摘要
利用常规等离子喷涂和高能等离子喷涂工艺分别制备了不同结构的8YSZ热障涂层，研究了不同结构涂层在高温退火（1250℃，2h）和燃气热冲击条件（1200℃／900℃）下对CMAS沉积物防护作用。结果表明：提高8YSZ涂层致密度和在其表面制备致密氧化铝封阻层可延缓CMAS沉积物渗入和反应，并提高涂层在CMAS耦合条件下燃气热冲击寿命，在孔隙率12．9％的8YSZ涂层表面制备厚度10～20gm致密氧化铝层，热冲击寿命提高4．4倍。8YSZ涂层致密度提高或表面致密氧化铝薄层制备，可进一步降低涂层表面粗糙度，同时燃气热冲击条件下氧化铝层自身逐层剥离的失效形式，均能减缓CMAS的粘附；1250℃下氧化铝层会溶解进入CMAS提高局部Al含量，从而使CMAS中局部低熔点相向高熔点钙长石相转变，会进一步提高界面稳定性。
8YSZ TBCs with different microstructures were prepared by conventional plasma spraying and high energy plasma spraying to examine coating protection effects against CMAS deposits under the conditions of high temperature annealing at 1 250 ℃, 2 h and of thermal cycling by burn rig at 1 200 ℃/900 ℃.The results show that increasing the coating density and preparing the dense alumina barrier coating can delay the infiltration and reaction of CMAS, and can also extend the thermal cycling life of coatings under the CMAS coupling condition. The life span of thermal cycling is increased by 4.4 times by preparing the dense alumina layer with 10-20 pm thickness on the 8YSZ coatings with the porosity of 12.9%. The CMAS adherence is reduced for two reasons. First, the surface roughness can be reduced by the increasing density of the 8YSZ coatings or by preparing the thin layer of dense alumina on the 8YSZ coating surface. Second, the failure of alumina coatings occurs when the coatings peel off layer by layer during the thermal cycling. The alumina barrier layer dissolved in the molten CMAS at 1 250 ℃ increases the content of Al, resulting in the transition from the partial phase with a low melting point to the anorthite phase with a high melting point in CMAS. This transition leads to the improved stability of the interface.
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2016年第4期86-95,共10页
China Surface Engineering
关键词
CMAS沉积物
热障涂层
氧化铝封阻层
防护作用
CMAS deposit
thermal barrier coatings （TBCs）
alumina environment barrier coating
protective effect
作者简介
通讯作者：何箐（1983-），男（汉），高级工程师，博士；研究方向：热障涂层；Tel：（010）64883291；E-mail：heqing68@gmail．com
