Structural and mechanical evolution of TiAlSiN nanocomposite coating under influence of Si3N4 power

Abstract

In this study, we have reported the microstructural and mechanical properties of nanocrystalline Titanium Aluminum Nitride (TiAlN) embedded in amorphous Silicon Nitride (Si3N4) nanocomposite films. The films were deposited on Si substrate by using DC\RF reactive magnetron co-sputtering of TiAl and Si3N4 targets by varying power to the Si3N4 target. The films were investigated using grazing incident X-ray diffraction (GIXRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), stylus profiler and nanoindentation. GIXRD shows the formation of crystalline cubic Ti3AlIN phase in the films. With the increase in Si3N4 power, crystal growth of MIN diminishes. FESEM micrographs showed the uniformly distributed, well developed, sharp-edged, irregular shaped grains on the surface of the films. The silicon rich region was observed at inter-grain boundary regio and the micrographs visualize the presence of amorphous Si3N4 on the edge of crystal grains. The amorphous content increases with Si3N4 power. EDS confirms the presence of all elements in the films. The optimum mechanical properties were observed at 70 W Si3N4 target power. Hardness, elastic modulus, elastic recovery and resistance to plastic deformation of film rises from 40 W to 70 W target power and then reduces at 90 W. (C) 2016 Elsevier B.V. All rights reserved.