Titanium alloys have been used in aerospace, aeronautic, automotive, biomedical, structural, and other applications because titanium alloys have less density than materials like steel and support higher stress than Al-alloys. However, components made of titanium alloys are exposed to corrosive environments, the most common being industrial and marine atmospheres. This research shows the corrosion behavior of three titanium alloys, specifically Ti-CP2, Ti-6Al-2Sn-4Zr-2Mo, and Ti-6Al-4V with α, near α, and α + β alloys phases. Alloys were exposed in two electrolytes to a 3.5 wt. % H₂SO₄ and NaCl solution at room temperature, and their electrochemical behavior was studied by electrochemical noise technique (EN) according to ASTM ASTM-G199 standard. EN signal was filtered by three different methods, and the polynomial method was employed to obtain R_n, kurtosis, skew, and the potential spectral density analysis (PSD). The wavelets method was used, from which energy dispersion plots were obtained. The last method was Hilbert–Huang Transform (HHT), where Hilbert Spectra were analyzed. Results indicated that R_n compared with PSD showed that Ti-6Al-2Sn-4Zr-2Mo presented less dissolution in both electrolytes. Statistical methods showed that the passive layer created on Ti alloys’ surfaces is unstable; this condition is notable for Ti-6Al-2Sn-4Zr-2Mo in NaCl solution.

中文翻译：

---

钛合金在NaCl和H2SO4溶液中腐蚀的电化学噪声分析

钛合金已用于航空航天，航空，汽车，生物医学，结构和其他应用，因为钛合金的密度低于钢之类的材料，并且比铝合金具有更高的应力。然而，由钛合金制成的部件暴露于腐蚀性环境中，最常见的是工业和海洋环境。这项研究显示了三种钛合金的腐蚀行为，特别是Ti-CP2，Ti-6Al-2Sn-4Zr-2Mo和Ti-6Al-4V，它们具有α，近α和α+β合金相。使合金在两种电解质中暴露于3.5 wt。％H ₂ SO ₄在室温下使用NaCl溶液和NaCl溶液，并根据ASTM ASTM-G199标准，通过电化学噪声技术（EN）研究了它们的电化学行为。通过三种不同的方法对EN信号进行滤波，然后采用多项式方法获得R _n，峰度，偏度和电势谱密度分析（PSD）。使用小波方法，从中获得能量色散图。最后一种方法是希尔伯特-黄变换（HHT），在其中分析了希尔伯特光谱。结果表明R _n与PSD相比，Ti-6Al-2Sn-4Zr-2Mo在两种电解液中的溶解度均较低。统计方法表明，在钛合金表面形成的钝化层是不稳定的。对于NaCl溶液中的Ti-6Al-2Sn-4Zr-2Mo，此条件值得注意。