High Density Diamond Copper Composite

 High-Density Diamond/Copper Composites

A high-density diamond/copper (diamond/Cu) composite with a high diamond volume fraction was fabricated through a combination of surface metallization, powder mixing, and spark plasma sintering (SPS). The process comprises the following steps:

1. Copper Electroplating on Diamond Particles:
   Diamond particles pre-coated with a thin iridium layer were subjected to electrochemical deposition of copper. The mass of the deposited copper was controlled to be between 50% and 200% of the mass of the iridium-coated diamond, ensuring sufficient interfacial bonding and thermal continuity.

2. Powder Mixing:
   The copper-coated diamond particles were homogeneously blended with pure copper powder using mechanical mixing techniques to ensure uniform distribution of the reinforcement phase.

3. Pre-Compaction:
   The mixed powder was loaded into a graphite die and subjected to uniaxial pre-compaction to form a green body with initial structural integrity.

4. Spark Plasma Sintering (SPS):
   The pre-compacted samples were sintered using the SPS technique under controlled temperature and pressure conditions. This method facilitates rapid densification while minimizing grain growth and thermal degradation of the diamond particles.

5. Post-Sintering Processing:
   After sintering, the bulk composite was demolded, followed by cutting and surface polishing to obtain specimens for characterization.

The resultant diamond/Cu composites exhibited a relative density exceeding 99%, indicating excellent densification. This approach enables the incorporation of a high volume fraction of diamond while maintaining favorable thermal and mechanical properties. Furthermore, the process is cost-effective and scalable, making it suitable for industrial applications where high thermal conductivity and mechanical strength are required.