Effect of heat treatment on properties of Ni–Sn–P coatings

ABSTRACT

The changes of the structure, microscopic morphology of electrodeposited Ni–Sn–P alloys before and after heat treatment in nitrogen were studied by means of X-ray diffraction and scanning electron microscopy. The corrosion behaviour was analysed by electrochemical impedance spectroscopy, anodic polarisation curves and potentiostatic polarisation corrosion. The results show that as the heat-treatment temperature increase, the structure of Ni–Sn–P alloy changed from amorphous to crystalline and the corrosion resistance of which decreased correspondingly. When the heat-treatment temperature was lower than 400°C, the electrodeposited Ni–Sn–P alloys remained amorphous structure and exhibited better corrosion resistance than that of electroless Ni–P coating in acidic medium.

KEYWORDS:

• Ni–Sn–P alloys
• heat-treatment
• crystal structure
• corrosion resistance

Disclosure statement

No potential conflict of interest was reported by the authors.