Pub Date : 2026-01-14DOI: 10.1016/j.msea.2026.149781
Shaojie Gu , Sungmin Yoon , Chang Liu , Yanhong Peng , Yi Cui , Yasuhiro Kimura , Yuhki Toku , Yasuyuki Morita , Yang Ju
Fatigue failure poses a serious threat to the safety and durability of engineering structures, making it crucial to enhance and restore the fatigue performance of critical components. In this study, we employed high-density pulsed electric current (HDPEC) treatment to improve the crack initiation life of Ni-based superalloy Inconel 718. Experimental results revealed that multiple HDPEC treatments can increase the crack initiation life by up to 108.3 %. This improvement is attributed to the recovery of the localized plastic zone, which effectively suppresses crack initiation. Quasi-in-situ electron backscatter diffraction observations confirmed a significant reduction in dislocations, slip bands, and sub-grain boundaries, likely driven by the coupled effects of electron wind force and Joule heating that promote dislocation motion and elimination. This work demonstrates that HDPEC is a simple and effective method for enhancing fatigue resistance and offers promising prospects for application in high-performance structural materials.
{"title":"Electric current-driven microstructural recovery and crack resistance enhancement in Ni-based superalloy Inconel 718","authors":"Shaojie Gu , Sungmin Yoon , Chang Liu , Yanhong Peng , Yi Cui , Yasuhiro Kimura , Yuhki Toku , Yasuyuki Morita , Yang Ju","doi":"10.1016/j.msea.2026.149781","DOIUrl":"10.1016/j.msea.2026.149781","url":null,"abstract":"<div><div>Fatigue failure poses a serious threat to the safety and durability of engineering structures, making it crucial to enhance and restore the fatigue performance of critical components. In this study, we employed high-density pulsed electric current (HDPEC) treatment to improve the crack initiation life of Ni-based superalloy Inconel 718. Experimental results revealed that multiple HDPEC treatments can increase the crack initiation life by up to 108.3 %. This improvement is attributed to the recovery of the localized plastic zone, which effectively suppresses crack initiation. Quasi-in-situ electron backscatter diffraction observations confirmed a significant reduction in dislocations, slip bands, and sub-grain boundaries, likely driven by the coupled effects of electron wind force and Joule heating that promote dislocation motion and elimination. This work demonstrates that HDPEC is a simple and effective method for enhancing fatigue resistance and offers promising prospects for application in high-performance structural materials.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"953 ","pages":"Article 149781"},"PeriodicalIF":7.0,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-14DOI: 10.1016/j.msea.2026.149787
Meng Qin , Xiaodan Li , Kai Feng , Zhuguo Li
A rotational scanning path-based remelting strategy tailors the melt pool geometry and microstructure of the Nb521 alloy during laser powder bed fusion. This strategy modifies the thermal gradients, suppresses columnar grain growth, weakens texture intensity (MUD from 14.45 to 4.95), and effectively mitigates mechanical anisotropy (with YS and UTS anisotropy decreasing from ∼14 % to ∼4 %).
{"title":"Tuning mechanical anisotropy in laser powder bed fusion via a rotational remelting scan strategy: A case study in niobium-based alloys","authors":"Meng Qin , Xiaodan Li , Kai Feng , Zhuguo Li","doi":"10.1016/j.msea.2026.149787","DOIUrl":"10.1016/j.msea.2026.149787","url":null,"abstract":"<div><div>A rotational scanning path-based remelting strategy tailors the melt pool geometry and microstructure of the Nb521 alloy during laser powder bed fusion. This strategy modifies the thermal gradients, suppresses columnar grain growth, weakens texture intensity (MUD from 14.45 to 4.95), and effectively mitigates mechanical anisotropy (with YS and UTS anisotropy decreasing from ∼14 % to ∼4 %).</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"953 ","pages":"Article 149787"},"PeriodicalIF":7.0,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-14DOI: 10.1016/j.msea.2026.149786
Peng Chen , Wenhao Chen , Jie Wang , Xiong Wen , Yang Tang , Bensheng Huang , Zhiqing Zhang
This study investigates the microstructure-property relationship in Al-Cu-Li alloys through systematic solution treatment and artificial aging treatment (AT) of fully annealed specimens. A comprehensive examination was conducted on the microstructural evolution during aging and its corresponding effects on mechanical properties and corrosion resistance. Microstructure characterization techniques including scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to analyze precipitation behavior, and mechanical properties were evaluated through microhardness measurements and tensile testing. Corrosion resistance was assessed via intergranular corrosion (IGC) tests and electrochemical analysis. The artificial aging process exhibited three distinct hardening stages: (ⅰ) rapid hardening stage (AT-0 to 24 h), (ⅱ) slow hardening stage (AT-24 to 84 h), and (ⅲ) steady hardness stage (>AT-84 h). During the rapid hardening stage, extensive phase transformation from Guinier-Preston Zones (GP zones) to θ′ phases developed, accompanied by an 81.3 % reduction in GPZs density (from 9.67 × 103 μm−2 to 1.81 × 103 μm−2) and microhardness increase to 109 HV. The peak-aged condition (AT-84) achieved maximum hardness (134.7 HV) and tensile strength (545 MPa, 40 % increase as compared with the AT-2), though with compromised elongation (9.1%, 55% decrease as compared with the AT-2). Prolonged aging to 120 h (AT-120) further increased strength (563 MPa) but severely reduced ductility (elongation about 5.6%). The limited solute supply during slow hardening decelerated θ′ precipitation kinetics, while steady hardness stage featured coarsening precipitates (exceeding 100 nm) with reduced number density. The formation of grain boundary precipitates (GBPs) and precipitate-free zones (PFZs) was found to deteriorate both mechanical properties and corrosion performance. In the electrochemical tests, the AT-2 exhibits the lowest Ecorr and superior corrosion performance. However, the higher density of GP zones in the alloy leads to a higher icorr and a faster corrosion rate for the AT-2. Extended aging caused cathodic Ecorr shifts, while GBPs and PFZs served as preferential corrosion paths. Furthermore, galvanic coupling between Cu-rich phases and the Cu-depleted matrix promoted localized pitting, accelerating overall corrosion degradation.
{"title":"Evolution mechanism of precipitates, mechanical properties, and corrosion behavior in Al-Cu-Li alloys during artificial aging","authors":"Peng Chen , Wenhao Chen , Jie Wang , Xiong Wen , Yang Tang , Bensheng Huang , Zhiqing Zhang","doi":"10.1016/j.msea.2026.149786","DOIUrl":"10.1016/j.msea.2026.149786","url":null,"abstract":"<div><div>This study investigates the microstructure-property relationship in Al-Cu-Li alloys through systematic solution treatment and artificial aging treatment (AT) of fully annealed specimens. A comprehensive examination was conducted on the microstructural evolution during aging and its corresponding effects on mechanical properties and corrosion resistance. Microstructure characterization techniques including scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to analyze precipitation behavior, and mechanical properties were evaluated through microhardness measurements and tensile testing. Corrosion resistance was assessed via intergranular corrosion (IGC) tests and electrochemical analysis. The artificial aging process exhibited three distinct hardening stages: (ⅰ) rapid hardening stage (AT-0 to 24 h), (ⅱ) slow hardening stage (AT-24 to 84 h), and (ⅲ) steady hardness stage (>AT-84 h). During the rapid hardening stage, extensive phase transformation from Guinier-Preston Zones (GP zones) to θ′ phases developed, accompanied by an 81.3 % reduction in GPZs density (from 9.67 × 10<sup>3</sup> μm<sup>−2</sup> to 1.81 × 10<sup>3</sup> μm<sup>−2</sup>) and microhardness increase to 109 HV. The peak-aged condition (AT-84) achieved maximum hardness (134.7 HV) and tensile strength (545 MPa, 40 % increase as compared with the AT-2), though with compromised elongation (9.1%, 55% decrease as compared with the AT-2). Prolonged aging to 120 h (AT-120) further increased strength (563 MPa) but severely reduced ductility (elongation about 5.6%). The limited solute supply during slow hardening decelerated θ′ precipitation kinetics, while steady hardness stage featured coarsening precipitates (exceeding 100 nm) with reduced number density. The formation of grain boundary precipitates (GBPs) and precipitate-free zones (PFZs) was found to deteriorate both mechanical properties and corrosion performance. In the electrochemical tests, the AT-2 exhibits the lowest E<sub>corr</sub> and superior corrosion performance. However, the higher density of GP zones in the alloy leads to a higher <em>i</em><sub><em>corr</em></sub> and a faster corrosion rate for the AT-2. Extended aging caused cathodic Ecorr shifts, while GBPs and PFZs served as preferential corrosion paths. Furthermore, galvanic coupling between Cu-rich phases and the Cu-depleted matrix promoted localized pitting, accelerating overall corrosion degradation.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"953 ","pages":"Article 149786"},"PeriodicalIF":7.0,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 addresses the critical need for localized strengthening of laser direct energy deposited components by developing an innovative induction heat treatment strategy. Focusing on the deposited 18Ni300 layer of a deposit-substrate composite (20Mn2SiCrMo bainitic steel substrate), a short-time (5–30 min) and high-temperature (600 °C) induction heat treatment was proposed to regulate the precipitate evolution and reversed austenite (RA’) formation of 18Ni300 deposits, the synergistic optimization of the strength/toughness was achieved without affecting the 20Mn2SiCrMo substrate’ performance. During heat treatment, the RA’ preferentially nucleates and grows up at the inter-dendritic α′-M laths, intra-dendritic α′-M laths, subgranular boundaries or near the Ni-rich precipitates; meanwhile, the nano-intermetallic compounds, such as η-Ni3Ti, Ni3Mo, and Laves-Fe2Mo, are precipitated sequentially, and the lattice mismatch degree between them and the parent phase increases with the heating time. This multi-scale synergistic evolution mechanism of microstructure enables the 18Ni300 deposit’ yield strength to be increased by 32.8 % under only 10 min of heating, while keeping the decrease in impact toughness within 16.4 %, reaching 1441 MPa and 77.72 J, respectively. Mechanistic analysis shows that the dynamic balance between the lattice mismatch reinforcement and the TRIP effect of RA’ is the key to achieving the strength-toughness synergy. This technology provides a new paradigm for localized control of bimetallic composites, which is of great value in repaired and remanufacturing components serviced in extreme environments, such as rail transportation and ocean engineering.
{"title":"Tailoring nanostructures and mechanical properties of laser direct energy deposited 18Ni300 via induction heat treatment","authors":"Beibei Zhu, Gaofeng Xu, Li Meng, Qianwu Hu, Xu Liu, Xiaoyan Zeng","doi":"10.1016/j.msea.2026.149776","DOIUrl":"10.1016/j.msea.2026.149776","url":null,"abstract":"<div><div>This study addresses the critical need for localized strengthening of laser direct energy deposited components by developing an innovative induction heat treatment strategy. Focusing on the deposited 18Ni300 layer of a deposit-substrate composite (20Mn2SiCrMo bainitic steel substrate), a short-time (5–30 min) and high-temperature (600 °C) induction heat treatment was proposed to regulate the precipitate evolution and reversed austenite (RA’) formation of 18Ni300 deposits, the synergistic optimization of the strength/toughness was achieved without affecting the 20Mn2SiCrMo substrate’ performance. During heat treatment, the RA’ preferentially nucleates and grows up at the inter-dendritic α′-M laths, intra-dendritic α′-M laths, subgranular boundaries or near the Ni-rich precipitates; meanwhile, the nano-intermetallic compounds, such as η-Ni<sub>3</sub>Ti, Ni<sub>3</sub>Mo, and Laves-Fe<sub>2</sub>Mo, are precipitated sequentially, and the lattice mismatch degree between them and the parent phase increases with the heating time. This multi-scale synergistic evolution mechanism of microstructure enables the 18Ni300 deposit’ yield strength to be increased by 32.8 % under only 10 min of heating, while keeping the decrease in impact toughness within 16.4 %, reaching 1441 MPa and 77.72 J, respectively. Mechanistic analysis shows that the dynamic balance between the lattice mismatch reinforcement and the TRIP effect of RA’ is the key to achieving the strength-toughness synergy. This technology provides a new paradigm for localized control of bimetallic composites, which is of great value in repaired and remanufacturing components serviced in extreme environments, such as rail transportation and ocean engineering.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"953 ","pages":"Article 149776"},"PeriodicalIF":7.0,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work investigates the effect of Al and Ti addition on the precipitation and recrystallization behavior of CrFeNi medium-entropy alloy during the aging and cold rolling-recrystallization annealing process. Al and Ti elements significantly encourage the formation of BCC-structured precipitates after aging treatment, which exhibits a peak volume fraction at 800–900 °C and helps to increase strength. Al2Ti1 alloy aging at 900 °C has a yield strength of 696 MPa, which is 221 % higher than the annealed CrFeNi alloy and 225 % higher than the as-cast Al2Ti1 alloy. Due to the introduction of flaws during cold rolling, the volume fraction of precipitates in the annealed CrFeNi alloy greatly increases, resulting in the strength differential between the two annealed alloys being clearly less than that between the two aged alloys. Overall, the yield strength of the Al2Ti1 alloy is consistently higher than that of the CrFeNi alloy. Both the CrFeNi and Al2Ti1 alloys annealed at 800 °C show a considerable strength-plasticity configuration, with a yield strength of 590 MPa and 948 MPa, and an elongation of 24 % and 17 %. The annealed CrFeNi alloy is strengthened by the fine-grain strengthening mechanism, while the annealed Al2Ti1 alloy is primarily strengthened by both the fine-grain and precipitation strengthening. This work thoroughly demonstrates the optimization potential of low-cost FCC-structured medium-entropy alloys and promotes their application in industrial domains.
{"title":"Effect of Al and Ti addition on precipitation and recrystallization behavior of CrFeNi medium-entropy alloy","authors":"Lili Ma, Panpan Zhao, Zhengfang Wei, Baiting Yang, Jilan Zhou, Mingmin Zhang, Shouyu Ji","doi":"10.1016/j.msea.2026.149767","DOIUrl":"10.1016/j.msea.2026.149767","url":null,"abstract":"<div><div>This work investigates the effect of Al and Ti addition on the precipitation and recrystallization behavior of CrFeNi medium-entropy alloy during the aging and cold rolling-recrystallization annealing process. Al and Ti elements significantly encourage the formation of BCC-structured precipitates after aging treatment, which exhibits a peak volume fraction at 800–900 °C and helps to increase strength. Al2Ti1 alloy aging at 900 °C has a yield strength of 696 MPa, which is 221 % higher than the annealed CrFeNi alloy and 225 % higher than the as-cast Al2Ti1 alloy. Due to the introduction of flaws during cold rolling, the volume fraction of precipitates in the annealed CrFeNi alloy greatly increases, resulting in the strength differential between the two annealed alloys being clearly less than that between the two aged alloys. Overall, the yield strength of the Al2Ti1 alloy is consistently higher than that of the CrFeNi alloy. Both the CrFeNi and Al2Ti1 alloys annealed at 800 °C show a considerable strength-plasticity configuration, with a yield strength of 590 MPa and 948 MPa, and an elongation of 24 % and 17 %. The annealed CrFeNi alloy is strengthened by the fine-grain strengthening mechanism, while the annealed Al2Ti1 alloy is primarily strengthened by both the fine-grain and precipitation strengthening. This work thoroughly demonstrates the optimization potential of low-cost FCC-structured medium-entropy alloys and promotes their application in industrial domains.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"953 ","pages":"Article 149767"},"PeriodicalIF":7.0,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-13DOI: 10.1016/j.msea.2026.149783
Huaijin Wang , Bohua Yu , Ning Ding , Hongmei Chen , Jiayin Chen , Chi Zhang , Xinxin Yang , Zeyun Cai , Guoqiang Xie
High-entropy and medium-entropy alloys (HEAs/MEAs) with face-centered cubic (FCC) structures have attracted significant interest. However, their low strength limits their use in structural applications. Traditional strengthening methods often sacrifice ductility to improve strength. This issue is particularly severe in Co-free alloys with high Cr content, which tend to form brittle precipitates during heat treatment. This study aims to mitigate the strength-ductility trade-off in a Co-free Ni2Cr2Fe MEA through a heterogeneous grain structure. After cold rolling and short-term high-temperature annealing (950 °C, 2 min), the alloy exhibits a yield strength of 1009 MPa and a fracture elongation of 21 %, without second phase strengthening or complex alloying. The microstructure includes non-recrystallized regions (NRX) with high dislocation density and recrystallized regions (RX) with ultrafine grains. Dislocation strengthening in the NRX regions contributes mainly to the yield strength. The sub-structures in the deformed regions sustain plastic deformation and promote uniform strain distribution. These findings provide insights into improving the strength-ductility balance in high-Cr content alloys.
{"title":"Mitigate the strength-ductility trade-off in high Cr content Ni2Cr2Fe MEA via heterogeneous structure design","authors":"Huaijin Wang , Bohua Yu , Ning Ding , Hongmei Chen , Jiayin Chen , Chi Zhang , Xinxin Yang , Zeyun Cai , Guoqiang Xie","doi":"10.1016/j.msea.2026.149783","DOIUrl":"10.1016/j.msea.2026.149783","url":null,"abstract":"<div><div>High-entropy and medium-entropy alloys (HEAs/MEAs) with face-centered cubic (FCC) structures have attracted significant interest. However, their low strength limits their use in structural applications. Traditional strengthening methods often sacrifice ductility to improve strength. This issue is particularly severe in Co-free alloys with high Cr content, which tend to form brittle precipitates during heat treatment. This study aims to mitigate the strength-ductility trade-off in a Co-free Ni<sub>2</sub>Cr<sub>2</sub>Fe MEA through a heterogeneous grain structure. After cold rolling and short-term high-temperature annealing (950 °C, 2 min), the alloy exhibits a yield strength of 1009 MPa and a fracture elongation of 21 %, without second phase strengthening or complex alloying. The microstructure includes non-recrystallized regions (NRX) with high dislocation density and recrystallized regions (RX) with ultrafine grains. Dislocation strengthening in the NRX regions contributes mainly to the yield strength. The sub-structures in the deformed regions sustain plastic deformation and promote uniform strain distribution. These findings provide insights into improving the strength-ductility balance in high-Cr content alloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"953 ","pages":"Article 149783"},"PeriodicalIF":7.0,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-12DOI: 10.1016/j.msea.2026.149779
Tingxiao Yu , Honglong Zhao , Qingdong Qin , Kai Feng , Juan Li , Chuang Yang , Yu Zeng
Achieving a high-quality joint in refractory high-entropy alloys (RHEAs) remains a significant challenge. In the present study, an appropriate filler metal of TiZrCuNi was selected to successfully join TiVNbTa RHEA using vacuum brazing. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and shear tests were used to systematically study the interfacial microstructure and mechanical properties of the joints. The results showed that the brazing seam consists of a diffusion-affected zone (Zone I) and a central brazed zone (Zone II), with a convex structure formed between these two zones. TEM images revealed α-Ti(Zr) nano-precipitates in Zone I. As the brazing temperature increased, the thickness of Zone I gradually increased, while the volume fraction of the blocky α-Ti phase in Zone II significantly decreased. The shear strength of the joints initially increased and then decreased with rising brazing temperature, reaching an optimal value of 179 ± 8 MPa after brazing at 880 °C for 15 min. The enhanced bonding strength of the joint is attributed to the interlocking effect of the convex structure and nano-precipitation strengthening. This study provides valuable insights into the welding challenges of TiVNbTa RHEA, offering guidance for achieving high-quality welding of RHEAs.
{"title":"Enhancing the interfacial strength of TiVNbTa refractory high entropy alloy joint for vacuum brazed via convex structure with nano-precipitates","authors":"Tingxiao Yu , Honglong Zhao , Qingdong Qin , Kai Feng , Juan Li , Chuang Yang , Yu Zeng","doi":"10.1016/j.msea.2026.149779","DOIUrl":"10.1016/j.msea.2026.149779","url":null,"abstract":"<div><div>Achieving a high-quality joint in refractory high-entropy alloys (RHEAs) remains a significant challenge. In the present study, an appropriate filler metal of TiZrCuNi was selected to successfully join TiVNbTa RHEA using vacuum brazing. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and shear tests were used to systematically study the interfacial microstructure and mechanical properties of the joints. The results showed that the brazing seam consists of a diffusion-affected zone (Zone I) and a central brazed zone (Zone II), with a convex structure formed between these two zones. TEM images revealed α-Ti(Zr) nano-precipitates in Zone I. As the brazing temperature increased, the thickness of Zone I gradually increased, while the volume fraction of the blocky α-Ti phase in Zone II significantly decreased. The shear strength of the joints initially increased and then decreased with rising brazing temperature, reaching an optimal value of 179 ± 8 MPa after brazing at 880 °C for 15 min. The enhanced bonding strength of the joint is attributed to the interlocking effect of the convex structure and nano-precipitation strengthening. This study provides valuable insights into the welding challenges of TiVNbTa RHEA, offering guidance for achieving high-quality welding of RHEAs.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"953 ","pages":"Article 149779"},"PeriodicalIF":7.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 presents an investigation into the tensile creep behavior of the Ti-43Al-9V-0.2Y alloy characterized by α2/γ and β0/γ lamellar microstructures, following heat treatment at various temperatures and under differing levels of applied stress. The study explores the intricate relationships among microstructural evolution, phase orientation rotation, interface energy, and failure mechanisms. The creep behavior of the alloy exhibits a pronounced temperature dependence, indicating the presence of distinct creep mechanisms at varying temperatures. During the creep process, the microstructural transformation is characterized by the decomposition of the lamellae and the α2→γ phase transition. The rotation of the orientation relationship of β0/γ lamellae from to leads to a significant increase in the interface energy of the new orientation relationship, which becomes a preferential site for defect generation. At 800 °C high temperature, although the dynamic recrystallization in the matrix of the β0 phase alleviates stress concentration, the primary slip system of the γ phase is simultaneously altered to (111)//[101], resulting in the formation of the K-W pinning structure. Consequently, the plasticity of the sample deteriorates further.
{"title":"The effects of various temperatures and stress levels on the microstructure and failure mechanism of Ti-43Al-9V-0.2Y alloy after creep","authors":"Yang-jie Gao, Hai-tao Jiang, Shi-wei Tian, Si-yuan Zhang, Chun-hui Wang, Yi Wu, Hui Zhang","doi":"10.1016/j.msea.2026.149771","DOIUrl":"10.1016/j.msea.2026.149771","url":null,"abstract":"<div><div>This study presents an investigation into the tensile creep behavior of the Ti-43Al-9V-0.2Y alloy characterized by α<sub>2</sub>/γ and β<sub>0</sub>/γ lamellar microstructures, following heat treatment at various temperatures and under differing levels of applied stress. The study explores the intricate relationships among microstructural evolution, phase orientation rotation, interface energy, and failure mechanisms. The creep behavior of the alloy exhibits a pronounced temperature dependence, indicating the presence of distinct creep mechanisms at varying temperatures. During the creep process, the microstructural transformation is characterized by the decomposition of the lamellae and the α<sub>2</sub>→γ phase transition. The rotation of the orientation relationship of β<sub>0</sub>/γ lamellae from <span><math><mrow><mo><</mo><mn>110</mn><msub><mo>></mo><mi>γ</mi></msub><mo>/</mo><mo>/</mo><mo><</mo><mn>111</mn><msub><mo>></mo><msub><mi>β</mi><mn>0</mn></msub></msub></mrow></math></span> to <span><math><mrow><mo><</mo><mn>110</mn><msub><mo>></mo><mi>γ</mi></msub><mo>/</mo><mo>/</mo><mo><</mo><mn>100</mn><msub><mo>></mo><msub><mi>β</mi><mn>0</mn></msub></msub></mrow></math></span> leads to a significant increase in the interface energy of the new orientation relationship, which becomes a preferential site for defect generation. At 800 °C high temperature, although the dynamic recrystallization in the matrix of the β<sub>0</sub> phase alleviates stress concentration, the primary slip system of the γ phase is simultaneously altered to (111)//[101], resulting in the formation of the K-W pinning structure. Consequently, the plasticity of the sample deteriorates further.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"953 ","pages":"Article 149771"},"PeriodicalIF":7.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-12DOI: 10.1016/j.msea.2026.149777
Fuming Yang , Si-Wei Liu , Ahmed Y. Elghazouli
Wire-based laser directed energy deposition, referred to as DED-LB or WLAM, is an emerging additive method using laser-melted wire feedstock, offering high deposition rate, smooth surfaces, and high precision. These capabilities indicate strong potential for construction, particularly for complex and optimised components, yet structural adoption necessitates in-depth assessments of mechanical and microstructural properties. This study describes a detailed experimental investigation into the mechanical behaviour and microstructural characteristics of ER70S-6 normal-strength and ER110S-G high-strength steels produced by DED-LB, with focus on property variability and orientation-induced anisotropy, compared with wire-based arc directed energy deposition (i.e., DED-Arc or WAAM). Tensile tests are performed on as-built specimens extracted from various orientations, with 3D scanning quantifying surface undulations, and digital image correlation recording full-field strains. The microstructures are characterised using optical and scanning electron microscopy and electron backscatter diffraction, and microhardness is mapped to microstructural phases. The results show that both steels show favourable stiffness properties and ductility with modest orientation-dependent anisotropy, where ultimate strength ratios across orientations are 0.95–1.00, and elongation ratios are 0.94–1.06. Most coefficients of variation for tensile strength and fracture elongation are found to be below 0.07, comparable to conventional steels. Dominant microstructural phases are shown to be uniformly distributed, with observed layer boundary regions in agreement with local microhardness. Relative to DED-Arc, DED-LB steels, especially for the high-strength grade, are shown to exhibit higher ductility with reduced orientation sensitivity while maintaining comparable strengths. Overall, the findings provide as-built dataset for informing wire-based process assessment and selection for civil engineering applications.
{"title":"Tensile behaviour and microstructure of wire-based laser directed energy deposited normal- and high-strength steels","authors":"Fuming Yang , Si-Wei Liu , Ahmed Y. Elghazouli","doi":"10.1016/j.msea.2026.149777","DOIUrl":"10.1016/j.msea.2026.149777","url":null,"abstract":"<div><div>Wire-based laser directed energy deposition, referred to as DED-LB or WLAM, is an emerging additive method using laser-melted wire feedstock, offering high deposition rate, smooth surfaces, and high precision. These capabilities indicate strong potential for construction, particularly for complex and optimised components, yet structural adoption necessitates in-depth assessments of mechanical and microstructural properties. This study describes a detailed experimental investigation into the mechanical behaviour and microstructural characteristics of ER70S-6 normal-strength and ER110S-G high-strength steels produced by DED-LB, with focus on property variability and orientation-induced anisotropy, compared with wire-based arc directed energy deposition (i.e., DED-Arc or WAAM). Tensile tests are performed on as-built specimens extracted from various orientations, with 3D scanning quantifying surface undulations, and digital image correlation recording full-field strains. The microstructures are characterised using optical and scanning electron microscopy and electron backscatter diffraction, and microhardness is mapped to microstructural phases. The results show that both steels show favourable stiffness properties and ductility with modest orientation-dependent anisotropy, where ultimate strength ratios across orientations are 0.95–1.00, and elongation ratios are 0.94–1.06. Most coefficients of variation for tensile strength and fracture elongation are found to be below 0.07, comparable to conventional steels. Dominant microstructural phases are shown to be uniformly distributed, with observed layer boundary regions in agreement with local microhardness. Relative to DED-Arc, DED-LB steels, especially for the high-strength grade, are shown to exhibit higher ductility with reduced orientation sensitivity while maintaining comparable strengths. Overall, the findings provide as-built dataset for informing wire-based process assessment and selection for civil engineering applications.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"953 ","pages":"Article 149777"},"PeriodicalIF":7.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-11DOI: 10.1016/j.msea.2026.149769
Peng Lyu , Lei Hao , Ken Deng , Shun Guo , Yu Liu , Xinlin Liu , Haixia Liu
In the present study, CoCrFeNiZrx (x = 0.1, 0.3, 0.5, 1) high-entropy alloys (HEAs) were successfully fabricated using vacuum arc melting. The effects of Zr content on the microstructure, mechanical properties, wear resistance, and corrosion behavior were systematically examined. With increasing Zr content, the phase structure of the alloys progressively evolved from a face-centered cubic (FCC) + Laves phase assemblage to a Laves + body-centered cubic (BCC) phase assemblage. This evolution was accompanied by a corresponding microstructural transformation from a dendritic structure to eutectic and hypereutectic morphologies. Mechanical property characterization revealed that the addition of Zr significantly improved the hardness and strength of the alloys through the combined effects of solid-solution strengthening, second-phase strengthening, and interfacial strengthening. Among these alloys, the CoCrFeNiZr0.3 alloy exhibited an optimal strength-plasticity balance. It showed yield and tensile strengths of 418 and 609 MPa, respectively, while retaining an elongation at break of 20.87 %. The CoCrFeNiZr1 alloy achieved the highest hardness of 897.54 HV. However, its ductility decreased drastically. As Zr content increased, the wear mechanism transitioned from abrasive wear to oxidative wear, resulting in a marked improvement in wear resistance. Electrochemical measurements revealed that Zr addition was negatively correlated with the corrosion resistance of the alloys. Nevertheless, all compositions except CoCrFeNiZr1 exhibited corrosion resistance superior to that of SS304 stainless steel. The present study clarified the mechanism by which Zr content modulated the microstructure of HEAs. As a result, a balance between optimized mechanical properties and corrosion resistance was achieved in these alloys.
{"title":"Correlation between microstructural regulation and material properties: Effects of Zr content on mechanical and corrosion behaviors of CoCrFeNi high-entropy alloy","authors":"Peng Lyu , Lei Hao , Ken Deng , Shun Guo , Yu Liu , Xinlin Liu , Haixia Liu","doi":"10.1016/j.msea.2026.149769","DOIUrl":"10.1016/j.msea.2026.149769","url":null,"abstract":"<div><div>In the present study, CoCrFeNiZr<sub><em>x</em></sub> (<em>x</em> = 0.1, 0.3, 0.5, 1) high-entropy alloys (HEAs) were successfully fabricated using vacuum arc melting. The effects of Zr content on the microstructure, mechanical properties, wear resistance, and corrosion behavior were systematically examined. With increasing Zr content, the phase structure of the alloys progressively evolved from a face-centered cubic (FCC) + Laves phase assemblage to a Laves + body-centered cubic (BCC) phase assemblage. This evolution was accompanied by a corresponding microstructural transformation from a dendritic structure to eutectic and hypereutectic morphologies. Mechanical property characterization revealed that the addition of Zr significantly improved the hardness and strength of the alloys through the combined effects of solid-solution strengthening, second-phase strengthening, and interfacial strengthening. Among these alloys, the CoCrFeNiZr<sub>0.3</sub> alloy exhibited an optimal strength-plasticity balance. It showed yield and tensile strengths of 418 and 609 MPa, respectively, while retaining an elongation at break of 20.87 %. The CoCrFeNiZr<sub>1</sub> alloy achieved the highest hardness of 897.54 HV. However, its ductility decreased drastically. As Zr content increased, the wear mechanism transitioned from abrasive wear to oxidative wear, resulting in a marked improvement in wear resistance. Electrochemical measurements revealed that Zr addition was negatively correlated with the corrosion resistance of the alloys. Nevertheless, all compositions except CoCrFeNiZr<sub>1</sub> exhibited corrosion resistance superior to that of SS304 stainless steel. The present study clarified the mechanism by which Zr content modulated the microstructure of HEAs. As a result, a balance between optimized mechanical properties and corrosion resistance was achieved in these alloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"953 ","pages":"Article 149769"},"PeriodicalIF":7.0,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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