摘要
采用Ti3SiC2作为新型自愈合剂,利用大气等离子喷涂将混合均匀的YSZ-Ti3SiC2粉体制备成厚涂层。为观测高温下涂层氧化及裂纹的自愈合行为,通过外加载荷的方式在涂层表面预制裂纹,并将样品置于1050℃空气气氛中进行等温热处理。通过分析涂层制备、热处理前后的物相和形貌演变发现:涂层中的部分Ti3SiC2在喷涂后分解为TiC与SiO2,热处理后涂层表面形成外层为TiO2,内层为TiO2和SiO2混合物的双层结构。在自愈合过程中,裂纹内的愈合剂氧化生成SiO2与TiO2,随着扩散控制的氧化反应不断进行,氧化物逐渐积累并填补裂纹。此外,在SiO2与TiO2生成的同时引起的体积膨胀使裂纹周围产生一定的压应力,强化了愈合效果,最终完全愈合裂纹。
As a new self-healing agent,Ti3SiC2 was added into yttria-stabilized zirconia(YSZ)thermal barrier coatings.By atmospheric plasma spraying(APS),thick coatings were prepared using an YSZ-Ti3SiC2 mixing powder.To observe oxidation and self-healing behavior,cracks were prefabricated on the surface of YSZ-Ti3SiC2 coating by uniform external load.The prepared samples were then isothermally treated at 1050℃in air.The phase and morphology evolution of the coatings,as well as the self-healing behavior were investigated via several analyzing methods.The results showed that a part of Ti3SiC2 was decomposed into amorphous SiO2 and TiC after spraying and a double layered structure composed of a TiO2 outer layer and a TiO2+SiO2 inner layer was formed after isothermal treatment.In the process of self-healing,oxidation of the healing agent in the coating led to the growth of silicon oxide and titanium oxide in the cracks.These oxides gradually filled the cracks due to the diffusion-controlled oxidation.Meanwhile,the compressive stress induced by the volume expansion due to SiO2 and TiO2 growth in the crack enhanced the healing effect.Eventually the prefabricated cracks were healed.
作者
陈宏飞
张弛
杨光
刘斌
高彦峰
钱凌翼
高栋
CHEN Hongfei;ZHANG Chi;YANG Guang;LIU Bin;GAO Yanfeng;QIAN Lingyi;GAO Dong(School of Material Science and Engineering,Shanghai University,Shanghai 200444,China;AECC Commercial Aircraft Engine Co.,Ltd.,Shanghai 200241,China)
出处
《航空制造技术》
2019年第18期90-96,共7页
Aeronautical Manufacturing Technology
基金
国家自然科学基金（51402183）
航空科学基金（2017ZFS6002）
关键词
热障涂层
等离子喷涂
自愈合
高温氧化
裂纹
MAX相
Thermal barrier coating
Atmospheric plasma spraying
Self-healing
High-temperature oxidation
Crack
MAX phase
