Study On Preparing Technique Of Arc Spraying Al₂O₃/al Multi-Cored Composite Wire

Composite cored wire combines the advantages of solid wire and powder particles. It can be used to obtain special coatings. But it also has disadvantages which is the content of the powder particles in the coating is small and not distributed evenly.In this study, in order to improve the uniformity of coating, the concept of Multi-core technology is proposed firstly. The aim of using the Multi-core technology is to improve the uniformity of the coating. Design parameters and process parameters were studied to find the effect of composite cored wire and coating performance. In this experiment single-core, seven-core, nineteen-core composite multi-core wire was designed by metal-based Al₂O₃/Al Composite cored to verify the uniformity of the distribution of the powder particles in the coating.In this experiment, drawing round tubes technique was used to investigate arc spraying metal-based Al₂O₃/Al composite cored wire. In the course of our drawing surface hardness and thickness of the tube and powder density are detected. The results showed that the surface hardness of the tube is effected by tube wall, mold and powder; The variation of tube wall thickness is different with theoretical calculations;Powder density fluctuates in the drawing process.The XRD and SEM results showed that multi-core technology can increase the content of Al₂O₃ in coatings. The SEM results showed there is a small phenomenon of Al₂O₃ gathered in the seven-core composite coating and nineteen-core composite coating. The SEM results showed Al₂O₃ volume in the seven-core composite coating is more than those in nineteen-core composite coating, it can be explained that the proportion of Al₂O₃ in the seven composite cored wire is higher than nineteen composite cored wire. It is because the proportion of Al₂O₃ in the seven composite cored wire is higher than nineteen composite cored wire.The results show that Multi-core composite drawing technology can be used for preparing wire arc spraying material, which possess optimal technical applicability.The uniformity of the resulting coating microstructure is better than that of single cored wire.