Mechanical and fatigue properties of diamond reinforced Cu and Al metal matrix composites prepared by cold spray

Diamond reinforced composites prepared via cold spray are emerging materials featuring outstanding thermal conductivity and wear resistance at the same time. The mechanical and fatigue properties relevant for perspective engineering applications were investigated using miniature bending specimens. Two different mass concentrations of diamond 20% and 50% were compared with pure metallic cold sprayed specimens. The pure Al matrix showed significant ductility whereas the ductility of Cu was limited. The diamond addition significantly improved fracture toughness of Cu based composites, having small effect on fatigue crack growth resistance. For Al composites both fatigue crack growth resistance and fracture toughness was improved. The static and fatigue failure mechanisms were fractographicaly described and related to the microstructure of the coatings.