The investigation of the microstructure behavior of the spray distances and argon gas flow rates effects on the aluminum coating using self-generated atmospheric plasma spray system

In the present paper, our aims are the investigationof the effects of the spray parameters of the aluminum-coated layer on the microstructure and mechanicalproperties. For this purpose, we use the self-generatedatmospheric plasma spray system for coating of aluminumon the carbon steel substrate to protect it against corrosiondegradation. This system allows us to achieve the bestchoice for parameters. In this paper, the effects of spraydistance and argon flow rate on the characteristics of aluminumcoating are investigated. To obtain the results, theanalyses are used such as X-ray diffraction, scanningelectron microscope, micro hardness of the coating byVickers method, and adhesion strength behaviors by pullofftest. The results show that the porosity increases withincreasing distance. This phenomenon reduces the hardnessand adhesion, which is clearly evident in our results. Theother important conclusion is that, if the gas flow rateincreases, the porosity decreases. It is shown that the bestadhesion strength is obtained at the special value of thespraying distance.