| 基于溶胶-凝胶法的YAlO3/Ti2AlC复合涂层在干燥与热分解过程中的开裂行为研究 | |
| Alternative Title | Cracking Behavior of Sol-Gel Derived YAlO3/Ti2AlC Composite Coatings During Drying and Pyrolysis |
| 范超; 贾清; 崔玉友; 杨锐 | |
| 2018 | |
| Source Publication | 金属学报
 |
| ISSN | 0412-1961 |
| Volume | 54.0Issue:007Pages:991-998 |
| Abstract | 采用高温金相显微镜（HTOM）等原位观察和分析手段研究了溶胶-凝胶法制备YAlO3/Ti2AlC复合陶瓷涂层过程中干燥与热分解阶段的开裂行为。研究发现,涂层中的开裂现象发生于凝胶体系热分解阶段,是凝胶分子链的断裂导致体系所能承受的最大应力不足以抵抗涂层内逐渐积聚的应力,从而发生了涂层的开裂以及后续升温过程中裂纹的扩展现象。涂层的开裂最初往往发生在较厚的位置,因为在这些位置涂层内的应力集中更为严重。较快速升温可以使涂层表面的应力分布被局限在较小范围内,从而实现减小裂纹尺寸达到改善涂层表面质量的目的,升温速率为5℃/min时YAlO3/Ti2AlC复合陶瓷涂层的表面质量最佳。 |
| Other Abstract | Sol-gel derived YAlO3/MAX composite coatings were designed as protective coatings for gTi Al base intermetallic compounds which exhibit insufficient oxidation resistance at temperatures above800 ℃. However, at present, it＇s still a big challenge to achieve crack-free surfaces while preparing YAlO3/MAX composite coatings via sol-gel processing, especially during drying and low temperature heat treatment. Hence, cracking behavior of YAlO3/Ti2 AlC composite coatings, which were derived from nanoparticles-gel system, was studied in this work by means of in situ techniques such as high-temperature optical microscopy（HTOM）. According to this work, cracking of YAlO3/Ti2 AlC composite coatings during drying and pyrolysis mainly occurred in stage 3, i.e., the pyrolysis stage of slurry, in which the maximum stress that coating system can tolerate decreased gradually as a result of pyrolysis of the gel network and was eventually exceeded by the increasing internal stresses generated owing to heating and volume change of coating system. Coating thickness, which varied in the plane of coatings and was affected by the difference of drying rate during stage 1, was a critical factor that determined the positions where cracks may be initiated. It was observed that cracks were more easily formed on those sites with thicker coatings,where often produced great stress concentration. Both crack width and spacing can be decreased by applying fast heating rate, since large-scale non-homogeneous distribution of internal stress concentration in coatings was reduced in this way and cracking behavior of coatings was consequently confined into very small region. In this work, a heating rate of 5 ℃/min was the best choice to obtain YAlO3/Ti2 AlC composite coatings with acceptable surface quality. |
| Keyword | 开裂 涂层 溶胶-凝胶 干燥 热分解 |
| Indexed By | CSCD |
| Language | 中文 |
| CSCD ID | CSCD:6285043 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.imr.ac.cn/handle/321006/148571 |
| Collection | 中国科学院金属研究所 |
| Affiliation | 中国科学院金属研究所 |
| Recommended Citation GB/T 7714 | 范超,贾清,崔玉友,等. 基于溶胶-凝胶法的YAlO3/Ti2AlC复合涂层在干燥与热分解过程中的开裂行为研究[J]. 金属学报,2018,54.0(007):991-998. |
| APA | 范超,贾清,崔玉友,&杨锐.(2018).基于溶胶-凝胶法的YAlO3/Ti2AlC复合涂层在干燥与热分解过程中的开裂行为研究.金属学报,54.0(007),991-998. |
| MLA | 范超,et al."基于溶胶-凝胶法的YAlO3/Ti2AlC复合涂层在干燥与热分解过程中的开裂行为研究".金属学报 54.0.007(2018):991-998. |
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