Corrosion Of Titanium Research Articles

The influence of 1-(2-pyridylazo)-2-naphthol (PAN) on the corrosion of titanium in 10 N sulfuric acid solution

The influence of several naphthol derivatives on the corrosion behavior of titanium in 10 N H 2SO 4 solution has been studied by measuring the weight loss and analysing the polarization curves, electrode impedance, voltammograms and UV-visible spectra. 1-(2-pyridylazo)-2-naphthol (PAN) is an excellent inhibitor for titanium corrosion in concentrated acid solution at room temperature, 35 °C and 55 °C, even at a low concentration of 2 mM. Its inhibition efficiency is higher than that of some well-known organic inhibitors for titanium corrosion at high temperature. The stability of PAN as an inhibitor and the influence of the surface state of titanium on the inhibition efficiency of PAN have also been investigated.

Corrosion of titanium and amalgam couples: Effect of fluoride, area size, surface preparation and fabrication procedures

Objectives. The aim of this investigation was to study the effect of surface treatments and electrode area size on the corrosion of cast and machined titanium in contact with conventional and high-copper amalgams in saline solutions with and without added fluoride ions. Methods. The potentials and the charges transferred between amalgam and titanium couples were registered using standard electrochemical methods. Results. Conventiional amalgam corroded more than high-copper amalgams in contact with titanium in saline solutions. Adding fluoride to the solution made the titanium potential more active and enhanced the corrosion of titanium in combination with high-copper amalgams. The amalgam corrosion increased with a five-fold enlargement of the titanium area. The increase was significant for one titanium-amalgam combination. Surface preparations affected the electrochemical behavior, and surface alterations were occasionally observed on wet-ground titanium specimens. No significant differences were found in comparisons of cast and lathe-cut titanium. Significance. Surface preparations and fluoride affect the electrochemical activity of titanium.

チタンの耐食性に及ぼす各種添加金属の影響

チタンの耐食性に及ぼす各種添加金属の影響

Hydrogen absorption and its prevention of titanium in a simulated descaling environment in a desalination plant

In a desalination plant constructed with titanium (tubes), copper alloy (tube plate) and steel or Fe-9% Ni alloy (sacrificial anode), the most preferred condition of acid dosing for descaling seems to be sulfamic acid solution containing IBIT (trade name of Asahi Chemical) as an inhibitor, from the point of view of prevention of titanium, copper alloy steel and Fe-9% Ni alloy against corrosion and hydrogen absorption. In this case the conditions should be kept in the following range: Concentration of sulfamic acid, 1–4%; temperature, under 60°C; and concentration of IBIT, approximately 0.2%. A 4% H 2SO 4 with 0.5% HNO 3 or IBIT solution can also prevent the corrosion and hydrogen absorption of titanium, but operation conditions for descaling (temperature, operation time, etc.) must be strictly controlled in this case because the corrosion rate of Cu-Ni alloy and steel are higher than that in sulfamic acid.

Corrosion of Carbon Steels, Stainless Steels, and Titanium in Aqueous Lithium Bromide Solution

Abstract Effects of lithium bromide (LiBr) concentration, pH, temperature, exposure time, and the action of some inhibitors on corrosion of several carbon (C) steels, stainless steels (SS), and a titanium (Ti) alloy were studied. Corrosion rates were determined by the polarization resistance method and compared to rates determined by weight-loss measurements. Pitting potentials (Ep) were evaluated in neutral LiBr solution and with different inhibitors. Pit density and average pit depth depended on the metal tested, with lowest values for Ti, the next lowest values for type 316 SS (UNS S31600), and the highest values for UNS G41350 tempered steel.

Pitting Corrosion of Titanium

The breakdown of native and anodically grown oxide films on Ti electrodes is investigated by scanning electrochemical microscopy (SECM), video microscopy, transmission electron microscopy, and voltammetry. SECM is used to demonstrate that the oxidation of Br− on Ti occurs at microscopic surface sites (10 to 50 μm diam, 30 sites/cm2) that are randomly positioned across the oxide surface. After determining the position of the active sites for Br− oxidation, breakdown of the oxide is initiated by increasing the electrode potential to more positive values. Direct correspondence is observed between the location of the electroactive sites and corrosion pits, indicating that oxide breakdown is associated with a localized site of high electrical conductivity. The potential at which pitting is observed in voltammetric experiments is found to be proportional to the average oxide thickness, for values ranging between 20 and 100 Å, indicating that breakdown is determined either by the magnitude of the electric field within the oxide or by the interfacial potential at the oxide/Br−solution interface. Pitting occurs at significantly lower potentials in Br− solutions than in Cl− solutions, suggesting a strong chemical interaction between the surface and Br−. A mechanism of oxide breakdown is proposed that is based on the potential‐dependent chemical dissolution of the oxide at microscopic surface sites.

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.

Corrosion of coupled metals in a dental magnetic attachment system.

Implants and magnetic attachments are becoming widespread in dental treatment. Their associated use, implants and magnetic attachments, can be seen often too. In those cases, it is difficult to avoid coupling of different metals. The corrosion behavior of the metals is expected to be different depending on whether it is found in an isolated or a coupled condition. Potential corrosion couples in a dental magnetic attachment system among titanium, ferromagnetic stainless steel, gold alloy type IV, and gold-silver-palladium alloy were studied by an immersion test in 1% lactic acid for 7 days and potential/current density curves were measured. Corrosion of titanium and ferromagnetic stainless steel seemed to be accelerated by coupling with gold alloys or gold-silver-palladium alloys. On the other hand, the corrosion amount of gold alloy and gold-silver-palladium alloys were attenuated by coupling.

The kinetics and mechanism of the low temperature corrosion of titanium with copper(I) chloride. A comparison with silicon and an SiTi alloy

Kinetics analysis of the thermogravimetric curves obtained for the corrosion of titanium or TiSi 2 with copper(I) chloride(CuCl) in the temperature range 240–290 °C revealed that the isothermal reaction is governed by a nucleation-growth mechanism with an apparent activation energy of 207 kJ mol −1 for the Ti/CuCl and 153 kJ mol −1 for the TiSi 2/CuCl system. In both cases X-ray diffraction analysis indicated the formation of only copper during the course of the reaction, in contrast to Me/CuCl systems (Me ≡ Si, Ge) where MeCu χ compounds are also identified as intermediate reaction products.

Lifetimes of Titanium and Copper Containers for the Disposal of Used Nuclear Fuel

ABSTRACTTitanium and copper have been proposed as suitable container materials for disposal of nuclear fuel waste in plutonic rock of the Canadian Shield. Studies of the corrosion of these materials have led to the development of container failure models to predict long-term performance. Crevice corrosion and hydrogen-induced cracking of titanium have been identified as potential failure mechanisms, and these two processes have been studied in detail. Using data from these studies as well as a number of conservative assumptions, titanium container lifetimes of 1200 to 7000 a have been estimated. For copper, general corrosion has been studied in detail in bulk solution and in compacted clay-based buffer material. Results indicate that the copper corrosion rate is likely to be controlled by the rate of transport of copper species away from the container surface. An assessment of copper pitting data suggests that pitting is an extremely improbable failure mechanism. The copper container failure model predicts minimum container lifetimes of 30 000 a. The results demonstrate that long lifetime containment can be provided, should performance assessment studies indicate the need for such an option.

Method for prevention of corrosion of titanium and its alloys in sulfuric acid by inhibition with titanyl ion

Method for prevention of corrosion of titanium and its alloys in sulfuric acid by inhibition with titanyl ion

電子論によるチタン合金の耐食性の評価

In order to understand alloying effects on the corrosion of titanium, polarization curves were measured at 343 K in 10 mass%H2SO4 solution for various Ti-M binary alloys (M=Al, Nb, Ta, Zr, Hf, Fe, V, Cr and Mo). The results were interpreted in terms of two parameters obtained by the molecular orbital calculation; one is the bond order (Bo) and the other is the metal d-orbital level (Md). Bo is a measure of the strength of covalent bonds between titanium and alloying elements. Md is correlative with the electronegativity of elements.It was found that alloys containing elements with higher Bo values showed a lower critical anodic current density in the polarization curve and hence higher corrosion resistance. On the other hand, Md appears to be associated with the corrosion potential of alloys. It is likely that both Bo and Md are useful parameters for describing the corrosion of titanium alloys in a reducing atmosphere such as hydrochloric or sulfuric acid.

Effect of nitride coatings on corrosion and electrochemical properties of technical titanium

Effect of nitride coatings on corrosion and electrochemical properties of technical titanium

A sims investigation of hydrogen penetration of titanium electrodes

The corrosion of titanium in acidic solution leads to the accumulation of substantial amounts of hydrogen in the metal, modifying the subsequent voltammetric behaviour of the electrode. SIMS has been used to show that hydrogen penetrates into the metal to a depth of several microns during prolonged exposure to acid solutions and the SIMS images obtained suggest that crystalline platelets of titanium hydride are formed in a titanium matrix under these conditions. The hydride is only partially oxidised during subsequent anodisation of the titanium, so that successive passivation/activation cycles lead to the progressive build up of hydride.

Corrosion and hydrogen embrittlement of titanium in aqueous sulfate and sulfidic solutions

Aqueous solutions which contain H2SO4, H2S or mixtures of H2S and NH3 are corrosive to carbon steel and other commonly used alloys. Therefore, titanium has been evaluated as a possible construction material in these environments. This paper summarizes the results of a study of the corrosion, galvanic and hydrogen embrittlement behaviour of titanium in aqueous sulfidic and sulfate solutions. Variables discussed include the effect of solution pH, temperature and solution composition on the corrosion and electro chemical behaviour including galvanic effects of titanium. This paper also considers the effect of pH, temperature and mechanical loading rate (strain‐rate) on the ductility and embrittlement of titanium.

ChemInform Abstract: The Influence of Hydrofluoric Acid and Fluoride Ion on the Corrosion and Passive Behavior of Titanium

Abstracthas been studied by stationary and transient polarization measurements on Ti electrodes in HCl/HF and NaOH/NaAc/NaF mixtures of varying F‐ content and the oxide films formed are studied by AES and ESCA.

The influence of hydrofluoric acid and fluoride ion on the corrosion and passive behaviour of titanium

The title subject has been studied by stationary and transient polarization measurements on titanium electrodes in 1.0 M HCl + x M HF and in 0.1 M NaOH + (0.9− x)M NaAc + x M NaF ( x = 0–0.1) and by AES and ESCA measurements on the oxide films formed. It is found that HF strongly stimulates the anodic dissolution of passive titanium as opposed to F − which has no effect on the passive behaviour. Potentiostatic transients accord with the Cabrera-Mott equation and exhibit transient super-polarization. Galvanostatic transients yield capacitance data which give linear C −1/ E′ curves with slopes depending on the HF concentration. The surface analytical studies reveal incorporation of fluoride into the oxide film and increased film thickness only at low pH. The AES depth profiles show a smoothly changing fluoride concentration with highest fluoride concentration in the outer part of the passive film (near the oxide—solution interface). Both the AES depth profiles and the capacitance data indicate increased surface roughness of titanium in HF solutions.

ChemInform Abstract: The Inhibition of the Corrosion of Titanium in 10 N H2SO4 by Cupferron (N‐Nitrosophenyl hydroxylamine)

Abstractis investigated using electrochemical techniques, Raman and UV spectrometries and compared with some oxidizing inhibitors.

The inhibition of the corrosion of titanium in 10 N sulphuric acid by cupferron ( N-nitrosophenyl hydroxylamine)

The mechanism of inhibition of cupferron ( N-nitrosophenyl hydroxylamine) towards Ti in 10 N sulphuric acid solutions is studied using electrochemical techniques. Raman and UV spectrometries analysis are performed on the 6 mM l −1 cupferron sulphuric solution and on the yellow lay obtained on the surface of the Ti electrode during electrochemical experiments.

The reduction of chlorate and perchlorate ions at an active titanium electrode

Perchlorate ion is electrochemically reduced to chloride ion at an active titanium electrode in aqueous 1.0 M HClO 4. The reduction occurs by direct reaction at the surface rather than a pathway involving catalysis by soluble titanium corrosion products. The reaction occurs by oxygen atom transfer to the titanium surface, and the implications of this mechanism for the surface composition of active titanium electrodes are discussed. Chlorate ion is also reduced at titanium, and the rate constant for chlorate reduction is at least 10 5 times greater than that for perchlorate reduction.