Measurement Of Fracture Toughness And Interfacial Shear Strength Of Hard And Brittle Cr Coating On Ductile Steel Substrate

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	Measurement Of Fracture Toughness And Interfacial Shear Strength Of Hard And Brittle Cr Coating On Ductile Steel Substrate
	Yang BQ(杨班权); Zhang K(张坤); Chen GN(陈光南); Luo GX(罗耕星); Xiao JH(肖京华)
刊名	Surface Engineering
	2008
通讯作者邮箱	yangbq1022@tom.com
页码	332-336
关键词	Hard And Brittle Coating Fracture Toughness Ductile Steel Substrate Interfacial Shear Strength Tensile Test Thermal Barrier Coatings Thin-Films Adhesion Cracking Decohesion Behavior Indentation Chromium Erosion Tensile
ISSN号	0267-0844
通讯作者	Yang, BQ (reprint author), Armored Force Engn Inst, Dept Mech Engn, Div Engn Mech, 21 Jia Kan, Beijing 100072, Peoples R China.
中文摘要	The fracture toughness and interfacial adhesion properties of a coating on its substrate are considered to be crucial intrinsic parameters determining performance and reliability of coating-substrate system. In this work, the fracture toughness and interfacial shear strength of a hard and brittle Cr coating on a normal medium carbon steel substrate were investigated by means of a tensile test. The normal medium carbon steel substrate electroplated with a hard and brittle Cr coating was quasi-statically stretched to induce an array of parallel cracks in the coating. An optical microscope was used to observe the cracking of the coating and the interfacial decohesion between the coating and the substrate during the loading. It was found that the cracking of the coating initiated at critical strain, and then the number of the cracks of the coating per unit axial distance increased with the increase in the tensile strain. At another critical strain, the number of the cracks of the coating became saturated, i.e. the number of cracks per unit axial distance became a constant after this critical strain. Based on the experiment result, the fracture toughness of the brittle coating can be determined using a mechanical model. Interestingly, even when the whole specimen fractured completely under an extreme strain of the substrate, the interfacial decohesion or buckling of the coating on its substrate was completely absent. The test result is different from that appeared in the literature though the identical test method and the brittle coating/ductile metal substrate system are taken. It was found that this difference can be attributed to an important mechanism that the Cr coating on the steel substrate has a good adhesion, and the ultimate interfacial shear strength between the Cr coating and the steel substrate has exceeded the maximum shear flow strength level of the steel substrate. This result also indicates that the maximum shear flow strength level of the ductile steel substrate can be only taken as a lower bound estimate on the ultimate shear strength of the interface. This estimation of the ultimate interfacial shear strength is consistent with the theoretical analysis and prediction presented in the literature.
类目[WOS]	Materials Science, Coatings & Films
研究领域[WOS]	Materials Science
关键词[WOS]	THERMAL BARRIER COATINGS ; THIN-FILMS ; ADHESION ; CRACKING ; DECOHESION ; BEHAVIOR ; INDENTATION ; CHROMIUM ; EROSION ; TENSILE
收录类别	SCI
语种	英语
WOS记录号	WOS:000259639000004
公开日期	2009-08-03 ; 2009-09-14
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/25894]
专题	力学研究所_力学所知识产出(1956-2008)
推荐引用方式 GB/T 7714	Yang BQ,Zhang K,Chen GN,et al. Measurement Of Fracture Toughness And Interfacial Shear Strength Of Hard And Brittle Cr Coating On Ductile Steel Substrate[J]. Surface Engineering,2008:332-336.
APA	杨班权,张坤,陈光南,罗耕星,&肖京华.(2008).Measurement Of Fracture Toughness And Interfacial Shear Strength Of Hard And Brittle Cr Coating On Ductile Steel Substrate.Surface Engineering,332-336.
MLA	杨班权,et al."Measurement Of Fracture Toughness And Interfacial Shear Strength Of Hard And Brittle Cr Coating On Ductile Steel Substrate".Surface Engineering (2008):332-336.