Effect of on time and off time on the crystal structure and properties of hard chromium pulse electrodeposition

The present research deals with the synthesizing of chromium coating by pulse and direct current from standard bath chromium in the same condition. Crystal structure, morphology, hardness, and surface roughness of fabricated coatings were controlled by varying processing parameter including on time and off time.X-ray diffraction and scanning electron microscopy were employed to evaluate the phase identification and surface morphology of coating. It was found that β-chromium with hexagonal structure forms in pulse plating; however with an increase in off time, the amount of β-chromium in the structure was increased. Finally the coating morphology was affected and varied from trigonal pyramidal like in 50% duty cycle to cubic structure in 20% and caused a decrease in coating properties.