Mechanical metallization of alumina substrate through shot impact treatment

The present study examines the potentialities of a novel surface treatment process for the metallization of ceramics. The process combines the principles of ball milling and shot peening using the energy of ultrasonic vibrations. Experiments were performed by using alumina and powdered nickel as a ceramic substrate and metallizing agent, respectively. The main emphasis was placed on characterizing the deposited films and elucidating their formation mechanisms. The results showed that 3-min impact treatment at ambient temperature and pressure leads to the formation of 2-4 μm thin, dense, and highly adherent films of nanostructured Ni on the surface of alumina substrate. SEM and TEM observations revealed a very tight contact between the deposited films and substrate suggesting the shot-impact induced plastic flow in the Ni film. It is assumed that the van der Waals interaction is the main origin of the high adhesion strength observed.