Residual Stress Characteristics Thermal Sprayed Aluminum Coatings
Abstract:The thermal spraying process is widely used to the metalizing of electronic ceramic for forming the electric conductor and/or the under layer for bonding. However, residual stress Characteristics of thermal sprayed coatings, which have an important effect on the adherent strength, have not always been clarified. Thermal and mechanical properties were measured for two kinds of thermal sprayed aluminum coatings, which were formed by an atmospheric. plasma spraying (APS) process and an electric arc spraying (EAS) process for investigating the characteristics of residual stress. It was confirmed by the X-ray diffraction technique that the residual stress of sprayed aluminum coatings over zinc-oxide substrate was always compressive in no relation to the spraying process and coating thickness. It was found that the compressive residual stress of sprayed aluminum coatings was induced by the low thermal conduction effect of zinc-oxide substrate. Key Words:Atmospheric plasma spraying, Electric arc spraying, Aluminum coating, Residual stress, X-ray diffraction technique, Thermal conductivity