductivity can be explained as follows.…”

“…A few studies [13,30,31] examined the interfacial features of Cu/diamond composites by transmission electron microscopy (TEM). Most studies assumed that the interfacial layer thickness varies with alloying element content in Cu matrix [12,32] or with coating thickness on diamond particles [6,11], but direct evidence of interfacial layer thickness is rarely presented. So far the correlation between composite thermal conductivity and interfacial layer thickness has not been explicitly established in the Cu/diamond composites.…”

Effect of boron addition on interface microstructure and thermal conductivity of Cu/diamond composites produced by high temperature–high pressure method

“…The thermal conductivity of 731 W m −1 K −1 is higher than reported values for CuB/diamond composites such as 490 W m −1 K −1 derived with a PW method and 538 W m −1 K −1 with a vacuum hot‐pressing method . The high thermal conductivity is attributed to high diamond volume fractions in the CuB/diamond composites achieved by the HTHP method.…”

“…It has become a key issue to enhance the interfacial bonding between diamond and Cu. Literature has proved that the addition of Zr, B, or Cr to Cu matrix can largely enhance the thermal conductivity of Cu/diamond composites produced by hot pressing, PW or SPS . Nevertheless, the effect of B addition on Cu/diamond composites produced with HTHP method is rarely reported.…”

Thermal conductivity of bulk nanocrystalline nickel-diamond composites produced by electrodeposition

“…In theory, P depends on the incident angle of the incoming phonon, but it was assumed to be constant in this study since its variation within the critical cone is negligible and does not significantly change h [8,49].…”