Metals

16 pages, 5721 KiB

Open AccessArticle

Hydrogen-Induced Cracking in CGHAZ of Welded X80 Steel under Tension Load

by Jinxin Gou, Xiao Xing, Gan Cui, Zili Li, Jianguo Liu and Xiangyuan Deng

Metals 2023, 13(7), 1325; https://doi.org/10.3390/met13071325 - 24 Jul 2023

Viewed by 1272

X80 steel is extensively used in hydrogen environments and is susceptible to hydrogen embrittlement (HE). This paper studied the hydrogen-induced cracking (HIC) behavior in the coarse-grained heat-affected zone (CGHAZ) of X80 steel welds, through applying in situ hydrogen-charging tensile experiments, hydrogen permeation experiments, [...] Read more.

X80 steel is extensively used in hydrogen environments and is susceptible to hydrogen embrittlement (HE). This paper studied the hydrogen-induced cracking (HIC) behavior in the coarse-grained heat-affected zone (CGHAZ) of X80 steel welds, through applying in situ hydrogen-charging tensile experiments, hydrogen permeation experiments, and various surface analysis techniques. It is shown that a few hydrogen atoms can significantly decrease a material’s elongation and reduction of area. When the heat input (HI) was 29.2 kJ/cm, the material had minor sensitivity to hydrogen embrittlement. The tensile fractures were ductile without hydrogen. However, the fracture surface exhibited brittle fracture with hydrogen. With increased HI, the HE fracture showed a transition of intergranular fracture→intergranular and transgranular mixed fracture→transgranular fracture. In the presence of hydrogen, the grain boundaries of elongated strips were prone to the formation of intergranular cracks under a tension load, and the hydrogen embrittlement resistance of the bulk lath bainite (LB) was weak. The hydrogen embrittlement susceptibility of pure granular bainite (GB) was lower. Fine LB and GB composite structures could remarkably inhibit intergranular cracks, giving the steel a superior resistance to hydrogen embrittlement. Full article

(This article belongs to the Topic Environmental Sensitivity and Safety Assessment of Materials)

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14 pages, 2988 KiB

Open AccessArticle

Hydrogen’s Effect on the Shape Memory Effect of TiNi Alloy Single Crystals

by Irina V. Kireeva, Yuriy I. Chumlyakov, Liya P. Yakovleva and Anna V. Vyrodova

Metals 2023, 13(7), 1324; https://doi.org/10.3390/met13071324 - 24 Jul 2023

Cited by 1 | Viewed by 874

Abstract

Hydrogen’s effect on the shape memory effect (SME) of

[\bar{1} 17]

-oriented Ti_49.7-Ni_50.3 (at.%) alloy single crystals, with a B2–B19′ martensitic transformation (MT), was studied after being electrolytically hydrogenated at a current density of 1500 A/m² [...] Read more.

Hydrogen’s effect on the shape memory effect (SME) of

[\bar{1} 17]

-oriented Ti_49.7-Ni_50.3 (at.%) alloy single crystals, with a B2–B19′ martensitic transformation (MT), was studied after being electrolytically hydrogenated at a current density of 1500 A/m² for 3 h at room temperature under isobaric tensile deformation. It was shown that, under the used hydrogenation regime, hydrogen was in a solid solution and lowered the elastic modulus of B19′ martensite. The hydrogen in a solid solution increased (i) the yield strength σ_0.1 of the initial B2 phase by 100 MPa at Md temperature, (ii) the σ_0.1 of the stress-induced B2–B19′ MT by 25 MPa at Ms temperature, and (iii) the plasticity of B19′ martensite relative to the hydrogen-free crystals. At the same level of external stresses, the SME in the hydrogenated crystals was greater than that in hydrogen-free crystals. At external tensile stresses σ_ex = 200 MPa, the SME was 4.4 ± 0.2% in the hydrogenated crystals and 1.8 ± 0.2% without hydrogen. Hydrogen initiated a two-way SME of 0.5 ± 0.2% at σ_ex = 0 MPa, which was absent in the hydrogen-free crystals. The physical reasons leading to an increase in the SME upon hydrogenation are discussed. Full article

(This article belongs to the Special Issue Research Progress of Metal Smart Materials)

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18 pages, 2642 KiB

Open AccessArticle

Investigation of Laser-Welded Co-Cr Dental Alloys by Microscopy and Mechanical Testing

by Andreja Carek, Ljerka Slokar Benić, Dino Buković and Martina Šlaj

Metals 2023, 13(7), 1323; https://doi.org/10.3390/met13071323 - 24 Jul 2023

Viewed by 862

Abstract

In order to improve the hold and function of dentures for the patient, various prostheses made of metal, mostly metal alloys, are used every day in dental practise. Cobalt-chromium alloys are usually the first choice because they have very good mechanical properties and [...] Read more.

In order to improve the hold and function of dentures for the patient, various prostheses made of metal, mostly metal alloys, are used every day in dental practise. Cobalt-chromium alloys are usually the first choice because they have very good mechanical properties and satisfactory clinical conditions. Nowadays, laser welding is increasingly used in dental practise due to its numerous advantages over other technologies. In this work, therefore, six commercially available Co-Cr alloys were investigated. Three of them are used for metal-ceramic work, two for denture frameworks and one is suitable for both applications. They were joined by laser welding and subsequently analysed microscopically. Their mechanical properties were determined and statistically evaluated. The microhardness of the laser-welded alloys is in the range of 282–465 MPa in the weld zone and between 283 and 435 MPa in the heat-affected zone. The flexural strength of the laser-welded alloys is lower than the control group, but an alloy for the metal-ceramic work (I-BOND NF) shows very similar value. Furthermore, this alloy, together with two other metal-ceramic alloys, survived a maximum of cycles in dynamic tests. It was found that the laser method can be used for joining Co-Cr alloys while ensuring appropriate parameters that guarantee the quality of the dental work. Full article

(This article belongs to the Section Biobased and Biodegradable Metals)

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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://doi.org/10.3390/met13071322 - 24 Jul 2023

Cited by 5 | Viewed by 1611

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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14 pages, 2776 KiB

Open AccessArticle

Influence of the Straining Path during Cold Drawing on the Hydrogen Embrittlement of Prestressing Steel Wires

by Jesús Toribio and Miguel Lorenzo

Metals 2023, 13(7), 1321; https://doi.org/10.3390/met13071321 - 24 Jul 2023

Cited by 1 | Viewed by 910

Abstract

Cold drawing is a commonly used technique for manufacturing the prestressing steel wires used as structural elements in prestressed concrete structures. As a result of this manufacturing process, a non-uniform plastic strain and residual stress states are generated in the wire. These stress [...] Read more.

Cold drawing is a commonly used technique for manufacturing the prestressing steel wires used as structural elements in prestressed concrete structures. As a result of this manufacturing process, a non-uniform plastic strain and residual stress states are generated in the wire. These stress and strain fields play a relevant role as the main cause of the in-service failure of prestressing steel wires in the presence of an aggressive environment, hydrogen embrittlement (HE). In this paper, hydrogen susceptibility to HE is compared in two different commercial cold-drawn wires with the same dimensions at the beginning and at the end of manufacturing that follow different straining paths. To achieve this goal, numerical simulation with the finite element (FE) method is carried out for two different industrial cold-drawing chains. Later, the HE susceptibility of both prestressing steel wires was estimated in terms of the hydrogen accumulation given by FE numerical simulations of hydrogen diffusion assisted by stress and strain states, considering the previously obtained residual stress and plastic strain fields generated after each wire-drawing process. According to the obtained results, the hardening history modifies the residual stress and strain states in the wires, affecting their behavior in hydrogen environments. Full article

(This article belongs to the Special Issue Study of Hydrogen Embrittlement of Metallic Materials)

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8 pages, 224 KiB

Open AccessEditorial

Microstructure and Properties in Metals and Alloys

by Andrea Di Schino and Claudio Testani

Metals 2023, 13(7), 1320; https://doi.org/10.3390/met13071320 - 24 Jul 2023

Viewed by 791

Abstract

Microstructure design is key in targeting the desired material’s properties [...] Full article

(This article belongs to the Topic Microstructure and Properties in Metals and Alloys)

23 pages, 6456 KiB

Open AccessArticle

Comparative Analysis of the Hot Isostatic Pressing Densification Behavior of Uniform and Non-Uniform Distributed Powder

by Fandi Meng, Lihui Lang and Yi Xiao

Metals 2023, 13(7), 1319; https://doi.org/10.3390/met13071319 - 24 Jul 2023

Viewed by 1333

Abstract

Hot isostatic pressing (HIP) technology can directly produce nearly clean shaped workpieces that meet the requirements while ensuring machining accuracy and surface quality. Usually, people use numerical simulation methods to reduce experimental costs. Generally, a uniform powder relative density distribution of about 65% [...] Read more.

Hot isostatic pressing (HIP) technology can directly produce nearly clean shaped workpieces that meet the requirements while ensuring machining accuracy and surface quality. Usually, people use numerical simulation methods to reduce experimental costs. Generally, a uniform powder relative density distribution of about 65% is used in the simulation. However, in practical engineering, we found that even with additional tools such as vibration tables, the powder filling is not uniform. The non-uniform distribution causes uneven shrinkage of the powder and capsule after HIP. In this paper, a numerical model for HIPing of Ti-6Al-4V powder is developed to improve the prediction by comparing the uniform and non-uniform initial powder distribution. The results show that different initial relative density distributions affect the powder densification process and further affect the deformation of the capsule. It also leads to non-uniform stress distribution after HIP, which increases the risk of capsule rupture. The analysis of the numerical simulation results and the comparison with the experimental results highlights that taking into account the non-uniform powder distribution inside the capsule is vital to improve numerical results and produce near-net shape components. The maximum error of the simulation with the usual initial relative density setting of 65% is 4.2%. However, considering the uneven distribution of initial powder, the maximum error is reduced to 3.16%, and the average error is also less than 2%. Full article

(This article belongs to the Topic Advanced Processes in Metallurgical Technologies)

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4 pages, 179 KiB

Open AccessEditorial

Advances in Metal-Containing Magnetic Materials and Magnetic Technologies

by Zhongwu Liu

Metals 2023, 13(7), 1318; https://doi.org/10.3390/met13071318 - 24 Jul 2023

Viewed by 864

Abstract

Magnetic materials generally refer to materials with ferromagnetic or ferrimagnetic ordering [...] Full article

(This article belongs to the Special Issue Advances in Metal-Containing Magnetic Materials)

15 pages, 3244 KiB

Open AccessArticle

High-Throughput Synthesis and Characterization Screening of Mg-Cu-Y Metallic Glass

by Dan J. Thoma, Janine T. Spethson, Carter S. Francis, Paul M. Voyles and John H. Perepezko

Metals 2023, 13(7), 1317; https://doi.org/10.3390/met13071317 - 24 Jul 2023

Cited by 1 | Viewed by 1002

Abstract

Bulk metallic glasses can exhibit novel material properties for engineering scale components, but the experimental discovery of new alloy compositions is time intensive and thwarts the rate of discovery. This study presents an experimental, high-throughput methodology to increase the speed of discovery for [...] Read more.

Bulk metallic glasses can exhibit novel material properties for engineering scale components, but the experimental discovery of new alloy compositions is time intensive and thwarts the rate of discovery. This study presents an experimental, high-throughput methodology to increase the speed of discovery for potential bulk metallic glass alloys. A well-documented system, Mg-Cu-Y, was used as a model system. A laser additive manufacturing technique, directed energy deposition, was used for the in situ alloying of elemental powders to synthesize discrete compositions in the ternary system. The laser processing technique can supply the necessary cooling rates of 10³–10⁴ Ks⁻¹ for bulk metallic glass formation. The in situ alloying enables the rapid synthesis of compositional libraries with larger sample sizes and discrete compositions than are provided by combinatorial thin films. Approximately 1000 discrete compositions can be synthesized in a day. Surface smoothness, as discerned by optical reflectivity, can suggest glass-forming alloys. X-ray diffraction coupled with energy dispersive X-ray spectroscopy can further refine amorphous alloy signatures and compositions. Transmission electron microscopy confirms amorphous samples. The tiered rate of amorphous alloy synthesis and characterization can survey a large compositional space and permits a glass-forming range to be identified within one week, making the process at least three orders of magnitude faster than other discrete composition techniques such as arc-melting or melt-spinning. Full article

(This article belongs to the Special Issue Additive Manufacturing: Technological Advancements, Processes, Materials, and Applications)

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12 pages, 9438 KiB

Open AccessArticle

Stress Corrosion Cracking of Ultrafine-Grained Ti-2Fe-0.1B Alloying after Equal Channel Angular Pressing

by Shuai Huang, Yutong Jin, Yu Wang, Yuecheng Dong, Hui Chang and Igor V. Alexandrov

Metals 2023, 13(7), 1316; https://doi.org/10.3390/met13071316 - 24 Jul 2023

Viewed by 864

Abstract

In the present study, the stress corrosion cracking (SCC) of ultrafine-grained (UFG) Ti-2Fe-0.1B prepared by equal channel angular pressing (ECAP) was investigated by a slow strain rate test (SSRT) with in-site electrochemical equipment. In comparison with the atmosphere, results indicated that the mechanical [...] Read more.

In the present study, the stress corrosion cracking (SCC) of ultrafine-grained (UFG) Ti-2Fe-0.1B prepared by equal channel angular pressing (ECAP) was investigated by a slow strain rate test (SSRT) with in-site electrochemical equipment. In comparison with the atmosphere, results indicated that the mechanical properties of Ti-2Fe-0.1B alloy degraded in the simulated sea water, and the SCC sensitivity of UFG Ti-2Fe-0.1B alloy is much lower than the initial coarse-grained (CG) state. The enhanced SCC resistance of UFG Ti-2Fe-0.1B alloy could be attributed to the mechanical and corrosive aspects simultaneously. First of all, the strength of UFG Ti-2Fe-0.1B alloy is much higher than the CG state, but the elongation to failure of UFG Ti-2Fe-0.1B alloy decreased more than 1.8 times. The UFG sample suffered crack initiation until failure with a relative short time and low plastic deformation, which weakened the effect of corrosion during SSRT. In addition, X-ray photoelectron spectroscopy (XPS) revealed that the thickness of the passivation film of the UFG Ti-2Fe-0.1B alloy is thicker and that the component of the passivation film possesses a higher proportion of TiO₂ in the same etched depth, which is beneficial to the corrosion resistance. Furthermore, according to the in-site electrochemical experiment curves, it is believed that the passivation film has a higher repair ability after cracking during SSRT for the UFG Ti-2Fe-0.1B alloy due to the decrease in grain size and the increase in dislocation density. Full article

(This article belongs to the Special Issue Passivity and Localized Corrosion of Metallic Materials)

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19 pages, 6580 KiB

Open AccessArticle

Effect of Cu Content on the PBF-LB/M Processing of the Promising Al-Si-Cu-Mg Composition

by Alessandra Martucci, Emilio Bassini and Mariangela Lombardi

Metals 2023, 13(7), 1315; https://doi.org/10.3390/met13071315 - 23 Jul 2023

Cited by 1 | Viewed by 796

Abstract

Over the past few years, several studies have been conducted on the development of Al-Si-Cu-Mg alloys for PBF-LB/M processing. The attention gained by these systems can be attributed to their light weight and strength provided by a solid solution in the as-built state [...] Read more.

Over the past few years, several studies have been conducted on the development of Al-Si-Cu-Mg alloys for PBF-LB/M processing. The attention gained by these systems can be attributed to their light weight and strength provided by a solid solution in the as-built state and by precipitation after heat treatment. However, published studies have kept the copper content below its solubility limit in the Al-Cu binary system under equilibrium conditions (5.65 wt%). The present study aims to explore Al-Si-Cu-Mg systems with high copper content, starting with the well-known AlSi10Cu4Mg system, moving towards AlSi10Cu8Mg, and arriving at AlCu20Si10Mg, a system never before processed with PBF-LB/M. Through the SST approach, the production of bulk samples, advanced microstructural characterization by SEM and FESEM analysis, phase identification by XRD analysis, and preliminary investigation of the mechanical properties through Vickers micro indentations, the effects of copper quantities on the processability, microstructural properties, and mechanical behavior of these compositions were investigated. The obtained results demonstrated the benefits of the supersaturated solid solution and the fine precipitation resulting from the addition of high Cu contents. In particular, the AlCu20Si10Mg system showed a very distinctive microstructure and unprecedented microhardness values. Full article

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15 pages, 4528 KiB

Open AccessArticle

Effect of Increasing Oscillation Width on the Arc Characteristics and Droplet Transfer Behavior of X80 Steel in the Overhead Welding Position of Narrow Gap P-GMAW

by Yang Bao, Ruilei Xue, Jianping Zhou and Yan Xu

Metals 2023, 13(7), 1314; https://doi.org/10.3390/met13071314 - 23 Jul 2023

Viewed by 897

Abstract

In the welding process of thick plate narrow gap pulse gas metal arc welding (P-GMAW) overhead welding station, the arc characteristics and droplet transfer behavior that become more complex due to the combined effects of narrow gap groove, gravity, and welding torch oscillation. [...] Read more.

In the welding process of thick plate narrow gap pulse gas metal arc welding (P-GMAW) overhead welding station, the arc characteristics and droplet transfer behavior that become more complex due to the combined effects of narrow gap groove, gravity, and welding torch oscillation. The welding stability is more difficult to control. High-speed imaging and electrical signal acquisition systems were established to observe and record the arc behavior and droplet transfer during the welding process at different oscillation widths, further revealing the formation mechanism of welding seam in narrow gap P-GMAW overhead welding station. Research has found that with an increased oscillation width, the arc deflects towards the sidewall from a trumpet-shaped symmetrically distributed around the center of the groove at an increasing deflection angle, and the droplet transfer changes from one droplet per pulse to multiple droplets per pulse, resulting in defects such as lack of sidewall fusion and undercutting of the weld seam. Based on the welding process discussed in this study, it is recommended to use an oscillation width of 2.6 mm. Full article

(This article belongs to the Topic Welding and Joining of Materials in Off-Shore and Energy Industry)

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18 pages, 6695 KiB

Open AccessArticle

Use of Sn60Pb40 Solder in Resistance Element Soldering Technology

by Pavol Sejč, Branislav Vanko, Alexander Schrek and Zuzana Gábrišová

Metals 2023, 13(7), 1313; https://doi.org/10.3390/met13071313 - 22 Jul 2023

Viewed by 889

Abstract

This work presents a new technology for joining dissimilar materials, Resistance Element Soldering (RES). This technology is fundamentally based on Resistance Element Welding (REW) technology; the difference is that the presented RES uses a bimetallic element composed of a hard Cu shell and [...] Read more.

This work presents a new technology for joining dissimilar materials, Resistance Element Soldering (RES). This technology is fundamentally based on Resistance Element Welding (REW) technology; the difference is that the presented RES uses a bimetallic element composed of a hard Cu shell and a core made of Sn60Pb40 solder. The RES technology using the Cu/Sn60Pb40 bimetallic element was tested when joining a galvanized steel sheet (HX220BD-100MBO) to a thermoplastic (PMMA). The effect of the process parameters on the volume of the melted solder, the deformation of the element, and the structure of the soldered joint was investigated on the joints made. The final criterion for assessing the influence of the process parameters was the joint strength. Due to the low strength of PPMA, the maximum joint strength was determined on RES joints of galvanized steel sheet and aluminum. The results showed that, to ensure the joint strength at the level of the strength of the Sn60Pb40 solder used, a heat input of 952 J and a clamping force of 623 N are required. The mentioned parameters ensure the necessary conditions for the creation of a soldered joint with a galvanized steel sheet as well as the deformation of the bimetallic element to create a form-fit effect in the opening of the PMMA to create a mechanical connection. Full article

(This article belongs to the Special Issue Advanced Studies in Metal Joining)

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30 pages, 10825 KiB

Open AccessArticle

Numerical Simulations and Experimental Verification of T-Structure Welding Deformation Using the Step-by-Step Loading Inherent Strain Method

by Lin Wang, Yugang Miao, Guangxu Hu, Yuyang Zhao and Qingwen Deng

Metals 2023, 13(7), 1312; https://doi.org/10.3390/met13071312 - 21 Jul 2023

Viewed by 1020

Abstract

The existing inherent strain method is improved in this paper to address the shortcomings of the existing inherent strain method in the process of loading inherent strain. Unlike the traditional inherent strain method, which uses one-step loading inherent strain for each weld seam [...] Read more.

The existing inherent strain method is improved in this paper to address the shortcomings of the existing inherent strain method in the process of loading inherent strain. Unlike the traditional inherent strain method, which uses one-step loading inherent strain for each weld seam for one-time elastic calculation, the improved inherent strain method uses step-by-step loading inherent strain for each weld seam for multiple elastic calculations to predict welding deformation. The step-by-step loading inherent strain method (SBS-ISM) is more in line with the actual welding deformation generation process. Firstly, the local finite element model of the T-joint was used to analyze the welding deformation and extract the inherent strain by using the thermal elastic–plastic finite element method (TEP-FEM). Subsequently, the one-step loading inherent strain method (OS-ISM) and the step-by-step loading inherent strain method (SBS-ISM) were used to predict the welding deformation for the same local finite element model, respectively. The comparative results showed that the trend and magnitude of welding deformation calculated using SBS-ISM was much closer to those calculated using TEP-FEM. The OS-ISM and SBS-ISM were used to predict the welding deformation of the backward centrifugal fan impeller under different welding sequences, respectively. By comparing the welding deformation results calculated using the two inherent strain methods with the experimental results, it was demonstrated that the step-by-step loading inherent strain method (SBS-ISM) provides more accurate and reliable predictions of welding deformation for large and complex thin-walled T-shaped structural components compared to the one-step loading inherent strain method (OS-ISM). Full article

(This article belongs to the Section Welding and Joining)

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17 pages, 3116 KiB

Open AccessReview

A Review on Shape Memory Alloys with Martensitic Transition at Cryogenic Temperatures

by Adelaide Nespoli, Davide Ninarello and Carlo Fanciulli

Metals 2023, 13(7), 1311; https://doi.org/10.3390/met13071311 - 21 Jul 2023

Cited by 3 | Viewed by 1712

Abstract

Shape memory alloys (SMA) are functional materials known for their shape memory and pseudoelastic properties, which originated from a thermoelastic phase transition between two solid phases: austenite and martensite. The ranges of temperature at which austenite and martensite are stable depend primarily on [...] Read more.

Shape memory alloys (SMA) are functional materials known for their shape memory and pseudoelastic properties, which originated from a thermoelastic phase transition between two solid phases: austenite and martensite. The ranges of temperature at which austenite and martensite are stable depend primarily on the chemical composition and the thermomechanical history of the alloy. This work presents a broad overview of shape memory alloys presenting the thermoelastic phase transition at cryogenic temperatures—that is, at temperatures below the freezing point of water. Currently, this class of SMA is not very well explored due to the difficulties in conducting both structural and functional experimentations at very low temperatures. However, these materials are of great importance for extreme environments such as space. In this work, the different classes of cryogenic SMA will first be presented as a function of their phase transformation temperatures. Hints of their mechanical performance will also be reported. Cu-based systems have been identified as cryogenic SMA presenting the lowest phase transformation temperatures. The lowest measured M_s (45 K) was found for the Cu-8.8Al-13.1Mn (wt.%) alloy. Full article

(This article belongs to the Special Issue Design and Mechanical Behavior of Martensitic Alloys)

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15 pages, 3600 KiB

Open AccessArticle

Hydrogen Production by Methane Pyrolysis in Molten Cu-Ni-Sn Alloys

by David Scheiblehner, Helmut Antrekowitsch, David Neuschitzer, Stefan Wibner and Andreas Sprung

Metals 2023, 13(7), 1310; https://doi.org/10.3390/met13071310 - 21 Jul 2023

Cited by 4 | Viewed by 1735

Abstract

Hydrogen is an essential vector for transitioning today’s energy system. As a fuel or reactant in critical industrial sectors such as transportation and metallurgy, H₂ can diversify the energy mix and supply and provide an opportunity to mitigate greenhouse-gas emissions. The pyrolysis [...] Read more.

Hydrogen is an essential vector for transitioning today’s energy system. As a fuel or reactant in critical industrial sectors such as transportation and metallurgy, H₂ can diversify the energy mix and supply and provide an opportunity to mitigate greenhouse-gas emissions. The pyrolysis of methane in liquid catalysts represents a promising alternative to producing hydrogen, as its energy demand is comparable to steam methane reforming, and no CO₂ is produced in the base reaction. In this work, methane pyrolysis experiments were conducted using a graphite crucible filled with liquid ternary Cu-Ni-Sn alloys at 1160.0 °C. A statistical design of experiments allowed the generation of a model equation that predicts the achievable conversion rates in the ranges of the experiments. Furthermore, the experimental results are evaluated considering densities as well as surface tensions and viscosities in the investigated system, calculated with Butler and KRP equations, respectively. The highest methane conversion rate of 40.15% was achieved utilizing a melt of pure copper. The findings show that a combination of high catalytic activity with a high density and a low viscosity and surface tension of the melt results in a higher hydrogen yield. Furthermore, the autocatalytic effect of pyrolysis carbon is measured. Full article

(This article belongs to the Special Issue Novel Raw Materials and Energy Sources for Ironmaking and Steelmaking)

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21 pages, 24301 KiB

Open AccessArticle

Mechanism and Control Scheme of Central Defects in Cross Wedge Rolling of Railway Vehicle Axles

by Wenhui Sun, Xuan Wu and Cuiping Yang

Metals 2023, 13(7), 1309; https://doi.org/10.3390/met13071309 - 21 Jul 2023

Cited by 1 | Viewed by 766

Abstract

Faced with a great demand for railway axles, the cross wedge rolling (CWR) process has the advantages of high efficiency and material saving, and good forming quality of axles is significant for railway transportation safety. The stress inside the railway axle of CWR [...] Read more.

Faced with a great demand for railway axles, the cross wedge rolling (CWR) process has the advantages of high efficiency and material saving, and good forming quality of axles is significant for railway transportation safety. The stress inside the railway axle of CWR was analyzed by the finite element method. It was found that the center of the rolled piece is subjected to tensile stress in transverse and axial directions and compressive stress in radial direction, making it more prone to defects. By simulating the evolution of micro voids in the center of the CWR piece, it was found that the presence of voids makes the strain around them significantly large and concentrated and the material between the voids deforms intensely. When voids expand relative to the rolled piece and the internal necking between voids is significant, void coalescence is easy to occur, and central defects are formed. The influence of process parameters on void evolution was analyzed. The scheme of detaching die was proposed to avoid central defects of the CWR piece and the optimal parameter conditions of CWR of railway axles were determined, which proved that the quality of railway axles formed with optimized parameters meets the technical requirements of railway vehicle axles. Full article

(This article belongs to the Special Issue Rolling Process of Metallic Materials)

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12 pages, 13652 KiB

Open AccessArticle

Fracture of Fe₉₅Ni₅ Alloys with Gradient-Grained Structure under Uniaxial Tension

by Aleksandr Korchuganov, Dmitrij Kryzhevich and Konstantin Zolnikov

Metals 2023, 13(7), 1308; https://doi.org/10.3390/met13071308 - 21 Jul 2023

Viewed by 807

Abstract

The fracture behavior of single- (fcc) and two-phase (fcc + bcc) Fe₉₅Ni₅ samples with gradient-grained structure, under uniaxial tension, was analyzed via molecular dynamics simulation. The study revealed that fracture initiation and propagation is always associated with grain boundaries. The [...] Read more.

The fracture behavior of single- (fcc) and two-phase (fcc + bcc) Fe₉₅Ni₅ samples with gradient-grained structure, under uniaxial tension, was analyzed via molecular dynamics simulation. The study revealed that fracture initiation and propagation is always associated with grain boundaries. The fracture process develops in three stages. In the first stage, nanopores are formed in the boundaries of coarse grains. The total volume of nanopores at this stage increases slowly due to the formation of new nanopores. The second stage is characterized by a rapid increase in the total nanopore volume due to the formation of nanopores, their growth along the grain boundaries, and their coalescence. At the third stage, the total nanopore volume increases linearly with deformation due to the growth of the largest nanopores. Fracture of two-phase samples begins at higher strains compared to a single-phase sample. With an increase in the volume fraction of bcc lamellae in the original sample, the number of nanopores at the third stage of fracture decreases and tends to one. Full article

(This article belongs to the Special Issue Development, Deformation, Fracture and Phase Transformation of New Generation Metallic Structural Materials)

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11 pages, 2028 KiB

Open AccessArticle

Structure Refinement and Bauschinger Effect in fcc and hcp Metals

by Vladimir V. Stolyarov

Metals 2023, 13(7), 1307; https://doi.org/10.3390/met13071307 - 21 Jul 2023

Viewed by 763

Abstract

Although the Bauschinger effect has been investigated in some detail in various materials, the number of articles on the effect of grain size is extremely limited, and in current nanostructured materials it is practically absent. Since such materials are considered as promising for [...] Read more.

Although the Bauschinger effect has been investigated in some detail in various materials, the number of articles on the effect of grain size is extremely limited, and in current nanostructured materials it is practically absent. Since such materials are considered as promising for structural applications, it is important to understand their mechanical behavior under conditions of changing the direction of deformation, and, therefore, it is necessary to study the Bauschinger effect and its dependence on grain size. The Bauschinger effect was investigated by a single exemplary method for tensile compression of commercially pure hcp titanium and fcc copper, with different grain sizes in the range from hundreds of microns to hundreds of nanometers. The change in grain size was performed by structure refinement by the method of severe plastic deformation using equal-channel angular pressing and subsequent annealing. It has been established that, in both materials, the Bauschinger effect increases with a decrease in grain size, the degree of permanent strain and the duration of exposure between forward and reverse deformation. The signs of the Bauschinger parameter in copper and titanium are opposite. The relationship between the Bauschinger effect and the nature of strain hardening in titanium and softening in copper in the ultrafine-grained state is discussed. Full article

(This article belongs to the Special Issue Ultrafine-Grained Metals and Alloys)

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18 pages, 5976 KiB

Open AccessArticle

Erosion Performance of TiAlSiN Coatings Prepared by High-Power Pulsed Magnetron Sputtering

by Hua Li, Liuhe Li, Duoduo Li, Ling Tang, Yang Luo, Guang Li, Yuehan Wu, Guodong Li, Yi Xu, Mingyue Han, Jiabin Gu, Kai Huang, Pengbo Feng and Xiaolei Xu

Metals 2023, 13(7), 1306; https://doi.org/10.3390/met13071306 - 21 Jul 2023

Viewed by 905

Abstract

Erosion seriously threatens the safety of high-speed rotating mechanical components in very harsh service environments, particularly for lightweight titanium alloy matrix material. In order to improve the erosion resistance of titanium alloy, TiAlSiN coatings with different phase compositions are deposited on TC6 titanium [...] Read more.

Erosion seriously threatens the safety of high-speed rotating mechanical components in very harsh service environments, particularly for lightweight titanium alloy matrix material. In order to improve the erosion resistance of titanium alloy, TiAlSiN coatings with different phase compositions are deposited on TC6 titanium alloy using a high-power pulse magnetron sputtering discharge (HPPMS) system under various discharge voltages. The componential and microstructural evolution as well as mechanical properties of the TiAlSiN coatings are evaluated by X-ray diffraction, scanning electron microscopy, and nanoindentation, respectively. The erosion performance relative to titanium alloy is investigated by a sand blasting tester. With the increase in discharge voltage from −500 to −600 V, the peak of discharge current increases from 105 to 225 A. The prepared TiAlSiN coatings show a shift of the preferred crystallographic orientation from (220) to (200), but all of them have a dense nanocomposite structure. Their hardness (H) and elastic modulus (E) gradually increase before decreasing, arriving at maximum values of 35.34 and 360.5 GPa at −570 V. The erosion resistance of the TiAlSiN coatings dependent on the discharge voltage is consistent with the H/E ratio change. The TiAlSiN coatings prepared at −560 V exhibit the optimal erosion resistance, which is 15 times that of the TC6 substrate. The erosion behavior of the coatings is positively correlated with their hardness and toughness. Adjusting the discharge voltage of the HPPMS pulse is finally proved to be an effective way of tailoring the coating phase compositions to improve the erosion resistance of titanium alloy. Full article

(This article belongs to the Special Issue Wear- and Corrosion-Resistant Cermet Coatings)

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22 pages, 17412 KiB

Open AccessArticle

Experimental and Numerical Fracture Characterization of DP1180 Steel in Combined Simple Shear and Uniaxial Tension

by Farinaz Khameneh, Armin Abedini and Clifford Butcher

Metals 2023, 13(7), 1305; https://doi.org/10.3390/met13071305 - 21 Jul 2023

Cited by 1 | Viewed by 1195

Abstract

Current tests for plane stress characterization of fracture in automotive sheet metals include simple shear, uniaxial, plane strain, and biaxial tension, but there is a significant gap between shear and uniaxial tension. Presently, it remains uncertain whether the fracture strain experiences a reduction [...] Read more.

Current tests for plane stress characterization of fracture in automotive sheet metals include simple shear, uniaxial, plane strain, and biaxial tension, but there is a significant gap between shear and uniaxial tension. Presently, it remains uncertain whether the fracture strain experiences a reduction between simple shear and uniaxial tension or undergoes an exponential increase as the triaxiality decreases. Fracture in combined simple shear and tension is complicated by premature edge cracking in tension along with a strong sensitivity of fracture strain to the measurement lengthscale. To address these issues, several existing simple shear geometries were modified and evaluated, with a focus on obtaining approximately linear strain paths corresponding to combined uniaxial tension and simple shear suitable for experimental fracture characterization using digital image correlation (DIC). An experimental and numerical investigation was conducted using two planar geometries that do not require through-thickness machining and can be easily tested on a universal test frame. Finite-element analysis was used to investigate the influence of the notch eccentricity on the stress state and predicted fracture location. The most promising geometry in each coupon type was then selected and tested for a dual-phase advanced high-strength steel, DP1180. The performance of the two planar geometries was evaluated based on the linearity of strain and stress state, along with the location of fracture initiation. The best geometry was then used to evaluate and recalibrate the modified Mohr-Coulomb (MMC) fracture locus with data in combined shear and tension. The initial MMC calibration using four fracture tests that suppressed necking provided an accurate estimate for the fracture strain in combined uniaxial tension and simple shear. The MMC model correctly predicted a valley in the fracture strain between these two loading conditions. Full article

(This article belongs to the Special Issue Mechanical Behaviors and Damage Mechanisms of Metallic Materials)

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12 pages, 8608 KiB

Open AccessArticle

Mechanical and Corrosion Behavior of a Composite Gradient-Structured Cu-Fe Alloy

by Bo Guan, Xiao Li, Jing Xu, Rui Fu, Changjian Yan, Jiawei Huang, Qiang Hu, Jin Zou, Wenzheng Liu and Zhi Hu

Metals 2023, 13(7), 1304; https://doi.org/10.3390/met13071304 - 21 Jul 2023

Cited by 2 | Viewed by 841

Abstract

Immiscible Cu-Fe alloys exhibit poor corrosion resistance due to different corrosion potentials between the constituent phases, which limits their application. In this paper, a composite gradient-structured Cu-10 wt.%Fe plate was prepared via the ultrasonic surface rolling process (USRP). The microstructure evolution, mechanical properties [...] Read more.

Immiscible Cu-Fe alloys exhibit poor corrosion resistance due to different corrosion potentials between the constituent phases, which limits their application. In this paper, a composite gradient-structured Cu-10 wt.%Fe plate was prepared via the ultrasonic surface rolling process (USRP). The microstructure evolution, mechanical properties and corrosion behavior were studied. The results demonstrate that USRP effectively enhances both the strength and corrosion resistance of the Cu-10Fe alloy. The improved strength is related to the combined effects of Hall–Petch strengthening, dislocation strengthening, and additional strengthening resulting from homogeneous deformation between the surface layer and the matrix. The enhanced corrosion resistance is primarily attributed to the refined microstructure of the surface layer after USRP, which facilitates the formation of a protective passivation film. Full article

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2 pages, 162 KiB

Open AccessEditorial

Numerical Simulation of Solidification Processes

by Mohsen Eshraghi

Metals 2023, 13(7), 1303; https://doi.org/10.3390/met13071303 - 21 Jul 2023

Viewed by 885

Abstract

Solidification is a critical step for many manufacturing processes, including casting, welding, and additive manufacturing [...] Full article

(This article belongs to the Special Issue Numerical Simulation of Solidification Processes)

11 pages, 3860 KiB

Open AccessArticle

The Phase Transformation in a Low-Carbon 13Cr4Ni Martensitic Stainless Steel during Two-Stage Intercritical Tempering

by Zhiyang He, Pei Wang, Gongmei Liu, Jie Liu and Shenghua Zhang

Metals 2023, 13(7), 1302; https://doi.org/10.3390/met13071302 - 20 Jul 2023

Viewed by 1106

Abstract

The microstructure evolution of a low-carbon 13Cr4Ni martensitic stainless steel during two-stage intercritical tempering at 630 °C and 590 °C has been investigated by X-ray diffraction, thermodilatometry, and transmission electron microscopy. It was found that the amount and size of reversed austenite increase [...] Read more.

The microstructure evolution of a low-carbon 13Cr4Ni martensitic stainless steel during two-stage intercritical tempering at 630 °C and 590 °C has been investigated by X-ray diffraction, thermodilatometry, and transmission electron microscopy. It was found that the amount and size of reversed austenite increase remarkably after second-stage tempering at 590 °C. However, there is no remarkable variation in the chemical composition and nucleation site of the reversed austenite during the first- and second-stage tempering. The dynamics of the phase transformation and elements distribution imply that the martensite-to-austenite phase transformation during second-stage tempering is controlled by diffusion. The unstable austenite transformation into martensite during the cooling process of the first-stage tempering induces high density dislocations and inhomogeneous element distribution, which facilitate the nucleation and growth of the reversed austenite in the second-stage intercritical tempering. Additionally, some lathy reversed austenite spheroidizes to granular during second-stage tempering. Full article

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11 pages, 5588 KiB

Open AccessArticle

Effects of Variated Final Temperature and Workpiece Thickness for Hot Rolling of Aluminum Alloy EN AW-8011

by Jakob Kraner, Peter Cvahte, Primož Šuštarič, Tomaž Šuštar, Črtomir Donik, Irena Paulin, Shae K. Kim and Kyung Il Kim

Metals 2023, 13(7), 1301; https://doi.org/10.3390/met13071301 - 20 Jul 2023

Cited by 1 | Viewed by 1042

Abstract

Hot rolling in the process chain of aluminum-rolled products presents the critical element of material quality and influences productivity. To increase the letter demand modifications of hot rolling, the consequential changes of microstructure, crystallographic texture, and mechanical and formability properties must be acknowledged [...] Read more.

Hot rolling in the process chain of aluminum-rolled products presents the critical element of material quality and influences productivity. To increase the letter demand modifications of hot rolling, the consequential changes of microstructure, crystallographic texture, and mechanical and formability properties must be acknowledged and consistently considered when planning the rolling process and rolled product. Achieving lower thicknesses of the hot-rolled band would enable fewer passes with cold rolling; consequently, hot rolling with the same number of passes can be completed with lower temperatures. Microstructural and texture characterizations conducted using the light microscope and scanning electron microscope, respectively, of the 3.25 mm hot-rolled band revealed that the smaller grains appeared in the center of the cross-section, unlike for the 6 mm hot-rolled band, where smaller grains were detected on the top and bottom positions of the cross-section. Furthermore, the comparison also shows that the 6 mm hot-rolled band had 64% of random texture components and 83% of recrystallized grains, whereas the proportional adjustment for the 3.25 mm hot-rolled band had 42% of random texture components and 55% of recrystallized grains. For the mechanical testing results, the elongation values in rolling and transverse directions significantly differ only in the case of a hot-rolled band of 3.25 mm. Consequently, the earing results are more than 1.5% higher for the 3.25 mm hot-rolled band, than the 6 mm hot-rolled band. Full article

(This article belongs to the Special Issue Hot Sheet Metal Forming of High Performance Materials)

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19 pages, 18064 KiB

Open AccessArticle

Modelling Crack Growth in Additively Manufactured Inconel 718 and Inconel 625

by Rhys Jones, Andrew Ang, Daren Peng, Victor K. Champagne, Alex Michelson and Aaron Birt

Metals 2023, 13(7), 1300; https://doi.org/10.3390/met13071300 - 20 Jul 2023

Cited by 2 | Viewed by 1149

Abstract

This paper first examines crack growth in a range of tests on additively manufactured (AM) and conventionally manufactured Inconel 718. It is shown that whereas when the crack growth rate (da/dN) is plotted as a function of the range [...] Read more.

This paper first examines crack growth in a range of tests on additively manufactured (AM) and conventionally manufactured Inconel 718. It is shown that whereas when the crack growth rate (da/dN) is plotted as a function of the range of the stress intensity factor (ΔK), the crack growth curves exhibit considerable scatter/variability, when da/dN is expressed in terms of the Schwalbe crack driving force (Δκ), then each of the 33 different curves essentially collapse onto a single curve. This relationship appears to hold over approximately six orders of magnitude in da/dN. The same phenomenon also appears to hold for 20 room temperature tests on both conventionally and additively manufactured Inconel 625. Given that the 53 studies examined in this paper were taken from a wide cross section of research studies it would appear that the variability in the da/dN and ΔK curves can (to a first approximation) be accounted for by allowing for the variability in the fatigue threshold and the cyclic fracture toughness terms in the Schwalbe crack driving force. As such, the materials science community is challenged to address the fundamental science underpinning this observation. Full article

(This article belongs to the Special Issue Advances in Additive Manufacturing and Their Applications)

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31 pages, 2809 KiB

Open AccessReview

Surface Engineering of Metals: Techniques, Characterizations and Applications

by Maziar Ramezani, Zaidi Mohd Ripin, Tim Pasang and Cho-Pei Jiang

Metals 2023, 13(7), 1299; https://doi.org/10.3390/met13071299 - 20 Jul 2023

Cited by 12 | Viewed by 4851

Abstract

This paper presents a comprehensive review of recent advancements in surface engineering of metals, encompassing techniques, characterization methods and applications. The study emphasizes the significance of surface engineering in enhancing the performance and functionality of metallic materials in various industries. The paper discusses [...] Read more.

This paper presents a comprehensive review of recent advancements in surface engineering of metals, encompassing techniques, characterization methods and applications. The study emphasizes the significance of surface engineering in enhancing the performance and functionality of metallic materials in various industries. The paper discusses the different techniques employed in surface engineering, including physical techniques such as thermal spray coatings and chemical techniques such as electroplating. It also explores characterization methods used to assess the microstructural, topographical, and mechanical properties of engineered surfaces. Furthermore, the paper highlights recent advancements in the field, focusing on nanostructured coatings, surface modification for corrosion protection, biomedical applications, and energy-related surface functionalization. It discusses the improved mechanical and tribological properties of nanostructured coatings, as well as the development of corrosion-resistant coatings and bioactive surface treatments for medical implants. The applications of surface engineering in industries such as aerospace, automotive, electronics, and healthcare are presented, showcasing the use of surface engineering techniques to enhance components, provide wear resistance, and improve corrosion protection. The paper concludes by discussing the challenges and future directions in surface engineering, highlighting the need for further research and development to address limitations and exploit emerging trends. The findings of this review contribute to advancing the understanding of surface engineering and its applications in various sectors, paving the way for future innovations and advancements. Full article

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23 pages, 6582 KiB

Open AccessReview

Dealloyed Nanoporous Gold-Based Materials for Energy Storage and Conversion

by Mengdan Yu, Xiaoyu Wu, Chunling Qin and Zhifeng Wang

Metals 2023, 13(7), 1298; https://doi.org/10.3390/met13071298 - 20 Jul 2023

Cited by 1 | Viewed by 1214

Abstract

The unique bicontinuous porous structure and superior electrical conductivity of nanoporous gold (NPG) make it a highly promising material for energy storage and conversion. Although the number of articles on the study of NPG-based materials in energy fields has increased significantly in recent [...] Read more.

The unique bicontinuous porous structure and superior electrical conductivity of nanoporous gold (NPG) make it a highly promising material for energy storage and conversion. Although the number of articles on the study of NPG-based materials in energy fields has increased significantly in recent years, the collation and review of these articles are still lacking. Herein, we address this gap by reviewing recent research activities on dealloyed NPG for energy storage and conversion applications. Firstly, the typical dealloying process for forming NPG is introduced. Subsequently, NPG-based composite catalysts used to catalyze water splitting and fuel cells electrode reactions are presented. Afterward, the applications of NPG for different types of electrodes of supercapacitors (SCs) and batteries are discussed. Finally, the studies on NPG for catalyzing CO₂ reduction reaction (CO₂RR) are reviewed. In a word, the recent research progress of NPG-based materials is reviewed and the future research directions are outlined, laying the cornerstone for the preparation of more advanced energy storage and conversion devices in the future. Full article

(This article belongs to the Special Issue Advances in Nanoporous Metallic Materials)

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12 pages, 1271 KiB

Open AccessArticle

Melt–Vapor Phase Transition in the Aluminum–Selenium System in Vacuum

by Alina Nitsenko, Valeriy Volodin, Xeniya Linnik, Nurila Burabayeva and Sergey Trebukhov

Metals 2023, 13(7), 1297; https://doi.org/10.3390/met13071297 - 19 Jul 2023

Cited by 4 | Viewed by 733

Abstract

The boundaries of liquid and vapor coexistence fields at pressures of 101.3 and 0.133 kPa were calculated based on the partial vapor pressure values of the components in the Al-Al₂Se₃ and Al₂Se₃-Se partial systems. The vapor [...] Read more.

The boundaries of liquid and vapor coexistence fields at pressures of 101.3 and 0.133 kPa were calculated based on the partial vapor pressure values of the components in the Al-Al₂Se₃ and Al₂Se₃-Se partial systems. The vapor pressures of the more volatile aluminum selenide and selenium in the above systems were determined by the isothermal version of the boiling-point method. The partial pressures of the fewer volatile components were determined by numerical integration of the Gibbs–Duhem equation. The partial and integral values of the thermodynamic functions of the formation and evaporation of solutions were calculated based on the values of the partial vapor pressure of the system components. Based on the analysis of the complete phase diagram, it was found that the purification of aluminum by vacuum distillation in a single operation can remove aluminum selenide and selenium at an appropriate rate. The distillation of selenium from melts in vacuum in the whole concentration range of the Al₂Se₃-Se system will proceed from the mixture of the solution with Al₂Se_3 cryst., with accumulation of the latter in the distillation residue. Full article

(This article belongs to the Special Issue Separation and Purification of Metals)

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13 pages, 5177 KiB

Open AccessArticle

Microstructure and Phase Transition of Ag_50.5Cu_33.3Sn_16.2-xIn_x Alloys through Experimental Study and Thermodynamic Calculation

by Qingsong Tong, Maohua Rong and Jiang Wang

Metals 2023, 13(7), 1296; https://doi.org/10.3390/met13071296 - 19 Jul 2023

Viewed by 937

Abstract

In this study, the solidified microstructure and phase transition temperatures of Ag_50.5Cu_33.3Sn_16.2-xIn_x (x = 5.0, 6.6, 8.2, 9.1, 9.9, 10.7, 11.5, 12.3; at.%) alloys were investigated using a scanning electron microscope with energy dispersive spectrometer (SEM-EDS) [...] Read more.

In this study, the solidified microstructure and phase transition temperatures of Ag_50.5Cu_33.3Sn_16.2-xIn_x (x = 5.0, 6.6, 8.2, 9.1, 9.9, 10.7, 11.5, 12.3; at.%) alloys were investigated using a scanning electron microscope with energy dispersive spectrometer (SEM-EDS) and differential thermal analysis (DTA). The experimental microstructure of Ag_50.5Cu_33.3Sn_16.2-xIn_x alloys demonstrates that the phase fraction of Fcc(Ag) phase increased gradually as the addition of In increased, while the phase fraction of Fcc(Cu) phase decreased. Moreover, the liquidus temperatures of Ag_50.5Cu_33.3Sn_16.2-xIn_x alloys also decrease with increasing In content. In this work, the Ag-Cu-Sn-In quaternary thermodynamic database was ideally extrapolated from the published literature for Ag-Cu-Sn, Ag-Cu-In, Ag-Sn-In and Cu-Sn-In thermodynamic databases. The calculated vertical section of Ag_50.5Cu_33.3Sn_16.2-Ag_50.5Cu_33.3In_16.2 agreed generally with the phase transition temperatures measured in the present experiment. Finally, the solidification behaviors of Ag_50.5Cu_33.3Sn_16.2-xIn_x as-cast alloys were analyzed by thermodynamic calculation of the Scheil–Gulliver non-equilibrium model. The simulated solidification processes of some Ag_50.5Cu_33.3Sn_16.2-xIn_x alloys are, in general, consistent with the experimental results in the present work, which would provide a theoretical basis for the design of novel Ag-Cu-Sn-In brazing alloys. Full article

(This article belongs to the Topic Phase Diagram, Phase Transition and Advanced Materials Design)

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