Corrosion Rate Of Titanium Research Articles

ANALISIS PENGARUH VARIASI HOLDING TIME ANNEALING TERHADAP LAJU KOROSI TITANIUM PADA LARUTAN CAIRAN TUBUH SINTETIS

Biomaterials are crucial for bone implants due to their biocompatible and inert nature, ensuring no adverse effects within the human body. Titanium is renowned for its exceptional corrosion resistance. This research aims to analyze the impact of annealing holding time and pH of synthetic body fluid on the hardness and corrosion rate of titanium. The annealing process was performed at 700°C, with holding times of 30, 60, and 90 minutes. As an electrolyte medium, a Hanks' solution with pH variations of 4, 6, and 8 was used and maintained at 37°C. Potentiodynamic corrosion testing demonstrated the lowest corrosion rate in specimens treated with 30 minutes of annealing at pH 8, measuring 0.32 x 10-2 mmpy. The 30-minute annealing exhibited the lowest corrosion rate, which was confirmed by Electrochemical Impedance Spectroscopy (EIS) results showing a higher Rp value, indicating a lower corrosion rate. This is attributed to the presence of a passive Rutile TiO2 layer formed during the annealing process, as confirmed by X-ray Diffraction (XRD) analysis. Metallography observations indicated that the microstructure of untreated specimens consisted of α and β phases. Scanning Electron Microscopy (SEM) analysis of specimens annealed for 30 minutes revealed an oxide layer on the surface without any visible pores. However, an increase in annealing holding time led to the formation of pores, particularly noticeable after 90 minutes of annealing. The presence of pores in the oxide layer resulted in an increased corrosion rate with longer annealing holding times. Conversely, hardness testing demonstrated that longer annealing holding times resulted in higher hardness values.

Активация реакции с участием твёрдого металла энергией электростатического заряда на металле

There are quantitative parameters of an electric energy capacitor artificially created in a chemical reactor were measured in this article. One of the components of this capacitor is the studied samples. Moreover, there are qualitative and quantitative relationships between samples and the accumulated electrical energy reserve of a metal (titanium) in the volume of the surface layer. There is penetration depth of the electrostatic charge into the metal from the outside of the system, energy of the electric field in the dielectric (carbon tetrachloride) and the corrosion rate of titanium in carbon tetrachloride determinate the reserve of electrical energy of the metal. In accordance with these equations, it can be argued that an external message due to the electrostatic charge of titanium in the surface layer of electric energy in the amount for 50 J/mol leads to a 2-fold increase in the reaction rate. There’s an analogy was made in the result of exposure to the samples between other non-standard methods of activation of the chemical reactions and the message from outside of the electrostatic charge in this article. According to this, the developed method for increasing the internal energy of the metal in the surface layer is proposed to be called electrostatic activation, and the reactions are called electrostatic-chemical.

Effects of dissolved oxygen on the electrochemical corrosion behavior of pure titanium in fluoride-containing weakly acidic solutions

The effects of dissolved oxygen (DO) on the electrochemical behavior of titanium in fluoride-containing weakly acidic solutions (pH = 5.0) were evaluated quantitatively by electrochemical methods, such as open circuit potential (OCP) measurements and potentiodynamic polarization tests, combined with corrosion morphology observation. The results showed that the electrochemical behavior changed from spontaneously passive to active-passive behavior with increasing the fluoride concentration irrespective of the DO content. DO was found to increase the critical fluoride concentration for the corrosion of titanium due to the increased limiting diffusion current density of oxygen reduction reaction and decreased maximum anodic current density caused by DO. But the corrosion rate of titanium would be accelerated by DO once the fluoride concentration exceeded the critical value. Moreover, corrosion products were observed on the surface when the fluoride concentrations were high enough and titanium was in the active state, which altered the electrochemical behavior of titanium further, such as facilitating the occurrence of OCP oscillation.

Corrosion behaviour of carbon steel, titanium and titanium alloy in simulated underground water in Beishan area preselected for nuclear waste repository in China

ABSTRACTThe groundwater will completely infiltrate to the surface of nuclear waste container after the closure of its deep geological disposal. Therefore, the corrosion behaviour of Q235 carbon steel, titanium and titanium alloy, which were the candidates as the container materials for high-level nuclear waste disposal in simulated groundwater solution of Beishan to be served as the preselected high-level nuclear waste disposal area in China at different temperatures, was studied through electrochemical methods including open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarisation curve measurements. The results show that the corrosion rate of titanium and titanium alloy is lower than that of carbon steel at all temperatures, and they are more promising as container materials. Another phenomenon is that higher temperatures facilitate the protection performance of corrosion products compared with lower temperatures.

Evaluation of Corrosion Rate and Surface Oxides Formed of Zr-2.5%Nb as an Implant Material in Ringer's Solution

Background/Objectives: Corrosion causes complications such as toxicity and inflammation by making changes in metals, fracture, relaxation and loss of implant strength. In biomaterial science, we try to select and combine materials to construct and design the implants that have less corrosion and consequently reduce complications as much as possible. Methods/ Statistical analysis: In this study, Zirconium-2.5 Niobium alloy was heat-treated to remove its residual stress after rolling operations. Surface oxides were diagnosed by XPS analysis on the desired alloy which had been kept for two years in Ringer's solution. To measure the corrosion rate parameter on the desired sample, corrosion test was conducted using a three-electrode cell method. Findings: Surface oxides Nb2O5 and ZrO2 were diagnosed by XPS analysis. The results showed that the corrosion rate in this alloy was less than the usual corrosion rate of Titanium implant and its alloys. Application/ Improvements: Biocompatible oxides alongside high in vitro corrosion make Zr-2.5Nb alloy as favorable surgical implants.

High Temperature Corrosion of Titanium Under Conditions Relevant to Pressure Leaching: Mass Loss and Electrochemistry

The corrosion behavior of titanium was studied using mass loss and electrochemical measurements in sulfuric acid with Cl−, Cu2+, and Fe3+ additions up to 175°C. The corrosion rate of titanium in 30 g L−1 H2SO4 + 12 g L−1 Cl− solution at 150°C measured by mass loss was higher than 62 mm y−1. The corrosion rates of titanium under simulated pressure-leaching conditions determined by both mass loss and polarization resistance measurements were consistent, and also suggest that Cu2+ and Fe3+ ions are excellent corrosion inhibitors for titanium. Results from mass loss and electrochemical measurements all confirmed that the corrosion rate of titanium decreased remarkably with the addition of 1 g L−1 Fe3+ to the leaching solution at 150°C, and that the presence of Fe3+ is the most important factor for the growth of titanium oxide films under pressure-leaching conditions. In addition, iso-corrosion diagrams, with 0.1, 0.5, and 1 mm y−1 lines for titanium in H2SO4 solutions from room temperature to 175°C, were cons...

Effect of plasma treatment on corrosion-electrochemical behavior of titanium in molten mixture of cesium and sodium chlorides

The effect of high-temperature pulsed plasma (HTPP) on the corrosion-electrochemical behavior of titanium in a molten eutectic mixture of cesium and sodium chlorides in an argon atmosphere at temperatures of 790–810 K is studied. Upon the HTPP treatment in an oxygen or helium environment, a modified corrosion-resistant layer with a thickness up to 20 µm is formed on the titanium surface and decreases the corrosion rate of titanium in a chloride melt by a factor of 10–16.

Corrosion rate of titanium in H 2SO 4

The corrosion rates of titanium in 1–4 M H 2SO 4 at temperatures of 298, 313 and 333 K were measured. It was found that etching in 5% HF strongly decreases the time for the passive-active transition (self-activation) of titanium in H 2SO 4 and it was therefore used as an initial pretreatment for all samples. The steady state corrosion rates of titanium in H 2SO 4 increased linearly with the cube of the molar concentration.

The influence of pulverised fuel ash on the corrosion rate of titanium

Titanium has been used as a lining material for ductwork and chimneys in power and flue gas desulphurisation plants. In these environments the metal will be exposed to both condensed acids and pulverised fuel ash. Experience on a pilot plant indicated that the resistance of titanium to corrosion by condensed acids was significantly enhanced by the presence of ash. The corrosion of titanium in aerated hydrochloric acid solutions at 50°C containing varying amounts of ash was investigated by potentiodynamic scans and electrochemical impedance spectroscopy. In the absence of ash the titanium corroded freely, an active peak was observed in the potentiodynamic scans and semi-circles in Nyquist plots of the impedance spectra. Modelling of the impedance spectra gave corrosion rates between 0.8 and 1.0 mm y −1. With additions of ash to the solution of greater than 1%, the corrosion rate was reduced by two orders of magnitude. It was found that a minium level of ash was required to inhibit corrosion. An unusual potential cycling effect was observed in the presence of low levels of ash. A mechanism involving anodic inhibition of the titanium by metal ions leached from the ash is proposed.

Inhibitor Development for Titanium Corrosion

Abstract An aromatic derivative study showed how corrosion inhibitors were developed for the control of titanium dissolution in sulfuric acid. Included were the effects of temperature and concentration on the corrosion rate of titanium. Test results indicated distinctly critical concentrations for effectiveness; lower concentrations accelerated dissolution rates. The more effective inhibitors apparently formed permanent complexes with the titanium atom within the lattice structure. Potentiodynamic polarization curves suggest that the class of derivatives were passivator type inhibitors. The root structures were: phenol, aniline, toluene, and nitrobenzene. The more effective structures were: 2,4, 6-trinitrophenol, 5-nitroquinoline, 8-nitroquinoline, o-dinitrobenzene, and m-nitroacetanilide.

The anodic behaviour of titanium in HCl-methanol solutions

The anodic behaviour of titanium has been studied in 0·1–11 ·0 M HCl-methanol solutions. At cds up to 1 A/cm 2 dissolution occurs with 100 per cent efficiency based on the reaction Ti → Ti 3+ + 3e. Anodic disintegration occurs at these cds, the disintegration product being particles of α-titanium of similar size to that of the metal grains in the anode. The amount of disintegration product formed on the passage of constant electrical charge increases proportionately with the reciprocal of the cd and this relationship has been derived theoretically. The presence of hydride films on dissolving titanium (TiH 1·9) has been confirmed by X-ray diffraction. Disintegration is accompanied by surface pitting. In the presence of > 1 per cent H 2O the amount of disintegration decreases until at > 10 per cent H 2O disintegration does not occur and the features of the surface are similar to those in HCl(aq) solutions. When anodically polarized in 0·1–11.0 M HCl-methanol solutions titanium dissolves at cds of up to 50–100 mA/cm 2 under activation control and Tafel behaviour is observed. The Tafel slope is 0·115 ± 0·004 V at 25°C and is independent of HCl concentration. The corrosion cds (0·22–0.34 mA/cm 2) are also independent of HCl concentration. At cds > 50–100 mA/cm 2 a limiting cd is observed, although this is only clearly defined in 11·0 M solutions. The corrosion rate of titanium as determined from immersion tests is in agreement with that deduced from kinetic studies. The mechanism of dissolution of titanium is discussed and it is concluded that the over-all dissolution reaction is of the type [TiCl ads] − → [TiCl ads] 2+ + 3e. Solvation of such species with methanol is also possible but there is as yet insufficient evidence to decide upon the individual rate-controlling step.

Effect of Platinum, Copper and Iron Ions On Corrosion and Passivity of Titanium In 15 Percent Hydrochloric Acid

Abstract An investigation has been made of the effect on corrosion rate of titanium in 15 percent hydrochloric acid of introducing cations of more noble metals, particularly Pt4+, Cu2+ and Fe3+. It was found that such ions cause a shift in metal potential in the positive direction, enhancing the cathodic process and resulting in anodic passivity of the titanium. In addition to acting initially as cathodic depolarizers, the noble metals deposit galvanically, forming more effective cathodic areas and further accelerating cathodic depolarization. However, in concentrations lower than those required to attain passivity, the noble metal ions increase rather than decrease the corrosion rate of titanium in 15 percent hydrochloric acid. In the presence of the fluoride ion, Pt4+ ions accelerate the corrosion rate of titanium in HCI with increases in their concentration, the opposite of the effect when concentrating Pt4+ ions before fluoride is introduced.

チタンの電氣化學的性質に關する研究(第1報)

The reason why the spontaneous potential of titanium vibrates periodically to positive and negative directions in distilled or tap water, changing gradually to positive value with time, is that the positive and the negative ions accumulated in anodic (in pin holes of the oxide film) and cathodic (the oxide film) areas respectively, are not neutralized until they attain a certain amount in water. The spontaneous potential of titanium changes to a negative value with time in such solutions under natural aeration as HF>0.005%, HCl>10%, H2SO4>5%, H3PO4>30%, NH4F>0.01%. On the contrary, in such solutions as of HNO3, CrO3, K2Cr2O7 and K2MnO4 in acid solutions, Cu++, Fe+++, Ag+, it varies largely to a positive value and titanium is passivated. The corrosion rate of titanium in naturally aerated HF, H2SO4 or HCl solutions containing different oxidizing agents was measured.