Advanced Diamond-Reinforced Copper Composite Coatings Via Cold Spray and Material Characterization

Diamond-reinforced copper matrix composites (DCMC) have great potential for heat sink applications due to their excellent thermal properties. In this investigation, thick DCMC coatings were fabricated via cold spraying using copper-clad diamond powder or its mixture with copper powder. With pure clad diamond powder, the diamond in the original feedstock was almost completely retained in the coating, which contained more than 40 wt% diamond. With mechanically mixed clad diamond and Cu powder, the diamond fraction in the coating was even larger than that of the original feedstock. It was found that the added Cu powder acts as a buffer, effectively preventing the fracture of diamond in the coating.