Optimization and characterization of friction surfaced coatings of ferrous alloys

In the present work, the scientists were successful in obtaining a friction surfaced coating of mild steel over mild steel, mild steel over stainless steel (AISI 304) and stainless steel over stainless steel using a low-cost conventional milling machine. A 22 factorial method with three replications was used to design the experiments. The influence of variation in rotational speed (1400 rpm and 1000 rpm) and table feed rate (4.17 mm/s and 2.67 mm/s) on coating width, thickness and interface temperature of the coating and substrate was investigated. Multi-response optimization was performed and the developed model was validated by confirmatory experiments. The results showed that, with an increase in rotational speed and table feed rate, width and thickness of the coating decreases, while temperature increases. An infrared (IR) camera provided thermographs that elaborated the distinct stages of heat dissipation during the process of coating formation. The bond integrity and strength of the coating was analyzed by bend tests and Vickers micro hardness test. The results revealed that a higher hardness value was obtained at the interface of the coating as compared to coating and interface.