Ti-Mo系焼結合金の腐食挙動について Corrosion Behavior of Ti-Mo Sintered Alloy
The corrosion behavior of Ti-(0-40)mass%Mo alloys prepared through P/M technology was studied by corrosion test and electrochemical measurements. The corrosion rate of sintered Ti-Mo alloys in 35% HCl solution decreased remarkably with increasing molybdenum content. The corrosion rate of Ti-40mass%Mo alloy, for example, exhibited 5*10<SUP>-3</SUP> [mm/year], which was 10<SUP>4</SUP> times lower than that of pure titanium. On the other hand, the corrosion rate in 3%NaCl solution wasn't affected by molybdenum content in alloys and was less than 10<SUP>-3</SUP> [mm/Year].<BR>Potentiodynamic polarization curves in 35%HCl solution showed that increasing molybdenum content caused the open circuit potential (corrosion potential) to be noble and the anodic current density to be low. It was thought that the presence of spontaneously passivated film in which molybdenum was enriched by preferential dissolution of titanium suppressed the anodic reaction and improved their corrosion resistance. On the other hand, potentiodynamic polarization curves in 3%NaCl solution revealed that increasing molybdenum content caused the open circuit potential to be base and the anodic current density to be high because molybdenum dissolved actively.
粉体および粉末冶金 44(3), 241-246, 1997-03-15
Japan Society of Powder and Powder Metallurgy