Corrosion Behavior Of Titanium Alloy Research Articles

Comparative corrosion behavior of three titanium alloy base materials and their welds in a simulated chimney environment

This study investigates the corrosion behavior of titanium alloys (TA2, TC4, TB6) in a 3 % sulfuric acid flue gas environment using electrochemical tests and microscopic analyses (SEM/EDS, XRD, metallographic microscopy). Results show that TA2 base metal has lower corrosion resistance compared to its weld metal, while TC4 and TB6 exhibit opposite trends. Specifically, TC4 and TB6 base metals have lower corrosion current densities (0.9 and 0.5 μA/cm2) and higher corrosion potentials then their weld metals (1.93 and 2 μA/cm2). In contrast, TA2 base metal showed higher corrosion current density (2 μA/cm2) than its weld metal (0.35 μA/cm2) and HAZ metal (0.16 μA/cm2).Microscopic analyses reveal β phase transitions in TC4 and TB6 weld areas, leading to larger grain sizes and reduced corrosion resistance. Conversely, TA2 retains finer grains post-welding, enhancing its corrosion resistance. These insights clarify weld corrosion effects and provide valuable guidance for industrial applications of titanium alloys, particularly in designing and maintaining titanium alloy chimneys.

Effect of gadolinium addition on microstructure, mechanical properties and corrosion behavior of titanium alloys for spent fuel storage and neutron shielding

Ti-Gd alloys with Gd contents of 2 wt%–8 wt% were prepared, and the influence of Gd content on the microstructure, mechanical properties, corrosion behavior, neutron absorption property and density of the alloy weas investigated. The microstructure changes from full lamellar α phase to fine equiaxed crystals, and the area fraction of Gd-rich phase decreases from 3.2% to 1.8% and then increases to 9.1%. Gd has three existing forms: pure Gd, compound oxide of Gd2TiO5 and/or Gd2O3 and solidifies in the Ti matrix. Ti-4Gd exhibits the best mechanical properties, its tensile strength and elongation is 102 MPa and 49%, respectively. The neutron transmittancy of Ti-8Gd alloy in water is the lowest, which is 3.75%. The corrosion rate of Ti-Gd alloy is 0.00097–0.00238 mm/a, which meets the corrosion standard of small-scale nuclear reactors and containers for spent fuel.

Corrosion Behavior of Titanium Alloys (Ti CP2, Ti-6Al-2Sn-4Zr-2Mo, Ti-6Al-4V and Ti Beta-C) with Anodized and Exposed in NaCl and H2SO4 Solutions

Nowadays, different industries, such as the aerospace and biomedical industries, prefer using Ti alloys due to their excellent anti-corrosion properties and ability to generate a TiO2 oxide layer; this induces the use of anodization to increase the useful life of components. The aim of this work is to characterize the electrochemical effect of anodizing treatment on titanium alloys (Ti CP2, Ti-6Al-2Sn-4Zr-2Mo, Ti-6Al-4V, and Ti Beta-C) in NaOH and KOH at 1 M, applying a current density of 0.0025 A/cm2. The electrochemical techniques employed were electrochemical noise (EN) and electrochemical impedance spectroscopy (EIS), supported by ASTM G199 and ASTM G106 in electrolytes of NaCl and H2SO4 at 3.5 wt. % as a simulation of marine and industrial atmospheres. Also, the anodized transversal section and surface morphology were characterized by a scanning electron microscope (SEM). The results of both electrochemical techniques indicated that Ti-6Al-2Sn-4Zr-2Mo anodized in NaOH presented the best properties against corrosion, and the thickness of the oxide was the biggest.

Influence of Silicon and Chromium on the Na2SO4-Induced Hot Corrosion Behavior of Titanium Alloys

Titanium alloys are widely used as construction materials in the aerospace and automotive industries. They have many advantages but also have limitations related to their susceptibility to high-temperature oxidation and hot corrosion. Many efforts to increase the lifetime of components made of titanium alloys have been reported in the literature; the most promising ones involve the deposition of coatings. The present paper is focused on the development of coatings containing chromium and silicon, and their further evaluation in hot corrosion tests. It was proved that the Cr-Si coatings were more effective than Si coatings alone in protecting the titanium alloys against Na2SO4-induced hot corrosion at 800 °C. The enhanced corrosion resistance was attributed to the preferential formation of a thick and continuous SiO2 layer on the surface and—in the case of titanium aluminide alloy—the growth of an Al2O3-rich inner layer of the scale, promoted by chromium.

Early corrosion properties of titanium alloys, Ni-based alloys and stainless steel in supercritical water oxidation of sewage sludge

Supercritical water oxidation (SCWO) can efficiently and harmlessly dispose sewage sludge, while corrosion phenomena can lead to rapid shutdown and/or failure of expensive process equipments in a supercritical water system. The corrosion behavior of titanium alloys, Ni-based alloys and stainless steel exposed in supercritical water oxidation of sewage sludge at 450 °C, 26 MPa for 60 h was investigated by means of gravimetry, scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. 316 SS (stainless steel) showed the highest corrosion rate, while TA10 had the lowest corrosion rate. The oxide scale on the surface of 316 SS contained magnetite and FeCr2O4, while Cr2O3 and NiCr2O4 were the main components of oxide layer on Inconel 600. Among them, magnetite and NiCr2O4 mainly existed in the inner oxide layers of SS 316 and Inconel 600, respectively. The lack of Cr2O3 on the 316 SS surface resulted in severe pitting corrosion and poor corrosion resistance.

Cyclic Potentiodynamic Polarization on Titanium Alloys Anodizing in Alkaline Solutions

Titanium alloys are used in different industries such as biomedical, aerospace, aeronautic, chemical, and naval. Those industries have high requirements with few damage tolerances. The aim of this work was to study the corrosion behavior of titanium alloys anodizing and non-anodizing in alkaline (KOH and NaOH) solutions, exposed in 3.5%wt. NaCl and 3.5% wt. H2SO4 solutions at room temperature using cyclic potentiodynamic polarization (CPP) according to standards to obtain electrochemical parameters as the passivation range (PR), corrosion type, passive layer persistence, corrosion potential (Ecorr), and corrosion rate. The alloy Ti Beta-C anodized presented better corrosion resistance than Ti-6Al-4V in both media. The smallest corrosion rate is presented in Beta-C samples (4.72 E-8 A/cm2) and the highest corrosion rate is CP2 (1.61 E-5 A/cm2)

Research progress on the corrosion behavior of titanium alloys

Abstract Titanium and its alloys show outstanding application prospects in many industrial fields due to their high specific strength, good corrosion resistance, high temperature resistance, etc. However, at present the corrosion failure of Ti alloys is attracted great attention with gradual increasing applications. The different localized corrosion forms are introduced in this review, including galvanic corrosion, crevice corrosion, pitting corrosion, hydrogen-induced cracking, stress corrosion crack, microbiological corrosion, corrosion fatigue, and corrosion wear. Among them, the corrosion failure caused by stress corrosion crack and hydrogen-induced cracking is the most serious, accounting for about 40–60% of the actual failure accidents. The effects of temperature, pressure, corrosive media and microstructure on the failure of titanium alloys are discussed. Particularly noteworthy, F− is extremely aggressive to the passive film of titanium alloys. The corrosion behavior of titanium alloys applied in aerospace, marine, petrochemical industries and biomedical environments are introduced. In the above environments, the passive film is most easily damaged and difficult to passive in high temperature and oxygen-deficient environments. The current controversies in the corrosion mechanism have also been proposed, especially the stress corrosion that has the most serious impact on titanium alloys, and its mechanism will be the focus of future research.

Study of the Corrosion of the Nickel-titanium Orthodontics Archwires in the Mouth

Objective: The corrosion behavior of titanium alloy (NiTi) orthodontic wires shows a high resistance to corrosion in various solutions, such as Ringer's solution, artificial saliva, sodium chloride solution, and others. In these different liquids, NiTi corrosion resistance is higher than that of stainless steel or cobalt-based alloys. These research studies the behavior of the nickel-titanium Orthodontics archwires in the mouth by three methods. Methods: The first testing was the SEM that can perform EPMA (Electro Probing Micro Analysis), microanalysis X, and local and quantitative elementary analysis, and the examination of NiTi are observed in two ways: cross sectional and surface examination. The second one was the electrochemical analysis performed by immersion in an artificial saliva solution consisting of lactic acid at 0.1 moles per liter and sodium chloride at 0.1 mole per liter: Two types of NiTi orthodontic arches were tested. The first ones are from the manufacturer Ortho Classic and were used in the mouth for 4-6 weeks. The second arches are from the manufacturer AZ Dent and were new. The last test was the TEM cartography that shows the atoms and their dispersion on the surface of the wire. Results: The results showed that the presence of corrosion cells in the artificial saliva proved that the NiTi orthodontic archwires were able to initiate the process of corrosion in the mouth, particularly at the point of friction in contact with the braces (Ti6Al4V). Conclusion: The results obtained by the MET on thin sections of orthodontic arches prepared by the FIB method revealed the presence of double or multiple layers of titanium oxide and N-oxide plus aluminum.

Corrosion Behaviour of Titanium Alloy and Carbon Steel in a High-Temperature, Single and Mixed-Phase, Simulated Geothermal Environment Containing H2S, CO2 and HCl

The corrosion behaviour of a new titanium-based alloy, with nickel, molybdenum and zirconium as the main alloying elements, was studied in a simulated geothermal environment at various phase conditions of a corrosive fluid. Corrosion testing of carbon steel was also conducted for comparison. Both materials were tested at an elevated temperature between 180 and 350 °C and at a 10 bar gauge pressure in H2O containing HCl, H2S, and CO2 gases with an acidic condensate of pH = 3. The study found that the titanium alloy demonstrated good corrosion resistance in a single- and multiphase geothermal environment. In the testing volume, where the boiling of testing fluid occurred, the carbon steel was prone to localized damage of oxide, sulphide and chloride corrosion products. In the superheated testing volume, a homogeneous oxide corrosion layer was observed on the carbon steel. In the testing volume where condensation of the testing fluid occurred, a sulphide layer with an oxide sublayer was formed on the carbon steel.

Impact of Hydrogen Peroxide and Albumin on the Corrosion Behavior of Titanium Alloy (Ti6Al4V) in Saline Solution

Impact of Hydrogen Peroxide and Albumin on the Corrosion Behavior of Titanium Alloy (Ti6Al4V) in Saline Solution

Effect of nickel-based laser coatings on phase composition and corrosion behaviour of titanium alloy for offshore application

Recent advances in titanium alloy applications in the offshore industry have been realized through the development of laser surface modification technique. The distinctive outcome of this technique has provided increase in the utilization of titanium in offshore drilling risers for special drilling operations and various subsea and tubing applications. In this work, surface mitigation and corrosion degradation of titanium alloy in aggressive sulfuric acid were investigated using electrochemical technique (linear potentiodynamic polarization) while the surface characterization (morphology) and phases of the resultant coatings were analyzed using X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Prior to that, laser surface technique was used to fabricate Nickel-based powder on the substrate (Ti-6Al-4V). Results revealed that laser clad sample with high scan speed was more effective in improving the corrosion resistance compared to low scan speed. The enhanced corrosion resistance with high laser scan speed has been attributed to the presence of hard intermetallic compounds in the metallic coating.

Corrosion behavior of titanium alloys in acidic and saline media: role of alloy design, passivation integrity, and electrolyte modification

AbstractThis paper presents an overview of the corrosion behavior of titanium (Ti) alloys in both acidic and saline solutions. The solutions covered in this review are essentially the typical electrolytes encountered by Ti alloys when applied under service conditions. Although Ti alloys are generally known to be corrosion resistant, this review identifies strong reducing acids and fluoride-containing solutions as electrolytes that corrode Ti and its alloys. The pathways that the knowledge of the corrosion behavior of Ti alloys have followed from the 1950s to date are captured in this review. Based on this, the different factors influencing the corrosion behavior of Ti alloys are highlighted and the different research concepts for improving the corrosion resistance of Ti alloys in both solutions are discussed. The limitations of these research concepts are mentioned and the directions for future research are proposed.

Mechanical and corrosion behavior of titanium alloys additively manufactured by selective laser melting – A comparison between nearly β titanium, α titanium and α + β titanium

Mechanical and corrosion behaviors of SLM-processed Ti-13Nb-13Zr alloy with primarily β phase and acicular martensitic α′ microstructure, CP Ti in martensitic α′ structure and Ti-6Al-4V with martensitic α′ and a small amount of β phase microstructural conditions were studied in this work. A factor f (tensile strength/elastic modulus) was used to define the mechanical performance and the Ti-13Nb-13Zr alloy exhibits the highest f (15.22 ± 0.19) comparing with CP Ti (9.90 ± 0.10) and Ti-6Al-4V (12.47 ± 0.14). Among the three materials, Ti-13Nb-13Zr alloy demonstrates lower stress-controlled fatigue resistance but higher strain-controlled fatigue performance than CP Ti and Ti-6Al-4V. Fatigue crack initiation occurred in the surface/subsurface pores and the river pattern was observed in the crack initiation zone and crack propagation zone. The results of the potentiodynamic polarization indicate that the Ti-13Nb-13Zr alloy has the highest corrosion potential comparing with that of CP Ti and Ti-6Al-4V alloy because that Nb2O5 is more chemically stable than V2O5 and solid layers of Nb2O and ZrO2 are existed in passive TiO2 layers during the corrosion process which could reduce the Cl− ingress into the oxide layer and increase the structural integrity of the oxide film.

Laser shock peening wavelength conditions for enhancing corrosion behaviour of titanium alloy in chloride environment

The present study has been carried out to analyse the effect of the laser shock peening (LSP) with the absence of a coating on titanium alloy (Grade 5—Ti6Al4V) and to establish the best set of LSP parameters for enhanced surface characteristics. Ti6Al4V which has excellent mechanical properties is penned using Nd:YAG pulsed laser with 2D XY translation with water as confinement medium. Power density (3, 6, 9 GW/cm2), wavelength (532, 1064 nm) and overlap (60%, 70%) are the three process parameters considered to perform laser shock peening without coating (LSPwC). Surface roughness is increased with raise in wavelength and as well as other parameters too. Even though hardness is increased in both wavelengths, enhanced hardness is caused with 1064 nm wavelength. An adequate amount of compressive stress is induced with 3 GW/cm2 at 50 μm depth. The rate of corrosion is dropped in samples LSPwC with 532 nm compared with 1064 nm wavelength due to its low surface roughness and surface oxide layer which holds the fluctuation of current density with respect to potential. SEM observation showed pits on the surface of samples peened with a 1064 nm wavelength. And this surface pitting is correlated with the fall of charge transfer resistance in such samples.

The effect of shot peening on the corrosion behaviour of Ti-6Al-4V alloy made by DMLS

Abstract Additive Manufacturing processes are being used increasingly in the scope of medicine and dentistry. As indicated by literature data, the durability and quality of medical implants is decisively influenced by surface modification. Insufficient quality of surface finishing leads, among others, to reduced service life of applied implants and to increased number of necessary revision surgeries. Furthermore, various types of finishing processes e.g. cleaning, shot peening or abrasive techniques are suggested by the manufacturers of products made by means of DMLS processes. Due to this fact, the analysis of proper formation of the surface layer of titanium products made by means of the method consisting in the direct laser sintering of metal powders (DMLS) was the subject matter of our research. Therefore, Ti-6Al-4V titanium alloy has been used for tests. The samples have been produced by means of EOSINT M280 system dedicated for laser sintering of metal powders. The surfaces of prepared samples have been subjected to shot peening process at three different values of working pressure (0.2, 0.3 and 0.4 MPa) by means of three different working media i.e. CrNi steel shot, crushed nut shells and ceramic balls. The characteristics of the materials used for shot peening process have been determined by means of Zeiss Ultra Plus scanning electron microscope. The samples have been subjected to profilometric measurements on Bruker Contour GT optical profilometer and the corrosion behaviour of Ti-6Al-4V titanium alloy in Ringer solution has been determined in electrode impedance spectroscopy (EIS) measurements by means of Atlas 0531 set dedicated for corrosion testing. The overall results of all tests indicate to favourable influence of the shot peening process on the corrosion behaviour of titanium alloy.

Analysis of Electrochemical Noise in Titanium Alloys Used in Aeronautics

Corrosion is an essential factor to consider when designing and manufacturing a metallic component. In aeronautical industry is not the exception, especially because there are many types of corrosion that can affect different elements of aircrafts. Analysis is a way to determine the behavior of the material selected to decide if it's the appropriated to the purpose. This project is focused in electrochemical noise, which is a technique that measures oscillations in potential and electrochemical current of a material exposed in different solutions that represent the environment. In this case, the alloy Ti-6Al-4V composed by 90% titanium (Ti), 6% aluminum, and 4% vanadium (4V), will be studied under diverse conditions. In this research the corrosion behavior of Titanium alloys is studied by means of the electrochemical noise technique, using 2048 data per sec. The materials were evaluated in the presence of 3 different electrolytes: (water), NaCl (sodium chloride) and (sulfuric acid) at 25ºC and 3.5% of concentration. The results indicate that the behavior of the time series does not have transients of high frequency and amplitude and with the localization index the type of corrosion is generalized.

Tribo-Corrosion and Corrosion Behaviour of Titanium Alloys with and Without DLC Films Immersed in Synthetic Urine

Nowadays, potable water is becoming scarcer, and chemicals components present in wastewater increase corrosion of devices and decrease its lifespan, especially from bearings used in water recovery system. The bearings are subjected to severe corrosion due to harsh environmental conditions from urine composition. 60NiTi alloy which was developed to attend International space station requirements as a resistant material to recycle wastewater to potable water, together DLC film as a solid lubricant, could be new protective material to avoid tribo-corrosion and corrosion from devices under hostile environment. In this work, we compared the tribocorrosion resistance of 60NiTi, also named as NiTi60T and thermally treated, and Ti–6Al–4V alloys with and without diamond-like carbon (DLC) film. The NiTi60T is a promising candidate to be used for the centrifuge bearings to expand their lifespan when in contact with synthetic urine. The DLC film presented high levels of wear resistance, metallic adhesion, and corrosion protection for both tested alloys.

Microstructure and Corrosion Behavior of Laser Synthesized Cobalt Based Powder on Ti-6Al-4V

The corrosion behavior of titanium alloys when used for various dynamic offshore components has been a major concern of titanium drilling risers in deepwater energy extraction. A way of achieving specified requirement is the development of coatings suitable to protect the base material against corrosion. In this work, laser cladding technique which is known as a leading edge due to its distinctive properties and outcomes was used in synthesizing Co-based powder on titanium alloy. The processing parameters used were laser power of 900W; scan speed of 0.6 to 1.2 m/min; powderfeedrate1.0g/min;beamspotsize3mm;gasflowrate1.2L/min.The effects of cobalt addition and laser parameters on corrosion behavior of laser clad Ti6AL4V coating in 0.5M sulfuric medium were investigated using linear potentiodynamic polarization. The changes in microstructure and corrosion behavior were analyzed using scanning electron microscopy (SEM) while the X –ray diffraction (XRD) indicates the intermetallics in the coatings. Results showed that the coatings displayed good metallurgical bonding with dendritic formations between the coatings and the substrate. The anodic current density increased with lower scan speed. However, the corrosion current densities of laser-clad samples were lower than Ti6Al4V alloy.

Corrosion behavior of erbium chromium-doped yattrium-scandium-gallium-garnet (Er,Cr:YSGG 2780 nm) laser-treated titanium alloy used for dental applications at different pH conditions (in vitro study)

Titanium alloys are most often used in the design of dental implants. Although these biomaterials have good mechanical and biological properties, their corrosion resistance is still critical for the overall success of the treatment procedure. Implant failure is more likely to occur in inflammatory diseases related to low pH levels. Er,Cr:YSGG laser is most often used in implant dentistry. The aim of the this study was to assess the effect of Er,Cr:YSGG laser surface treatment on the corrosion behavior of titanium alloy (Ti–6Al–4V) at different pH. A total of 40 discs were used. Twenty discs were irradiated with Er,Cr:YSGG laser, which was operating in a normal room atmosphere and temperature at power 2 W. The corrosion behavior was investigated in simulated body fluid at pH of 7.40 and 5.20. At each pH, corrosion behavior was studied for up to 864 h at 192, 360, 696, and 864 h intervals using potentiodynamic polarization test and electrochemical impedance spectroscopy. The laser-treated and -untreated discs were examined with scanning electron microscope before and after the electrochemical tests. Laser treatment significantly improves the corrosion resistance compared to the untreated group. Immersion time and pH also significantly affect the corrosion behavior. The acidity yielded more aggressive changes on the untreated titanium alloy. Er,Cr:YSGG laser could improve the corrosion resistance of Ti–6Al–4V.

The effect of fluoride-containing oral rinses on the corrosion resistance of titanium alloy (Ti-6Al-4V).

ObjectiveThe purpose of this study was to examine the effect of commercially available fluoride-containing oral rinses on the corrosion behavior of titanium alloys, which are the main components of orthodontic miniscrews.MethodsFour commercially available oral rinses (solution A, pH 4.46/260 ppm fluoride; solution B, pH 4.41/178 ppm fluoride; solution C, pH 6.30/117 ppm fluoride; and solution D, pH 4.17/3.92 ppm fluoride) were tested on titanium alloy (Ti-6Al-4V) circular plates, and saline was used as the control. The open-circuit potential and potentiodynamic polarization of these materials were measured. Thereafter, all samples were evaluated under a field-emission scanning electron microscope.ResultsAmong the tested oral rinses, except solution D, the more the fluoride content was, the greater was the corrosion potential downtrend; the corrosion resistance of the titanium alloy sample was also lowered significantly (p < 0.05). Field-emission scanning electron microscopic analysis of the surface morphology of the titanium alloy samples revealed that all samples had some defects, crevices, or pitting after exposure to the oral rinses than before treatment. In particular, the samples in solution A showed the most changes.ConclusionsCommercially available oral rinses having a high fluoride concentration and a low pH may reduce the corrosion resistance of titanium alloys used in dental appliances such as orthodontic titanium miniscrews and brackets.