Open Access Nano Express

New understanding of hardening mechanism of TiN/SiNx-based nanocomposite films

Wei Li1*, Ping Liu1, Yongsheng Zhao2, Fengcang Ma1, Xinkuan Liu1, Xiaohong Chen1 and Daihua He1

Author Affiliations

1 School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China

2 School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China

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Nanoscale Research Letters 2013, 8:427  doi:10.1186/1556-276X-8-427

Published: 17 October 2013


In order to clarify the controversies of hardening mechanism for TiN/SiNx-based nanocomposite films, the microstructure and hardness for TiN/SiNx and TiAlN/SiNx nanocomposite films with different Si content were studied. With the increase of Si content, the crystallization degree for two series of films firstly increases and then decreases. The microstructural observations suggest that when SiNx interfacial phase reaches to a proper thickness, it can be crystallized between adjacent TiN or TiAlN nanocrystallites, which can coordinate misorientations between nanocrystallites and grow coherently with them, resulting in blocking of the dislocation motions and hardening of the film. The microstructure of TiN/SiNx-based nanocomposite film can be characterized as the nanocomposite structure with TiN-based nanocrystallites surrounded by crystallized SiNx interfacial phase, which can be denoted by nc-TiN/c-SiNx model ('c’ before SiNx means crystallized) and well explain the coexistence between nanocomposite structure and columnar growth structure within the TiN/SiNx-based film.

TiN/SiNx film; Nanocomposite; Hardening mechanism; Microstructure