Metallized diamond deposition and heat transfer characteristics in supersonic laser deposited diamond/Cu composite coating

With increasing integration of electronic devices, localized heat flux has exceeded 1000 W/cm², necessitating advanced thermal management solutions. Conventional metallic materials such as Cu–Mo, Cu–W, and Al/SiC lack sufficient thermal conductivity and often suffer delamination under thermal stress, limiting reliability. Diamond/Cu composites are considered next-generation heat spreaders due to diamond’s ultrahigh thermal conductivity (~2200 W·m⁻¹·K⁻¹) and low thermal expansion coefficient (1.2 × 10⁻⁶ K⁻¹), which closely matches semiconductor substrates. However, poor wettability and phonon mismatch at the diamond/Cu interface result in high interfacial resistance, restricting performance (typically ~133 W·m⁻¹·K⁻¹ without modification). Metallization with elements such as Cr, Ti, or W can suppress diamond graphitization, reduce acoustic impedance mismatch, and enhance interfacial thermal conductance.

Conventional fabrication methods, including solid-state sintering and liquid-phase infiltration, are limited by porosity, graphitization, substrate size, and cost. Cold spray (CS) offers a low-temperature alternative, but low-pressure CS produces porous coatings, while high-pressure CS requires bulky, costly systems. Supersonic laser deposition (SLD), integrating laser heating with CS, reduces particle critical velocity, improves bonding, and broadens processability. While SLD has been applied to metals and ceramics, its application to diamond-reinforced composites remains underexplored. 

This study aims to enhance interfacial heat transfer in diamond/Cu composites by combining diamond metallization with laser-assisted low-pressure cold spray (SLD). Cr-coated diamond and Cu mixed powders were deposited via SLD to synthesize composite coatings. The deposition behavior of metallized diamonds under laser irradiation was examined, and interfacial structures were characterized to correlate with thermal transport properties. Thermal conductivity was predicted and validated against experimental measurements. SLD enables low-temperature fabrication while preserving diamond crystallinity and mitigating interfacial resistance through metallization, thereby achieving efficient deposition of high-conductivity coatings. The proposed approach provides a scalable pathway for advanced thermal management materials in electronic device cooling, where simultaneous high thermal conductivity and structural stability are critical.

 #diamond/Cu composite 

#copper and diamond

#heatsink