The behaviour of titanium in nitric-hydrofluoric acid solutions

Sutter, Éliane; Goetz-Grandmont, G.J.

doi:10.1016/0010-938x(90)90051-6

Cited by 50 publications

(33 citation statements)

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“…A similar effect was observed by Sutter et al for Ti dissolving in 1.13 M HF + 4.5 M HNO 3 and was described as current instabilities. 16 The instabilities were not observed in lower HF concentrations. The exact reason for the occurrence of sudden drop in current at high HF concentrations is not clear.…”

Section: Resultsmentioning

confidence: 97%

“…10 HF, in combination with HNO 3 and a few other additives such as acetic acid, H 3 PO 4 , dodecyl benzene sulfonic acid, carbamide, sodium benzoate or sodium nitrate, have been used for chemical milling of In Ti pickling, addition of nitric acid is used to prevent hydride formation at the metal surface, which can lead to hydrogen embrittlement. 16 Ti dissolution in HF + HNO 3 solution is modeled using a mechanistic approach with Ti 3+ and TiO 2 as intermediate species. …”

mentioning

confidence: 99%

“…[11][12][13][14][15] In Ti pickling, addition of nitric acid is used to prevent hydride formation at the metal surface, which can lead to hydrogen embrittlement. 16 Ti dissolution in HF + HNO 3 solution is modeled using a mechanistic approach with Ti 3+ and TiO 2 as intermediate species. 16 The effect of pH on Ti dissolution, mainly in the passive region, has been published in the literature.…”

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confidence: 99%

“…16 Ti dissolution in HF + HNO 3 solution is modeled using a mechanistic approach with Ti 3+ and TiO 2 as intermediate species. 16 The effect of pH on Ti dissolution, mainly in the passive region, has been published in the literature. [17][18][19] Recently, Wang et al have reported the effect of dissolved oxygen (DO) on the corrosion of pure Ti in acidic fluoride medium using electrochemical methods.…”

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Effect of HF Concentration on Anodic Dissolution of Titanium

Amrutha

Fasmin

Ramanathan

2017

J. Electrochem. Soc.

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Anodic dissolution of Ti metal in varying concentrations of hydrofluoric acid (10-1000 mM HF) was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy. Polarization curves obtained at all concentrations of HF solution showed that current initially rises with potential, and decreases at higher potentials. Complex plane plot of the impedance spectra of Ti dissolution in 25 and 50 mM HF solutions exhibited three capacitive loops in the active region and a capacitive behavior with negative resistance in the passive region. The surface was characterized using X-ray photoelectron spectroscopy. A four step mechanism with chemical and electrochemical dissolution steps was employed to model Ti dissolution. The analysis shows that the simulated results match the polarization trends satisfactorily in all the solutions investigated. The model predicts that HF − 2 and remaining HF are the species that influence chemical and electrochemical dissolution steps respectively. The estimates of surface coverage values of the adsorbed species showed that with increasing over potential, the metal surface was progressively covered with oxide film, while an increase in nominal HF concentration leads to a decrease in fractional surface coverage. Titanium is used as engineering material in medical implants, aerospace applications, and in industrial applications by virtue of its low density, high strength and high corrosion resistance.1 Due to the presence of a tenacious passive oxide layer on its surface, Ti is highly corrosion resistant in most of the harsh chemical environments. 2,3However, the oxide layer readily dissolves in acidic fluoride medium. The anodic dissolution phenomena of Ti in fluoride media is important not only in corrosion but also in several technologies and industrial applications such as pickling of Ti, 4 manufacture of Ti based automobile parts, 5 and formation of self-organized TiO 2 nano tubes. 2,3,6Ti dissolution in fluoride medium has been studied extensively, and its dissolution in acidic fluoride media depends mainly on the concentrations of various species formed by HF dissolution, pH of the solution and temperature.3,6-8 Straumanis and Chen measured the volume of hydrogen produced during Ti dissolution in HF and proposed that the reaction order is 0.66 when the HF concentration is below 0.2 N and unity when it is more than 0.2 N.9 Ti dissolution in a solution of 0.1 N HF + 1 M HCl was measured at various temperatures, and the order was reported to be 0.76 while the activation energy was 6.9 kcal/mol. 10 HF, in combination with HNO 3 and a few other additives such as acetic acid, H 3 PO 4 , dodecyl benzene sulfonic acid, carbamide, sodium benzoate or sodium nitrate, have been used for chemical milling of In Ti pickling, addition of nitric acid is used to prevent hydride formation at the metal surface, which can lead to hydrogen embrittlement. 16 Ti dissolution in HF + HNO 3 solution is modeled using a mechanistic approach with Ti 3+ and TiO 2 as intermediate species. 1...

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Section: Resultsmentioning

confidence: 97%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Effect of HF Concentration on Anodic Dissolution of Titanium

Amrutha

Fasmin

Ramanathan

2017

J. Electrochem. Soc.

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“…The corrosion resistance of titanium is significantly affected by fluoride concentration and pH. [16][17][18][19][20][21][22] Some researchers examined the corrosion behavior of titanium under the PEFC conditions and found that titanium has high corrosion resistance but has high contact resistance. [25][26][27] However, there is no examination on the growth behavior of oxide films on titanium in PEFC environments and on the relationship between the film properties and the contact resistance.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Properties of Titanium in PEFC Bipolar Plate Environments

2010

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In order to assess the applicability of titanium as a bipolar plate for polymer electrolyte fuel cells (PEFCs), the electrochemical surface characteristics of commercially available pure titanium were examined in simulated PEFC conditions. The results of the electrochemical tests showed that the cathode operating potential of PEFC, 0.64 V (vs. Ag/AgCl(3.33 kmolÁm À3 KCl)), lay in the anodic passivation region for titanium. The operating potential of the PEFC anode, À0:36 V, lay in the cathodic region or the cathodic to anodic transition region. Under the PEFC cathode condition, a barrier-type film with high charge transfer resistance and high contact resistance formed on the specimen. Under the PEFC anode condition, an oxide film with low charge transfer resistance and low contact resistance formed by a dissolution-precipitation mechanism.

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