The work focuses on the effect of plasma spraying factors such as plasma current, plasma voltage, and air flow rate on particle velocity because the effectiveness of the coating is heavily dependent on it. The inclusion of ordinary air as the plasma-generating gas and the explanation of the mathematical model justifying the alteration of particle velocity are the innovative aspects of this work. The newly discovered regression function helps the mathematical model optimize the procedure to achieve the greatest particle velocity. The parameter validity study confirmed the good comparative adaptation between the mathematical model and the experiment results. The introduction paragraph explained why this study is necessary. The paragraph "Methodology" introduced the equipment, instrument for analysis, the chemical composition of the material 85Ni15Al. The paragraph "Experiment" focused on a series of experiments. The multi-criteria planning design helps to conclude the significance of all parameter and well adopted to the experiment.