常规和纳米ZrO_2-7%Y_2O_3等离子喷涂热障层及其激光重熔后的抗热震性能

Effect of Laser Remelting on Thermal Shock Resistance of Plasma Sprayed Conventional and Nanostructured Zirconium Dioxide-7% Yttrium Oxide Thermal Barrier Coatings

为了探讨激光重熔对等离子喷涂常规和纳米热障涂层(TBCs)的影响,采用等离子喷涂工艺在γ-TiAl合金表面制备了常规和纳米ZrO2-7%Y2O3TBCs,并对其进行激光重熔处理,研究了等离子喷涂常规TBCs、激光重熔-等离子喷涂常规TBCs、等离子喷涂纳米TBCs及激光重熔-等离子喷涂纳米TBCs 4种涂层在850℃下的抗热震性能。结果表明:4种TBCs热震失效次数依次为73,118,146,163次,相应的热震破坏形式分别为整体剥落、局部剥落、边角剥落和局部剥落;纳米结构有利于提高涂层的抗热震性能;激光重熔在一定程度上改善了等离子喷涂层的抗热震性能。

Conventional and nanostructured ZrO2-7% Y2O3 thermal barrier coatings(TBCs) were prepared on the surafce of γ-TiAl alloy substrate by plasma spraying.As-obtained plasma sprayed TBCs were laser remelted,and the effect of laser remelting on the thermal shock resistance of the two kinds of plasma sprayed TBCs at 850 ℃ was investigated.It was found that plasma-sprayed conventional TBCs,laser-remelted conventional TBCs,plasma-sprayed nano-sturctured TBCs and laser-remelted nanosturctured TBCs had thermal shock failure times of 73,118,146 and 163,and their failure mechanisms were whole spalling,local spalling,corner spalling and local spalling respectively.Besides,plasma sprayed nanostructured TBCs had better thermal shock resistane,while laser remelting contributed to improved thermal shock resistance of the TBCs to some extent.