W. Liuying, W. Hangong, H. Shaochun, C. Xiaoping, Xi’an Research Institute of Hi-Tech, Xi’an, China
According to “expert in one thing and good at many ”, multi-functional micro-plasma spraying system have been developed. It not only possesses spraying function, but also used such as welding, cutting and quenching etc. The micro-plasma spraying gun adopted unique passage and spraying nozzle structure and center axial to be sent the powder method. High frequency inverse technology of IGBT and micro-computer control engineering and varying the gentle switch technology are used in design of power, which possesses the characteristics of small volume, light weight, strong anti-jamming and high reliability etc. It is widely used in preparing coatings of metal and carbide ceramic and oxide ceramic. The bonding strength and porosity and hardness of coatings produced by micro-plasma spraying are superior to the same coatings produced by ordinary plasma spraying. It possesses vast application foreground in the fields, such as industry, national defence and aviation etc.
Summary: According to aerodynamics, plasma spray theory and “expert in one thing and good at many ”, multi-functional micro-plasma spraying systems have been developed. The IGBT inverse technology, micro-computer control engineering, gentle switch technology, Laval nozzle structure and center axial powder feed have been adopted in the designs of micro-plasma spraying systems, which make it possess the characteristics of small volume, light weight, strong anti-jamming, accurate control, high velocity of spray particles, high deposit efficiency of powder and high reliability etc. The system can produce different kinds of high quality coatings. The experimental results show that the bonding strength and microhardness of nano-structured Al2O3＋13%TiO2 coatings produced by multi-functional micro-plasma spraying are superior to the same coatings produced by 9M plasma spraying. As the result, the coatings with the identical properties as those of the coatings produced by conventional plasma spray can also be deposited by multi-functional micro-plasma spraying on condition of lower power by means of improving power design, spray gun structure and powder feed method. Moreover, this system possesses the functions of welding, cutting and quenching besides plasma spray.
