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Titanium Grade 4 (Ti G4) is the most commonly used material for dental implants due to its excellent mechanical properties, chemical stability and biocompatibility. A thin, self-passive oxide layer with protective properties to corrosion is formed on its surface. However, the spontaneous TiO2 layer is chemically unstable. In this work, the impact of autoclaving time on corrosion resistance of Ti G4 in artificial saliva solution with pH = 7.4 at 37 °C was studied. Ti G4 was sandblasted with white Al2O3 particles and autoclaved for 30–120 min. SEM, EDS, 2D roughness profiles, confocal laser scanning microscopy, and a Kelvin scanning probe were used for the surface characterization of the Ti G4 under study. In vitro corrosion resistance tests were conducted using open circuit potential, polarization curves, and electrochemical impedance spectroscopy measurements. It was found that Sa parameter, electron work function, and thickness of the oxide layers, determined based on impedance measurements, increased after autoclaving. The capacitive behavior and high corrosion resistance of tested materials were revealed. The improvement in the corrosion resistance after autoclaving was due to the presence of oxide layers with high chemical stability. The optimal Ti G4 surface for dentistry can be obtained by sandblasting with Al2O3 with an average grain size of 53 µm, followed by autoclaving for 90 min.

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The subject of this work is Ni50Mo40Ti10 alloy produced by mechanical alloying and subsequent heat treatment. The obtained material was tested as electrode for the hydrogen evolution reaction (HER) in an alkaline environment. The results were compared with those obtained for the Ni50Mo50 catalyst. Electrochemical characterization was carried out by the steady‐state polarization method and the electrochemical impedance spectroscopy (EIS). On the basis of the results of the EIS measurements, the average rate constant of the HER was determined. The calculated values of surface roughness factor, Rf, allowed to evaluate the true catalytic effect of the investigated electrode material. It was stated that Ni50Mo40Ti10 alloy annealed at 1173 K exhibits the higher electrocatalytic activity for the HER compared with the Ni50Mo50. The increase in the intrinsic activity could be attributed to the presence of NiMo intermetallic phase and Ni(Ti) solid solution. Copyright © 2014 John Wiley & Sons, Ltd.

Calcium phosphate coatings are able to improve the osseointegration process due to their chemical composition, which is similar to that of bone tissues. In this work, to increase the long-term corrosion resistance and to improve the osseointegration process of commercially pure titanium Grade 4 (CpTi G4), biomimetic amorphous calcium phosphate (ACP) coatings were electrodeposited for the first time from an acetate bath with a pH level of 7.0 and a Ca:P ratio of 1.67. ACP coatings were obtained on CpTi G4 substrate subjected to sandblasting and autoclaving using electrochemically assisted deposition at a potential of −3 V relative to the open circuit potential for 30 min at room temperature. SEM, EDS, 2D roughness profiles, amplitude-sensitive eddy current method, and Kelvin scanning probe were used for the surface characterization of the biomaterial under study. In vitro corrosion resistance tests were conducted for 21 days in artificial saliva using open circuit potential, polarization curves, and electrochemical impedance spectroscopy measurements. The passive-transpassive behavior was revealed for the obtained ACP coatings. The long-term corrosion resistance test showed a deterioration of the protective properties for CpTi G4 uncoated and coated with ACP with immersion time. The mechanism and kinetics of the pitting corrosion on the CpTi G4|TiO2|ACP coating system are discussed in detail.

Solvents are widely used in organic synthesis. Sulfolane is a five-membered heterocyclic organosulfur sulfone (R-SO2-R’, where R/R’ is alkyl, alkenyl, or aryl) and an anthropogenic medium commonly used as industrial extractive solvent in the liquid-liquid and liquid-vapor extraction processes. Under standard conditions sulfolane is not aggressive towards steel, but at higher temperatures and in oxygen, water, or chlorides presence, it can be decomposed into some corrosive (by-)products with generation of SO2 and subsequent formation of corrosive H2SO3. This pilot-case study provides data from laboratory measurements performed in low conductivity sulfolane-based fluids using an industrial multi-electrochemical technique for reliable detection of corrosion processes. In particular, a comprehensive evaluation of the aqueous phase impact on general and localized corrosion of AISI 1010 carbon steel in sulfolane is presented. Assessment of corrosive damage was carried out using an open circuit potential method, potentiodynamic polarization curves, SEM/EDS and scanning Kelvin probe technique. It was found that an increase in the water content (1–3 vol.%) in sulfolane causes a decrease in the corrosion resistance of AISI 1010 carbon steel on both uniform and pitting corrosion due to higher conductance of the sulfolane-based fluids.