Studies on NiTi Alloys for Dental Casting : Part 1: The Improvement of the Mechanical Properties and the Corrosion Resistance by the Addition of Au

Abstract

This study investigated the effects of the addition of Au to NiTi alloys in order to improve their properties for medicine and dentistry. Ni-49.4Ti-4〜5Au (at%) cast specimens showed super-elasticity at 37℃, which allowed them to recover their shapes from the deformation of 3%, about ten times more than the strain of the proportional limit of Au-Pt alloys. Cast specimens consisting of Ni-49.4Ti-3Au (at%) and Ni-49.5〜49.6Ti-4Au (at%) recovered their shapes by heating to 55〜65℃. These alloys had adequate tensile strength and adequate elongation, and the amount Ni cations that dissolved from them was very small in 0.9% NaCl solution and 1% lactic acid.