Pub Date : 2025-02-25DOI: 10.1007/s12540-025-01913-y
Jaehun Kim, Gang Hee Gu, Jihye Kwon, Min Hong Seo, Hyoung Seop Kim
In this study, we propose a novel method for deriving an extensive true stress-strain curve from uniaxial tensile tests by applying a two-dimensional digital image correlation (DIC) technique. The gauge section of the specimen deforms uniformly within the uniform elongation regime, but in the post-necking non-uniform elongation regime, stress and strain become localized exclusively within the necked section due to plastic instability. Based on the volume constancy condition of plastic deformation, the transverse, axial, and thickness strain components are estimated, enabling the visualization of the evolving cross-sectional area. True stress and true strain over a wide strain range are evaluated by developing a method that encompasses the stress and strain concentrated in the necked section. As a result, the true stress-strain curve over the wide strain range accurately describes the nonlinear hardening behavior over higher strain levels compared to the conventional gauge length method. The accuracy of the proposed approach is validated using finite element method (FEM) simulation. This method offers a straightforward and precise means of obtaining wide range true stress-strain curves through uniaxial tensile tests and two-dimensional DIC equipment, without requiring separate FEM simulations, correction factors, or constitutive equations.
{"title":"A Novel Framework for Evaluating the Intrinsic Mechanical Properties of Sheet Metals Using Two-dimensional Digital Image Correlation","authors":"Jaehun Kim, Gang Hee Gu, Jihye Kwon, Min Hong Seo, Hyoung Seop Kim","doi":"10.1007/s12540-025-01913-y","DOIUrl":"10.1007/s12540-025-01913-y","url":null,"abstract":"<div><p>In this study, we propose a novel method for deriving an extensive true stress-strain curve from uniaxial tensile tests by applying a two-dimensional digital image correlation (DIC) technique. The gauge section of the specimen deforms uniformly within the uniform elongation regime, but in the post-necking non-uniform elongation regime, stress and strain become localized exclusively within the necked section due to plastic instability. Based on the volume constancy condition of plastic deformation, the transverse, axial, and thickness strain components are estimated, enabling the visualization of the evolving cross-sectional area. True stress and true strain over a wide strain range are evaluated by developing a method that encompasses the stress and strain concentrated in the necked section. As a result, the true stress-strain curve over the wide strain range accurately describes the nonlinear hardening behavior over higher strain levels compared to the conventional gauge length method. The accuracy of the proposed approach is validated using finite element method (FEM) simulation. This method offers a straightforward and precise means of obtaining wide range true stress-strain curves through uniaxial tensile tests and two-dimensional DIC equipment, without requiring separate FEM simulations, correction factors, or constitutive equations.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":703,"journal":{"name":"Metals and Materials International","volume":"31 10","pages":"2837 - 2844"},"PeriodicalIF":4.0,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12540-025-01913-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145128597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, the grain refinement mechanism of VW93A alloy under different temperature paths during reciprocating upsetting and extrusion processes were investigated, and elucidates the evolution mechanism of long-period stacking order Long-period stacked ordered (LPSO) phase with different shapes. It is found that with the increase of the cumulative strain, the alloy microstructure of constant temperature reciprocating (CTR) and decrease temperature reciprocating upsetting-extrusion (DTR) is significantly refined, and the refinement mechanisms are mainly CDRX (continuous dynamic recrystallization) and DDRX (discontinuous dynamic recrystallization). Under the combined action of non-basal slip and second-phase particle-stimulated nucleation (PSN), the dynamic recrystallization (DRX) degree of CTR-treated alloy was higher and the structure was more uniform. The early commencement and production of dislocation walls facilitated by LPSO phase kinking, as well as the occurrence of non-basal slip under these deformation conditions, are the primary causes of the CTR-treated alloy's quick refining. The more fragmented LPSO phase in the deformed alloy is conducive to the nucleation and microstructure homogenization of dynamic recrystallization. Furthermore, following three deformations, a high number of small needle-like phases precipitate, which effectively pins the recrystallized grains' grain borders and inhibits their growth.
{"title":"Effects of Different Temperature Paths During Reciprocating Upsetting-Extrusion on Dynamic Recrystallization Refinement of VW93A Alloy","authors":"Xiaoxia Han, Renyuan Lu, Yunfang Liu, Qianning Liu, Zhimin Zhang, Jianmin Yu, Linlin Li","doi":"10.1007/s12540-025-01914-x","DOIUrl":"10.1007/s12540-025-01914-x","url":null,"abstract":"<div><p>In this paper, the grain refinement mechanism of VW93A alloy under different temperature paths during reciprocating upsetting and extrusion processes were investigated, and elucidates the evolution mechanism of long-period stacking order Long-period stacked ordered (LPSO) phase with different shapes. It is found that with the increase of the cumulative strain, the alloy microstructure of constant temperature reciprocating (CTR) and decrease temperature reciprocating upsetting-extrusion (DTR) is significantly refined, and the refinement mechanisms are mainly CDRX (continuous dynamic recrystallization) and DDRX (discontinuous dynamic recrystallization). Under the combined action of non-basal slip and second-phase particle-stimulated nucleation (PSN), the dynamic recrystallization (DRX) degree of CTR-treated alloy was higher and the structure was more uniform. The early commencement and production of dislocation walls facilitated by LPSO phase kinking, as well as the occurrence of non-basal slip under these deformation conditions, are the primary causes of the CTR-treated alloy's quick refining. The more fragmented LPSO phase in the deformed alloy is conducive to the nucleation and microstructure homogenization of dynamic recrystallization. Furthermore, following three deformations, a high number of small needle-like phases precipitate, which effectively pins the recrystallized grains' grain borders and inhibits their growth.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":703,"journal":{"name":"Metals and Materials International","volume":"31 9","pages":"2692 - 2709"},"PeriodicalIF":4.0,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigated the microstructure and texture evolution of HX (Hastelloy X), HX-C (CeO2 doped), and HX-W (wrought) alloys fabricated using selective laser melting (SLM). HX and HX-C samples exhibited a finer grain structure (10–25 μm and 5–15 μm, respectively) compared to HX-W (20–50 μm) in the XY plane (normal to the building direction) with dominant (:left(100right)) grain orientation and significant elongation in the XZ plane (parallel to the building direction). The presence of low-angle grain boundaries (LAGBs) was higher in HX (60.7%) and HX-C (64.9%) compared to HX-W (1.4%), indicating higher internal energy and stored energy within the grains. The orientation distribution function (ODF) analysis revealed similar texture patterns in HX and HX-C samples for both XY and XZ planes, suggesting minimal influence of cerium oxide on texture development. Pole figure analysis confirmed a strong (:<110>) fiber texture for HX and HX-C, further suggesting minimal impact on texture from cerium addition. Conversely, HX-W displayed a mixed grain orientation with reduced LAGBs and a distinct texture, indicating a more advanced recrystallization state. These findings suggest that cerium oxide addition refines the grain structure and enhances specific grain orientation while minimally affecting the overall texture development during SLM processing.
Graphical Abstract
研究了选择性激光熔化（SLM）制备的HX（哈氏合金X）、HX- c（掺杂CeO2）和HX- w（变形）合金的显微组织和织构演变。与HX- w （20-50 μm）相比，HX和HX- c样品在XY平面（垂直于建筑方向）表现出更细的晶粒结构（分别为10-25 μm和5-15 μm），并在平行于建筑方向的XZ平面上表现出显著的(:left(100right))晶粒取向和延伸率。低角度晶界（LAGBs）的存在在HX中较高（60.7）%) and HX-C (64.9%) compared to HX-W (1.4%), indicating higher internal energy and stored energy within the grains. The orientation distribution function (ODF) analysis revealed similar texture patterns in HX and HX-C samples for both XY and XZ planes, suggesting minimal influence of cerium oxide on texture development. Pole figure analysis confirmed a strong (:<110>) fiber texture for HX and HX-C, further suggesting minimal impact on texture from cerium addition. Conversely, HX-W displayed a mixed grain orientation with reduced LAGBs and a distinct texture, indicating a more advanced recrystallization state. These findings suggest that cerium oxide addition refines the grain structure and enhances specific grain orientation while minimally affecting the overall texture development during SLM processing.Graphical Abstract
{"title":"Microstructure and Texture Evolution of Hastelloy X and CeO2-Hastelloy X Composite Fabricated by Selective Laser Melting","authors":"Khalil Ranjbar, Mohsen Reihanian, Marwah Ali Harb, Mahdi Yeganeh, Javid Naseri, Zhao Xiaolin","doi":"10.1007/s12540-025-01910-1","DOIUrl":"10.1007/s12540-025-01910-1","url":null,"abstract":"<div><p>This study investigated the microstructure and texture evolution of HX (Hastelloy X), HX-C (CeO<sub>2</sub> doped), and HX-W (wrought) alloys fabricated using selective laser melting (SLM). HX and HX-C samples exhibited a finer grain structure (10–25 μm and 5–15 μm, respectively) compared to HX-W (20–50 μm) in the XY plane (normal to the building direction) with dominant <span>(:left(100right))</span> grain orientation and significant elongation in the XZ plane (parallel to the building direction). The presence of low-angle grain boundaries (LAGBs) was higher in HX (60.7%) and HX-C (64.9%) compared to HX-W (1.4%), indicating higher internal energy and stored energy within the grains. The orientation distribution function (ODF) analysis revealed similar texture patterns in HX and HX-C samples for both XY and XZ planes, suggesting minimal influence of cerium oxide on texture development. Pole figure analysis confirmed a strong <span>(:<110>)</span> fiber texture for HX and HX-C, further suggesting minimal impact on texture from cerium addition. Conversely, HX-W displayed a mixed grain orientation with reduced LAGBs and a distinct texture, indicating a more advanced recrystallization state. These findings suggest that cerium oxide addition refines the grain structure and enhances specific grain orientation while minimally affecting the overall texture development during SLM processing.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":703,"journal":{"name":"Metals and Materials International","volume":"31 9","pages":"2629 - 2642"},"PeriodicalIF":4.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-21DOI: 10.1007/s12540-025-01915-w
Jie Su, Juncheng Wang, Junkang Wu, Yan Wang, Liming Tan, Lan Huang, Xin Ma, Yi Zhang, Qi Zeng, Feng Liu
Selective laser melting (SLM) process without support is crucial for fabricating complex components of superalloy at some conditions. To realize that, it is indispensable to uncover the effects of inclination angles on microstructural evolution and mechanical property. In this research, the microstructure and mechanical properties of IN718 superalloy samples fabricated by SLM under different inclination angles of 40°, 50°, 60°, 70°, 80° and 90°were investigated. The results show that the relative densities of the SLM-ed alloy rise with the increase of the inclination angle. Improved densities and surface smoothness are achieved when the inclination angle exceeds 60°. As the inclination angle changes from 40° to 90°, the texture is transformed from < 111>∥width direction (WD) to < 111>∥length direction (LD), and the content of columnar and V-shaped grains is increased correspondingly. The alteration in inclination angle induces the shift in the heat flow direction, therefore influencing the epitaxial growth of grains. Thereafter, textures and the angles between tensile direction and building direction have significant effects on the strength of the alloy. The alloy built at 40° exhibits a maximum yield strength of 742.4 MPa, and the yield strength decreases to 715.9 MPa when the inclination angle elevates to 90°.
{"title":"Effect of Inclination Angle on Microstructural Evolution and Mechanical Property of Support-Free IN718 Alloy Fabricated by Selective Laser Melting","authors":"Jie Su, Juncheng Wang, Junkang Wu, Yan Wang, Liming Tan, Lan Huang, Xin Ma, Yi Zhang, Qi Zeng, Feng Liu","doi":"10.1007/s12540-025-01915-w","DOIUrl":"10.1007/s12540-025-01915-w","url":null,"abstract":"<div><p>Selective laser melting (SLM) process without support is crucial for fabricating complex components of superalloy at some conditions. To realize that, it is indispensable to uncover the effects of inclination angles on microstructural evolution and mechanical property. In this research, the microstructure and mechanical properties of IN718 superalloy samples fabricated by SLM under different inclination angles of 40°, 50°, 60°, 70°, 80° and 90°were investigated. The results show that the relative densities of the SLM-ed alloy rise with the increase of the inclination angle. Improved densities and surface smoothness are achieved when the inclination angle exceeds 60°. As the inclination angle changes from 40° to 90°, the texture is transformed from < 111>∥width direction (WD) to < 111>∥length direction (LD), and the content of columnar and V-shaped grains is increased correspondingly. The alteration in inclination angle induces the shift in the heat flow direction, therefore influencing the epitaxial growth of grains. Thereafter, textures and the angles between tensile direction and building direction have significant effects on the strength of the alloy. The alloy built at 40° exhibits a maximum yield strength of 742.4 MPa, and the yield strength decreases to 715.9 MPa when the inclination angle elevates to 90°.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":703,"journal":{"name":"Metals and Materials International","volume":"31 10","pages":"2875 - 2889"},"PeriodicalIF":4.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145128594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-20DOI: 10.1007/s12540-025-01911-0
Farooz Ahmad Najar, Sandeep Rathee, Manu Srivastava, Deepak Chhabra
In the present study, surface composites (SCs) of AA6082/SiC were developed using the friction stir processing (FSP) method to improve properties of AA6082. One, three, and five passes of FSP were employed in order to examine the changes in microstructure and properties of AA6082. Microstructural examination showed that the five pass FSPed AA6082/SiC SCs exhibited finer grain structure and better dispersion of SiC nanoparticles. Mechanical and tribological properties revealed that on increasing number of FSP passes resulted in improved ultimate tensile strength and wear resistance. Similarly better corrosion resistance was obtained in 5-pass SCs compared to the base metal. The results provided valuable insights for the developmental and homogeneous distribution of SiC nano-particles within the metal matrix and strongly validate with microstructural evolution.
{"title":"Surface Modification and Properties Enhancement of AA6082 Using Multi-Pass Friction Stir Processing","authors":"Farooz Ahmad Najar, Sandeep Rathee, Manu Srivastava, Deepak Chhabra","doi":"10.1007/s12540-025-01911-0","DOIUrl":"10.1007/s12540-025-01911-0","url":null,"abstract":"<div><p>In the present study, surface composites (SCs) of AA6082/SiC were developed using the friction stir processing (FSP) method to improve properties of AA6082. One, three, and five passes of FSP were employed in order to examine the changes in microstructure and properties of AA6082. Microstructural examination showed that the five pass FSPed AA6082/SiC SCs exhibited finer grain structure and better dispersion of SiC nanoparticles. Mechanical and tribological properties revealed that on increasing number of FSP passes resulted in improved ultimate tensile strength and wear resistance. Similarly better corrosion resistance was obtained in 5-pass SCs compared to the base metal. The results provided valuable insights for the developmental and homogeneous distribution of SiC nano-particles within the metal matrix and strongly validate with microstructural evolution.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":703,"journal":{"name":"Metals and Materials International","volume":"31 9","pages":"2673 - 2691"},"PeriodicalIF":4.0,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-18DOI: 10.1007/s12540-025-01916-9
Qifeng Cai, Hua Zhang, Huwei Tao, Xiaoteng Zhu, Weicheng Zhang, Yan Liu, Geng Cao
This study investigates the mechanical performance of 2195/2219 friction stir welded joints under different process parameters and environmental temperatures, providing a theoretical basis for aerospace manufacturing. The results indicate that defect-free, closely bonded, and high-low temperature mechanically superior Friction Stir Welding joints can be achieved when 2219 aluminum alloy is positioned on the advancing side and welding parameters are controlled at 800 rpm–400 mm/min. Welding speed significantly influences the hardness of the weld zone (WZ) more than the rotational speed, leading to a notable hardness drop in the WZ region. Under the process parameters of 800 rpm–400 mm/min, the microhardness of the joint reaches a peak value of 125.84 HV, representing 69.91% of the hardness of the 2195 base material (BM) and 89.89% of the hardness of the 2219 BM. Regardless of the experimental environment, the tensile properties of the joint increase with rising welding speed, while the rotational speed has a minor impact on tensile performance. At room temperature, the tensile strength of the joint falls between high and low temperatures, with fracture occurring in the low hardness region near the 2219-Thermomechanically Affected Zone (TMAZ) and Heat-Affected Zone (HAZ), where the WZ experiences severe plastic deformation and dynamic recrystallization due to the shearing action of the stirring pin. This results in grain refinement and a transition from small angle to high angle grain boundaries, forming mainly recrystallized equiaxed grains. The 2195/2219-TMAZ region consists of a significant proportion of small angle grain boundaries, comprising deformed and substructured grains. In the 2219-HAZ region, the θ′′ and θ′ phases dissolve and coarsen, precipitating coarse θ (Al2Cu) phases, making this area more prone to fracture.
{"title":"Influence of Process Parameters on Microstructure and High-Low Temperature Mechanical Properties of 2195/2219 Dissimilar Alloy Welded Joints","authors":"Qifeng Cai, Hua Zhang, Huwei Tao, Xiaoteng Zhu, Weicheng Zhang, Yan Liu, Geng Cao","doi":"10.1007/s12540-025-01916-9","DOIUrl":"10.1007/s12540-025-01916-9","url":null,"abstract":"<div><p>This study investigates the mechanical performance of 2195/2219 friction stir welded joints under different process parameters and environmental temperatures, providing a theoretical basis for aerospace manufacturing. The results indicate that defect-free, closely bonded, and high-low temperature mechanically superior Friction Stir Welding joints can be achieved when 2219 aluminum alloy is positioned on the advancing side and welding parameters are controlled at 800 rpm–400 mm/min. Welding speed significantly influences the hardness of the weld zone (WZ) more than the rotational speed, leading to a notable hardness drop in the WZ region. Under the process parameters of 800 rpm–400 mm/min, the microhardness of the joint reaches a peak value of 125.84 HV, representing 69.91% of the hardness of the 2195 base material (BM) and 89.89% of the hardness of the 2219 BM. Regardless of the experimental environment, the tensile properties of the joint increase with rising welding speed, while the rotational speed has a minor impact on tensile performance. At room temperature, the tensile strength of the joint falls between high and low temperatures, with fracture occurring in the low hardness region near the 2219-Thermomechanically Affected Zone (TMAZ) and Heat-Affected Zone (HAZ), where the WZ experiences severe plastic deformation and dynamic recrystallization due to the shearing action of the stirring pin. This results in grain refinement and a transition from small angle to high angle grain boundaries, forming mainly recrystallized equiaxed grains. The 2195/2219-TMAZ region consists of a significant proportion of small angle grain boundaries, comprising deformed and substructured grains. In the 2219-HAZ region, the θ′′ and θ′ phases dissolve and coarsen, precipitating coarse θ (Al<sub>2</sub>Cu) phases, making this area more prone to fracture.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":703,"journal":{"name":"Metals and Materials International","volume":"31 10","pages":"2976 - 2991"},"PeriodicalIF":4.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145128626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1007/s12540-025-01908-9
Km Rakhi, Joonghan Shin
Hot cracking during laser welding of the aluminum alloy (AA) 6061-T6 adversely impacts the structural integrity and performance of welded joints. This study examined the effects of the beam inclination angle and welding speed on hot cracking during laser fillet welding of AA6061-T6 sheet lap joints. The welds were subjected to morphological and microstructural analyses, and their chemical compositions were determined. Good welds (without defects such as hot cracks and voids) were achieved using a beam inclination angle of 15°, moderate to high welding speeds (20–40 mm/s), and a constant laser power of 1500 W. Microstructural analysis revealed that fine grain structures and small grain misorientation angles were associated with fewer hot cracks. Additionally, hot cracks exhibited a considerably higher silicon concentration (3.92%) than other regions. Microcracks and voids were subjected to microcomputed tomographic analysis. The small beam inclination angle (15°) reduced the amount of microvoids. These results demonstrate how hot cracking of AA6061-T6 fillet lap joints can be avoided.
{"title":"Effect of Process Parameters on Hot Cracking During Laser Fillet Welding of AA6061-T6","authors":"Km Rakhi, Joonghan Shin","doi":"10.1007/s12540-025-01908-9","DOIUrl":"10.1007/s12540-025-01908-9","url":null,"abstract":"<div><p>Hot cracking during laser welding of the aluminum alloy (AA) 6061-T6 adversely impacts the structural integrity and performance of welded joints. This study examined the effects of the beam inclination angle and welding speed on hot cracking during laser fillet welding of AA6061-T6 sheet lap joints. The welds were subjected to morphological and microstructural analyses, and their chemical compositions were determined. Good welds (without defects such as hot cracks and voids) were achieved using a beam inclination angle of 15°, moderate to high welding speeds (20–40 mm/s), and a constant laser power of 1500 W. Microstructural analysis revealed that fine grain structures and small grain misorientation angles were associated with fewer hot cracks. Additionally, hot cracks exhibited a considerably higher silicon concentration (3.92%) than other regions. Microcracks and voids were subjected to microcomputed tomographic analysis. The small beam inclination angle (15°) reduced the amount of microvoids. These results demonstrate how hot cracking of AA6061-T6 fillet lap joints can be avoided.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":703,"journal":{"name":"Metals and Materials International","volume":"31 9","pages":"2749 - 2762"},"PeriodicalIF":4.0,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-16DOI: 10.1007/s12540-025-01907-w
Sadik Sefa Acar, Tuncay Yalçinkaya
This study investigates the strain ratcheting behavior of 304L stainless steel under complex stress-controlled cyclic loading conditions employing crystal plasticity models in the DAMASK framework. Strain ratcheting, a phenomenon characterized by the accumulation of plastic strain during cyclic loading, is particularly important in industries such as aerospace and nuclear energy, where components are subjected to non-proportional multiaxial loading. A polycrystalline representative volume element with 200 randomly oriented grains was generated to predict the material response under various stress paths, including Uniaxial, Shear, Cross, Square, and Circle loading conditions. Two crystal plasticity models were used: a phenomenological power-law (PP) model and a combined isotropic-kinematic hardening (IK) model. Simulations were conducted to identify parameters under monotonic and cyclic strain-controlled loading conditions. Model parameters are identified by using experimental results from literature and conducting strain-controlled uniaxial monotonic and cyclic loading simulations for PP and IK models, respectively. In addition, FEM and spectral solvers are compared for monotonic and cyclic loading conditions, and very similar macroscopic responses are obtained. The uniaxial strain ratcheting simulations under stress-controlled cyclic loading were compared against experimental data, with the IK model producing closer results due to its back-stress and memory terms. The analysis also revealed that the mechanical response, both at the macroscopic and local levels, is highly sensitive to the applied stress path, with significant differences in strain accumulation observed across different loading conditions. Torsional and axial strain evolutions were analyzed in detail, showing that the PP and IK models each performed better under certain stress paths. This study emphasizes the critical role of stress path effects in strain ratcheting and the variation in torsional and axial ratcheting predictions of two models for different stress paths.
{"title":"Modeling of the Stress Path-Dependent Strain Ratcheting Behaviour of 304L Stainless Steel Through Crystal Plasticity Frameworks","authors":"Sadik Sefa Acar, Tuncay Yalçinkaya","doi":"10.1007/s12540-025-01907-w","DOIUrl":"10.1007/s12540-025-01907-w","url":null,"abstract":"<div><p>This study investigates the strain ratcheting behavior of 304L stainless steel under complex stress-controlled cyclic loading conditions employing crystal plasticity models in the DAMASK framework. Strain ratcheting, a phenomenon characterized by the accumulation of plastic strain during cyclic loading, is particularly important in industries such as aerospace and nuclear energy, where components are subjected to non-proportional multiaxial loading. A polycrystalline representative volume element with 200 randomly oriented grains was generated to predict the material response under various stress paths, including Uniaxial, Shear, Cross, Square, and Circle loading conditions. Two crystal plasticity models were used: a phenomenological power-law (PP) model and a combined isotropic-kinematic hardening (IK) model. Simulations were conducted to identify parameters under monotonic and cyclic strain-controlled loading conditions. Model parameters are identified by using experimental results from literature and conducting strain-controlled uniaxial monotonic and cyclic loading simulations for PP and IK models, respectively. In addition, FEM and spectral solvers are compared for monotonic and cyclic loading conditions, and very similar macroscopic responses are obtained. The uniaxial strain ratcheting simulations under stress-controlled cyclic loading were compared against experimental data, with the IK model producing closer results due to its back-stress and memory terms. The analysis also revealed that the mechanical response, both at the macroscopic and local levels, is highly sensitive to the applied stress path, with significant differences in strain accumulation observed across different loading conditions. Torsional and axial strain evolutions were analyzed in detail, showing that the PP and IK models each performed better under certain stress paths. This study emphasizes the critical role of stress path effects in strain ratcheting and the variation in torsional and axial ratcheting predictions of two models for different stress paths.</p><h3>Graphic Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":703,"journal":{"name":"Metals and Materials International","volume":"31 9","pages":"2525 - 2540"},"PeriodicalIF":4.0,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12540-025-01907-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-15DOI: 10.1007/s12540-024-01887-3
Van Hung Dao, Hee Soo Yun, Sang Koo Jeon, Jaeyeong Park, Seung Hoon Nahm
The fatigue behavior of a second-generation single-crystal nickel-based superalloy was examined under thermomechanical fatigue (TMF) at temperatures ranging from 450 to 850 °C, using strain-controlled conditions. The study aimed to analyze cyclic deformation behavior, investigate dominant damage mechanisms, and assess cracking behavior in both in-phase (IP) and out-of-phase (OP) tests. Under IP TMF conditions, the primary damage manifestation was primarily attributed to creep-fatigue interactions, collectively leading to a reduced lifetime. Conversely, in the OP tests, the damage predominantly stemmed from the oxidation-fatigue mechanisms occurring at high mechanical strains. Creep-induced damage emerges as an additional factor at lower mechanical strains, rendering the material more susceptible to crack propagation. Consequently, the fatigue life exhibited considerable reduction and tended to reverse compared to the IP case. Further tests were conducted across various maximum temperature cycling ranges of 950 and 1038 °C to explore the effect of temperature on IP TMF lifespans. Increased mobility of dislocations and oxidation penetration were found to further reduce the fatigue life of ruptured specimens, with this effect believed to be proportional to the temperature variation in the IP TMF test. The microstructures and damage evolution were examined to provide insights into the changes in fatigue life.
{"title":"Temperature Dependence on Cracking Behavior in Thermomechanical Fatigue of Nickel-Based Single-Crystal Superalloy","authors":"Van Hung Dao, Hee Soo Yun, Sang Koo Jeon, Jaeyeong Park, Seung Hoon Nahm","doi":"10.1007/s12540-024-01887-3","DOIUrl":"10.1007/s12540-024-01887-3","url":null,"abstract":"<div><p>The fatigue behavior of a second-generation single-crystal nickel-based superalloy was examined under thermomechanical fatigue (TMF) at temperatures ranging from 450 to 850 °C, using strain-controlled conditions. The study aimed to analyze cyclic deformation behavior, investigate dominant damage mechanisms, and assess cracking behavior in both in-phase (IP) and out-of-phase (OP) tests. Under IP TMF conditions, the primary damage manifestation was primarily attributed to creep-fatigue interactions, collectively leading to a reduced lifetime. Conversely, in the OP tests, the damage predominantly stemmed from the oxidation-fatigue mechanisms occurring at high mechanical strains. Creep-induced damage emerges as an additional factor at lower mechanical strains, rendering the material more susceptible to crack propagation. Consequently, the fatigue life exhibited considerable reduction and tended to reverse compared to the IP case. Further tests were conducted across various maximum temperature cycling ranges of 950 and 1038 °C to explore the effect of temperature on IP TMF lifespans. Increased mobility of dislocations and oxidation penetration were found to further reduce the fatigue life of ruptured specimens, with this effect believed to be proportional to the temperature variation in the IP TMF test. The microstructures and damage evolution were examined to provide insights into the changes in fatigue life.</p><h3>Graphic Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":703,"journal":{"name":"Metals and Materials International","volume":"31 8","pages":"2297 - 2314"},"PeriodicalIF":4.0,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145165206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-15DOI: 10.1007/s12540-025-01901-2
Harisingh Kshatri, M. Rajasekhar, M. Komaleswara Rao, H. Jeevan Rao, Andrey Melnikov, Christos Spitas, T. Rajesh Kumar Dora
Friction stir processing (FSP) is an innovative solid-state technique in which the material remains unmelted and unrecast, with process parameters such as tool rotational speed, tool feed, and axial force significantly influencing the mechanical properties. Recent studies have included metal oxides or carbides in the FSP process, yielding surface composites of aluminum alloys. In addition to the process parameters, it is posited that the composition of additives may influence the mechanical properties. Traditionally, statistical analyses focused on modeling process parameters to enhance the response behavior of composites. In this investigation, however, both process parameters (tool rotational speed and tool feed) and composition parameters (SiC wt% and Graphene wt%) were incorporated to achieve optimal mechanical properties of the composites. The research involves the synthesis of AA6101 aluminum composites by the modulation of tool rotational speed and feed, while concurrently adjusting the concentration of reinforcement additives (SiC wt% and Graphene wt%). The ultimate tensile strength, flexural strength, and hardness of the produced composites were evaluated using a universal testing machine and a Vickers hardness tester. The central composite design technique and mathematical model were developed using response surface methodology, incorporating two parameters, three levels, and 15 runs, to establish the relationship between the FSP parameters (process and composition) and the responses (tensile strength, flexural strength, and hardness). The findings indicate that the optimal responses of the FSP process, as assessed by the response optimizer, are 330 MPa (UTS), 130 MPa (FS), and 110 HV (Hardness).
{"title":"Process and Composition Parameter Optimization of Friction Stir Process of AA 6101 Aluminum Composites using Response Surface Methodology","authors":"Harisingh Kshatri, M. Rajasekhar, M. Komaleswara Rao, H. Jeevan Rao, Andrey Melnikov, Christos Spitas, T. Rajesh Kumar Dora","doi":"10.1007/s12540-025-01901-2","DOIUrl":"10.1007/s12540-025-01901-2","url":null,"abstract":"<div><p>Friction stir processing (FSP) is an innovative solid-state technique in which the material remains unmelted and unrecast, with process parameters such as tool rotational speed, tool feed, and axial force significantly influencing the mechanical properties. Recent studies have included metal oxides or carbides in the FSP process, yielding surface composites of aluminum alloys. In addition to the process parameters, it is posited that the composition of additives may influence the mechanical properties. Traditionally, statistical analyses focused on modeling process parameters to enhance the response behavior of composites. In this investigation, however, both process parameters (tool rotational speed and tool feed) and composition parameters (SiC wt% and Graphene wt%) were incorporated to achieve optimal mechanical properties of the composites. The research involves the synthesis of AA6101 aluminum composites by the modulation of tool rotational speed and feed, while concurrently adjusting the concentration of reinforcement additives (SiC wt% and Graphene wt%). The ultimate tensile strength, flexural strength, and hardness of the produced composites were evaluated using a universal testing machine and a Vickers hardness tester. The central composite design technique and mathematical model were developed using response surface methodology, incorporating two parameters, three levels, and 15 runs, to establish the relationship between the FSP parameters (process and composition) and the responses (tensile strength, flexural strength, and hardness). The findings indicate that the optimal responses of the FSP process, as assessed by the response optimizer, are 330 MPa (UTS), 130 MPa (FS), and 110 HV (Hardness).</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":703,"journal":{"name":"Metals and Materials International","volume":"31 9","pages":"2797 - 2810"},"PeriodicalIF":4.0,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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