Effect of Spray Angle on Adhesion Strength of Aluminum Coating and Particle Impact Behavior on Glass and Ceramic Substrate in Cold Spray

摘要

Coating adhesion is a critical factor on coating technology. However, the adhesion mechanism of cold sprayed coating and substrate has not understood sufficiently yet. Generally, shear localization that occurs at the interface between a particle and a substrate during particle impact has a notable effect on adhesion strength of cold sprayed coatings. In this study, spray angle is focused to improve the shearing area and force. And also, the effects of spray angle, substrate hardness and surface roughness on adhesion strength of aluminum coatings were investigated. The spray angle was varied to two different levels: 60 and 90 degree. Used substrate materials were soda glass and ceramics, such as, alumina (Al_2O_3) and silicon nitride (Si_3N_4). In addition, morphology of individual aluminum particles and coatings were observed. As a result, the adhesion strength of the aluminum coating on various substrates increased with the spray angle change from 90 degree to 60 degree. Then, it is shown that the adhesion strength of the aluminum coating on the Al_2O_3 substrate is higher than that of it on the Si_3N_4 substrate. The morphology of aluminum particles varied depending on the spray angle.