Taguchi and utility based concept for determining optimal process parameters of cold sprayed coatings for multiple responses

Most of the existing multi-response optimization approaches focus on subjective and practical know how of the process. As a result some confusions and uncertainties are introduced in overall decision making process. In this investigation, an approach based on a Utility theory and Taguchi quality loss function has been applied to low-pressure cold spray process to deposit copper coatings, for simultaneous optimization of more than one response characteristics. In the present paper, three potential response parameters i.e. coating density, surface roughness and Micro hardness have been selected. Utility values based upon these response parameters have been analyzed for optimization by using Taguchi approach. The selected input parameters of powder feeding arrangement, substrate material, air stagnation pressure, air stagnation temperature and stand-off distance significantly improves the Utility function (raw data) comprising of quality characteristics (coating density, surface roughness and micro hardness). The percentage contribution of the parameters to achieve a higher value of utility function is: substrate material (64.59%), air stagnation pressure (16.35%), powder feeding arrangement (6.92%), air stagnation temperature (6.49%) and stand-off distance (1.84%) respectively.