This work aims to assess the influence of corrosion on fracture of nickel titanium (NiTi) superelastic wires in physiological solutions (9 g/l NaCl) with and without addition of 1 g/l NaF. The electrochemical cell was coupled to a Hounsfield Tensiometer tensile machine commonly used for corrosion investigation of alloys under stress and strain. Corrosion tests were performed on unstrained and strained conditions up to 4% total strain. This strain limit corresponds to 50% of the total elongation achieved into the superelastic stress plateau of the alloy. All wire specimens were analyzed after testing by scanning electron microscopy (SEM). The results showed that localized corrosion occurred for NiTi wires in solution containing fluoride, while no corrosion attack was detected in NaCl 9 g/l solution. There was no significant difference between the corrosion resistance of unstrained and strained wires. However, brittle like fracture occurred in NaCl + NaF solution within the superelastic domain of the material. The most relevant conclusion achieved is that the use of superelastically strained NiTi in oral environments in the presence of fluoride is followed by significant risk of corrosion induced fracture.

这项工作旨在评估在添加或不添加1 g / l NaF的情况下，腐蚀对生理溶液（9 g / l NaCl）中镍钛（NiTi）超弹性线材断裂的影响。电化学电池与Hounsfield张力计拉伸机相连，该机通常用于研究应力和应变下合金的腐蚀。腐蚀试验是在总应变不超过4％的非应变和应变条件下进行的。该应变极限对应于达到合金超弹性应力平稳期的总伸长的50％。在测试之后，通过扫描电子显微镜（SEM）分析所有金属丝样品。结果表明，NiTi丝在含氟溶液中发生局部腐蚀，而在NaCl 9 g / l溶液中未发现腐蚀。未拉紧和拉紧的电线的耐腐蚀性之间没有显着差异。但是，在材料的超弹性域内的NaCl + NaF溶液中发生了脆性断裂。得出的最相关结论是，在存在氟化物的口腔环境中使用超弹性应变的NiTi会导致腐蚀引起的断裂的风险显着。