Improved thermal stability, mechanical and tribological properties of reactively sputtered Si doped TiAlC nanostructured hard coatings

Chaliyawala, HA and Srinivas, G and Bera, Parthasarathi and Siju, - and Kumar, P and Khan, Jakeer and Barshilia, Harish C (2016) Improved thermal stability, mechanical and tribological properties of reactively sputtered Si doped TiAlC nanostructured hard coatings. Surface and Coatings Technology, 288. pp. 95-104. ISSN 02578972

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Abstract

The influence of different Si contents on TiAlSiC nanocomposite coatings deposited on stainless steel and silicon (100) substrates using reactive unbalanced direct current magnetron sputtering has been studied. A comprehensive study of microstructure, mechanical, tribological and thermal stability of Si doped TiAlC has been carried out. X-ray diffraction (XRD) analysis reveals that the TiAlSiC coating exhibits fcc NaCl type TiC phase. The presence of a-AlC and a-Si phases was observed by correlating the X-ray photoelectron spectroscopy and XRD data. Moreover, micro-Raman spectroscopy studies indicate the existence of graphitic rich layer of a-C in the coating which limits the columnar growth on account of a-Si. Friction coefficient, adhesion, toughness and mechanical properties of the TiAlSiC coatings were characterized by nanoscratch tester and nanoindentation measurements. A high hardness ~ 28 GPa and a friction co-efficient of ~ 0.49 was achieved for TiAlSiC coatings prepared at a Si contents of 8 at.%. The maximum toughness of 2.14 MPa m1/2 was obtained for the optimized coating due to grain boundary strengthening. Although, increase in the Si content deteriorates the mechanical and tribological performance, but it improves the thermal stability of the coatings. A remarkable thermal stability up to 1000 °C in air for 4 h has been observed for higher Si contents (> 12 at.%).

Item Type:	Article
Subjects:	CHEMISTRY AND MATERIALS > Chemistry and Materials (General) CHEMISTRY AND MATERIALS > Composite Materials
Depositing User:	Mrs SK Pratibha
Date Deposited:	20 Aug 2018 11:49
Last Modified:	20 Aug 2018 11:49
URI:	http://nal-ir.nal.res.in/id/eprint/12946

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