The interfacial restructuring to amorphous: A new adhesion mechanism of cold-sprayed coatings

A new plausible adhesion mechanism of cold-sprayed coatings on hard, non-deformable substrates was proposed. Interface analysis of both the heavy (Cu) and light (Al) metal coatings on the ceramic substrates such as AIN and ZrO2 showed that the amorphous cascade volume fractions were created on impact. Furthermore, these amorphous volume fractions provided the channels for quick and effective atomic level intermixing to yield high bond strength in the cold spray process. The important parameters to determine the total amorphous cascade volume were relative hardness, mechanical deformability and density of colliding particles. Therefore, the final bonding strength would be predicted based on the fit between these parameters for coating and substrate materials. (C) 2016 Elsevier B.V. All rights reserved.