Enhanced wetting and properties of carbon/carbon-Cu composites with Cr3C2 coatings by Cr-solution immersion method

A facile ammonium-dichromate solution immersion method was introduced to synthesize the copper-wettable Cr3C2 coating on and inside the carbon-carbon (C/C) preform. The formation mechanism and the microstructures of the Cr3C2 coatings were studied. The contact angle between molten copper and the C/C decreased from 140° to 60°, demonstrating the significant improvement in the wettability. The Cr3C2-coated C/C-Cu composite with only 4.2% porosity and 3.69 g cm−3 density was manufactured through copper infiltration. As a result, the thermal and electrical conductivity of the modified C/C-Cu increased significantly due to the infiltrated copper. Also the mechanical properties of the composites including both the flexural and compressive strengths were enhanced by over 100%. The modified C/C-Cu composite exhibited lower friction coefficients and wear rates for different load levels than those of the commercial C/Cu composite. These results demonstrate the potential of the modified C/C-Cu material for use in electrical contacts.