Metals

Editorial

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3 pages, 180 KiB

Open AccessEditorial

Special Metal-Alloy Coating and Catalysis

by Wangping Wu

Metals 2023, 13(9), 1555; https://0-doi-org.brum.beds.ac.uk/10.3390/met13091555 - 4 Sep 2023

Viewed by 637

Abstract

Special metal alloy coating is an important material technology that has a wide range of applications in many fields [...] Full article

(This article belongs to the Special Issue Special Metal-Alloy Coating and Catalysis)

Research

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15 pages, 4028 KiB

Open AccessArticle

Investigation of Oxide Thickness on Technical Aluminium Alloys—A Comparison of Characterization Methods

by Ralph Gruber, Tanja Denise Singewald, Thomas Maximilian Bruckner, Laura Hader-Kregl, Martina Hafner, Heiko Groiss, Jiri Duchoslav and David Stifter

Metals 2023, 13(7), 1322; https://0-doi-org.brum.beds.ac.uk/10.3390/met13071322 - 24 Jul 2023

Cited by 5 | Viewed by 1993

Abstract

In this study the oxide layer of technical 6xxx aluminium surfaces, pickled as well as passivated, were comparatively investigated by means of transmission electron microscopy (TEM), Auger electron and X-ray photoelectron spectroscopy (AES, XPS), the latter in two different operating modes, standard and [...] Read more.

In this study the oxide layer of technical 6xxx aluminium surfaces, pickled as well as passivated, were comparatively investigated by means of transmission electron microscopy (TEM), Auger electron and X-ray photoelectron spectroscopy (AES, XPS), the latter in two different operating modes, standard and angle resolved mode. In addition, confocal microscopy and focused ion beam cutting were used for structural studies of the surfaces and for specimen preparation. The results illustrate in detail the strengths and weaknesses of each measurement technique. TEM offers a direct way to reliably quantify the thickness of the oxide layer, which is in the range of 5 nm, however, on a laterally restricted area of the surface. In comparison, for AES, the destructiveness of the electron beam did not allow to achieve comparable results for the thickness determination. XPS was proven to be the most reliable method to reproducibly quantify the average oxide thickness. By evaluating the angle resolved XPS data, additional information on the average depth distribution of the individual elements on the surface could be obtained. The findings obtained in this study were then successfully used for the investigation of the increase in the aluminium oxide thickness on technical samples during an aging test of 12 months under standard storage conditions. Full article

(This article belongs to the Special Issue Special Metal-Alloy Coating and Catalysis)

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18 pages, 5059 KiB

Open AccessArticle

A Determination of the Influence of Technological Parameters on the Quality of the Created Layer in the Process of Cataphoretic Coating

by Jozef Dobránsky, Miroslav Gombár, Patrik Fejko and Róbert Balint Bali

Metals 2023, 13(6), 1080; https://0-doi-org.brum.beds.ac.uk/10.3390/met13061080 - 7 Jun 2023

Cited by 1 | Viewed by 1387

Abstract

Cataphoresis varnishing enables an organic coating to form on an aluminum substrate, thus increasing its corrosion resistance and durability. Cataphoresis varnishing is known to ensure a high adhesion of the created cataphoresis layer and a good homogeneity of this layer, even on surfaces [...] Read more.

Cataphoresis varnishing enables an organic coating to form on an aluminum substrate, thus increasing its corrosion resistance and durability. Cataphoresis varnishing is known to ensure a high adhesion of the created cataphoresis layer and a good homogeneity of this layer, even on surfaces with complex geometry. This paper aimed to optimize the deposition process and to analyze and evaluate the thickness of a cataphoresis layer formed on an aluminum substrate from AW 1050—H24 material. In total, 30 separate samples were created in accordance with the Design of Experiments methodology, using a central composite plan. The independent input factors in the study were: the electrical voltage (U) and deposition time in the cataphoresis varnishing process (t_KTL) at the polymerization times of 15 min, 20 min, and 25 min, respectively. The results of the statistical analysis showed that the voltage accounted for 33.82% of the change in the thickness of the created layer and the deposition time contributed 28.67% to thi change. At the same time, the interaction of the voltage and deposition time (p < 0.0001) accounted for 20.25% of the change in the thickness of the layer under formation. The regression model that was constructed showed a high degree of prediction accuracy (85.8775%) and its use as a function for nonlinear optimization provided a maximum layer thickness t_h of max = 26.114 µm, at U = 240 V and t_KTL = 6.0 min, as was proven under experimental conditions. Full article

(This article belongs to the Special Issue Special Metal-Alloy Coating and Catalysis)

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14 pages, 5318 KiB

Open AccessFeature PaperArticle

Study on Nitrogen-Doped Biomass Carbon-Based Composite Cobalt Selenide Heterojunction and Its Electrocatalytic Performance

by Tengfei Meng, Hongjin Shi, Feng Ao, Peng Wang, Longyao Wang, Lan Wang, Yujun Zhu, Yunxiang Lu and Yupei Zhao

Metals 2023, 13(4), 767; https://0-doi-org.brum.beds.ac.uk/10.3390/met13040767 - 14 Apr 2023

Cited by 3 | Viewed by 1441

Abstract

With the increasing utilization of clean energy, the development and utilization of hydrogen energy has become a research topic of great significance. Cobalt selenide (CS) is an electrocatalyst with great potential for oxygen evolution reaction (OER). In this paper, a nitrogen-doped biomass carbon [...] Read more.

With the increasing utilization of clean energy, the development and utilization of hydrogen energy has become a research topic of great significance. Cobalt selenide (CS) is an electrocatalyst with great potential for oxygen evolution reaction (OER). In this paper, a nitrogen-doped biomass carbon (1NC@3)-based composite cobalt selenide (CS) heterojunction was prepared via a solvothermal method using kelp as the raw material. Structural, morphological, and electrochemical analyses were conducted to evaluate its performance. The electrochemical test results demonstrate that the overpotential of the CS/1NC@3 catalyst in the OER process was 292 mV, with a Tafel slope of 98.71 mV·dec⁻¹ at a current density of 10 mA·cm⁻². The electrochemical performance of the CS/1NC@3 catalyst was further confirmed by theoretical calculations, which revealed that the presence of the biomass carbon substrate enhanced the charge transport speed of the OER process and promoted the OER process. This study provides a promising strategy for the development of efficient electrocatalysts for OER applications. Full article

(This article belongs to the Special Issue Special Metal-Alloy Coating and Catalysis)

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11 pages, 4266 KiB

Open AccessArticle

Shear Transformation Zone and Its Correlation with Fracture Characteristics for Fe-Based Amorphous Ribbons in Different Structural States

by Weiwei Dong, Minshuai Dong, Danbo Qian, Jiankang Zhang and Shigen Zhu

Metals 2023, 13(4), 757; https://0-doi-org.brum.beds.ac.uk/10.3390/met13040757 - 13 Apr 2023

Cited by 1 | Viewed by 1172

Abstract

Fe-based amorphous alloys often exhibit severe brittleness induced by annealing treatment, which increases the difficulties in handling and application in the industry. In this work, the shear transformation zone and its correlation with fracture characteristics for FeSiB amorphous alloy ribbons in different structural [...] Read more.

Fe-based amorphous alloys often exhibit severe brittleness induced by annealing treatment, which increases the difficulties in handling and application in the industry. In this work, the shear transformation zone and its correlation with fracture characteristics for FeSiB amorphous alloy ribbons in different structural states were investigated. The results show that the bending strain decreases sharply with the annealing temperature increase, accompanied by decreased shear band density and the induced plastic deformation zone. Furthermore, the microscopic fracture surface features transform from a micron-scale dimple pattern to nano-scale dimples and periodic corrugations. According to nano-indentation results, the strain rate sensitivity and shear transformation zone volume change significantly upon annealing treatment, which is responsible for the deterioration of bending ductility and the transition of microscopic fracture surface features. Full article

(This article belongs to the Special Issue Special Metal-Alloy Coating and Catalysis)

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14 pages, 5849 KiB

Open AccessArticle

Effect of Ce Content on the Microstructure and Mechanical Properties of Al-Cu-Li Alloy

by Xianxian Ding, Yalin Lu, Jian Wang, Xingcheng Li and Dongshuai Zhou

Metals 2023, 13(2), 253; https://0-doi-org.brum.beds.ac.uk/10.3390/met13020253 - 28 Jan 2023

Cited by 6 | Viewed by 1417

Abstract

In this work, the effects of Ce content (0.1%, 0.2%, and 0.3 wt%) on the microstructures and mechanical properties of Al-Cu-Li alloys were investigated. The results show that the grains of Al-Cu-Li alloy are refined by adding Ce element. When Ce content is [...] Read more.

In this work, the effects of Ce content (0.1%, 0.2%, and 0.3 wt%) on the microstructures and mechanical properties of Al-Cu-Li alloys were investigated. The results show that the grains of Al-Cu-Li alloy are refined by adding Ce element. When Ce content is less than 0.1%, the ultimate strength of the alloy increases with the increase of Ce content. However, the ultimate strength of the alloy decreases when Ce content is above 0.1%. For Al-Cu-Li alloy with different Ce content, the aging precipitation of T₁ and θ′ phases play the main strengthening role. When Ce content increases from 0.1 to 0.3%, dynamic recrystallization is promoted during hot deformation. The recrystallization of the alloys is inhibited after T6 treatment with the increase of Ce content, which can be attributed to existence of the Al₈Cu₄Ce phases on the grain boundary. This work provides an economical and convenient method for improving the properties of Al-Cu-Li alloys by Ce addition. Full article

(This article belongs to the Special Issue Special Metal-Alloy Coating and Catalysis)

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21 pages, 11699 KiB

Open AccessArticle

Study on the Effect of Pulse Waveform Parameters on Droplet Transition, Dynamic Behavior of Weld Pool, and Weld Microstructure in P-GMAW

by Jie Huang, Tao Chen, Daqing Huang and Tengzhou Xu

Metals 2023, 13(2), 199; https://0-doi-org.brum.beds.ac.uk/10.3390/met13020199 - 19 Jan 2023

Cited by 4 | Viewed by 1441

Abstract

The heating and impact of arc and droplet acting on the weld pool lead to the transfer of mass, heat, and momentum, which affects the dynamic behavior of the weld pool and the microstructure in the P-GMAW process. In this paper, an image [...] Read more.

The heating and impact of arc and droplet acting on the weld pool lead to the transfer of mass, heat, and momentum, which affects the dynamic behavior of the weld pool and the microstructure in the P-GMAW process. In this paper, an image processing program is used to extract the dynamic behavior characteristics of the droplet transition and the weld pool in high-speed photography. The influence of the current waveform on the arc pressure and the impact of the droplet is quantitatively analyzed with different parameters. The dynamic behavior of the weld pool and the microstructure under different current waveform conditions are further studied. The internal relation of current waveform parameters to weld pool behavior and weld microstructure was expounded. The results show that the droplet impact is positively correlated with the pulse peak current. The rectangular wave pulse has a more significant droplet impact than the exponential wave with the same waveform parameters. The impact of droplet transition on the weld pool enhances the convective intensity of the weld pool. It slows down the cooling rate of the solidified weld microstructure below the tail of the weld pool, increasing the grain size of the weld microstructure. Full article

(This article belongs to the Special Issue Special Metal-Alloy Coating and Catalysis)

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12 pages, 3365 KiB

Open AccessArticle

Effect of Cladding Current on Microstructure and Wear Resistance of High-Entropy Powder-Cored Wire Coating

by Xinghai Shan, Mengqi Cong and Weining Lei

Metals 2022, 12(10), 1718; https://0-doi-org.brum.beds.ac.uk/10.3390/met12101718 - 14 Oct 2022

Cited by 4 | Viewed by 1195

Abstract

This paper investigated the effect of tungsten arc melting current on the microstructure and wear resistance of coatings prepared from high-entropy powder-cored wire, FeCrMnCuNiSi₁. A powder-cored wire of high-entropy composition was drawn by powder-cored wire-forming equipment, and a FeCrMnCuNiSi₁ high-entropy [...] Read more.

This paper investigated the effect of tungsten arc melting current on the microstructure and wear resistance of coatings prepared from high-entropy powder-cored wire, FeCrMnCuNiSi₁. A powder-cored wire of high-entropy composition was drawn by powder-cored wire-forming equipment, and a FeCrMnCuNiSi₁ high-entropy alloy coating was designed on the base material 40Cr by the tungsten arc fusion technique. The influence law and mechanism of melting current on the wear resistance of the coatings were obtained through analyzing the microstructure, physical phase, and wear resistance of the coatings prepared by different melting currents. At a melting current of 200A, the FeCrMnCuNiSi₁ coating exhibits fine equiaxed grains and a single BCC phase; the highest and average microhardness of the coating reach 790.36 HV and 689.73 HV, respectively, whose average microhardness is twice that of the base material. The wear rate of the coating is 2245.86 μm³/(N∙μm), which is only 8% of the base material and has excellent wear resistance. The FeCrMnCuNiSi₁ high-entropy alloy coating prepared by ordinary powder-cored wire-forming equipment and the tungsten arc cladding method has excellent performance and low cost, which can provide an essential basis for the development, preparation, and application of high-entropy alloy coatings. Full article

(This article belongs to the Special Issue Special Metal-Alloy Coating and Catalysis)

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12 pages, 8041 KiB

Open AccessArticle

Cause Analysis and Solution of Premature Fracture of Suspension Rod in Metro Gear Box

by Wenming Liu, Zhiqiang Xu, Hongmei Liu and Xuedong Liu

Metals 2022, 12(9), 1426; https://0-doi-org.brum.beds.ac.uk/10.3390/met12091426 - 29 Aug 2022

Cited by 3 | Viewed by 1374

Abstract

Through the appearance observation of suspension rod in the metro gearbox, macro and micro observation of the fracture and quantitative analysis of the fracture, combined with the metallographic and hardness examination results of the boom, the finite element model was established and the [...] Read more.

Through the appearance observation of suspension rod in the metro gearbox, macro and micro observation of the fracture and quantitative analysis of the fracture, combined with the metallographic and hardness examination results of the boom, the finite element model was established and the force analysis of suspension rod was carried out to explore the causes of the fracture of the gearbox boom. The results show that the nature of suspension rod fracture is fatigue. The cause of its fatigue fracture is related to the low fatigue tolerance for booms in metro operation, and the surface shallow decarburization plays a role in promoting the fatigue fracture of suspension rod. The life of fatigue crack growth in the boom is 819 stations (or 1210 km), and the fatigue initiation life is 522,452 km. Full article

(This article belongs to the Special Issue Special Metal-Alloy Coating and Catalysis)

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16 pages, 6560 KiB

Open AccessArticle

Influence of Pretreatment Processes on Adhesion of Ni/Cu/Ni Multilayer on Polyetherimide Resin Reinforced with Glass Fibers

by Xiaodong Xu, Dingkai Xie, Jiaqi Huang, Kunming Liu, Guang He, Yi Zhang, Peng Jiang, Lixin Tang and Wangping Wu

Metals 2022, 12(8), 1359; https://0-doi-org.brum.beds.ac.uk/10.3390/met12081359 - 16 Aug 2022

Cited by 4 | Viewed by 1951

Abstract

The metallization of polyetherimide (PEI) is widely considered to enhance its surface properties and enhance its application in engineering fields; however, adhesion is a key factor in determining the reliability of PEI metallization. A Ni/Cu/Ni multilayer coating was successfully manufactured on a batch [...] Read more.

The metallization of polyetherimide (PEI) is widely considered to enhance its surface properties and enhance its application in engineering fields; however, adhesion is a key factor in determining the reliability of PEI metallization. A Ni/Cu/Ni multilayer coating was successfully manufactured on a batch of PEI resin reinforced with glass fibers by a two-step metallization process, including sandblasting and activation/acceleration. The microstructure and morphology of the top-surface and cross-section of the coatings were observed by scanning electron microscopy. The chemical state and composition of the deposits were characterized by both X-ray photoelectron and energy-dispersive spectroscopy. The adhesion state was qualitatively evaluated by cross-cut tests with 3M tape. The surface roughness of the substrate significantly increased after the sandblasting process, which could improve the adhesion between the multilayer coating and the PEI substrate. After the standard activation process, the acceleration made an effect on the deposition of the initial Ni layer for electroless plating. The influence of acceleration on the appearance quality of metallization on the PEI substrate was studied and, at the same time, the mechanism of acceleration was investigated and addressed. Full article

(This article belongs to the Special Issue Special Metal-Alloy Coating and Catalysis)

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Review

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19 pages, 3304 KiB

Open AccessReview

Electrodeposition of Iron Triad Metal Coatings: Miles to Go

by Olga Lebedeva, Larisa Fishgoit, Andrey Knyazev, Dmitry Kultin and Leonid Kustov

Metals 2023, 13(4), 657; https://0-doi-org.brum.beds.ac.uk/10.3390/met13040657 - 26 Mar 2023

Cited by 2 | Viewed by 2101

Abstract

The possibilities and future perspectives of electrochemical deposition of bimetallic compositions and alloys containing Fe, Co, Ni, Cr, W, and Mo are reviewed. The synthesis of two- and three-component materials, as well as compositionally more complex alloys, is considered. The method of synthesizing [...] Read more.

The possibilities and future perspectives of electrochemical deposition of bimetallic compositions and alloys containing Fe, Co, Ni, Cr, W, and Mo are reviewed. The synthesis of two- and three-component materials, as well as compositionally more complex alloys, is considered. The method of synthesizing of materials via electrodeposition from solutions containing metal ions and metalloids is one of the most promising approaches because it is fast, cheap, and it is possible to control the composition of the final product with good precision. Corrosion, catalytic and magnetic properties should be distinguished. Due to these properties, the range of applications for these alloys is very wide. The idea of a correlation between the magnetic and catalytic properties of the iron-triad metal alloys is considered. This should lead to a deeper understanding of the interplay of the properties of electrodeposited alloys. In addition to deposition from aqueous (classical) solvents, the advantages and perspectives of electrochemical deposition from ionic liquids (ILs) and deep eutectic solvents (DES) are briefly discussed. The successful use and development of this method of electrodeposition of alloys, which are quite difficult or impossible to synthesize in classical solvents, has been demonstrated and confirmed. Full article

(This article belongs to the Special Issue Special Metal-Alloy Coating and Catalysis)

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