Factors governing the mechanical behaviour of CrSiN coatings: Combined nanoindentation testing and transmission electron microscopy

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:534

Article

Wo, P. C.¹  Munroe, P. R.¹  Li, Z.²  Jiang, Z. -T.³  Xie, Z. H.⁴  Zhou, Z. F.⁴  Li, K. Y.⁵ 

[1] Univ New S Wales, Electron Microscope Unit, Sydney, NSW 2052, Australia

[2] Southeast Univ, Sch Mat Sci & Engn, Nanjing, Jiangsu, Peoples R China

[3] Murdoch Univ, Sch Engn & Energy, Murdoch, WA 6150, Australia

[4] Edith Cowan Univ, Sch Engn, Joondalup, WA 6027, Australia

[5] City Univ Hong Kong, Dept Mech & Biomed Engn, Kowloon, Hong Kong, Peoples R China

关键词: Transmission electron microscopy (TEM);    Nanoindentation;    X-ray photoelectron spectroscopy (XPS);    Deformation structure;    Coatings Chromium silicon nitride;   

DOI  :  10.1016/j.msea.2011.11.072

来源: Elsevier

【 摘 要 】

A direct link between the microstructure and mechanical properties of CrSiN coatings with varying Si contents was established by examining their microstructural evolution and deformation behaviour, enabled by cross-sectional transmission electron microscopy. A transformation from a columnar-grained structure, in the binary compound, to a nanocomposite structure, consisting of CrN nanocrystallites embedded in an amorphous matrix, was observed in the coating having a Si content of 28.5 at.%. The columnar-structured coatings were observed to deform by grain boundary shear sliding, whilst cracks occurred in nanocomposite coatings. Moreover, the coating having a Si content of 14.3 at.% exhibited the highest hardness as a result of grain boundary strengthening facilitated by Si3N4 segregation, together with solid solution strengthening of Si in CrN, the Hall-Petch effect for the finer CrN grains and a high compressive residual stress. A further increase of Si content to 28.5 at.% led to a reduction in hardness due to the high volume fraction of the amorphous phase, together with the presence of cracks in the as-deposited coating. The findings provide deeper insight into the origin of the mechanical behaviour of CrSiN coatings. (C) 2011 Elsevier B.V. All rights reserved.

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