ABSTRACT

In this research, YSZ-Alumina top coat was deposited on the Hastelloy substrate with a NiCrAlY bond coat by Atmospheric plasma spraying process. YSZ-10 wt-% Al₂O₃ composite coatings with pyrolysed and un-pyrolysed Al₂O₃ powder were deposited. High temperature oxidation and thermal shock resistance of both coatings were investigated. Thermal shock test results showed that the lifetime of the YSZ-10 wt-% Al₂O₃ coating was increased by the pyrolysation of the un-pyrolysed Al₂O₃. The network of micro-segmented cracks produced by the pyrolysation of the un-pyrolysed Al₂O₃ improved the strain accommodation, introducing it as the main enhancement mechanism for TBC life extension. Using of pyrolysed alumina, resulted increased in the flattening degree of the splats, and so reduction of porosity and intra-splat cracks. This, in turn, reduced the permeability of the top coat and decreased the rate of oxide growth on the bond coat.

摘要

在本研究中，YSZ-Alumina 面漆通过大气等离子喷涂工艺沉积在具有 NiCrAlY 粘合涂层的哈氏合金基材上。沉积具有热解和未热解的Al ₂ O ₃粉末的YSZ-10wt-％Al ₂ O ₃复合涂层。研究了两种涂层的高温抗氧化性和抗热震性。热冲击试验结果表明，YSZ-10 wt-% Al ₂ O ₃涂层的寿命由于未热解的Al ₂ O ₃的热解而增加。未热解的 Al ₂ O ₃热解产生的微分段裂纹网络改进了应变调节，将其引入作为 TBC 寿命延长的主要增强机制。使用热解氧化铝，导致板片的扁平度增加，从而减少孔隙率和板片内裂纹。这反过来又降低了面漆的渗透性并降低了粘结层上氧化物的生长速度。