摘要
利用大气等离子喷涂技术在300、400和500 A电流下分别制备具有不同纳米结构及含量的涂层,于1 300℃高温下分别保温20 h与50 h后,采用场发射扫描电镜,X射线衍射技术及努氏压痕法研究涂层中纳米结构的变化。在1 000℃下进行热震性能测试,观察涂层结构对抗热震性能的影响。结果表明,300、400和500A电流下涂层的平均晶粒尺寸分别为62、98和104 nm,而300 A电流下涂层具有非常高的孔隙率,约44.8%±8%。高温加热后纳米结构涂层出现烧结收缩,涂层孔隙率降低,弹性模量增加。涂层初始纳米区域颗粒尺寸越低与完全熔化区域烧结速度差异越大越有利于涂层的抗烧结性。当涂层中含有较多纳米区域时涂层抗热裂纹扩展能力有所提高,但是较高的孔隙率加速了涂层与粘结层界面的失效,此时通过降低粉体熔化程度提高纳米区域含量对热障涂层的寿命有负面作用。
The coatings with different nano zone structure were fabricated via air plasma spray （APS） method and then were heat treated at 1 300 ℃ for 20 h and 50 h, The variation in nano zone structures were investigated using field emission scanning electronscopy （FESEM） and X-ray diffraction （XRD） method. Thermal shock test was performed at 1 000 ℃ to study the effect of the cotent of structures zone on coating properties. The results show that the average grain size of the coatings engineered with 300, 400, and 500 A are 62, 98 and 104 nm, respectively. However,the coating engineered with 300 A possesses the highest porosity （approximately 44.8%±8%）. After heat treatment, the coatings exhibit obvious sintering effect, with lower porosity and higher elastic modulus. Higher porosity accelerates the failure at the interface between the YSZ coating and the bond coat. Increasing the amount of the nanostructure through decreasing the melting degree of agglomerated powder shows negative effects on the life span of the thermal barrier coating.
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2016年第4期96-102,共7页
China Surface Engineering
基金
国家自然科学基金(51172033)
关键词
大气等离子喷涂
纳米结构
氧化钇稳定氧化锆
热震性能
atmospheric plasma spray
nano structure
yttria stabilized zirconia （YSZ）
thermal shock resistance
