The Study on the Anti-corrosion Performance of NiTi Alloy in Human Body Solution with the Fabricating Processes of Laser Irradiation and PDMS Modification

Abstract

This paper presents a new and safe method of fabricating super-hydrophobic surface on NiTi Shape Memory Alloy (SMA), which aims to further improve the corrosion resistance performance and biocompatibility of NiTi SMA. The super-hydrophobic surfaces with Water Contact Angle (WCA) of 155.4° ± 0.9° and Water Sliding Angle (WSA) of 4.4° ± 1.1° were obtained by the hybrid of laser irradiation and polydimethylsiloxane (PDMS) modification. The forming mechanism was systematically revealed via Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The anti-corrosion of samples was investigated in Simulated Body Fluid (SBF) via the potentiodynamic polarization (PDP) and Electrochemical Impedance Spectroscopy (EIS) tests. PDMS super-hydrophobic coatings showed superior anti-corrosion performance. The Ni ions release experiment was also conducted and the corresponding result demonstrated that the super-hydrophobic samples effectively inhibited the release of Ni ions both in electrolyte and SBF. Besides, biocompatibility was further analyzed, indicating that the prepared super-hydrophobic surfaces present a huge potential advantage in biocompatibility.

Corrosion characterization of NiTi alloy by femtosecond laser surface processing

“…The larger the diameter, the greater the corrosion resistance of the material. [ 26 ] NiTi‐V had the largest diameter, followed by NiTi‐III and NiTi‐I, while NiTi‐II and NiTi‐IV had the smallest diameters. As shown in Figure 5b, at the low frequency from 0.01 to 0.1 Hz, the impedance modulus | Z | ranks as follows: | Z | (NiTi‐V) > | Z | (NiTi‐III) > | Z | (NiTi‐I) > | Z | (NiTi‐IV) > | Z | (NiTi‐II) .…”

“…The treated samples, a Pt plate (20 mm × 20 mm × 0.1 mm) and a saturated calomel electrode were used as the working, counter, and reference electrodes, respectively. [ 26 ] The working electrode, with a surface area of 1 × 1 cm 2 , was exposed to Hank's solution. The compositions of the solutions are listed in Table 2.…”

“…NiTi-V 16.5 Yes electrodes, respectively. [26] The working electrode, with a surface area of 1 × 1 cm 2 , was exposed to Hank's solution.…”

“…[25] Furthermore, superhydrophobic NiTi alloy surfaces created through a combination of laser irradiation and polydimethylsiloxane modification exhibited superior anticorrosion performance and effectively inhibited corrosion. [26] Compared to chemical deposition after laser texturing, researchers have fabricated microstructures of different scales on 316 L stainless steel substrates by laser modification, which exhibit excellent self-cleaning performance and corrosion resistance. [27] The studies mentioned above generally concentrate on fabricating superhydrophobic structures on metal surfaces to increase surface corrosion resistance.…”

Investigation on the Corrosion Resistance Properties of Cobalt–Chromium–Molybdenum Alloy Artificial Human Body Components with Robust Biomimetic Superhydrophobic and Slippery Surfaces Based on Laser Texturing

“…In contrast, laser texturing has been increasingly used in the preparation of superhydrophobic surfaces and corrosion-resistant fields in recent years due to its advantages, such as processing efficiency, strong controllability, and low pollution. By imitating examples of superhydrophobicity in nature, such as lotus, water strider leg, fish scale, reed leaf, and so on, a micronanocomposite structure was established on the surface using laser texturing, and a superhydrophobic surface was prepared by adsorbing organic matter to reduce surface energy. − The general methods for adsorbing organic matter can be divided into placing and using modifiers in the air, with the latter having better effectiveness and rapidity. − Further research has found that superhydrophobic surfaces have enhanced salt corrosion resistance compared to the pristine surface, improving the service life of metals in production and usage. − There are several reasons for this corrosion resistance effect. First, the surface structure is a significant factor.…”