Plasma-Sprayed Al Alloy Coating with Enhanced Lamellar Bonding Through Novel Self-Bonding Strategy

Plasma spraying was employed to deposit an Al coating in order to create a self-metallurgical bonding effect through impact-induced melting with highly overheated molten droplets. Numerical simulation was employed to estimate the interface temperature between the molten Al splat and the Al substrate. The interface bonding was examined from cross sections of the Al splat and the etched coatings. The results show that, with Al droplets higher than 1800°C, impact-induced Al substrate melting occurs. The measurements showed that, during spraying, most Al particles were heated to temperatures theoretically causing an impact-induced melting effect, which subsequently produces a metallurgical self-bonding effect. The observed results confirm the metallurgical bonding in plasma-sprayed Al coating.