Corrosion stability of nickel in Ni-alloys in synthetic sweat

Abstract

Skin contact with a metallic object containing nickel is liable to provoke allergic reactions if the quantity of nickel released is higher than a threshold of 8·267·10−12 kg m−2 s−1 (0·5 μg cm−2 week−1). The release of nickel is determined by analysing the nickel in synthetic sweat in which the sample has lain for a week. The techniques used are atomic emission spectrophotometry for the analysis of the sweat and electron dispersive spectroscopy for the surface analysis. The results obtained for three different Ni-alloys enabled us to underscore the importance of the corrosion test parameter (volume of synthetic sweat per surface unit) on the quantity of nickel liberated, and thus leading us to a reflection about the mechanism of nickel dissolution within the framework of a reference test.