Cracking Behavior of Sol-Gel Derived YAlO3/Ti2AlC Composite Coatings During Drying and Pyrolysis

doi:10.11900/0412.1961.2017.00325

IMR OpenIR

	Cracking Behavior of Sol-Gel Derived YAlO3/Ti2AlC Composite Coatings During Drying and Pyrolysis
	Fan Chao; Jia Qing; Cui Yuyou; Yang Rui
通讯作者	Jia Qing(qjia@imr.ac.cn)
	2018-07-01
发表期刊	ACTA METALLURGICA SINICA
ISSN	0412-1961
卷号	54 期号:7 页码:991-998
摘要	Sol-gel derived YAlO3/MAX composite coatings were designed as protective coatings for gamma-TiAl base intermetallic compounds which exhibit insufficient oxidation resistance at temperatures above 800 degrees C. 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/Ti2AlC 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/Ti2AlC 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 degrees C/min was the best choice to obtain YAlO3/Ti2AlC composite coatings with acceptable surface quality.
关键词	cracking coating sol-gel drying pyrolysis
DOI	10.11900/0412.1961.2017.00325
收录类别	SCI
语种	英语
WOS研究方向	Metallurgy & Metallurgical Engineering
WOS类目	Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000435961500004
出版者	SCIENCE PRESS
引用统计	被引频次：2[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/128709
专题	中国科学院金属研究所
通讯作者	Jia Qing
作者单位	Chinese Acad Sci, Inst Met Res, Shenyang 110016, Liaoning, Peoples R China
推荐引用方式 GB/T 7714	Fan Chao,Jia Qing,Cui Yuyou,et al. Cracking Behavior of Sol-Gel Derived YAlO3/Ti2AlC Composite Coatings During Drying and Pyrolysis[J]. ACTA METALLURGICA SINICA,2018,54(7):991-998.
APA	Fan Chao,Jia Qing,Cui Yuyou,&Yang Rui.(2018).Cracking Behavior of Sol-Gel Derived YAlO3/Ti2AlC Composite Coatings During Drying and Pyrolysis.ACTA METALLURGICA SINICA,54(7),991-998.
MLA	Fan Chao,et al."Cracking Behavior of Sol-Gel Derived YAlO3/Ti2AlC Composite Coatings During Drying and Pyrolysis".ACTA METALLURGICA SINICA 54.7(2018):991-998.