Fabrication and characterization of highly thermal conductive Si3N4/diamond composite materials

Abstract

A novel composite materials using silicon nitride (Si3N4) as the substrate and diamond particles as the reinforcement phase were developed to increase both thermal conductivity and mechanical properties. The Ti coating on the surfaces of the diamond particles facilitated the formation of a titanium carbonitride (TiCiN1-i) interface between the two constituents during sintering, creating a strong bonding for high thermal conduction at the diamond-Si3N4 interface and inhibiting the graphitization of diamond during the sintering process. Furthermore, a sandwiched material design was made whereby Si3N4 and Si3N4/Ti-coated diamond layers were stacked alternately to endow the composites with a directional heat conduction characteristic. The thermal conductivity of the fabricated Si3N4/diamond composites increased by up to 272.87 % compared to that of commercially available Si3N4, making them excellent candidates for thermal management materials required in high-performance electronic devices.

Keywords

• Silicon nitride
• Diamond particle
• Multilayer structure
• Chemical bonding interface
• Thermal conductivity