The Corrosion Resistance of Hard Anodised EN AW 7075 T6 Alloy

In this paper, commercially cold-rolled and artificial aged EN AW 7075 T6 alloy has been used. To ensure increased corrosion resistance, surface hardness, scratching resistance, and aesthetic features, this aluminium alloy was subsequently hard anodised and hot-water sealed (AC-A). The hard anodizing and sealing process increased surface hardness up to 304±13 HV 1 from an initial surface hardness of 194±3 HV 1. Also, the microhardness of the anodised layer and bulk material has been documented. Scanning electron microscopy (SEM) was used for microstructure and trapped precipitates investigation in the 42.9±1.4 thick formed anodised layer investigation. The T6 treated (AC) and hard anodised together with sealed (AC-A) EN AW 7075 alloy corrosion properties were evaluated using the anodic potentiodynamic polarisation tests (PPT) in a neutral 2.5% NaCl deaerated solution. The corrosion rate CR (mm/y) decreased approx. 39-times for the hard anodised and sealed EN AW 7075 alloy (AC-A), associated with the shift of the Ecorr (mV) to more positive values, degreased Icorr (µA) and increased Rp (Ohm) values compared to the artificial aged (AC) alloy. Additionally, the pitting was evaluated using laser confocal microscopy, and the pitting coefficient was also calculated.

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Titanium Alloy Ti6Al4V’s Corrosion Resistance Behavior by Double Glow Discharge Plasma Hydrogen-Free Carburizing Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.47-50.1197 ◽

2008 ◽

Vol 47-50 ◽

pp. 1197-1200

Author(s):

Gao Hui Zhang ◽

Ping Ze Zhang ◽

Ming Zhou Yu ◽

Zhong Xu

Keyword(s):

Corrosion Resistance ◽

Titanium Alloy ◽

Glow Discharge ◽

High Purity ◽

Discharge Plasma ◽

Pure Titanium ◽

Surface Hardness ◽

Electrochemical Corrosion ◽

Glow Discharge Plasma ◽

Corrosion Properties

The surface-modified Titanium alloy Ti6Al4V was obtained in the process of the double glow discharge plasma hydrogen-free carburizing. The high purity solid graphite as the source cathode supplied the carbon elements; pure titanium and its alloys were used as the cathode and argon as the working gas. At certain pressure and voltage, the glow discharge appeared between cathode and anode, source cathode and anode. The carbon plasma flux, including carbon atoms, ions, sputtered by argon ions diffused into the substrate, which depended on ions bombardment and thermal diffusion at a negative voltage. High purity solid graphite cathode was done in a honeycomb shape or grid shape. A layer with TiC and C phases was formed during the process. Surface hardness was increased by four times due to the presence of TiC and C phases, and wear resistance was enormously improved. The C concentration and hardness of alloying layer changed gradually with the depth. The corrosion properties of hydrogen-free carburized specimens were tested in the solution of 5% NaCl and 5% H2SO4, using electrochemical corrosion method. The results showed that the corrosion resistance of carburized specimens was significantly improved in 5% H2SO4 solution.

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Investigation about Electro-Deposition Properties of Special Nickel Electroplating Coating for 45# Steel with Different Surface Roughnesses

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.146-147.962 ◽

2010 ◽

Vol 146-147 ◽

pp. 962-965 ◽

Cited By ~ 2

Author(s):

Wei Lin Zhao ◽

Hui Huang ◽

Zhen Lin Wang

Keyword(s):

Surface Roughness ◽

Corrosion Resistance ◽

Adhesion Force ◽

Surface Hardness ◽

Lower Surface ◽

Electro Deposition ◽

Resistance Surface ◽

Nickel Electroplating

The effects of the surface roughness on electro-deposition properties of the special nickel electroplating coating for the 45# steel were investigated. The results indicate that the surface roughness has great effects on the corrosion resistance and the surface hardness of the coating, the adhesion force between the coating and the substrate. Among the three 45# samples with different surface roughnesses, the sample with moderate surface roughness (Ra≈0.1um) has the relatively higher corrosion resistance, surface hardness and adhesion force than the samples with higher and lower surface roughness.

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Effect Of Ti-Ion Implantation On The Mechanical And Corrosion Properties Of The Fecrni Super Alloy

KnE Energy ◽

10.18502/ken.v1i1.454 ◽

2016 ◽

Vol 1 (1) ◽

Author(s):

Ari Handayani

Keyword(s):

Corrosion Resistance ◽

Ion Implantation ◽

Surface Hardness ◽

Hardness Measurement ◽

Alloy Sample ◽

X Ray Diffraction ◽

Corrosion Properties ◽

Near Surface ◽

X Ray ◽

Super Alloy

Ion implantation is widely used for surface treatment to modify the near surface properties of materials especially semiconductors without changing their bulk properties. In this work an investigation on the effect of implantation by Ti-ion on the mechanical properties and the wet corrosion of the high Cr and Ni content FeCrNi alloy was performed. Because of its superior properties this alloy is also well known as super alloy and often used as structure material in nuclear reactors. The alloy <del cite="mailto:USER" datetime="2016-05-18T11:01">was fabricated </del><del cite="mailto:USER" datetime="2016-05-18T10:59">at </del><del cite="mailto:USER" datetime="2016-05-18T11:01">BATAN </del><del cite="mailto:USER" datetime="2016-05-18T11:00">in </del><del cite="mailto:USER" datetime="2016-05-18T11:01">Bandung </del>containing <ins cite="mailto:USER" datetime="2016-05-18T10:38">of </ins>55.98 wt.% Fe , 23.46 wt.% Cr, 18.23 wt.% Ni and small amount of other metal elements<ins cite="mailto:USER" datetime="2016-05-18T11:01">, </ins><ins cite="mailto:USER" datetime="2016-05-18T11:01">was fabricated </ins><ins cite="mailto:USER" datetime="2016-05-18T11:01">in</ins><ins cite="mailto:USER" datetime="2016-05-18T11:01"> BATAN Bandung</ins>. The alloy sample was subjected to Ti-ion implantation in an ion generator with theoretical doses varied between 0.89x1016, 2.68x1016, 3.58x1016 and 10.75x1016 ion/cm2respectivelly. The hardness measurement was conducted with Vickers method and the corrosion resistance test was carried out in the borax acid (HBO3) environment. The microstructure of the material after implantation was characterized and analyzed by means of the Scanning Electron Microscopy (SEM) equipped with the Energy Dispersive X-Ray Detector (EDX) while the surface crystal structure was idenfied using X-Ray Diffraction (XRD). The result showed that the Ti implantation improved the surface hardness when the dose was higher than 3.58x1016 ion/cm2, while the corrosion resistance increased abruptly at all ion doses. However, no microstructure change could be observed on the cross section. A thin layer which is indicated by BSE image contrast was observed in the top most surface. Analysis on the EDS spectrum revealed that the layer could be considered to be the titanium oxide elucidating the increasing of hardness and exceptionally higher resistance to wet corrosion.

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ALCOA 7075

Alloy Digest ◽

10.31399/asm.ad.al0350 ◽

1998 ◽

Vol 47 (7) ◽

Keyword(s):

Corrosion Resistance ◽

Physical Properties ◽

Surface Treatment ◽

Stress Corrosion ◽

Tensile Properties ◽

Stress Corrosion Cracking ◽

High Strength ◽

Structural Parts ◽

7075 Alloy ◽

Very High

Abstract Alcoa 7075 alloy has very high strength and is used for highly stressed structural parts. The T7351 temper offers improved stress-corrosion cracking resistance. The alloy’s strength level equals or exceeds mild steels. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as machining and surface treatment. Filing Code: AL-350. Producer or source: ALCOA Wire, Rod & Bar Division.

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Electrodeposition of Copper and Brass Coatings with Olive-Like Structure

Materials ◽

10.3390/ma14071762 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1762

Author(s):

Artur Maciej ◽

Natalia Łatanik ◽

Maciej Sowa ◽

Izabela Matuła ◽

Wojciech Simka

Keyword(s):

Corrosion Resistance ◽

Cathodic Current Density ◽

Bath Composition ◽

Cathodic Current ◽

Corrosion Properties ◽

Fine Grained ◽

Electrodeposited Coating ◽

Copper Zinc ◽

New Generation ◽

First Time

One method of creating a brass coating is through electrodeposition, which is most often completed in cyanide galvanic baths. Due to their toxicity, many investigations focused on the development of more environmentally friendly alternatives. The purpose of the study was to explore a new generation of non-aqueous cyanide-free baths based on 1-ethyl-3-methylimidazolium acetate ionic liquids. The study involved the formation of copper, zinc, and brass coatings. The influence of the bath composition, cathodic current density, and temperature was determined. The obtained coatings were characterized in terms of their morphology, chemical composition, phase composition, roughness, and corrosion resistance. It was found that the structure of the obtained coatings is strongly dependent on the process parameters. The three main structure types observed were as follows: fine-grained, porous, and olive-like. To the best knowledge of the authors, it is the first time the olive-like structure was observed in the case of an electrodeposited coating. The Cu-Zn coatings consisted of 19–96 at. % copper and exhibited relatively good corrosion resistance. A significant improvement of corrosion properties was found in the case of copper and brass coatings with the olive-like structure.

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Influence of Rust Inhibitor on the Corrosion Resistance of Reinforcement in Cement Paste with Chloride

Coatings ◽

10.3390/coatings11050606 ◽

2021 ◽

Vol 11 (5) ◽

pp. 606

Author(s):

Linchun Zhang ◽

Ailian Zhang ◽

Ke Li ◽

Qian Wang ◽

Junzhe Liu ◽

...

Keyword(s):

Corrosion Resistance ◽

Cement Paste ◽

Photoelectron Spectroscopy ◽

Electrical Resistance ◽

Corrosion Properties ◽

Passivation Film ◽

Steel Bars ◽

Assembly Unit ◽

Chloride Environment ◽

Rust Inhibitor

The electrical resistance and polarization effect of cement paste containing reinforcement were tested to research the anti-corrosion properties of steel bars in cement paste. Moreover, the microstructure and composition of passivation film and rust on the steel bars were studied. The water–cement ratio of the cement paste in this study was 0.3, with 0.5% NaCl, 1% NaNO2, and 1% Benzotriazole, and an assembly unit of 0.5% NaNO2 + 0.5% Benzotriazole by mass of cement was added to the cement to provide a chloride environment. X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) were applied to research the composition of the passivation film and the microstructure of the cement paste, respectively. The results indicated that the samples with the assembly unit of 0.5% NaNO2 + 0.5% Benzotriazole showed the highest electrical resistance and polarization electrical resistance, while the specimens with 1.0% Benzotriazole showed the lowest electrical resistance and polarization electrical resistance. Moreover, the passivation film of steel bars weakened with increasing distance from the surface of the steel bars. Therefore, the corrosion of steel bars becomes more serious with increasing distance. Finally, the influence of the rust inhibitor on the corrosion resistance of steel bars in the specimens decreased in the following order: 0.5% NaNO2 + 0.5% Benzotriazole >1.0% NaNO2>1.0% Benzotriazole.

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Development of Al–Mg–Si alloy performance by addition of grain refiner Al–5Ti–1B alloy

Science Progress ◽

10.1177/00368504211029469 ◽

2021 ◽

Vol 104 (2) ◽

pp. 003685042110294

Author(s):

Khaled Abd El-Aziz ◽

Emad M Ahmed ◽

Abdulaziz H Alghtani ◽

Bassem F Felemban ◽

Hafiz T Ali ◽

...

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Corrosion Resistance ◽

Testing Machine ◽

Dendritic Structure ◽

Grain Refiner ◽

Corrosion Properties ◽

Average Grain Size ◽

Structural Applications ◽

Alloy Addition

Aluminum alloys are the most essential part of all shaped castings manufactured, mainly in the automotive, food industry, and structural applications. There is little consensus as to the precise relationship between grain size after grain refinement and corrosion resistance; conflicting conclusions have been published showing that reduced grain size can decrease or increase corrosion resistance. The effect of Al–5Ti–1B grain refiner (GR alloy) with different percentages on the mechanical properties and corrosion behavior of Aluminum-magnesium-silicon alloy (Al–Mg–Si) was studied. The average grain size is determined according to the E112ASTM standard. The compressive test specimens were made as per ASTM: E8/E8M-16 standard to get their compressive properties. The bulk hardness using Vickers hardness testing machine at a load of 50 g. Electrochemical corrosion tests were carried out in 3.5 % NaCl solution using Autolab Potentiostat/Galvanostat (PGSTAT 30).The grain size of the Al–Mg–Si alloy was reduced from 82 to 46 µm by the addition of GR alloy. The morphology of α-Al dendrites changes from coarse dendritic structure to fine equiaxed grains due to the addition of GR alloy and segregation of Ti, which controls the growth of primary α-Al. In addition, the mechanical properties of the Al–Mg–Si alloy were improved by GR alloy addition. GR alloy addition to Al–Mg–Si alloy produced fine-grained structure and better hardness and compressive strength. The addition of GR alloy did not reveal any marked improvements in the corrosion properties of Al–Mg–Si alloy.

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Corrosion behavior of new type Co-based superalloys with different Ni contents

Corrosion Reviews ◽

10.1515/corrrev-2017-0003 ◽

2017 ◽

Vol 35 (6) ◽

pp. 455-462 ◽

Cited By ~ 2

Author(s):

Bo Gao ◽

Lei Wang ◽

Yang Liu ◽

Xiu Song ◽

Shu-Yu Yang ◽

...

Keyword(s):

Corrosion Resistance ◽

Corrosion Behavior ◽

Hot Corrosion ◽

Corrosion Layer ◽

Corrosion Process ◽

Corrosion Properties ◽

Oxidation Processes ◽

Ni Content ◽

Ni Addition ◽

New Type

AbstractThe corrosion properties of γ′-strengthened Co-xNi-Al-W-Cr (where x=15, 20, 25, and 30 at.%) superalloys were investigated in the mixture of 75 wt.% Na2SO4+25 wt.% NaCl at 900°C. The results showed that the corrosion behavior is associated with both sulfuration and oxidation processes. It was demonstrated that increasing the addition of Ni effectively promoted the formation of continuous Al2O3 scales, so that the hot corrosion resistance could be improved. When Ni content is more than 20 at.%, a large amount of Ni3S2 precipitates during the corrosion process. Sulfuration can destroy the integrity of the corrosion layer and increase the activity of oxygen. In this way, the internal oxidation of the alloys becomes more serious. Therefore, it is recommended that the optimum Ni addition is about 20 at.% for new type Co-Ni-Al-W-Cr superalloys.

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Effect of Plasma Nitriding Process Conditions on Corrosion Resistance of 440B Martensitic Stainless Steel

Acta Mechanica et Automatica ◽

10.2478/ama-2014-0028 ◽

2014 ◽

Vol 8 (3) ◽

pp. 156-159 ◽

Cited By ~ 1

Author(s):

Magdalena Łępicka ◽

Małgorzata Grądzka-Dahlke

Keyword(s):

Stainless Steel ◽

Corrosion Resistance ◽

Degradation Products ◽

Plasma Nitriding ◽

Electrochemical Corrosion ◽

Industrial Applications ◽

Process Conditions ◽

Corrosion Properties ◽

Dental Instruments ◽

Increased Risk

Abstract Martensitic stainless steels are used in a large number of various industrial applications, e.g. molds for plastic injections and glass moldings, automotive components, cutting tools, surgical and dental instruments. The improvement of their tribological and corrosion properties is a problem of high interest especially in medical applications, where patient safety becomes a priority. The paper covers findings from plasma nitrided AISI 440B (PN-EN or DIN X90CrMoV18) stainless steel corrosion resistance studies. Conventionally heat treated and plasma nitrided in N2:H2 reaction gas mixture (50:50, 65:35 and 80:20, respectively) in two different temperature ranges (380 or 450°C) specimens groups were examined. Microscopic observations and electrochemical corrosion tests were performed using a variety of analytical techniques. As obtained findings show, plasma nitriding of AISI 440B stainless steel, regardless of the process temperature, results in reduction of corrosion current density. Nevertheless, applying thermo-chemical process which requires exceeding temperature of about 400°C is not recommended due to increased risk of steel sensitization to intergranular and stress corrosion. According to the results, material ion nitrided in 450°C underwent leaching corrosion processes, which led to significant disproportion in chemical composition of the corroded and corrosion-free areas. The authors suggest further research into corrosion process of plasma nitrided materials and its degradation products.

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Relationships between Textures and Surface Roughness, Frictional Behavior, Erosion and Corrosion Properties of TiN Films

Materials Science Forum ◽

10.4028/www.scientific.net/msf.449-452.781 ◽

2004 ◽

Vol 449-452 ◽

pp. 781-784 ◽

Cited By ~ 2

Author(s):

Hee Dong Kim ◽

In Soo Kim ◽

Dong Young Sung ◽

Min Gu Lee ◽

S. Dost ◽

...

Keyword(s):

Surface Roughness ◽

Corrosion Resistance ◽

Friction Coefficient ◽

Physical Vapor Deposition ◽

Textured Surface ◽

Corrosion Properties ◽

Tin Films ◽

Physical Vapor Deposition Method ◽

Erosion Corrosion ◽

Better Than

TiN coated films were prepared by a reactive ion physical vapor deposition method. In this research, we studied the relationships between textures and friction coefficient, erosion-corrosion resistance and corrosion resistance in textured TiN films. The surface roughness of (115) textured TiN films is lower than that of (111) textured TiN films. The friction coefficient of (115) textured surface is similar with that of (111) textured surface of TiN coated films. The erosion-corrosion and corrosion resistance of (115) textured surface is better than that of (111) textured surface of TiN coated films.

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