Influence of spray gun parameters on inflight particle's characteristics, the splat-type distribution, and microstructure of plasma-sprayed YSZ coatings
Influence of spray gun parameters on inflight particle's characteristics, the splat-type distribution, and microstructure of plasma-sprayed YSZ coatings
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DOI：
10.1016/j.surfcoat.2020.126705
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发表时间：
2021
影响因子：
5.4
通讯作者：
W. Tillmann;O. Khalil;I. Baumann
中科院分区：
文献类型：
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作者：
W. Tillmann;O. Khalil;I. Baumann
采用大气等离子喷涂（APS）工艺制备的陶瓷涂层具有特殊的性能，被广泛应用于许多领域，其中孔隙率和飞溅界面是影响涂层性能的主要因素。由于涂层组织是由大量的熔融和半熔融颗粒成功地撞击在基体上组成，（称为飞溅），所产生的涂层的特征在于这些颗粒的熔融程度及其相对飞溅型分数。在本工作中，工艺参数设置的影响已经被系统地研究，将撞击颗粒的特性与飞溅形成以及最终与涂层的微观结构发展和性能相关联。因此，在镜面抛光的基底上收集单个飞溅物，并使用图像分析（IA）进行观察。在每种喷涂条件组合下，根据其熔融程度和形态，对这些进行评估并将其分类为不同的飞溅类型。结果表明，枪流和靶距对撞击粒子的特性有很大的影响。这些又决定了碎屑类型的相对比例、层状结构和存款的最终性质。研究了溅射型分布对层间结合强度、层状结构和涂层孔隙率的影响。
Ceramic coatings, fabricated with specific properties using the atmospheric plasma spray (APS) process, are widely used for many applications in which the porosity and splat interfaces are the main factors affecting the performance. Since the coating microstructure is composed of large numbers of molten and semi-molten particles impinged successfully at the substrate (known as splats), the produced coatings are characterized by the melting degree of these particles and their relative splat-type fractions.In the present work, the effect of process parameters settings has been studied systematically, relating the characteristics of impinging particles to splat formation and eventually to microstructure development and properties of the coating. Therefore, individual splats were collected on mirror-polished substrates and observed using image analysis (IA). These were evaluated and categorized into different splat types, based on their melting degree and morphology, under each combination of spray conditions. It was found that gun current and standoff distance have a profound effect on the characteristics of impinging particles. These, in turn, determine the relative fractions of splat types, layered structure, and final properties of the deposit. The effect of splat-type distribution on the bonding strength between layers, lamellar structure, and coating porosity was investigated.