Effect of substrate preheating on bonding strength of cold-sprayed Mg coatings

A poor bonding strength between the magnesium coating and substrate limits magnesium coating's application. This paper aims at improving the bonding strength between the coating and substrate using substrate preheating. Aluminum substrates were heated to 100, 200 and 300 °C by a flame nozzle prior to cold spraying. The effects of substrate preheating on the microstructure and bonding strength were studied. The deformation behavior of single particles was simulated by a commercial software ABAQUS, and observed using SEM. The results show that substrate preheating can increase the bonding strength significantly. The bonding strength increased from 3.3 ± 0.8 to 11.6 ± 0.5 MPa when the substrate temperature increased from room-temperature to 200 °C. The fracture analyses show that the coating fracture occurred within the coating when the substrate was preheated at 200 °C.