Bonding Mechanism in Cold-sprayed Coatings: Localized Interatomic Bonds

 it is widely demonstrated that bonding between particles in the cold-sprayed coating is result of impact-induced extensive deformation in the interfacial area. However, the main mechanism of bonding has been still obscure. This present work is attempting to supply evidences of localized interatomic bonds between particles in the light of both theory and experiment. The metallic bonding energy differences between Me-O (bonding energy of metallic and oxygen atoms) and Me-Me (bonding energy of metallic atoms) indicated a preferential trend of breaking down of Me-Me bonds and therefore a new interatomic bond was established. The hypothesis was also discussed in terms of dynamics, in which data of numerical modeling was utilized. In addition,    interfacial regions of cold-sprayed composite coating were observed by TEM. The results revealed that whether recrystallization occurred in these places was determined by development of metallic bonding between particles.