大功率等离子喷涂枪的设计

针对等离子喷涂大功率化的要求，设计了大功率等离子喷涂枪，利用二次喷嘴，功率可达100kW以上，喷嘴管型采用拉筏儿管，使等离子焰流速度达到超音速，出口的焰流为匀直流，利用双水内冷，分别调节钨极与喷嘴的冷动水流量，从而控制等离子流的热焓，有效提高了能源利用率，延长了喷枪的使用寿命。     

电弧喷涂枪的研究与设计

研究了喷涂电弧特点、喷嘴理论以及目前国内外最常用电弧喷涂枪的结构及其特点，提出了2种改进设计方案，最后介绍了电弧喷涂喷枪的最新发展状况。     

Optimal design of a novel cold spray gun nozzle at a limited space

Numerical analysis for the accelerating behavior of spray particles in cold spraying is conducted using a computational fluid dynamics program, FLUENT. The optimal design of the spray gun nozzle is achieved based on simulation results to solve the problem of coating for the limited inner wall of a small cylinder or pipe. It is found that the nozzle expansion ratio, particle size, accelerating gas type, operating pressure, and temperature are main factors influencing the accelerating behavior of spray particles in a limited space. The experimental results using the designed short nozzle with a whole gun length of <70 mm confirmed the feasibility of optimal design for a spray gun nozzle used in a limited space.     

Properties of alumina-based coatings deposited by plasma spray and detonation gun spray processes

Alumina, Al₂O₃ + 3 to 40 wt% TiO₂, and Al₂O₃ + 40 wt% ZrO₂ coatings were deposited by atmospheric plasma spraying (APS) and detonation gun spraying (DGS). The coatings were evaluated by optical microscopy, microhardness measurements, and X- ray diffraction. Wear resistance of the coatings was evaluated by rubber wheel sand abrasion and particle erosion test methods. Detonation gun- sprayed coatings exhibited more homogeneous microstructures and somewhat higher microhardness than corresponding plasma- sprayed coatings. Small additions of TiO₂ (3 wt%) improved both the abrasion and erosion wear resistance, whereas 40 wt% TiO₂ significantly decreased the erosion wear resistance of both APS and DGS coatings. Alumina + 40% ZrO₂ coatings exhibited the best abrasion wear resistance of both APS and DGS coatings, but the erosion wear resistance of these coatings was lower than that of the Al₂O₃ and Al₂O₃ + 3 wt% TiO₂ coatings. The best abrasion wear resistance of the coatings studied was obtained with DGS Al₂O₃ + 40 wt% ZrO₂ and Al₂O₃ + 3 to 40 wt% TiCh coatings. These coatings exhibited lower wear rates than bulk Al₂O₃. The best erosion wear resistance was obtained with the DGS Al₂O₃ + 3 wt% TiO₂ coating; however, it exhibited a higher wear rate than bulk Al₂O₃. In general, detonation gun- sprayed coatings showed significantly enhanced abrasion and erosion wear resistance than the corresponding plasma- sprayed coatings.     

可送粉末复合式电弧喷涂枪的设计

基于针对电弧喷涂应用的局限性,设计了一种能有效结合电弧喷涂和火焰喷涂优点的复合式电孤喷涂枪.该喷涂枪设有一个送粉装置,可同时实现电弧喷涂和粉末喷涂,扩大了电弧喷涂的应用范围.通过改变合金粉末的种类和送入量,实现不同性能要求的复合涂层的制备.