目的 了解等离子喷涂涂层过程中的晶须偏转行为,为提高涂层的抗冲蚀性能提供新思路。方法 分别采用计算力体动力学软件 FLUENT 和有限元分析软件 ANSYS,模拟研究等离子喷涂熔滴碰撞基体后的扁平过程,以及熔滴扁平期间晶须在力矩作用下的偏转行为。 结果 熔滴碰撞基体后,可以观察到熔滴的扁平化过程大约持续 1. 5 μs。 在力矩从 1×10-18 N·m 变化到 3×10-18 N·m 时,最大偏转角度从 23°增长到 70°。 结论 通过研究熔滴形状和最大扁平速度随时间的变化,得到了扁平化完成时间。熔滴沿基体表面的最大铺展速度与碰撞速度有关。 当力矩在一定范围内改变时,晶须发生偏转。

Objective To research the deflection of the whisker in the plasma sprayed alumina coatings, thus provide new ideas to enhance the erosion resistance. Methods The flattening of plasma sprayed droplets was simulated by FLUENT software after the droplets impacted on a flat substrate. And the deflection of whisker was characterized using ANSYS software during the flattening process of droplets. Results The flattening of droplets was observed after the impact which lasted about 1. 5 μs. When the moment shifted in the range of 1×10 -18 to 3×10 -18 N·m, the maximum deflection angle was increased from 23° to 70°. Conclusion The finish-time of flattening is obtained by studying the effect of impacting duration on the droplet shape and maximum flattening velocity. The flattening velocity of droplet flow along the substrate surface is affected by the impact velocity. Deflection of whisker occurs when the moment is changed in certain range.