Temperature driven texture and grain boundary engineering of electrodeposited β-Sn coatings and its effect on the coating corrosion behaviour: Five-parameter grain boundary character distribution analysis study

Sn coatings were electrodeposited at four different temperatures (24 C, 47 C, 70 C, and 80 C) over mild steel. Electrochemical impedance spectroscopy revealed the highest and lowest corrosion resistance for Sn coating fabricated at 70 C (Sn3 coating) and 80 C, respectively. Electron backscattered diffraction technique was utilized to correlate the electrochemical properties with the coating texture. A significant increase in the low angle grain boundary fraction was noticed with an increase in the electrodeposition temperature. Five-parameter grain boundary character distribution analysis revealed that the highest fraction of (031)[01 ̅3] twin boundaries at 62.8/[100] misorientation and a high fraction of exposed low energy {100} planar orientations led to the highest corrosion resistance for Sn3 coating. Whereas a low fraction of (031)[01 ̅3] twin boundaries with a high fraction of exposed high energy 'near-(110)' planar orientations led to the poor corrosion resistance of Sn coating fabricated at 80 C.