Corrosion degradation of surface modified bio–magnesium materials by heat–self–assembled monolayer

Mg and a Mg–Ca alloy were heat treated at 773 K for 10h and self–assembled in stearic acid alcohol solution of 0.5mol/L for 1.5 h to improve the corrosion properties and biocompatibility of bio–magnesium materials. And then comparison research was carried out for the bio–magnesium materials with and without modification by putting in simulated body fluid and in vivo animal test. Electronic balance, SEM, EDS, XRD FTIR, digital electronic pH meter and atomic absorption spectrometry were used to analyse the corrosion process, corrosion rate and the products. The results showed that the corrosion resistance and bioactivity of the bio–magnesium materials with heat–self–assembled monolayer were improved. The corrosion rate of Mg changed from 0.11 mm/y to 0.05 mm/y, and that of Mg–Ca alloy from 0.38 mm/y to 0.32 mm/y. The diameter of Mg in thigh bone of the tested rabbit for 12 weeks decreased from 0.97 mm to 0.20 mm, and thickness of new bone increased from 2.563 mm to 3.135 mm.