摘要
采用大气等离子喷涂制备莫来石涂层,对涂层进行了热震试验。以OLYCIA m3图像分析软件测定涂层孔隙率,以MH-5-VM型显微硬度仪测定涂层硬度,依照ASTMC633-79标准测定涂层结合强度,以X射线衍射(XRD)和扫描电镜(SEM)表征涂层的相组成和微观形貌。结果表明,莫来石涂层主要由变形颗粒、未熔融粉末及少量孔隙组成,涂层中没有微观裂纹;涂层中含有莫来石晶体和部分非晶态玻璃相;热震过程中,涂层中的非晶转变为晶态莫来石,同时伴随应力释放,导致涂层出现微观裂纹。
The mullite coatings were prepared by air plasma sprayed. The as-sprayed coating were carried out thermal shock experiment. The porosity and microhardness were measured by OLYCIA m3 image analysis software and MH-5-VM microhardness tester, respectively. The bond strength of mullite coatings were determined according to ASTM C633-79 standard. The composition and morphology of the mullite coatings were examined by X-ray diffraction （XRD） and scanning electron microscope（SEM）. The results show that as-sprayed coating includes splats grains, partially melted powders and a few pores. The microcracks do not appear in the coating. The as-sprayed coating is largely crystal mullite and only a small quantity of amorphous phase. During thermal shock experiment, amorphous phase in coating changes to crystal mullite and gives rise to stress, leading to microcracks.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2011年第2期36-39,共4页
Materials Reports
基金
国家自然科学基金委创新研究群体科学基金资助项目(50421502)
关键词
大气等离子喷涂
莫来石涂层
热震试验
非晶
air plasma spray, mullite coatings, thermal shock experiment, amorphous
