Nickel–boron electrochemical properties investigations

• Published in: Journal of alloys and compounds Vol. 505; no. 1; pp. 151 - 156
• Main Authors: Kanta, A.-F., Poelman, M., Vitry, V., Delaunois, F.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 27.08.2010; Elsevier
• Subjects: Abrasion resistance; Applied sciences; Coating; Condensed matter: structure, mechanical and thermal properties; Corrosion; Corrosion mechanisms; Corrosion resistance; Electrochemical impedance spectroscopy; Electroless; Exact sciences and technology; Heat treatment; Mechanical and acoustical properties; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Metals. Metallurgy; Nickel; Nickel–boron; Physical properties of thin films, nonelectronic; Physics; Protective coatings; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Transport properties of condensed matter (nonelectronic); Tribology and hardness; Wear; Wear resistance; Electroless; Nickel–boron; Corrosion; Wear; Abrasion; Scanning electron microscopy; Roughness; Carbon steels; Mechanical properties; Nickel-boron; Sodium chloride; Coatings; Heat treatments; Corrosion resistance; Boron; Electrochemical properties; Nickel; Wear resistance; Diffusion; Electrochemical impedance spectroscopy; Tribology
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2010.05.168

Electroless nickel–boron (Ni–B) was synthesized on mild steel. Coating thickness was approximately 30 μm. Some of the coatings were submitted to a hardening heat treatment at 400 °C for 1 h in an atmosphere containing 95% Ar and 5% H 2 to improve their mechanical performance. Heat treated and untreated samples were submitted to the Taber abrasion test to assess their wear resistance. The wear track was then examined by SEM and roughness measurement. The Taber Wear Index of untreated samples was slightly better than that of steel but heat treated samples attained TWI as small as 13. The corrosion resistance of the Ni–B coatings was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy. The EIS results showed diffusion phenomena in 0.1 M NaCl solution. Electroless Ni–B coating increases the corrosion resistance of steel and heat treatments allow a further enhancement. Wear decreases that resistance but the worn product keeps a better behaviour than uncoated parts.