8YSZ团聚粉体压溃强度及其对PS-PVD沉积行为的影响研究

Study on Crushing Strength of 8YSZ Agglomerated Powders and its Effect on PS-PVD Deposition Behavior

等离子物理气相沉积(PS-PVD)作为一种热障涂层新型制备技术,受到国内外的广泛关注。PS-PVD工艺采用细小球形团聚粉体为原料,原料在高温高速等离子射流中瞬时加热-熔融-气化,这一复杂过程中粉体-等离子体射流相互作用机理尚未完全揭示,特别是粉体颗粒在高温高速射流中快速溃散气化过程研究较少。本文研究了细小球形团聚粉体的压溃强度测试方法,进而对不同粘结剂类型、含量、不同颗粒尺寸的粉体压溃强度进行表征,研究了粉体特性对压溃强度影响规律,并系统分析了粉体沉积效果。结果表明,随着粉体颗粒尺寸的增大,其压溃强度呈现逐步降低趋势,不同特性粉体趋势不同;粘结剂类型变化、特别是一定含量纳米尺度颗粒的存在,会增大粉体压溃强度,一定范围内粉体压溃强度越高,涂层沉积速率越高。

Plasma Spray-Physical Vapor Deposition(PS-PVD), as a new preparation technology of thermal barrier coatings, has attracted extensive attention at home and abroad. The PS-PVD process uses fne spherical agglomerated powders as material, and the raw materials are instantaneously heated, melted and vaporized in high temperature and high speed plasma jet. The mechanism of the powder plasma jet interaction in this complex process has not been fully revealed.In particular, there is little research on the rapid collapsing gasifcation process of powder particles in high temperature and high speed jet. In this paper, the test method of crushing strength of fne spherical agglomerated powder was studied, and then the crushing strength of powder with different binder types, contents and particle sizes were characterized, the infuence of powder characteristics on crushing strength were investigated, and the effect of powder deposition was systematically analyzed. The results showed that with the increase of the particle size of the powder, the crushing strength of the powder gradually decreased, and the trend of powder with different characteristics was different;the type of binder, especially the existence of a certain content of nano-scale particles, would increase the crushing strength of the powder. The higher the crushing strength of the powder within a certain range, the higher the deposition rate of the coating.