喷涂工艺参数对Y_2O_3飞行粒子状态及涂层性能的影响

Influence of Spraying Parameters on State of In-flight Yttrium Oxide Particles and Property of Coating

使用大气等离子喷涂方法制备氧化钇涂层并进行结构和形貌表征。结果表明,喷涂后,Y2O3涂层基本保持Y2O3粉末的单一立方相结构,仅有少量向单斜相发生转变,Y2O3粉末充分熔融,仅有极少数未熔颗粒。利用AccuraSpray-g3在线监测系统对不同喷涂参数条件下Y2O3飞行粒子的速度和温度进行监测发现,通过改变电流和电压调节功率的效果不同:增大电流时,Y2O3粒子的速度、温度均有提升;增大电压时,Y2O3粒子的速度得到提升,温度反而有所降低。相比于普通90°角外送粉方式,75°角外送粉方式主要提高了粒子的温度,速度无显著变化;而内送粉方式则主要提高了粒子的速度,温度无显著变化。受Y2O3飞行粒子的状态和热传递时间等综合因素的影响,Y2O3涂层与Al基底的结合强度随喷涂距离的增大呈现先提高后降低的特点,在180 mm处出现极大值。

Y2O3 coating was prepared by atmospheric plasma spraying method and the structure and morphology were characterized. The results show that the Y2O3 coating mainly keeps the cubic phase owned the Y2O3 powder after spraying, and that only a little transforms from cubic to monoclinic. The Y2O3 powder melted sufficiently and only little unmelted. The velocity and temperature of in-flight Y2O3 particles in different spraying parameters are monitored by Accura Spray-g3 on-line monitoring system. It reveals that the influences are different with the change of current and voltage. The velocity and temperature of Y2O3 particles are both promoted when the current increass, while the velocity of Y2O3 particles is promoted, on the contrary, the temperature of Y2O3 particles is lowered when the voltage increases. Compared with the 90° angle outside-beam powder feeding way, the 75~ angle outside-beam powder feeding way mainly promotes the particles temperature while the inside-beam powder feeding way mainly promotes the particles velocity. Affected by the composite factors of the state of in-flight Y2O3 particles and the heat transfer time, the bonding strength between Y2O3 coating and A1 substrate increases firstly and then decreases with the increase of spraying distance, and a maximum value appears at the spraying distance of 180 mm.