Understanding the non-monotonic variation in the corrosion rate of Sn-Ni coatings with Ni addition by the analysis of texture and grain boundary constitution of the matrix phase and spatial distribution of the intermetallic phase in the coating microstructure

• Published in: Corrosion science Vol. 211; p. 110787
• Main Authors: Singh, Akhand Pratap, Srivastava, Chandan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-02-2023
• Subjects: Corrosion; Grain boundary constitution; Intermetallic; Sn-Ni coatings; Texture; Grain boundary constitution; Corrosion; Intermetallic; Texture; Sn-Ni coatings
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2022.110787

Sn-Ni coatings (0–13 wt% Ni) were electrodeposited on mild steel. The highest (Rp = 18,561.1 Ω·cm2) and the lowest (Rp = 4756.7 Ω·cm2) corrosion resistance was observed for Sn-6 wt% Ni and Sn-13 wt% Ni coating, respectively. Higher corrosion resistance of Sn-6 wt% Ni coating was due to low energy (100) surface texture, low energy CSL boundaries and formation of Ni3Sn4 phase at grain boundaries. Higher corrosion rate of Sn-13 wt% Ni coating was due to highest fraction of high energy high angle grain boundaries, higher matrix strain and higher volume fraction of cathodic Ni3Sn4 phase.
•Sn-Ni coating (0–13 wt% Ni) were electrodeposited over mild steel.•Corrosion properties and coating texture was highly sensitive to the Ni content.•An optimum addition of Ni in Sn coating (6 wt% Ni) yielded high corrosion resistance.•High corrosion resistance was due to Ni3Sn4 at grain boundaries, (100) surface texture and abundant CSL boundaries.