Synthesis of TiC coating on Ti substrate using pulsed laser deposition and mechanical milling techniques along with statistical modeling of the process by response surface methodology

In this work, two methods including mechanical milling (MM) and pulsed laser deposition (PLD) followed by MM were employed for coating of Ti samples by TiC powder. The objective of the present study is finding the relationships between the input variables and the process responses as well as making the predictive model used in the design of TiC coating on Ti substrate. Central composite design (CCD) was applied to optimize some important factors involved in the mechanical coating procedure. Three factors including milling time, rotation per minute and employed technique (PLD + MM and MM) were examined as numerical, numerical, and categorical factors, respectively. Coating thickness, microhardness, and scratch hardness number were defined as process responses. The study revealed that the effect of all factors on the responses was significant. Optimum levels obtained using the response surface method (optimization levels: 27 h, 350 rpm and PLD + MM method) met the corresponding experimental results. The obtained results proved that CCD can be efficiently used in predicting behavior of the given system. Regarding the optimized condition, it was observed that combination of PLD and MM methods presents better outcomes. Moreover, the results proposed that the model provides desirable TiC coating properties. (C) 2016 Elsevier B.V. All rights reserved.