Relative improvements in anti reflection property of black coating produced on stainless steel 310 using conversion coating techniques

Abstract The present work focuses on the enhancement of the antireflective property of black coatings produced on 310-grade stainless steel by hot conversion coating techniques. The optimum process parameter has been determined by using Taguchi L9 orthogonal array. Coating duration (d) and bath temperature (t) were selected as control variables (process parameters). The percentage reflectance (%R) was considered response characteristics. To analyze the effect of each process parameter on percentage reflectance, Taguchi analysis, ANOVA, main effect plots, interaction plots, and contour plots were considered. It has been found that 1100 g/L potassium hydroxide, 200 g/L of potassium nitrate, 40-minute duration of coating, and 140 °C bath temperature produces coating with lowest average percentage reflectance (%R). The characterization of coated samples was done by scanning electron microscope (SEM). The surface morphological studies revealed that a uniform coating with a wavy structure act as a good light absorber in the visible region of 350–800 nm.