Research

Jump to: Review

12 pages, 7595 KiB

Open AccessArticle

Oxidation Behavior of FeNiCoCrMo_0.5Al_1.3 High-Entropy Alloy Powder

by Anton Semikolenov, Mikhail Goshkoderya, Tigran Uglunts, Tatyana Larionova and Oleg Tolochko

Materials 2024, 17(2), 531; https://doi.org/10.3390/ma17020531 - 22 Jan 2024

Viewed by 600

One of the most promising applications of FeNiCoCrMoAl-based high-entropy alloy is the fabrication of protective coatings. In this work, gas-atomized powder of FeNiCoCrMo_0.5Al_1.3 composition was deposited via high-velocity oxygen fuel spraying. It was shown that in-flight oxidation of the powder [...] Read more.

One of the most promising applications of FeNiCoCrMoAl-based high-entropy alloy is the fabrication of protective coatings. In this work, gas-atomized powder of FeNiCoCrMo_0.5Al_1.3 composition was deposited via high-velocity oxygen fuel spraying. It was shown that in-flight oxidation of the powder influences the coating’s phase composition and properties. Powder oxidation and phase transformations were studied under HVOF deposition, and during continuous heating and prolonged isothermal annealing at 800 °C. Optical and scanning electron microscopy observation, energy dispersive X-ray analysis, X-ray diffraction analysis, thermogravimetric analysis, differential thermal analysis, and microhardness tests were used for study. In a gas-atomized state, the powder consisted of BCC supersaturated solid solution. The high rate of heating and cooling and high oxygen concentration during spraying led to oxidation development prior to decomposition of the supersaturated solid solution. Depleted Al layers of BCC transferred to the FCC phase. An increase in the spraying distance resulted in an increase in α-Al₂O₃ content; however, higher oxide content does not result in a higher microhardness. In contrast, under annealing, the supersaturated BCC solid solution decomposition occurs earlier than pronounced oxidation, which leads to considerable strengthening to 910 HV. Full article

(This article belongs to the Special Issue Research on Forming and Serving Performance of Advanced Alloys)

► Show Figures

Figure 1

12 pages, 19232 KiB

Open AccessArticle

Solid-State Processing of CoCrMoNbTi High-Entropy Alloy for Biomedical Applications

by Alina Elena Bololoi, Laura Elena Geambazu, Iulian Vasile Antoniac, Robert Viorel Bololoi, Ciprian Alexandru Manea, Vasile Dănuţ Cojocaru and Delia Pătroi

Materials 2023, 16(19), 6520; https://doi.org/10.3390/ma16196520 - 30 Sep 2023

Cited by 2 | Viewed by 877

Abstract

High-entropy alloys (HEAs) gained interest in the field of biomedical applications due to their unique effects and to the combination of the properties of the constituent elements. In addition to the required property of biocompatibility, other requirements include properties such as mechanical resistance, [...] Read more.

High-entropy alloys (HEAs) gained interest in the field of biomedical applications due to their unique effects and to the combination of the properties of the constituent elements. In addition to the required property of biocompatibility, other requirements include properties such as mechanical resistance, bioactivity, sterility, stability, cost effectiveness, etc. For this paper, a biocompatible high-entropy alloy, defined as bio-HEA by the literature, can be considered as an alternative to the market-available materials due to their superior properties. According to the calculation of the valence electron concentration, a majority of body-centered cubic (BCC) phases were expected, resulting in properties such as high strength and plasticity for the studied alloy, confirmed by the XRD analysis. The tetragonal (TVC) phase was also identified, indicating that the presence of face-centered cubic (FCC) phases in the alloyed materials resulted in high ductility. Microstructural and compositional analyses revealed refined and uniform metallic powder particles, with a homogeneous distribution of the elemental particles observed from the mapping analyses, indicating that alloying had occurred. The technological characterization of the high-entropy alloy-elaborated powder revealed the particle dimension reduction due to the welding and fracturing process that occurs during mechanical alloying, with a calculated average particle size of 45.12 µm. Full article

(This article belongs to the Special Issue Research on Forming and Serving Performance of Advanced Alloys)

► Show Figures

Figure 1

21 pages, 8793 KiB

Open AccessArticle

Experimental Research on Wolfram Inert Gas AA1050 Aluminum Alloy Tailor Welded Blanks Processed by Single Point Incremental Forming Process

by Gabriela-Petruța Rusu, Radu-Eugen Breaz, Mihai-Octavian Popp, Valentin Oleksik and Sever-Gabriel Racz

Materials 2023, 16(19), 6408; https://doi.org/10.3390/ma16196408 - 26 Sep 2023

Cited by 2 | Viewed by 579

Abstract

The present paper aims to study the behavior of tailor welded blanks subjected to a single point incremental forming (SPIF) process from an experimental point of view. This process was chosen to deform truncated cone shapes of AA1050 aluminum alloy with different thicknesses. [...] Read more.

The present paper aims to study the behavior of tailor welded blanks subjected to a single point incremental forming (SPIF) process from an experimental point of view. This process was chosen to deform truncated cone shapes of AA1050 aluminum alloy with different thicknesses. A uniaxial tensile test was performed to determine the mechanical characteristics of the alloy. Initial experimental tests implicated the use of variable wall angle parts which were processed on unwelded sheet blanks for determination of the behavior of the material and the forming forces. Afterwards, the wolfram inert gas (WIG) welding technique was used for joining two sheet blanks with different thicknesses either through one pass on one side, or by one pass on both sides. The conclusion of this paper indicates that one-sided welded blanks cannot be deformed successfully without fracture. In case of two-sided welded blanks, the results showed that the desired depth of 25 mm can be reached successfully. In case of the SPIF process, if welded blanks must be deformed, then the suitable method is to weld the blanks on both sides. Full article

(This article belongs to the Special Issue Research on Forming and Serving Performance of Advanced Alloys)

► Show Figures

Figure 1

17 pages, 10446 KiB

Open AccessArticle

The Development of a High-Strength Mg-10.3Gd-4.4Y-0.9Zn-0.7Mn Alloy Subjected to Large Differential-Thermal Extrusion and Isothermal Aging

by Kui Wang, Xinwei Wang, Jinxing Wang, Cong Dang, Xiaoxu Dou, Song Huang, Manping Liu and Jingfeng Wang

Materials 2023, 16(18), 6103; https://doi.org/10.3390/ma16186103 - 07 Sep 2023

Viewed by 738

Abstract

The large differential-thermal extrusion (LDTE) process, a novel approach for efficiently fabricating a high-strength Mg-10.3Gd-4.4Y-0.9Zn-0.7Mn (wt.%) alloy, is introduced in this work. Unlike typical isothermal extrusion processes, where the ingot and die temperatures are kept the same, LDTE involves significantly higher ingot temperatures [...] Read more.

The large differential-thermal extrusion (LDTE) process, a novel approach for efficiently fabricating a high-strength Mg-10.3Gd-4.4Y-0.9Zn-0.7Mn (wt.%) alloy, is introduced in this work. Unlike typical isothermal extrusion processes, where the ingot and die temperatures are kept the same, LDTE involves significantly higher ingot temperatures (~120 °C) compared to the die temperature. For high-strength Mg-RE alloys, the maximum isothermal extrusion ram speed is normally limited to 1 mm/s. This research uses the LDTE process to significantly increase the ram speed to 2.0 mm/s. The LPTE-processed alloy possesses a phase composition that is similar to that of isothermal extruded alloys, including α-Mg, 14H-type long-period stacking ordered (LPSO) and β-Mg₅(Gd, Y) phases. The weakly preferentially oriented α-Mg grains in the LDTE-processed alloy have

< 10 \bar{1} 0 >

_Mg//ED fibrous and <0001>_Mg//ED anomalous textures as their two main constituents. After isothermal aging, high quantitative densities of prismatic β′ and basal γ′ precipitates are produced, which have the beneficial effect of precipitation hardening. With a yield tensile strength of 344 MPa, an ultimate tensile strength of 488 MPa, and an elongation of 9.7%, the alloy produced by the LDTE process exhibits an exceptional strength–ductility balance, further demonstrating the potential of this method for efficiently producing high-strength Mg alloys. Full article

(This article belongs to the Special Issue Research on Forming and Serving Performance of Advanced Alloys)

► Show Figures

Figure 1

16 pages, 4423 KiB

Open AccessEditor’s ChoiceArticle

Influence of Pre-Tension on Free-End Torsion Behavior and Mechanical Properties of an Extruded Magnesium Alloy

by Hongbing Chen, Zhikang Shen, Bo Song and Jia She

Materials 2023, 16(15), 5343; https://doi.org/10.3390/ma16155343 - 29 Jul 2023

Viewed by 688

Abstract

In this study, the influence of pre-tension on free-end torsion behavior and compression mechanical properties and micro-hardness of an extruded AZ31 Mg alloy was investigated using electron backscatter diffraction (EBSD), compression testing and micro-hardness testing. The result indicates that pre-tension can cause significant [...] Read more.

In this study, the influence of pre-tension on free-end torsion behavior and compression mechanical properties and micro-hardness of an extruded AZ31 Mg alloy was investigated using electron backscatter diffraction (EBSD), compression testing and micro-hardness testing. The result indicates that pre-tension can cause significant dislocation strengthening, which can increase the torsion yield strength and make the shear stress–shear strain curve of the pre-tension sample almost parallel to that of the as-extruded sample during plastic deformation stage. Texture in edge position on the cross-section of both the pre-tension and as-extruded samples can be rotated towards the extrusion direction by about ~30° by free-end torsion. The Swift effect is mainly responsible for the occurrence of massive extension twins in the central region. In contrast, normal stress is the main cause of extension twins occurring in the edge region. However, the effect of extension twins on micro-hardness is less than that of dislocations. The micro-hardness of both free-end torsion specimens increases almost linearly with increasing distance from center to edge on the cross-section. Nevertheless, the increase in micro-hardness of the pre-tension and then torsion sample is inconspicuous because pre-tension leads to dislocation proliferation and dislocation accumulation saturation. The result also indicates that both pre-tension and free-end torsion can lead to dislocation strengthening, which can obviously increase the micro-hardness and compressive yield stress. The underlying mechanisms were explored and discussed in detail. Full article

(This article belongs to the Special Issue Research on Forming and Serving Performance of Advanced Alloys)

► Show Figures

Figure 1

18 pages, 9750 KiB

Open AccessArticle

The Microstructure Evolution and Mechanical Properties of Rotary Friction Welded Duplex Stainless Steel Pipe

by Shuxin Zhang, Faqin Xie, Xiangqing Wu, Jinheng Luo, Weiwei Li and Xi Yan

Materials 2023, 16(9), 3569; https://doi.org/10.3390/ma16093569 - 06 May 2023

Cited by 3 | Viewed by 1482

Abstract

The use of duplex stainless steel (DSS) in various fields is promising due to its excellent anti-corrosion properties, but traditional welding can lead to the formation of unfavorable phases that deteriorate its quality. This study aimed to use the rotary friction weld (RFW) [...] Read more.

The use of duplex stainless steel (DSS) in various fields is promising due to its excellent anti-corrosion properties, but traditional welding can lead to the formation of unfavorable phases that deteriorate its quality. This study aimed to use the rotary friction weld (RFW) technique to prevent the formation of harmful phases in the welding of an S32205 alloy pipe. The welding parameters used included a rotating speed of 20 m/s, a friction pressure of 10 MPa, a friction time of 30 s, and a forging pressure of 30 MPa. The microstructure and mechanical properties of the resulting RFWed joint were investigated. The results revealed that the weld zone exhibited a microstructure consisting of ferrite and austenite phases, with no deleterious phase detected. The ferrite content was measured to be 53.3%, 54.5%, and 68.7% in the base metal, thermomechanical affected zone (TMAZ), and weld, respectively, owing to the rapid cooling rate in the RFW process, which prevented any harmful phase formation in the weld zone. Furthermore, the RFW process successfully produced an ultrafine grain with a ferrite/austenite grain size of 0.40 μm and 0.41 μm, respectively. The weld zone and TMAZ contained more low-angle grain boundaries (LAGBs) compared to the base metal, which was attributed to the dynamic recovery (DRV) within a grain. The high heating and cooling rates and short welding time of the RFW process did not allow sufficient time for the dynamic recrystallization of the microstructure in the weld zone. However, a slight increase in the ferrite content in the weld zone resulted in grain refinement and an increase in the dislocation density, resulting in a slight increase in the 358 HV0.2 hardness and 823 MPa tensile strength of the weld zone. This study offers a novel approach for obtaining ultrafine grain duplex stainless steel pipes with exceptional mechanical properties through the application of RFW. Full article

(This article belongs to the Special Issue Research on Forming and Serving Performance of Advanced Alloys)

► Show Figures

Figure 1

16 pages, 10260 KiB

Open AccessArticle

Mechanical Alloying Behavior and Thermal Stability of CoCrCuFeMnNi_x High-Entropy Alloy Powders Prepared via MA

by Baofeng Zhang, Ruifeng Zhao, Bo Ren, Aiyun Jiang, Chong Chen, Jianxiu Liu and Yajun Zhou

Materials 2023, 16(8), 3179; https://doi.org/10.3390/ma16083179 - 18 Apr 2023

Cited by 2 | Viewed by 1119

Abstract

CoCrCuFeMnNi_x (x = 0, 0.5, 1.0, 1.5, 2.0 mol, named as Ni₀, Ni_0.5, Ni_1.0, Ni_1.5, and Ni_2.0, respectively) high-entropy alloy powders (HEAPs) were prepared via mechanical alloying (MA), and XRD, SEM, EDS, [...] Read more.

CoCrCuFeMnNi_x (x = 0, 0.5, 1.0, 1.5, 2.0 mol, named as Ni₀, Ni_0.5, Ni_1.0, Ni_1.5, and Ni_2.0, respectively) high-entropy alloy powders (HEAPs) were prepared via mechanical alloying (MA), and XRD, SEM, EDS, and vacuum annealing were used to study the alloying behavior, phase transition, and thermal stability. The results indicated that the Ni₀, Ni_0.5, and Ni_1.0 HEAPs were alloyed at the initial stage (5–15 h), the metastable BCC + FCC two-phase solid solution structure was formed, and the BCC phase disappeared gradually with the prolonging of ball milling time. Finally, a single FCC structure was formed. Both Ni_1.5 and Ni_2.0 alloys with high nickel content formed a single FCC structure during the whole mechanical alloying process. The five kinds of HEAPs showed equiaxed particles in dry milling, and the particle size increased with an increase in milling time. After wet milling, they changed into lamellar morphology with thickness less than 1 μm and maximum size less than 20 μm. The composition of each component was close to its nominal composition, and the alloying sequence during ball milling was Cu→Mn→Co→Ni→Fe→Cr. After vacuum annealing at 700~900 °C, the FCC phase in the HEAPs with low Ni content transformed into FCC2 secondary phase, FCC1 primary phase, and a minor σ phase. The thermal stability of HEAPs can be improved by increasing Ni content. Full article

(This article belongs to the Special Issue Research on Forming and Serving Performance of Advanced Alloys)

► Show Figures

Graphical abstract

26 pages, 87339 KiB

Open AccessArticle

The Quadratic Constitutive Model Based on Partial Derivative and Taylor Series of Ti6242s Alloy and Predictability Analysis

by Jiansheng Zhang, Guiqian Xiao, Guoyong Deng, Yancheng Zhang and Jie Zhou

Materials 2023, 16(7), 2928; https://doi.org/10.3390/ma16072928 - 06 Apr 2023

Cited by 2 | Viewed by 993

Abstract

To solve the problem of insufficient predictability in the classical models for the Ti6242s alloy, a new constitutive model was proposed, based on the partial derivatives from experimental data and the Taylor series. Firstly, hot compression experiments on the Ti6242s alloy at different [...] Read more.

To solve the problem of insufficient predictability in the classical models for the Ti6242s alloy, a new constitutive model was proposed, based on the partial derivatives from experimental data and the Taylor series. Firstly, hot compression experiments on the Ti6242s alloy at different temperatures and different strain rates were carried out, and the Arrhenius model and Hensel–Spittel model were constructed. Secondly, the partial derivatives of logarithmic stress with respect to temperature and logarithmic strain rate at low, medium and high strain levels were analyzed. Thirdly, two new constitutive models with first- and second-order approximation were proposed to meet the requirements of high precision. In this new model, by analyzing the high-order differential data of experimental data and combining the Taylor series theory, the minimum number of terms that can accurately approximate the experimental rheological data was found, thereby achieving an accurate prediction of flow stress with minimal material parameters. In the new model, by analyzing the high-order differential of the experimental data and combining the theory of the Taylor series, the minimum number of terms that can accurately approximate the experimental rheological data was found, thereby achieving an accurate prediction of flow stress with minimal material parameters. Finally, the prediction accuracies for the classical model and the new model were compared, and the predictabilities for the classical models and the new model were proved by mathematical means. The results show that the prediction accuracies of the Arrhenius model and the Hensel–Spittel model are low in the single-phase region and high in the two-phase region. In addition, second-order approximation is required between the logarithmic stress and logarithmic strain rate, and first-order approximation is required between logarithmic stress and temperature to establish a high-precision model. The order of prediction accuracy of the four models from high to low is the quadratic model, Arrhenius model, linear model and HS model. The prediction accuracy of the quadratic model in all temperatures and strain rates had no significant difference, and was higher than the other models. The quadratic model can greatly improve prediction accuracy without significantly increasing the material parameters. Full article

(This article belongs to the Special Issue Research on Forming and Serving Performance of Advanced Alloys)

► Show Figures

Figure 1

Review

Jump to: Research

29 pages, 2366 KiB

Open AccessReview

Research Progress and the Prospect of Damping Magnesium Alloys

by Jinxing Wang, Yi Zou, Cong Dang, Zhicheng Wan, Jingfeng Wang and Fusheng Pan

Materials 2024, 17(6), 1285; https://doi.org/10.3390/ma17061285 - 11 Mar 2024

Viewed by 603

Abstract

As the lightest structural metal material, magnesium alloys possess good casting properties, high electrical and thermal conductivity, high electromagnetic shielding, and excellent damping properties. With the increasing demand for lightweight, high-strength, and high-damping structural materials in aviation, automobiles, rail transit, and other industries [...] Read more.

As the lightest structural metal material, magnesium alloys possess good casting properties, high electrical and thermal conductivity, high electromagnetic shielding, and excellent damping properties. With the increasing demand for lightweight, high-strength, and high-damping structural materials in aviation, automobiles, rail transit, and other industries with serious vibration and noise, damping magnesium alloy materials are becoming one of the important development directions of magnesium alloys. A comprehensive review of the progress in this field is conducive to the development of damping magnesium alloys. This review not only looks back on the traditional damping magnesium alloys represented by Mg-Zr alloys, Mg-Cu-Mn alloys, etc. but also introduces the new damping magnesium materials, such as magnesium matrix composites and porous magnesium. But up to now, there have still been some problems in the research of damping magnesium materials. The effect of spiral dislocation on damping is still unknown and needs to be studied; the contradiction between damping performance and mechanical properties still lacks a good balance method. In the future, the introduction of more diversified damping regulating methods, such as adding other elements and reinforcements, optimizing the manufacturing method of damping magnesium alloy, etc., to solve these issues, will be the development trend of damping magnesium materials. Full article

(This article belongs to the Special Issue Research on Forming and Serving Performance of Advanced Alloys)

► Show Figures

Figure 1

27 pages, 10599 KiB

Open AccessReview

Review on Soil Corrosion and Protection of Grounding Grids

by Jing Zhao, Xian Meng, Xiao Ren, Shengfang Li, Fuhao Zhang, Xiaofang Yang, Junyao Xu and Yuan Yuan

Materials 2024, 17(2), 507; https://doi.org/10.3390/ma17020507 - 20 Jan 2024

Viewed by 964

Abstract

The corrosion of grounding grid materials in soil is a prominent factor in power and electrical equipment failure. This paper aims to delve into the corrosion characteristics of grounding grid materials and the corresponding methods of safeguarding against this phenomenon. Firstly, the influencing [...] Read more.

The corrosion of grounding grid materials in soil is a prominent factor in power and electrical equipment failure. This paper aims to delve into the corrosion characteristics of grounding grid materials and the corresponding methods of safeguarding against this phenomenon. Firstly, the influencing factors of the soil environment on the corrosion of the grounding grid are introduced, including soil physicochemical properties, microorganisms, and stray currents. Then, the corrosion behavior and durability of common grounding grid materials such as copper, carbon steel, and galvanized steel are discussed in detail and compared comprehensively. In addition, commonly used protective measures in China and outside China, including anti-corrosion coatings, electrochemical protection, and other technologies are introduced. Finally, it summarizes the current research progress and potential future directions of this field of study. Full article

(This article belongs to the Special Issue Research on Forming and Serving Performance of Advanced Alloys)

► Show Figures

Figure 1

21 pages, 4143 KiB

Open AccessReview

Recent Progress in Testing and Characterization of Hardenability of Aluminum Alloys: A Review

by Chang Gao, Xin Liu, Dong Zhao, Yiming Guo, Shaohua Chen, Fantao Gao, Tianle Liu, Zhenyang Cai, Danyang Liu and Jinfeng Li

Materials 2023, 16(13), 4736; https://doi.org/10.3390/ma16134736 - 30 Jun 2023

Viewed by 1030

Abstract

In this paper, the progress of the test methods and characterization approaches of aluminum alloys hardenability was reviewed in detail. The test method mainly included the traditional end-quenching method and the modified method. While the characterization approaches of alloy hardenability consist mainly of [...] Read more.

In this paper, the progress of the test methods and characterization approaches of aluminum alloys hardenability was reviewed in detail. The test method mainly included the traditional end-quenching method and the modified method. While the characterization approaches of alloy hardenability consist mainly of ageing hardness curves, solid solution conductivity curves, ageing tensile curves, time temperature transformation (TTT) curves, time temperature properties (TTP) curves, continuous cooling transformation (CCT) curves, and advanced theoretical derivation method have appeared in recent years. The hardenability testing equipment for different tested samples with different material natures, engineering applications properties, and measurement sizes was introduced. Meanwhile, the improvement programmed proposed for shortcomings in the traditional hardenability testing process and the current deficiencies during the overall hardenability testing process were also presented. In addition, the influence factors from the view of composition design applied to the hardenability behaviors of Aluminum alloys were summarized. Among them, the combined addition of micro-alloying elements is considered to be a better method for improving the hardenability of high-strength aluminum alloys. Full article

(This article belongs to the Special Issue Research on Forming and Serving Performance of Advanced Alloys)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Research on Forming and Serving Performance of Advanced Alloys

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (11 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI