Characteristics and corrosion behavior of Ti–30Nb–5Sn alloys in histidine solution with various NaCl concentrations

The electrochemical studies of the Ti-30Nb-5Sn arc vacuum furnace's corrosion behaviour were performed in histidine solution, and the effect of NaCl addition on the corrosion behaviour of Ti-30Nb-5Sn in histidine was investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, as well as Bode phase angle plot.Meanwhile, the microstructure and mechanical properties of Ti-30Nb-5Sn were examined before and after homogenization with micro-Vickers as well as optical microscopy.X-Ray Diffraction test was also conducted to characterize the phase contained before and after the homogenization of Ti-30Nb-5Sn alloys.Based on this analysis, the heat treatment at 1000°C for 5 h was discovered to increase the hardness properties of 346.7 HV and the respective beta phase transformation along the alloys' grain boundaries. Consequently, the corrosion potential in heat-treated alloys was increased by 0.14% histidine +0.12% NaCl, compared to 0.14% histidine + 3% NaCl -442.0 mV, hitting Ecorr -385.0 mV.In addition, the highest corrosion rate was observed in the samples within 0.14% histidine + 3% NaCl of 15.53•10 -3 mmpy.Therefore, the presence of histidine contributed to a higher level of corrosion potential and the addition of NaCl into the histidine solution increased the corrosion rate of Ti-30Nb-5Sn.