Multi-objective optimization of Pulsed direct current magnetron sputtered titanium nitride thin film using Grey relational analysis

Abstract

Titanium nitride coatings are extensively adopted as an intermediate adhesion layer in the cutting tools because of its superior mechanical properties. The interdependence of each process parameter during the deposition of such a coating process is nonlinear, and hence, it becomes a challenge to determine the output responses without carrying out a wide range of experiments. So to minimize the experiments, Taguchi-based L9 design of experiments were employed in this study with three factors and three levels such as Argon (Ar): Nitrogen (N2) gas mixture, Pulsed direct current power, and deposition time for depositing titanium nitride thin films on silicon (100) and tungsten carbide substrates using Pulsed direct current magnetron sputtering technique, where conventional direct current magnetron sputtering cannot be deployed using titanium nitride target. Multiple output responses such as average thickness, surface roughness, nano-hardness, Young’s modulus, wear track deformation, and coefficient of friction were measured by carrying out the systematic investigations, and a single optimum solution was obtained using Grey relational analysis. From the Grey relational analysis, the optimum Ar:N2 gas flow mixture, Pulsed direct current power, and deposition time for improved titanium nitride adhesion layer are 300 W, 10:5 sccm, and 5 min, respectively. Further, grazing incidence x-ray diffractometer profiles of deposited films exhibits (111) and (200) reflections corresponding to the titanium nitride phase, and the morphological analysis also revealed the existence of strongly faceted nano-grains with a triangular-shaped morphology.