Interfacial bonding of chromium-doped copper/diamond composites fabricated by powder metallurgy method

Abstract

Copper/diamond composites can be used as heat-sink materials for high-power electronic devices due to their potential high thermal conductivity. However, it is challenging to obtain well-bonded interface between the copper matrix and the diamond particles. In this paper, we fabricated copper/diamond composites with [Formula: see text] wt.% of chromium additive ([Formula: see text], 3 and 7.4, and the corresponding composite was referred to as 1Cr-Cu/Dia, 3Cr-Cu/Dia and 7Cr-Cu/Dia, respectively) by hot forging of powder preforms. Results showed that only Cr3C2 interfacial layer formed between the copper matrix and the diamond particles for the 1Cr-Cu/Dia and 3Cr-Cu/Dia composites with a thickness of about 100 and 500 nm, respectively. A Cr/Cr3C2 dual layer interface formed in the 7Cr-Cu/Dia composite and its thickness was [Formula: see text]m. The coverage of diamond surface by the interface layer increased with increasing the adding amount of chromium in the composites. The 3Cr-Cu/Dia composite achieved the highest relative density and bonding strength, comparing to 1Cr-Cu/Dia and 7Cr-Cu/Dia composites, attributed to the formation of an optimal interface structure.

High thermal conductive copper/diamond composites: state of the art

“…Compared to other fabrication methods, powder forging can rapidly and cost-effectively prepare copper/diamond composites without using expensive manufacturing equipment, and it offers an alternative and potentially more effective fabrication method for producing copper/diamond composites. Yang et al first applied the powder forging technique to producing copper/diamond composites from the powder mixture of artificial diamond and elemental copper powders [61][62][63][64]. The carbide-forming elements such as titanium and chromium are introduced in the materials system via adding alloying element powders in the powder mixture or precoated the alloying element on the diamond particle surface.…”

Tribological, mechanical and thermal response of diamond micro-particles reinforced copper matrix composites fabricated by powder metallurgy

“…It is noted that the addition of diamond particles in an optimum amount resulted in improved wear resistance of test samples (adding 1%wt diamond particle to the copper matrix gives the superlative result) [8]. The wear depends on the applied load, temperature, speed, and reinforcement behaviour.…”

“…The observations reported in the literature shows a relatively weak bond between pure copper matrix and the diamond powders in the final fabricated composite. The use of atomized copper alloy with optimum quantity of chromium to improve the bonding in Cu/diamond interface by a fine nano-sized Cr 3 C 2 layer facilitates the enhancement in the thermo-physical characteristics and bonding strength of the fabricated composites [8]. However, by adding a carbide producing element to the copper, such as chromium or boron, a suitable link between diamond and copper can be created [9].…”