Study of the Corrosion Behavior of Nanocrystalline Ni-P Electrodeposited Coating

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 41; no. 2; pp. 450 - 459
• Main Authors: Lee, H.B., Wuu, D.S., Lee, C.Y., Lin, C.S.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.02.2010; Springer; Springer Nature B.V
• Subjects: Alloys; Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion; Corrosion environments; Corrosion tests; Exact sciences and technology; Grain size; Materials Science; Mechanical properties; Metallic coatings; Metallic Materials; Metals. Metallurgy; Nanotechnology; Production techniques; Structural Materials; Surface treatment; Surfaces and Interfaces; Thin Films; Corrosion Test; Passive Film; Corrosion Behavior; Corrode Surface; Corrosion Attack; Nickel base alloys; Electrodeposition; Metal coating; Corrosion; Nanocrystal; Surface treatment
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-009-0101-1

The corrosion behavior of electrodeposited Ni-P coating in 5 pct (in weight) NaCl solution has been studied. The microstructure of the Ni-P electrodeposit displayed a layered structure composed of nanocrystalline grains revealed by transmission electron microscopy (TEM). With the increase in polarization potential and bath temperature, the corrosion rate as well as the weight loss was significantly increased. Under observation by a field-emission scanning electron microscope (FESEM), the pitting evolved into larger sizes with a diameter of approximately 30  μ m as the temperature and potential were increased to 50 °C and 600 mV SCE , respectively. Cracks and delamination among the layered structure were found inside the deepened corrosion pit. The increase in surface P content and the trace of the formation of phosphate were also observed by using X-ray photoelectron spectroscopy (XPS) analysis.