scholarly journals Structure and Corrosion Behavior of Sputter-Deposited W-Mo Alloys

1970 ◽  
Vol 21 ◽  
pp. 19-25 ◽  
Author(s):  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Magnetron Sputtering ◽  
Corrosion Behavior ◽  
Solid Solutions ◽  
Chemical Society ◽  
High Corrosion Resistance ◽  
Corrosion Rates ◽  
High Corrosion ◽  
Sputter Deposited

Nanocrystalline, single bcc solid solutions of W-Mo alloys have been successfully prepared by D. C. magnetron sputtering in a wide composition. The corrosion behavior of the sputter-deposited W-Mo alloys was studied. The W-Mo alloys showed significantly high corrosion resistance in 12 M HCl at 30o C. Their corrosion rates are about one and half orders of magnitude lower than that of sputter-deposited tungsten and lower than that of the sputter-deposited molybdenum even after prolonged immersion.DOI: 10.3126/jncs.v21i0.217Journal of Nepal Chemical Society Vol.21 2006 pp.19-25

scholarly journals An overview on the non-destructive in-depth surface analysis of corrosion-resistant films: A case study of W-xCr deposits in 12 M HCl solution

BIBECHANA ◽  
2021 ◽  
Vol 18 (1) ◽  
pp. 201-213
Author(s):  
Jagadish Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Depth Profiling ◽  
Surface Films ◽  
High Corrosion Resistance ◽  
Corrosion Rates ◽  
High Corrosion ◽  
Depth Analysis ◽  
Sputter Deposited ◽  
Non Destructive ◽  
Hcl Solution

Non-destructive in-depth analysis of the surface films formed on the sputter-deposited binary W-xCr (x = 25, 57, 91 at %) alloys in 12 M HCl solution open to air at 30 °C was investigated using an angle-resolved X-ray photoelectron spectroscopic (AR-XPS) technique to understand the synergistic corrosion resistance effects of showing very low corrosion rates, even lower than both alloying metals of the deposits. The average corrosion rates of these three tungsten-based sputter deposits found to be more than five orders of magnitude (between 3.1 × 10−3 and 7.2 × 10−3 mm/y) to that of chromium and also nearly one order of magnitude lower than that of tungsten metals. Such high corrosion resistance of the sputter-deposited W-xCr alloys is due to the formation of homogeneous passive double oxyhydroxide film consisting of Wox and Cr4+ cations without any concentration gradient in-depth after immersion in 12 M HCl solution open to air at 30 °C from the study of the non-destructive depth profiling technique of AR-XPS. Consequently, both alloying elements of tungsten and niobium are acted synergistically in enhancing high corrosion resistance properties of the alloys in such aggressive electrolyte. BIBECHANA 18 (2021) 201-213

scholarly journals The Corrosion Behavior of Sputter-Deposited Nanocrystalline W-Cr Alloys in Nacl and NaohaSolutions

1970 ◽  
Vol 25 ◽  
pp. 53-61
Author(s):  
Minu Basnet ◽  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Chromium Content ◽  
Open Circuit ◽  
Nacl Solution ◽  
Corrosion Rates ◽  
Naoh Solution ◽  
Order Of Magnitude ◽  
Sputter Deposited

The corrosion behavior of the sputter-deposited nanocrystalline W-Cr alloys wasstudied in 0.5 M NaCl and alkaline 1 M NaOH solutions at 25°C, open to air usingimmersion tests and electrochemical measurements. Chromium metal acts synergisticallywith tungsten in enhancing the corrosion resistance of the sputter-deposited W-Cr alloys soas to show higher corrosion resistance than those of alloy-constituting elements in both 0.5M NaCl and 1 M NaOH solutions. In particular, the nanocrystalline W-Cr alloys containing25-91 at% chromium showed about one order of magnitude lower corrosion rates (that is,about 1-2 × 10-3 mm.y-1) than those of tungsten and chromium metals even for prolongedimmersion in 0.5 M NaCl solution at 25°C. On the other hand, the corrosion rate of thesputter-deposited W-Cr alloys containing 25-75 at % chromium was decreased significantlywith increasing chromium content and showed lowest corrosion rates (that is, 1.5-2.0 × 10-3 mm.y-1) after immersed for prolonged immersion in 1 M NaOH solution. The corrosion ratesof these nanocrystalline W-(25-75)Cr alloys are nearly two orders of magnitude lower thanthat of tungsten and more than one order of magnitude lower corrosion rate than that ofsputter-deposited chromium metal in 1 M NaOH solution. The corrosion-resistant of all theexamined sputter-deposited W-Cr alloys in 0.5 M NaCl solution is higher than in alkaline 1M NaOH solution at 25°C. Open circuit potentials of all the examined W-Cr alloys areshifted to more noble direction with increasing the chromium content in the alloys afterimmersion for 72 h in both 0.5 M NaCl and 1 M NaOH solutions at 25°C, open to air.Keywords: Sputter deposition, nanocrystalline W-Cr alloys, corrosion test, electrochemicalmeasurement, NaCl and NaOH solutions.DOI:  10.3126/jncs.v25i0.3300Journal of Nepal Chemical Society Volume 25, 2010 pp 53-61

Amorphous Fe72Cr8P13C7 Powder with High Corrosion Resistance

1982 ◽  
Vol 37 (7) ◽  
pp. 676-679 ◽  
Author(s):  
Kangjo Cho ◽  
Choll-Hong Hwang ◽  
Chang-Su Pak ◽  
Yeong-Jo Ryeom
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Rapid Quenching ◽  
High Corrosion Resistance ◽  
High Corrosion ◽  
Spark Erosion

Abstract Amorphous Fe72Cr8P13C7 powder has been prepared by the spark erosion technique and its corrosion behavior investigated potentiodynamically. It is concluded that the powder prepared this way possesses a relatively high corrosion resistance, as does amorphous Fe72Cr8P13C7 ribbon prepared by rapid quenching.

scholarly journals The Corrosion Behavior of Sputter-deposited W-Ti Alloys in 0.5 M NaCl Solution

1970 ◽  
Vol 10 ◽  
pp. 109-113 ◽  
Author(s):  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Open Circuit ◽  
Nacl Solution ◽  
Corrosion Resistant ◽  
Corrosion Rates ◽  
Ti Alloys ◽  
Confocal Scanning ◽  
Confocal Scanning Laser ◽  
Sputter Deposited

The corrosion behavior of the sputter-deposited amorphous or nanocrystalline W-Ti alloys was studied in neutral 0.5 MNaCl solution at 25°C, open to air by immersion tests, electrochemical measurements and confocal scanning laser microscopic(CSLM) techniques. Titanium metal acts synergistically with tungsten in enhancing the corrosion resistance of the sputter-deposited W-Ti alloys so as to show higher corrosion resistance than those of alloy-constituting elements (that is, tungsten and titanium) in neutral 0.5 M NaCl solution. In particular, the amorphous W-Ti alloys containing 30-53 at% titanium showed lowest corrosion rates (that is, about 1 × 10-3 mm.y-1). Open circuit potentials of all the examined W-Ti alloys were shifted to more noble direction than those of the open circuit potentials of alloyconstituting elements in 0.5 M NaCl solution.Key words: Sputter deposition; W-Ti alloys; Corrosion-resistant; CSLM; NaCl solution.DOI: 10.3126/njst.v10i0.2899Nepal Journal of Science and Technology Volume 10, 2009 December Page:109-113 

scholarly journals A non–destructive compositional analysis of thin surface films formed on W–xTa alloys by angle resolved X–ray photoelectron spectroscopy

BIBECHANA ◽  
2012 ◽  
Vol 8 ◽  
pp. 8-16
Author(s):  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Photoelectron Spectroscopy ◽  
Compositional Analysis ◽  
Surface Films ◽  
Concentration Gradients ◽  
High Corrosion Resistance ◽  
X Ray ◽  
High Corrosion ◽  
Sputter Deposited ◽  
Non Destructive

Synergistic effect of the simultaneous additions of tungsten and tantalum in the extremely high corrosion resistance properties of the spontaneously passivated sputter–deposited W–xTa alloys was investigated using a non-destructive angle resolved X-ray photoelectron spectroscopy (angle resolved XPS) techniques in this study. In-depth surface analyses of the thin passive films formed on the spontaneously passivated amorphous/nanocrystalline W–xTA alloys using angle resolved XPS analyses revealed that the high corrosion resistance of the alloys is mostly due to the formation of homogeneous passive double oxyhydroxide films consisting of Wox and Ta4+ cations with a small concentration gradients in–depth particularly after immersion between 20–168 h in 12 M HCl solution open to air at 30°C. Consequently, tantalum metal acts synergistically with tungsten in enhancing the spontaneous passivity as well as the high corrosion resistance of the sputter–deposited binary W–xTa alloys in 12 M HCl solution.Keywords: Sputter deposition; W–xTa alloys; 12 M HCl; Take-off angleDOI: http://dx.doi.org/10.3126/bibechana.v8i0.4784BIBECHANA 8 (2012) 8-16

Electrochemical and surface characteristics of sputter-deposited amorphous Mn–Zr–Cr alloys in a 1 M H2SO4 solution

RSC Advances ◽  
2015 ◽  
Vol 5 (31) ◽  
pp. 24460-24468
Author(s):  
A. A. El-Moneim ◽  
M. Ezzat ◽  
W. A. Badawy
Keyword(s):  
Corrosion Resistance ◽  
Surface Characteristics ◽  
Passive Films ◽  
H2so4 Solution ◽  
High Corrosion Resistance ◽  
High Corrosion ◽  
Sputter Deposited

Passive films on Mn–Zr–Cr are composed of oxy-hydroxide which is responsible for the high corrosion resistance.

scholarly journals Angle resolver X-ray photoelectron spectroscopic analysis of the passive film of the corrosion-resistant W-32Zr alloy in 12 M HCl solution

2015 ◽  
Vol 49 (2) ◽  
pp. 103-110
Author(s):  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Synergistic Effects ◽  
High Corrosion Resistance ◽  
Corrosion Resistant ◽  
X Ray ◽  
High Corrosion ◽  
Average Corrosion Rate ◽  
Sputter Deposited ◽  
Zirconium Metal ◽  
Hcl Solution

The sputter-deposited amorphous W-32Zr alloy was passivated spontaneously and showed a fairly high corrosion resistance in 12 M HCl solution in open air at 30°C. The average corrosion rate of the W-32Zr alloy (i.e., 5.2 × 10-3 mm/y) was found to be lower than those of alloy-constituting tungsten and zirconium elements. Such synergistic effects of simultaneous addition of tungsten and zirconium in the W–32Zr alloy was investigated by corrosion tests, electrochemical measurements and angle resolved X-ray photoelectron spectroscopic (ARXPS) analyses. High corrosion resistance of the binary W–32Zr alloy is mostly due to the formation of homogeneous passive oxyhydroxide film consisting of Wox and Zr4+ cations with a small concentration gradient in–depth from ARXPS analysis. Consequently, zirconium metal acts synergistically with tungsten in enhancing the anodic passivity as well as the corrosion resistance properties of the sputter–deposited W–32Zr alloy in 12 M HCl solution open to air at 30°C. DOI: http://dx.doi.org/10.3329/bjsir.v49i2.22004 Bangladesh J. Sci. Ind. Res. 49(2), 103-110, 2014

scholarly journals Roles of Alloying Elements on the Corrosion Behavior of Amorphous W–Zr–(15–33)Cr Alloys in 1 M NaOH Solution

1970 ◽  
Vol 25 ◽  
pp. 93-100
Author(s):  
Raju Ram Kumal ◽  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Open Circuit Potential ◽  
Chromium Content ◽  
Chemical Society ◽  
Immersion Test ◽  
Open Circuit ◽  
Corrosion Rates ◽  
Naoh Solution ◽  
Zirconium Metal

Roles of alloy-constituting elements on the corrosion behavior of the sputter-depositedamorphous W-Zr-(15-33)Cr alloys was studied in 1 M NaOH solution open to air at 25°Cusing corrosion tests and open circuit potential measurements. Zirconium and chromiummetals act synergistically with tungsten in enhancing the corrosion resistance of the sputterdepositedamorphous W-Zr-Cr alloys containing 15-33 at % chromium content so as toshow higher corrosion resistance than those of alloy-constituting elements in 1 M NaOHsolution. The corrosion rates of the amorphous W-Zr-(15-33)Cr alloys containing 9-33 at %tungsten are in the ranges of 2.0-5.0×10-3 mm.y-1 after immersion for 240 h in 1 M NaOHsolution which is about two orders of magnitude lower corrosion rates lower than that oftungsten and even slightly lower than that of the zirconium metal. The simultaneousadditions of zirconium and chromium metals in W-Zr-(15-33)Cr alloys are effective forennoblement of the open circuit potential of the tungsten metal.Keywords: W-Zr-Cr alloys, corrosion resistance, immersion test, open circuit potential, 1 MNaOH.DOI:  10.3126/jncs.v25i0.3312Journal of Nepal Chemical Society Volume 25, 2010 pp 93-100

Improving Corrosion Behavior of Chemically Bonded Phosphate Ceramic Coating Reinforce with GO-TiO2 Hybrid Material

2021 ◽  
Author(s):  
Da Bian ◽  
Shanhua Qian ◽  
Zifeng Ni ◽  
Yongwu Zhao
Keyword(s):  
Corrosion Resistance ◽  
Crack Propagation ◽  
Fracture Energy ◽  
Corrosion Behavior ◽  
Hybrid Material ◽  
Interfacial Adhesion ◽  
Ceramic Coating ◽  
High Corrosion Resistance ◽  
High Corrosion

Abstract To further enhance the corrosion resistance of chemically bonded phosphate ceramic coating, TiO2 was grafted on the surface of GO to enhance the interfacial adhesion between GO and the coating. SEM results show that the presence of TiO2 on GO creates a good interfacial adhesion between GO and the coating. In addition, EIS experiments were carried out to investigate the performance of the coatings on the corrosion resistance. The result indicates that the corrosion resistance is enhanced with the introduction of GO-TiO2 hybrid material. Besides the influence of GO on the corrosion resistance, the good interfacial adhesion between GO and the coating with the presence of TiO2 hybrid material can consume more fracture energy to stop crack propagation, which leads to the high corrosion resistance.

scholarly journals The Corrosion Behavior of Sputter?deposited W?xTa Alloys in 0.5 M NaCl Solution

2013 ◽  
Vol 14 (1) ◽  
pp. 103-108
Author(s):  
Jagadeesh Bhattarai ◽  
Susil Baral
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Open Circuit ◽  
Nacl Solution ◽  
High Corrosion Resistance ◽  
Positive Direction ◽  
Sputter Deposited

The corrosion behavior of the sputter–deposited amorphous and nanocrystalline W–xTa (x = 8–77) alloys was studied in 0.5 M NaCl solution open to air at 25°C using corrosion tests and electrochemical measurements. Tungsten and tantalum metals act synergistically in enhancing the corrosion resistance of the sputter–deposited W–xTa alloys and hence additions of 23 at. % of tantalum or more to the sputter–deposited W–xTa alloys were found to be effective to achieve significantly high corrosion resistance properties of the alloys than those of alloy– constituting elements. In particular, the corrosion rate of the W–60Ta alloy showed the lowest corrosion rate (that is, 2.0×10-3). The open circuit potential of the alloys shifted noble (positive) direction with immersion time. Addition of tantalum metal in W–xTa alloys is effective for ennoblement of the open circuit corrosion potential of the tungsten metal in 0.5 M NaCl solution open to air at 25°C. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 103-108 DOI: http://dx.doi.org/10.3126/njst.v14i1.8929

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