Factors governing the mechanical behaviour of CrSiN coatings: Combined nanoindentation testing and transmission electron microscopy
Document Type
Journal Article
Faculty
Faculty of Computing, Health and Science
School
School of Engineering
RAS ID
15194
Abstract
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 28.5at.%. 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 14.3at.% exhibited the highest hardness as a result of grain boundary strengthening facilitated by Si 3N 4 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 28.5at.% 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.
DOI
10.1016/j.msea.2011.11.072
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Comments
Wo, P., Munroe, P., Li, Z., Jiang, Z., Xie, Z. , Zhou, Z. , & Li, K. (2012). Factors governing the mechanical behaviour of CrSiN coatings: Combined nanoindentation testing and transmission electron microscopy. Materials Science and Engineering A, 534(0), 297-308.