摘要
采用实验和数值方法研究了陶瓷层厚度比对La_2Ce_2O_7/YSZ(LC/YSZ)热障涂层热震性能的影响。实验结果表明,随着LC与YSZ厚度比的降低,涂层热震寿命显著提高,涂层失效区域逐渐向试样中心转移,剥离位置逐渐从两陶瓷层界面附近转移到LC内靠近上表面处。数值结果表明,界面边缘处较大的轴向应力与剪切应力易导致较大厚度比涂层边缘处剥落;LC表面中心区域较大的径向拉应力会导致垂直裂纹萌生,并伴随界面偏折,这是较小厚度比涂层自LC内部剥离的原因。
The effect of the thickness ratio between La2Ce2O7(LC) layer and YSZ layer on the thermal shock performance of La2Ce2O7/YSZ double-ceramic-layer thermal barrier coatings was studied by experimental and numerical method. The thermal cycling test indicates that with the decrease of the thickness ratio, the lifetime of double-ceramic-layer thermal barrier coatings is improved obviously and the failure region gradually transfers to the sample center. Meanwhile the separation position transfers from the LC/YSZ interface to the inner LC near the upper surface. The numerical results show that the lager axial tensile stress and shear stress of the interface of LC layer and YSZ layer at the edge leads to the spallation failure at the coating edge. The larger radial tensile stress at the central area of the LC surface leads to the initiation of vertical cracks accompanied by the interface deflection, which is the reason why the coating is peeled off from the inside of the LC layer.
作者
任晓雪
江鹏
范学领
王铁军
Ren Xiaoxue;Jiang Peng;Fan Xueling;Wang Tiejun(State Key Laboratory for Strength and Vibration of Mechanical Structures,Xi'an Jiaotong University,Xi'an 710049,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2018年第12期3703-3709,共7页
Rare Metal Materials and Engineering
基金
国家重点基础研究发展计划("973"计划)(2013CB035700)
国家自然科学基金(11472204)
关键词
热障涂层
双陶瓷层
热震寿命
失效模式
热应力
thermal barrier coatings
double-ceramic-layer
thermal shock lifetime
failure mode
thermal stress
