Wo, P.Munroe, P.Li, Z.Jiang, Z.Xie, Z.Zhou, Z.Li, K.2013-03-142013-03-142012Materials Science and Engineering A: Structural Materials: Properties, Microstructure and Processing, 2012; 534:297-3080921-5093http://hdl.handle.net/2440/75905A 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<inf>3</inf>N<inf>4</inf> 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. © 2011 Elsevier B.V..en© 2011 Elsevier B.V. All rights reserved.Transmission electron microscopy (TEM)NanoindentationX-ray photoelectron spectroscopy (XPS)Deformation structureCoatingsChromium silicon nitrideJournal article002012277610.1016/j.msea.2011.11.0720003019896000372-s2.0-8485654943022724