Effect of artificial aging conditions on corrosion resistance of a TiNi alloy

Abstract

The present paper is focused on three different aging treatment of a TiNi alloy in order to enhance corrosion resistance in oral cavity environment. The best corrosion resistance in artificial saliva after aging treatment was found in the case of sample which was heat treated at 700 °C/20 min/water cooled, followed by aging at 400 °C/1.5 h/water cooled. Subsequent to such a heat treatment, the EDX surface analysis indicated an increase of Ti content of the matrix. This effect is in connection with stable and metastable precipitates which appear during the aging. Also, based on the greater affinity to oxygen of Ti compared to Ni, a uniform Ti based oxide layer is predominant explaining the better electrochemical stability. The obtained precipitates morphology is also an important factor in the corrosion behavior.

DFT investigation of the dissolution trends of NiTi alloys with the B2 and B19′ phases during the initial oxidation stage

“…Studies have shown that the work function is related to corrosion resistance, and it is widely accepted that when the same metal is immersed in different solutions, an increase in the work function signifies a positive shift in the corrosion potential. 56,57 Based on this, we concluded that the adsorption of atomic O enhances the corrosion resistance of the NiTi alloy, which is not only because of the TiO 2 protective film 58 but also because atomic O adsorption impedes electron escape from the metal.…”

Obtaining and Characterization of Ni-Ti Alloys Processed through Powder Metallurgy

“…Compressed materials were then sintered into vacuum (P1) and those with severe plastic deformation, HPT, were also characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and optical microscopy (figure 1) [1,2,9,10,11,12].…”

Characterisation of passive film and corrosion behaviour of a new Ti-Ta-Zr alloy in artificial oral media: In time influence of pH and fluoride ion content

“…Three types of electrochemical techniques were used: cyclic potentiodynamic polarisation, linear polarisation, electrochemical impedance spectroscopy (EIS) . Also, the open circuit potentials, E OCP and corresponding open circuit potential gradients, ΔE OCP due to the pH and non‐uniformities content of the saliva were monitored for 1000 immersion hours in artificial Carter‐Brugirard saliva.…”