Influence of substrate bias on the scratch, wear and indentation response of TiSiN nanocomposite coatings

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

3 Scopus Citations
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  • Rumana Akhter
  • Zhifeng Zhou
  • Zonghan Xie
  • Paul Munroe


Original languageEnglish
Article number127687
Journal / PublicationSurface and Coatings Technology
Online published10 Sep 2021
Publication statusPublished - 15 Nov 2021


TiSiN coatings were synthesised onto AISI M42 tool steel substrates via closed field unbalanced magnetron sputtering ion plating, using bias voltages of −40 and −50 V. The aim of this study is to investigate the underlying deformation mechanisms of TiSiN coatings, prepared at two different substrate bias voltages, following scratching, wear and indentation tests. A graded columnar microstructure evolved in these coatings. A hardness value of ~30.2 GPa was determined in the coating prepared at the lower bias voltage (i.e., −40 V), which was correlated to the fine nanocomposite structure and the presence of a high compressive residual stress. Of note, for the coating deposited at −40 V enhanced scratch adhesion strength, i.e., higher critical loads (Lc1 and Lc2) against cohesive and adhesive failure were determined with the higher H/Er and H3/Er2 values. The improved scratch resistance was ascribed to the hierarchical structure that hindered crack propagation in the TiSiN coatings during progressive loading. An approximately 21% decrease in wear rate was obtained at the lower bias voltage, which was attributed to the slightly lower Si concentration (~8.3 at.%) and, in turn, higher hardness. Deformation behaviour under indentation loading was dominated by shear sliding along the columnar grain boundaries.

Research Area(s)

  • Indentation response, Mechanical response, Microstructure, Scratch behaviour, TiSiN coating, Tribological performance