Applied Sciences

Editorial

Jump to: Research

2 pages, 157 KiB

Open AccessEditorial

Special Issue on Microstructural and Mechanical Properties of Metallic Materials, Volume II

by Young-Min Kim

Appl. Sci. 2023, 13(1), 423; https://0-doi-org.brum.beds.ac.uk/10.3390/app13010423 - 29 Dec 2022

Viewed by 781

Abstract

Various metallic materials are applied to industrial fields and everyday life [...] Full article

(This article belongs to the Special Issue Microstructural and Mechanical Properties of Metallic Materials, Volume II)

Research

Jump to: Editorial

11 pages, 4253 KiB

Open AccessArticle

Mechanical Properties of Aluminum 5083 Alloy GMA Welds with Different Magnesium and Manganese Content of Filler Wires

by Gwang-Gook Kim, Dong-Yoon Kim, Insung Hwang, Dongcheol Kim, Young-Min Kim and Junhong Park

Appl. Sci. 2021, 11(24), 11655; https://0-doi-org.brum.beds.ac.uk/10.3390/app112411655 - 8 Dec 2021

Cited by 7 | Viewed by 3144

Abstract

Gas metal arc welding of aluminum 5083 alloys was performed using three new welding wires with different magnesium and manganese contents and compared with commercial aluminum 5183 alloy filler wire. To investigate the effect of magnesium and manganese contents on the mechanical properties [...] Read more.

Gas metal arc welding of aluminum 5083 alloys was performed using three new welding wires with different magnesium and manganese contents and compared with commercial aluminum 5183 alloy filler wire. To investigate the effect of magnesium and manganese contents on the mechanical properties of welds, mechanical properties were evaluated through tensile strength, bending, and microhardness tests. In addition, the microstructure and chemical composition were analyzed to compare the differences between each weld. The tensile strengths of welds using aluminum alloy filler wires with a magnesium content of 7.33 wt.% (W1) and 6.38 wt.% (W2), respectively, were similar. The tensile strength and hardness of welds using wires with a similar magnesium content, but a different manganese content of 0.004 wt.% (W2) and 0.46 wt.% (W3), respectively, were higher in the wire with a high manganese content. Through various mechanical and microstructural property analyses, when the magnesium content of the filler wire was 6 wt.% or more, the manganese content, rather than the magnesium content, had a dominant effect on the strengthening of the weld. Full article

(This article belongs to the Special Issue Microstructural and Mechanical Properties of Metallic Materials, Volume II)

► Show Figures

Figure 1

13 pages, 6844 KiB

Open AccessArticle

Microstructural Characterization of TiC-Reinforced Metal Matrix Composites Fabricated by Laser Cladding Using FeCrCoNiAlTiC High Entropy Alloy Powder

by Sangwoo Nam, Hyung Won Lee, In-Ho Jung and Young-Min Kim

Appl. Sci. 2021, 11(14), 6580; https://0-doi-org.brum.beds.ac.uk/10.3390/app11146580 - 17 Jul 2021

Cited by 9 | Viewed by 2267

Abstract

TiC-reinforced metal matrix composites were fabricated by laser cladding and FeCrCoNiAlTiC high entropy alloy powder. The heat of the laser formed a TiC phase, which was consistent with the thermodynamic calculation, and produced a coating layer without interfacial defects. TiC reinforcing particles exhibited [...] Read more.

TiC-reinforced metal matrix composites were fabricated by laser cladding and FeCrCoNiAlTiC high entropy alloy powder. The heat of the laser formed a TiC phase, which was consistent with the thermodynamic calculation, and produced a coating layer without interfacial defects. TiC reinforcing particles exhibited various morphologies, such as spherical, blocky, and dendritic particles, depending on the heat input and coating depth. A dendritic morphology is observed in the lower part of the coating layer near the AISI 304 substrate, where heat is rapidly transferred. Low heat input leads to an inhomogeneous microstructure and coating depth due to the poor fluidity of molten pool. On the other hand, high heat input dissolved reinforcing particles by dilution with the substrate. The coating layer under the effective heat input of 50 J/mm² had relatively homogeneous blocky particles of several micrometers in size. The micro-hardness value of the coating layer is over 900 HV, and the nano-hardness of the reinforcing particles and the matrix were 17 GPa and 10 GPa, respectively. Full article

(This article belongs to the Special Issue Microstructural and Mechanical Properties of Metallic Materials, Volume II)

► Show Figures

Figure 1

12 pages, 3288 KiB

Open AccessArticle

Effective Design of Cr-Co-Ni-Ta Eutectic Medium Entropy Alloys with High Compressive Properties Using Combined CALPHAD and Experimental Approaches

by Taiwen Huang, Jiachen Zhang, Jun Zhang and Lin Liu

Appl. Sci. 2021, 11(13), 6102; https://0-doi-org.brum.beds.ac.uk/10.3390/app11136102 - 30 Jun 2021

Cited by 6 | Viewed by 1752

Abstract

Alloy design of Cr-Co-Ni-Ta eutectic medium entropy alloys (EMEAs) was performed through a CALPHAD method coupled with experimental study, with the aim to attain high phase stability as well as excellent mechanical properties. Based on calculated pseudo-binary diagram, CrCoNiTax (x = 0.1, 0.3, [...] Read more.

Alloy design of Cr-Co-Ni-Ta eutectic medium entropy alloys (EMEAs) was performed through a CALPHAD method coupled with experimental study, with the aim to attain high phase stability as well as excellent mechanical properties. Based on calculated pseudo-binary diagram, CrCoNiTax (x = 0.1, 0.3, 0.4, 0.5, 0.7) medium entropy alloys were investigated. Two phases, FCC solid solution and Laves phase, were identified in the alloys. With increasing Ta content, the volume fraction of hard and brittle Laves phase increased, microstructure changed from hypoeutectic (Ta0.1, Ta0.3) to eutectic (Ta0.4) and then to hypereutectic (Ta0.5, Ta0.7). The stability of phases was assessed by considering the thermodynamic parameter Ω and valence electron concentration (VEC). The eutectic phases become stable when 1.42 < Ω < 0.74 and 7.5 < VEC < 8.25. In addition, based on nanoindentation, the results indicated that solid solution strengthening in γ phase was significantly enhanced, eutectic phase in CrCoNiTa_0.4 EMEA was found to process the highest microhardness and elastic modulus. Finally, the hardness of alloys was positively correlated with the content of Ta and the plastic strain of alloys obviously decreased, while the compression strength firstly increased and then decreased. CrCoNiTa0.4 was the most promising alloy with the highest compression strength (2502 MPa) and high plastic strain (20.6%). Full article

(This article belongs to the Special Issue Microstructural and Mechanical Properties of Metallic Materials, Volume II)

► Show Figures

Figure 1

9 pages, 5131 KiB

Open AccessArticle

Assessment of Heat-Affected Zone Softening of Hot-Press-Formed Steel over 2.0 GPa Tensile Strength with Bead-On-Plate Laser Welding

by Kwangsoo Kim, Namhyun Kang, Minjung Kang and Cheolhee Kim

Appl. Sci. 2021, 11(13), 5774; https://0-doi-org.brum.beds.ac.uk/10.3390/app11135774 - 22 Jun 2021

Cited by 11 | Viewed by 1945

Abstract

High-strength hot-press-formed (HPF) steels with a fully martensitic microstructure are being widely used in the fabrication of automotive body structure, and 2.0 GPa-strength HPF steel has recently been commercially launched. However, heat-affected zone (HAZ) softening is unavoidable in welding martensitic steel. In this [...] Read more.

High-strength hot-press-formed (HPF) steels with a fully martensitic microstructure are being widely used in the fabrication of automotive body structure, and 2.0 GPa-strength HPF steel has recently been commercially launched. However, heat-affected zone (HAZ) softening is unavoidable in welding martensitic steel. In this study, the HAZ softening characteristic of 2.0 GPa HPF steel was investigated by applying a high-brightness laser welding process, wherein the heat input was controlled by varying the welding speed. Microstructural evaluation and hardness test results showed that the base metal with a fully martensitic microstructure was changed to the same type of fully martensitic microstructure in the weld metal, while relatively soft microstructures of tempered martensite and ferrite phase were partially formed in the intercritical HAZ (ICHAZ) and subcritical HAZ (SCHAZ) areas. In the tensile test, the joint strength was 10–20% lower than that of the base metal, and the fracture initiation was estimated at the ICHAZ/SCHAZ boundary, where the lowest hardness was confirmed by the nanoindentation technique. Full article

(This article belongs to the Special Issue Microstructural and Mechanical Properties of Metallic Materials, Volume II)

► Show Figures

Figure 1

12 pages, 5338 KiB

Open AccessArticle

Comprehensive Analysis of the Microstructure and Mechanical Properties of Friction-Stir-Welded Low-Carbon High-Strength Steels with Tensile Strengths Ranging from 590 MPa to 1.5 GPa

by HyeonJeong You, Minjung Kang, Sung Yi, Soongkeun Hyun and Cheolhee Kim

Appl. Sci. 2021, 11(12), 5728; https://0-doi-org.brum.beds.ac.uk/10.3390/app11125728 - 21 Jun 2021

Cited by 5 | Viewed by 2868

Abstract

High-strength steels are being increasingly employed in the automotive industry, requiring efficient welding processes. This study analyzed the materials and mechanical properties of high-strength automotive steels with strengths ranging from 590 MPa to 1500 MPa, subjected to friction stir welding (FSW), which is [...] Read more.

High-strength steels are being increasingly employed in the automotive industry, requiring efficient welding processes. This study analyzed the materials and mechanical properties of high-strength automotive steels with strengths ranging from 590 MPa to 1500 MPa, subjected to friction stir welding (FSW), which is a solid-phase welding process. The high-strength steels were hardened by a high fraction of martensite, and the welds were composed of a recrystallized zone (RZ), a partially recrystallized zone (PRZ), a tempered zone (TZ), and an unaffected base metal (BM). The RZ exhibited a higher hardness than the BM and was fully martensitic when the BM strength was 980 MPa or higher. When the BM strength was 780 MPa or higher, the PRZ and TZ softened owing to tempered martensitic formation and were the fracture locations in the tensile test, whereas BM fracture occurred in the tensile test of the 590 MPa steel weld. The joint strength, determined by the hardness and width of the softened zone, increased and then saturated with an increase in the BM strength. From the results, we can conclude that the thermal history and size of the PRZ and TZ should be controlled to enhance the joint strength of automotive steels. Full article

(This article belongs to the Special Issue Microstructural and Mechanical Properties of Metallic Materials, Volume II)

► Show Figures

Figure 1

15 pages, 8347 KiB

Open AccessFeature PaperArticle

Fourier Transform (FT) Analysis of the Stress as a Tool to Follow the Fatigue Behavior of Metals

by Valerian Hirschberg and Denis Rodrigue

Appl. Sci. 2021, 11(8), 3549; https://0-doi-org.brum.beds.ac.uk/10.3390/app11083549 - 15 Apr 2021

Cited by 4 | Viewed by 2204

Abstract

This work investigates the possibility of applying Fourier Transform (FT) analysis of the force signal to follow fatigue behavior of metals under oscillatory displacement-controlled tests in uniaxial tension/tension. As a first step, three different materials were selected (cold rolled steel, aluminium and brass). [...] Read more.

This work investigates the possibility of applying Fourier Transform (FT) analysis of the force signal to follow fatigue behavior of metals under oscillatory displacement-controlled tests in uniaxial tension/tension. As a first step, three different materials were selected (cold rolled steel, aluminium and brass). The FT analysis revealed a low level of nonlinearities in the force response, which was possible to measure and quantify as higher harmonics of the imposed sinusoidal deformation. Due to geometric reasons, the odd higher harmonics represent the symmetric nonlinearity while even ones are related to asymmetry, so both odd and even harmonics need to be analyzed separately. The time evolution of the higher harmonics showed that the odd higher harmonics continuously increase during the test. Criteria to better predict the mechanical fatigue and failure (life time) are then proposed based on the integral and derivative based on the time evolution the odd higher harmonics. In contrast, for tests in the high cycle fatigue regime, the even higher harmonics are mainly noise at the beginning of the test (undamaged state), but start to rise after the occurrence of a crack due to internal crack friction. Based on the analysis performed, FT analysis of the force during mechanical fatigue testing of metals is a sensitive tool used to predict failure and to improve our understanding of the dynamics involved in mechanical fatigue. Full article

(This article belongs to the Special Issue Microstructural and Mechanical Properties of Metallic Materials, Volume II)

► Show Figures

Figure 1

7 pages, 2386 KiB

Open AccessArticle

Constitutive Analysis of the Anisotropic Flow Behavior of Commercially Pure Titanium

by Daehwan Kim, Taekyung Lee and Chong Soo Lee

Appl. Sci. 2020, 10(22), 7962; https://0-doi-org.brum.beds.ac.uk/10.3390/app10227962 - 10 Nov 2020

Cited by 1 | Viewed by 1886

Abstract

Plastic anisotropy is an important issue for metals possessing a hexagonal close-packed structure. This study investigated the anisotropic deformation characteristics of commercially pure titanium with basal texture. A quasi-static uniaxial compression gave rise to clear differences in flow curves and strain-hardening rates depending [...] Read more.

Plastic anisotropy is an important issue for metals possessing a hexagonal close-packed structure. This study investigated the anisotropic deformation characteristics of commercially pure titanium with basal texture. A quasi-static uniaxial compression gave rise to clear differences in flow curves and strain-hardening rates depending on the loading direction. This study employed a constitutive approach to quantify the contribution of (i) dynamic Hall–Petch strengthening, (ii) dislocation pile-up, and (iii) texture hardening with respect to the total flow stress. Such an approach calculated a flow stress comparable to the measured value, providing logical validity. The microstructural and mechanical differences depending on the loading direction (i.e., anisotropy) were successfully interpreted based on this approach. Full article

(This article belongs to the Special Issue Microstructural and Mechanical Properties of Metallic Materials, Volume II)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Microstructural and Mechanical Properties of Metallic Materials, Volume II

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (8 papers)

Editorial

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI