Interface Optimization and Thermal Conductivity of Cu/Diamond Composites by Spark Plasma Sintering Process

Area of Science:

• Materials Science
• Nanotechnology
• Thermal Engineering

Background:

• Copper/Diamond (Cu/Dia) composites are advanced thermal dissipation materials crucial for high-power electronics.
• The interface between copper and diamond significantly influences the composite's thermophysical properties.

Purpose of the Study:

• To investigate the effects of diamond particle size, sintering temperature, and chromium addition on Cu/Dia composite properties.
• To optimize the interface structure for enhanced thermal conductivity.

Main Methods:

• Fabrication of Cu/Dia composites using Spark Plasma Sintering (SPS).
• Systematic variation of diamond particle size (up to 200 μm) and sintering temperature (optimized at 900 °C).
• Addition of chromium (Cr) to the copper matrix to promote metallurgical bonding.

Main Results:

• Uniform diamond distribution achieved with 200 μm particles, reducing agglomeration.
• Optimal sintering at 900 °C enhanced interface bonding.
• Chromium addition formed Cr7C3, improving interface bonding from physical to metallurgical and increasing density.
• Thermal conductivity increased from 310 W/m K to 386 W/m K with optimized particle size.
• Further interface optimization resulted in a significant increase to 516 W/m K (66% improvement).

Conclusions:

• Diamond particle size and interface engineering are critical for Cu/Dia thermal performance.
• SPS is an effective method for fabricating high-performance Cu/Dia composites.
• Chromium addition is a viable strategy to achieve robust metallurgical bonding and superior thermal conductivity.