Corrosion Resistance of Titanium-Magnesium Alloy in Weak Acid Solution Containing Fluoride Ions

Abstract

  We have developed Ti-Mg alloy for dental material corrosion-resistant to aqueous fluoride solutions. Ti plates and granular Mg was put in a sealed vessel and heated at 950℃, so Ti plates were exposed in the liquid and the vapor Mg phases. The conditions made Mg diffuse into the Ti plates to produce Ti-Mg alloy. The Ti-Mg alloy produced in the vapor Mg phase for 430 h achieved homogeneous distribution in Mg concentration of 0.2 at%. A Vickers micro hardness increased almost linearly with an increase in the Mg concentration, and the hardness of the homogeneous Ti-0.2 at%Mg was about 1.2 times larger than that of Ti before alloying. It was confirmed that corrosion resistance of Ti in the fluoride solution was improved by alloying with Mg. The method using the vapor Mg phase contributed much more effective improvement of corrosion resistance than that using the liquid phase. The homogeneous Ti-0.2 at%Mg demonstrated a maximum corrosion resistance of all the specimens, by about 80 times to Ti.