不锈钢基体温度对NiCrCoAlY 和ZrO2涂层颗粒变形的影响

研究了等离子喷涂过程中, 不同基体预热温度下NiCrCoAl Y金属与ZrO₂ 陶瓷颗粒的变形规律。结果表明: 基体无预热时, NiCrCoAl Y金属颗粒沉积形貌呈盘形, 并伴随边缘堆积和飞溅碎块等不规则现象, 影响后续颗粒的顺利铺展; 基体预热至200 ℃时, 不规则现象减少, 后续颗粒铺展良好。ZrO₂ 颗粒在基体无预热条件下凝固后呈圆盘状, 并产生龟裂纹和条束状溅射, 随着基体预热温度的升高, 龟裂和溅射现象减少。基体预热对NiCrCoAl Y涂层孔隙率影响不大, 而ZrO₂涂层在基体预热至200 ℃时孔隙率明显降低。 

Effects of stainless steel substrate temperature on flattening behaviorof plasma sprayed NiCrCoAlY and zirconia droplets

Effect s of subst rate temperature on flattening morphologies of NiCrCoAlY and zirconia droplets in plasmaspraying metal mat rix composites were studied by analyzing and comparing SEM micrographs. The result s showthat when depositing on the non-preheated polished stainless steel subst rate , the NiCrCoAl Y splat s are in disk-likeshape with piled edges and splashed fragments , which have inevitably influence on the following flattening droplets.If the subst rate is preheated up to 200 ℃, the piled edges and splashed fragments within NiCrCoAl Y splatsdecrease , and the flattening behavior of the following droplet s is improved. The zirconia splat morphology on thenon-preheated polished stainless steel subst rate is round in shape with crack and finger prolongation. The number ofcracks and finger prolongations reduces correspondingly with increasing the subst rate temperature. Furthermore ,when the subst rate is preheated up to 200 ℃, NiCrCoAlY coating porosity changes unapparently while the zirconiacoating porosity reduces profoundly.