Materials Science and Engineering: A最新文献_第6页

The investigation of high-temperature shear deformation mechanism in Ti-44Al-4Nb-1.5Mo-0.1B alloy Ti-44Al-4Nb-1.5Mo-0.1B合金高温剪切变形机理研究

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-10 DOI: 10.1016/j.msea.2025.148298

Siyuan Zhang , Haitao Jiang , Jiangping Xin , Yefei Zhang , Zhichao Zhu , Shiwei Tian

TiAl alloys are attractive as promising aerospace structural materials. The high-temperature deformation performance of the intermetallic can be enhanced through controlled thermal mechanical processing and microstructure. This study utilized shear compression specimen (SCS) to investigate the shear deformation on the deformability and microstructure of Ti-44Al-4Nb-1.5Mo-0.1B (TNM) alloy. The compression test demonstrates that, compared to traditional symmetric deformation, shear deformation exhibits several advantageous characteristics: a low deformation stress (109.8 MPa), a slow dynamic softening, a large deformation conditions, and a low activation energy (163.3 kJ/mol). The good thermal deformation properties are related to the microstructure. During the shear deformation process, microscale shear bands (MSBs) are gradually formed under the combined effect of elemental enrichment and lattice distortion as the force at the α₂/γ interface in the lamellae increases. The internal stress values of MSBs are 5–10 times greater than at a typical α₂/γ interface, which promotes the nucleation of dynamic recrystallization (DRX). The evolution of the structure can be classified into two types such as high temperature and low strain rate, as well as low temperature and high strain rate. Under high temperatures and low strain rates conditions, deformation was primarily occurring in DRX. Shear deformation not only activates dislocation slip but also significantly promotes the formation of nanotwins, which in turn facilitates the nucleation of DRX. Under low temperatures and high strain rates conditions, the MSBs, DRX, and broken lamellae work together to coordinate the deformation. In conclusion, shear deformation can improve the thermal processing performance of TNM alloys, which is an effective means of molding TNM alloys.

TiAl合金是一种极具发展前景的航天结构材料。通过控制热机械加工和显微组织，可以提高金属间化合物的高温变形性能。采用剪切压缩试样（SCS）研究了剪切变形对Ti-44Al-4Nb-1.5Mo-0.1B （TNM）合金变形性能和组织的影响。压缩试验表明，与传统的对称变形相比，剪切变形具有变形应力低（109.8 MPa）、动态软化慢、变形条件大、活化能低（163.3 kJ/mol）等优点。良好的热变形性能与微观组织有关。剪切变形过程中，随着片层α2/γ界面作用力的增大，在元素富集和晶格畸变的共同作用下，逐渐形成微尺度剪切带。msb的内应力值是典型α2/γ界面的5 ~ 10倍，促进了动态再结晶（DRX）的成核。结构的演化可分为高温低应变速率和低温高应变速率两种类型。在高温和低应变率条件下，变形主要发生在DRX中。剪切变形不仅激活了位错滑移，而且显著促进了纳米孪晶的形成，从而促进了DRX的形核。在低温和高应变率条件下，msb、DRX和破碎片共同协调变形。综上所述，剪切变形可以改善TNM合金的热加工性能，是TNM合金成型的有效手段。

{"title":"The investigation of high-temperature shear deformation mechanism in Ti-44Al-4Nb-1.5Mo-0.1B alloy","authors":"Siyuan Zhang , Haitao Jiang , Jiangping Xin , Yefei Zhang , Zhichao Zhu , Shiwei Tian","doi":"10.1016/j.msea.2025.148298","DOIUrl":"10.1016/j.msea.2025.148298","url":null,"abstract":"<div><div>TiAl alloys are attractive as promising aerospace structural materials. The high-temperature deformation performance of the intermetallic can be enhanced through controlled thermal mechanical processing and microstructure. This study utilized shear compression specimen (SCS) to investigate the shear deformation on the deformability and microstructure of Ti-44Al-4Nb-1.5Mo-0.1B (TNM) alloy. The compression test demonstrates that, compared to traditional symmetric deformation, shear deformation exhibits several advantageous characteristics: a low deformation stress (109.8 MPa), a slow dynamic softening, a large deformation conditions, and a low activation energy (163.3 kJ/mol). The good thermal deformation properties are related to the microstructure. During the shear deformation process, microscale shear bands (MSBs) are gradually formed under the combined effect of elemental enrichment and lattice distortion as the force at the α<sub>2</sub>/γ interface in the lamellae increases. The internal stress values of MSBs are 5–10 times greater than at a typical α<sub>2</sub>/γ interface, which promotes the nucleation of dynamic recrystallization (DRX). The evolution of the structure can be classified into two types such as high temperature and low strain rate, as well as low temperature and high strain rate. Under high temperatures and low strain rates conditions, deformation was primarily occurring in DRX. Shear deformation not only activates dislocation slip but also significantly promotes the formation of nanotwins, which in turn facilitates the nucleation of DRX. Under low temperatures and high strain rates conditions, the MSBs, DRX, and broken lamellae work together to coordinate the deformation. In conclusion, shear deformation can improve the thermal processing performance of TNM alloys, which is an effective means of molding TNM alloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"934 ","pages":"Article 148298"},"PeriodicalIF":6.1,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828991","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}

引用次数: 0

Deformability enhancement of rare earth magnesium alloy during electroplastic rolling 稀土镁合金电塑性轧制变形性能的提高

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-09 DOI: 10.1016/j.msea.2025.148325

Di Wang , Shuyang Qin , Chaoran Guo , Hao Chen , Lingkun Xiao , Weijie Ren , Jingna Sun , Pengfei Wang , Luhan Hao , Huagui Huang

The rare earth magnesium alloys present poor deformability because of fewer slip systems and RE elements addition, which is manifested as edge cracks during hot rolling. Here it was found that applied pulsed current during rolling for Mg-13Gd-4Y-2Zn-0.5Zr rare earth magnesium alloy can effectively inhibit the generation of edge cracks. By comparing the number of macroscopic cracks around the hot and electroplastic rolled samples with the same initial rolling temperature (380 °C) and different reductions (30 %, 35 %, 40 %), the results showed the pure electric effect presents a senior enhancement on deformability of material, because the dislocation density and texture intensity can be decreased during electroplastic rolling. Meanwhile, the number of macroscopic edge cracks of the rolled plate is reduced from 38 of hot rolling (30 % reduction) to 0 of electroplastic rolling (30 % reduction), indicating that the deformability is improved. Besides, the intergranular W phases were basically dissolved, and the block-shaped Long-Period Stacking Ordered (LPSO) phases can be transferred to the lamellar ones. The grain size of the electroplastic rolling samples present finer than that of the hot rolling, because of the accelerated dynamic recrystallization.

稀土镁合金由于滑移体系较少和添加了 RE 元素，因此变形能力较差，在热轧过程中表现为边缘裂纹。研究发现，在 Mg-13Gd-4Y-2Zn-0.5Zr 稀土镁合金的轧制过程中施加脉冲电流可有效抑制边缘裂纹的产生。通过比较相同初始轧制温度（380 °C）和不同减薄率（30%、35%、40%）的热轧和电塑性轧制样品周围的宏观裂纹数量，结果表明纯电效应对材料的变形性有较高的增强作用，因为在电塑性轧制过程中位错密度和纹理强度会降低。同时，轧制板材的宏观边缘裂纹数量从热轧的 38 条（减少了 30%）减少到电塑性轧制的 0 条（减少了 30%），这表明材料的变形性得到了改善。此外，晶间 W 相基本溶解，块状长周期堆积有序相（LPSO）可以转移到片状相中。由于加速了动态再结晶，电塑性轧制样品的晶粒尺寸比热轧样品更细。

{"title":"Deformability enhancement of rare earth magnesium alloy during electroplastic rolling","authors":"Di Wang , Shuyang Qin , Chaoran Guo , Hao Chen , Lingkun Xiao , Weijie Ren , Jingna Sun , Pengfei Wang , Luhan Hao , Huagui Huang","doi":"10.1016/j.msea.2025.148325","DOIUrl":"10.1016/j.msea.2025.148325","url":null,"abstract":"<div><div>The rare earth magnesium alloys present poor deformability because of fewer slip systems and RE elements addition, which is manifested as edge cracks during hot rolling. Here it was found that applied pulsed current during rolling for Mg-13Gd-4Y-2Zn-0.5Zr rare earth magnesium alloy can effectively inhibit the generation of edge cracks. By comparing the number of macroscopic cracks around the hot and electroplastic rolled samples with the same initial rolling temperature (380 °C) and different reductions (30 %, 35 %, 40 %), the results showed the pure electric effect presents a senior enhancement on deformability of material, because the dislocation density and texture intensity can be decreased during electroplastic rolling. Meanwhile, the number of macroscopic edge cracks of the rolled plate is reduced from 38 of hot rolling (30 % reduction) to 0 of electroplastic rolling (30 % reduction), indicating that the deformability is improved. Besides, the intergranular W phases were basically dissolved, and the block-shaped Long-Period Stacking Ordered (LPSO) phases can be transferred to the lamellar ones. The grain size of the electroplastic rolling samples present finer than that of the hot rolling, because of the accelerated dynamic recrystallization.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"934 ","pages":"Article 148325"},"PeriodicalIF":6.1,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823522","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}

引用次数: 0

Effects of Cu additions on microstructures and mechanical properties of Al0.1CoCrFeNiCux high-entropy alloys Cu添加量对Al0.1CoCrFeNiCux高熵合金组织和力学性能的影响

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-09 DOI: 10.1016/j.msea.2025.148280

Q.K. Wang , L.F. Tang , Y.L. Bian , Meraj Majeed , H.W. Tang , Y. Cai , N.B. Zhang , L. Lu , S.N. Luo

The effects of Cu additions on microstructure evolution and mechanical properties of Al_0.1CoCrFeNiCu_x (x = 0, 0.1, 0.3, 0.5) high entropy alloys (HEA) prepared via the arc melting technique over a wide temperature range are investigated. The initial and postmortem samples are characterized by X-ray diffraction, scanning electron microscopy, electron backscatter diffraction, energy dispersive spectroscopy and transmission electron microscopy. The results indicate that with the increase of Cu content, the number of Cu-rich precipitates increases, and these Cu-rich precipitates share coherent interfaces with the matrix. Quasi-static tension tests reveal that the yield strength of Al_0.1CoCrFeNiCu_x alloy is enhanced at lower temperatures or with higher Cu contents. Given the structure-based strength model, the improvement can be attributed to precipitation strengthening of uniformly dispersed nano-size Cu-rich precipitates. All alloys exhibit simultaneous superior strength and ductility at low temperatures. The investigation reveals multiple deformation mechanisms in Al_0.1CoCrFeNiCu_x alloys with different Cu contents subjected to different degrees of deformation at different temperatures. Both Cu-rich precipitates and higher temperatures suppress the activation of deformation twinning. Dislocations, stacking faults, immobile Lomer-Cottrell locks, kink bands and deformation twins are found in Al_0.1CoCrFeNiCu_0.1 alloy at 123 K, in contrast with only dislocations in Al_0.1CoCrFeNiCu_0.5 alloy at 673 K.

研究了Cu添加量对宽温度弧熔法制备Al0.1CoCrFeNiCux （x = 0,0.1, 0.3, 0.5）高熵合金（HEA）组织演变和力学性能的影响。通过x射线衍射、扫描电镜、电子背散射衍射、能量色散光谱和透射电镜对样品进行了表征。结果表明：随着Cu含量的增加，富Cu析出相数量增加，且富Cu析出相与基体具有共格界面；准静态拉伸试验表明，Al0.1CoCrFeNiCux合金的屈服强度在较低温度和较高Cu含量下得到增强。在基于结构的强度模型中，这种改善可归因于均匀分散的纳米级富cu析出物的沉淀强化。所有合金在低温下同时表现出优异的强度和延展性。研究发现，不同Cu含量的Al0.1CoCrFeNiCux合金在不同温度下发生不同程度的变形时，存在多种变形机制。富cu析出相和较高温度均抑制变形孪晶的激活。Al0.1CoCrFeNiCu0.1合金在123 K时存在位错、层错、不移动的lmer - cottrell锁、结带和变形孪晶，而Al0.1CoCrFeNiCu0.5合金在673 K时只有位错。

{"title":"Effects of Cu additions on microstructures and mechanical properties of Al0.1CoCrFeNiCux high-entropy alloys","authors":"Q.K. Wang , L.F. Tang , Y.L. Bian , Meraj Majeed , H.W. Tang , Y. Cai , N.B. Zhang , L. Lu , S.N. Luo","doi":"10.1016/j.msea.2025.148280","DOIUrl":"10.1016/j.msea.2025.148280","url":null,"abstract":"<div><div>The effects of Cu additions on microstructure evolution and mechanical properties of Al<sub>0.1</sub>CoCrFeNiCu<sub><em>x</em></sub> (<em>x</em> = 0, 0.1, 0.3, 0.5) high entropy alloys (HEA) prepared via the arc melting technique over a wide temperature range are investigated. The initial and postmortem samples are characterized by X-ray diffraction, scanning electron microscopy, electron backscatter diffraction, energy dispersive spectroscopy and transmission electron microscopy. The results indicate that with the increase of Cu content, the number of Cu-rich precipitates increases, and these Cu-rich precipitates share coherent interfaces with the matrix. Quasi-static tension tests reveal that the yield strength of Al<sub>0.1</sub>CoCrFeNiCu<sub><em>x</em></sub> alloy is enhanced at lower temperatures or with higher Cu contents. Given the structure-based strength model, the improvement can be attributed to precipitation strengthening of uniformly dispersed nano-size Cu-rich precipitates. All alloys exhibit simultaneous superior strength and ductility at low temperatures. The investigation reveals multiple deformation mechanisms in Al<sub>0.1</sub>CoCrFeNiCu<sub><em>x</em></sub> alloys with different Cu contents subjected to different degrees of deformation at different temperatures. Both Cu-rich precipitates and higher temperatures suppress the activation of deformation twinning. Dislocations, stacking faults, immobile Lomer-Cottrell locks, kink bands and deformation twins are found in Al<sub>0.1</sub>CoCrFeNiCu<sub>0.1</sub> alloy at 123 K, in contrast with only dislocations in Al<sub>0.1</sub>CoCrFeNiCu<sub>0.5</sub> alloy at 673 K.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"934 ","pages":"Article 148280"},"PeriodicalIF":6.1,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823523","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}

引用次数: 0

The microstructure and precipitation analysis of the Cu-Ni-Fe-P alloy with high property 高性能Cu-Ni-Fe-P合金的显微组织及析出分析

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-09 DOI: 10.1016/j.msea.2025.148309

Jianguo Cui , Rui Zhou , Wendi Yang , Weilin Gao , Yang Song , Jilin He

This article systematically investigated the aging behavior and precipitation of Cu-Ni-P, Cu-Fe-P and Cu-Ni-Fe-P alloys. The results showed that the novel quaternary Cu-Ni-Fe-P alloy designed based on ternary Cu-Ni-P alloy and ternary Cu-Fe-P alloy had the superior properties. The electrical conductivity and tensile strength reached 69.1 %IACS and 658.7 MPa, respectively, by the process (solution treatment + 30 % cold rolling reduction + pre-aging (750 °C × 1 min) + 30 % cold rolling reduction + aging (450 °C × 4 h) + 60 % cold rolling reduction + annealing (450 °C × 1 min)). The nanoscale precipitation (Ni, Fe)₂P was a hexagonal structure in Cu-Ni-Fe-P alloy. The orientation relationship between the (Ni, Fe)₂P precipitation and the matrix was [110]_Cu//[111]_{(Ni, Fe)2P}, (1-1-1)_Cu//(1–21) (_{Ni, Fe)2P}. The synergistic effect of Ni and Fe atoms facilitated the precipitation of more uniform and fine phases, effectively enhancing the overall performance of NFP alloy. The synergistic contribution of dislocation strengthening and precipitation strengthening mainly driven the yield strength of alloys and were the major strengthening mechanism. The contribution of the precipitation strengthening in NFP alloy was significantly greater than that in NP and FP alloys. That was the reason for the increased strength of NFP alloy. This work indicates that the Cu-Ni-Fe-P alloy is a promising candidate for high property Cu alloys.

本文系统地研究了Cu-Ni-P、Cu-Fe-P和Cu-Ni-Fe-P合金的时效行为和析出。结果表明，基于三元Cu-Ni-P合金和三元Cu-Fe-P合金设计的新型四元Cu-Ni-Fe-P合金具有优异的性能。经固溶处理+ 30%冷轧压下+预时效（750℃× 1 min） + 30%冷轧压下+时效（450℃× 4 h） + 60%冷轧压下+退火（450℃× 1 min）处理，其电导率和抗拉强度分别达到69.1% IACS和658.7 MPa。Cu-Ni-Fe-P合金中纳米级析出（Ni, Fe）2P为六角形结构。（Ni, Fe）2P析出与基体的取向关系为[110]Cu//[111](Ni, Fe)2P, (1-1-1)Cu//(1-21) (Ni, Fe)2P。Ni和Fe原子的协同作用有利于析出更均匀、更细的相，有效地提高了NFP合金的整体性能。位错强化和析出强化的协同作用主要驱动合金的屈服强度，是合金屈服强度的主要强化机制。NFP合金中析出强化的贡献显著大于NP和FP合金。这是NFP合金强度提高的原因。这表明Cu- ni - fe - p合金是一种很有前途的高性能Cu合金。

{"title":"The microstructure and precipitation analysis of the Cu-Ni-Fe-P alloy with high property","authors":"Jianguo Cui , Rui Zhou , Wendi Yang , Weilin Gao , Yang Song , Jilin He","doi":"10.1016/j.msea.2025.148309","DOIUrl":"10.1016/j.msea.2025.148309","url":null,"abstract":"<div><div>This article systematically investigated the aging behavior and precipitation of Cu-Ni-P, Cu-Fe-P and Cu-Ni-Fe-P alloys. The results showed that the novel quaternary Cu-Ni-Fe-P alloy designed based on ternary Cu-Ni-P alloy and ternary Cu-Fe-P alloy had the superior properties. The electrical conductivity and tensile strength reached 69.1 %IACS and 658.7 MPa, respectively, by the process (solution treatment + 30 % cold rolling reduction + pre-aging (750 °C × 1 min) + 30 % cold rolling reduction + aging (450 °C × 4 h) + 60 % cold rolling reduction + annealing (450 °C × 1 min)). The nanoscale precipitation (Ni, Fe)<sub>2</sub>P was a hexagonal structure in Cu-Ni-Fe-P alloy. The orientation relationship between the (Ni, Fe)<sub>2</sub>P precipitation and the matrix was [110]<sub>Cu</sub>//[111]<sub>(Ni, Fe)2P</sub>, (1-1-1)<sub>Cu</sub>//(1–21) (<sub>Ni, Fe)2P</sub>. The synergistic effect of Ni and Fe atoms facilitated the precipitation of more uniform and fine phases, effectively enhancing the overall performance of NFP alloy. The synergistic contribution of dislocation strengthening and precipitation strengthening mainly driven the yield strength of alloys and were the major strengthening mechanism. The contribution of the precipitation strengthening in NFP alloy was significantly greater than that in NP and FP alloys. That was the reason for the increased strength of NFP alloy. This work indicates that the Cu-Ni-Fe-P alloy is a promising candidate for high property Cu alloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"934 ","pages":"Article 148309"},"PeriodicalIF":6.1,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820942","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}

引用次数: 0

Review of plastic deformation mechanisms and crystal plasticity modelling of uranium 铀的塑性变形机理及晶体塑性模型研究进展

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-09 DOI: 10.1016/j.msea.2025.148324

Sheng Zhang, Fan Liu, Dongli Zou, Shushan Cui, Mengsheng Zhai, Wenliang Xu, Chuan Mo, Shilv Yu, Lifeng He, Dawu Xiao, Bin Su

Uranium (U) and its alloys are not only critical energy materials but also serve as important structural materials in the nuclear industry due to their high density and favorable ductility. This work conducts a review on reported plastic deformation mechanisms of uranium for studies carried out dating back to the 1950s. Uranium exhibits three polymorphic phases from low temperature to its melting point at 1132 °C: the base-centered orthorhombic phase (α), the tetragonal phase (β), and the body-centered cubic (BCC) phase (γ). This review focuses on deformation mechanisms of α-U since α-U has been extensively studied while researches on deformation mechanisms of β-U and γ-U are limited. The introduced deformation mechanisms include dislocation slip, deformation twinning, and shear localization. Parameters that affect the deformation mechanisms such as strain rate, temperature, and microstructure are discussed separately. As crystal plasticity modelling is an effective method to quantify the contributions of various deformation mechanisms, advancements in crystal plasticity modelling of uranium are also reviewed. Finally, this review summarizes the current state of knowledge regarding the plastic deformation mechanisms of uranium and proposes future research pathways.

铀及其合金不仅是重要的能源材料，而且由于其高密度和良好的延展性，在核工业中也是重要的结构材料。本工作回顾了自20世纪50年代以来铀的塑性变形机制的研究。从低温到熔点1132℃，铀呈现出三种多晶相：碱心正交相（α）、四方相（β）和体心立方相（γ）。α-U的变形机理研究比较广泛，而β-U和γ-U的变形机理研究比较有限，本文主要对α-U的变形机理进行综述。引入的变形机制包括位错滑移、变形孪晶和剪切局部化。分别讨论了影响变形机制的参数，如应变速率、温度和显微组织。由于晶体塑性建模是一种量化各种变形机制贡献的有效方法，本文对铀晶体塑性建模的研究进展进行了综述。最后，对铀塑性变形机理的研究现状进行了总结，并提出了今后的研究方向。

{"title":"Review of plastic deformation mechanisms and crystal plasticity modelling of uranium","authors":"Sheng Zhang, Fan Liu, Dongli Zou, Shushan Cui, Mengsheng Zhai, Wenliang Xu, Chuan Mo, Shilv Yu, Lifeng He, Dawu Xiao, Bin Su","doi":"10.1016/j.msea.2025.148324","DOIUrl":"10.1016/j.msea.2025.148324","url":null,"abstract":"<div><div>Uranium (U) and its alloys are not only critical energy materials but also serve as important structural materials in the nuclear industry due to their high density and favorable ductility. This work conducts a review on reported plastic deformation mechanisms of uranium for studies carried out dating back to the 1950s. Uranium exhibits three polymorphic phases from low temperature to its melting point at 1132 °C: the base-centered orthorhombic phase (α), the tetragonal phase (β), and the body-centered cubic (BCC) phase (γ). This review focuses on deformation mechanisms of α-U since α-U has been extensively studied while researches on deformation mechanisms of β-U and γ-U are limited. The introduced deformation mechanisms include dislocation slip, deformation twinning, and shear localization. Parameters that affect the deformation mechanisms such as strain rate, temperature, and microstructure are discussed separately. As crystal plasticity modelling is an effective method to quantify the contributions of various deformation mechanisms, advancements in crystal plasticity modelling of uranium are also reviewed. Finally, this review summarizes the current state of knowledge regarding the plastic deformation mechanisms of uranium and proposes future research pathways.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"934 ","pages":"Article 148324"},"PeriodicalIF":6.1,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143825805","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}

引用次数: 0

Precipitation and strengthening behavior of η phase in polycrystalline Ni-based superalloy 多晶镍基高温合金中η相的析出与强化行为

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-09 DOI: 10.1016/j.msea.2025.148302

Leilei Zhang , Qing Yang , Jingyang Chen , Qing Li , Jinbin Chen , Mingjun Zhang , Chengbo Xiao

η phase has the potential to strengthen the alloy at high temperatures due to their stability compared to γ′ phase. Recently, the role of η phase with needle-like shape in creep resistance is insufficient studied. Moreover, the common effect of Ti/Al ratio and C content on microstructure and creep resistance in Ni-based superalloys is rarely investigated. The microstructure, particularly η phase precipitation and its role in 815 °C/379 MPa creep property for polycrystalline Ni-based superalloy were investigated by changing Ti/Al ratio and the C content in this research. The spherical γ′ phase evenly distributes within γ matrix of low Ti/Al ratio alloy. The size and volume fraction of γ′ phase slightly decrease in high Ti/Al ratio alloy, and η phase precipitates in the alloy. The creep life of the alloy has increased by 46.4 %. The crystallographic relationships are observed as (3

\overline{3} \overline{3}

)M₂₃C₆//(004)η and (1

\overline{1} \overline{1}

)γ′//(004)η, with the lattice misfits of 1.27 ± 0.05 % and 0.28 ± 0.03 %, respectively. The increased C content results in a reduction of η phase and a slight decrease in creep life of high Ti/Al ratio and C content alloy. γ′ phase impedes dislocation motion through coherency strengthening, order strengthening and Orowan bypass mechanisms. Additionally, the bent η phase occurs during creep deformation and coordinately deforms with γ matrix, γ′ phase layer could impede dislocation motion and buffer stress fluctuation to a certain extent. The specific crystallographic relationship between M₂₃C₆ carbide and η phase leads to the localized strengthening. The stress increment induced by η phase is decreased from 242.8 MPa to 52.2 MPa with the volume fraction of η phase decreasing from 0.98 ± 0.05 % to 0.21 ± 0.04 %.

与 γ′ 相相比，η 相具有稳定性，因此具有在高温下强化合金的潜力。最近，对具有针状形状的 η 相在抗蠕变性中的作用研究不足。此外，Ti/Al 比和 C 含量对 Ni 基超合金微观结构和抗蠕变性的共同影响也很少被研究。本研究通过改变 Ti/Al 比和 C 含量，研究了多晶镍基超合金的微观结构，尤其是 η 相析出及其在 815 °C/379 MPa 蠕变性能中的作用。在低 Ti/Al 比合金中，球形 γ′ 相均匀分布在 γ 基体中。在高 Ti/Al 比合金中，γ′相的尺寸和体积分数略有下降，合金中析出了 η 相。合金的蠕变寿命提高了 46.4%。晶体学关系观察到(3 3‾3‾)M23C6//(004)η和(1 1‾1‾)γ′//(004)η，晶格错位分别为 1.27 ± 0.05 %和 0.28 ± 0.03 %。C 含量的增加导致了 η 相的减少，并使高 Ti/Al 比和 C 含量合金的蠕变寿命略有下降。γ′相通过一致性强化、阶次强化和奥罗万旁路机制阻碍位错运动。此外，η相在蠕变变形过程中发生弯曲，并与γ基体发生协调变形，γ′相层可在一定程度上阻碍位错运动并缓冲应力波动。M23C6 碳化物与 η 相之间的特殊晶体学关系导致了局部强化。随着η相体积分数从 0.98 ± 0.05 % 降至 0.21 ± 0.04 %，η相诱导的应力增量从 242.8 MPa 降至 52.2 MPa。

{"title":"Precipitation and strengthening behavior of η phase in polycrystalline Ni-based superalloy","authors":"Leilei Zhang , Qing Yang , Jingyang Chen , Qing Li , Jinbin Chen , Mingjun Zhang , Chengbo Xiao","doi":"10.1016/j.msea.2025.148302","DOIUrl":"10.1016/j.msea.2025.148302","url":null,"abstract":"<div><div>η phase has the potential to strengthen the alloy at high temperatures due to their stability compared to γ′ phase. Recently, the role of η phase with needle-like shape in creep resistance is insufficient studied. Moreover, the common effect of Ti/Al ratio and C content on microstructure and creep resistance in Ni-based superalloys is rarely investigated. The microstructure, particularly η phase precipitation and its role in 815 °C/379 MPa creep property for polycrystalline Ni-based superalloy were investigated by changing Ti/Al ratio and the C content in this research. The spherical γ′ phase evenly distributes within γ matrix of low Ti/Al ratio alloy. The size and volume fraction of γ′ phase slightly decrease in high Ti/Al ratio alloy, and η phase precipitates in the alloy. The creep life of the alloy has increased by 46.4 %. The crystallographic relationships are observed as (3 <span><math><mrow><mover><mn>3</mn><mo>‾</mo></mover><mover><mn>3</mn><mo>‾</mo></mover></mrow></math></span>)M<sub>23</sub>C<sub>6</sub>//(004)η and (1 <span><math><mrow><mover><mn>1</mn><mo>‾</mo></mover><mover><mn>1</mn><mo>‾</mo></mover></mrow></math></span>)γ′//(004)η, with the lattice misfits of 1.27 ± 0.05 % and 0.28 ± 0.03 %, respectively. The increased C content results in a reduction of η phase and a slight decrease in creep life of high Ti/Al ratio and C content alloy. γ′ phase impedes dislocation motion through coherency strengthening, order strengthening and Orowan bypass mechanisms. Additionally, the bent η phase occurs during creep deformation and coordinately deforms with γ matrix, γ′ phase layer could impede dislocation motion and buffer stress fluctuation to a certain extent. The specific crystallographic relationship between M<sub>23</sub>C<sub>6</sub> carbide and η phase leads to the localized strengthening. The stress increment induced by η phase is decreased from 242.8 MPa to 52.2 MPa with the volume fraction of η phase decreasing from 0.98 ± 0.05 % to 0.21 ± 0.04 %.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"933 ","pages":"Article 148302"},"PeriodicalIF":6.1,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820414","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}

引用次数: 0

Reducing plastic anisotropy through stress induced martensitic transformation in an additively manufactured metastable medium entropy alloy 增材制造亚稳介质熵合金中通过应力诱导马氏体相变降低塑性各向异性

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-08 DOI: 10.1016/j.msea.2025.148308

Sri Bala Aditya Malladi , Tatiana Mishurova , Vishnu Anilkumar , Bharat Mehta , Alexander Evans , Kumar Babu Surreddi , Malte Blankenburg , Ulrich Lienert , Giovanni Bruno , Sheng Guo , Lars Nyborg

Powder bed fusion laser beam (PBF-LB) is particularly effective for fabricating compositionally complex alloys such as high-entropy alloys (HEAs) or medium-entropy alloys (MEAs). Fabricating non-equiatomic metastable MEAs using PBF-LB can lead to the formation of unique microstructures that enhance the mechanical performance of these alloys. Nevertheless, plastic anisotropy in materials prepared by additive manufacturing routes including PBF-LB remains to be a technical challenge. This work presents the fabrication of a metastable non-equiatomic Co₄₅Cr₂₅(FeNi)₃₀ MEA using PBF-LB. As-printed samples exhibited the formation of nano-scaled ε-martensite (HCP) phase along with the FCC phase. The HCP phase exhibited Shoji-Nishiyama orientation relationship with the FCC phase. High energy synchrotron X-ray diffraction (HEXRD) and electron backscatter diffraction (EBSD) in-situ tensile testing were employed to investigate the influence of the HCP phase on the alloy's deformation behavior. The presence of the HCP phase initiates stress-induced martensitic transformation well below the macroscopic yield strength. This transformation led to the non-linear stress and strain response for the FCC phase. Further straining resulted in significant load partitioning, with the HCP phase taking the majority of the load as it formed, significantly strain hardening the alloy and reducing the plastic anisotropy induced by texture in the as-printed material.

粉末床熔合激光束（PBF-LB）对于制造成分复杂的合金，如高熵合金（HEAs）或中熵合金（MEAs）特别有效。利用PBF-LB制备非等原子亚稳态MEAs可以形成独特的微观结构，从而提高这些合金的机械性能。然而，包括PBF-LB在内的增材制造路线制备的材料的塑性各向异性仍然是一个技术挑战。本文介绍了利用PBF-LB制备亚稳态非等原子Co45Cr25(FeNi)30 MEA的方法。随着FCC相的形成，印刷样品中出现了纳米级ε-马氏体（HCP）相。HCP相与FCC相呈Shoji-Nishiyama取向关系。采用高能同步x射线衍射（HEXRD）和电子背散射衍射（EBSD）原位拉伸试验研究了HCP相对合金变形行为的影响。HCP相的存在导致应力诱导马氏体转变，远低于宏观屈服强度。这种转变导致了FCC阶段的非线性应力应变响应。进一步的拉伸导致了显著的载荷分配，HCP相在形成时承担了大部分载荷，显著地使合金应变硬化，并降低了打印材料中织构引起的塑性各向异性。

{"title":"Reducing plastic anisotropy through stress induced martensitic transformation in an additively manufactured metastable medium entropy alloy","authors":"Sri Bala Aditya Malladi , Tatiana Mishurova , Vishnu Anilkumar , Bharat Mehta , Alexander Evans , Kumar Babu Surreddi , Malte Blankenburg , Ulrich Lienert , Giovanni Bruno , Sheng Guo , Lars Nyborg","doi":"10.1016/j.msea.2025.148308","DOIUrl":"10.1016/j.msea.2025.148308","url":null,"abstract":"<div><div>Powder bed fusion laser beam (PBF-LB) is particularly effective for fabricating compositionally complex alloys such as high-entropy alloys (HEAs) or medium-entropy alloys (MEAs). Fabricating non-equiatomic metastable MEAs using PBF-LB can lead to the formation of unique microstructures that enhance the mechanical performance of these alloys. Nevertheless, plastic anisotropy in materials prepared by additive manufacturing routes including PBF-LB remains to be a technical challenge. This work presents the fabrication of a metastable non-equiatomic Co<sub>45</sub>Cr<sub>25</sub>(FeNi)<sub>30</sub> MEA using PBF-LB. As-printed samples exhibited the formation of nano-scaled ε-martensite (HCP) phase along with the FCC phase. The HCP phase exhibited Shoji-Nishiyama orientation relationship with the FCC phase. High energy synchrotron X-ray diffraction (HEXRD) and electron backscatter diffraction (EBSD) in-situ tensile testing were employed to investigate the influence of the HCP phase on the alloy's deformation behavior. The presence of the HCP phase initiates stress-induced martensitic transformation well below the macroscopic yield strength. This transformation led to the non-linear stress and strain response for the FCC phase. Further straining resulted in significant load partitioning, with the HCP phase taking the majority of the load as it formed, significantly strain hardening the alloy and reducing the plastic anisotropy induced by texture in the as-printed material.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"933 ","pages":"Article 148308"},"PeriodicalIF":6.1,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814990","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}

引用次数: 0

Effect of Si addition on the microstructure and mechanical properties of a Cu-Cr-Ag alloy with high strength and electrical conductivity Si对高强高导电性Cu-Cr-Ag合金组织和力学性能的影响

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-08 DOI: 10.1016/j.msea.2025.148310

Shuang Zhou , Qian Lei , Jie Yin , Wen Liu , Xiang Yan , Hailong Hu , Xinde Mo , Tiansheng Wei , Jinyi Wang

The high-temperature mechanical properties of Cu-Cr alloys were limited, while adding alloying elements could inhibit the coarsening of Cr precipitates and improve the high-temperature mechanical properties. The Cu-Cr-Ag and Cu-Cr-Ag-Si alloys were designed and fabricated, and their microstructure and mechanical properties were investigated to achieve high-strength and high-electrical-conductivity copper alloys. The Cu-Cr-Ag alloy treated by two-step cold rolling and aging treatment achieved an ultimate tensile strength of 620 MPa, yield strength of 600 MPa, electrical conductivity of 85.6 % IACS, and elongation of 15.7 %. Adding Si increased the high-temperature strength, room-temperature elongation, and low-temperature elongation of the Cu-Cr-Ag alloy, while decreasing the electrical conductivity, room-temperature strength, and high-temperature elongation. Nanoscale Cr particles were detected in the Cu-Cr-Ag alloy, while nanoscale Cr and Cr₃Si particles co-existed in the Cu-Cr-Ag-Si alloy, among which Cr particles were the main strengthening precipitates. The curves of precipitation kinetics indicated that adding Si promoted the precipitation in the Cu-Cr-Ag alloy. Low-, room-, and high-temperature mechanical properties measurements showed that the strength variation depended on the average size of the main precipitates. The decrease in the high-temperature strength was attributed to the coarsening of the Cr precipitates. At low temperature, the average size of the precipitates was essentially the same as that at room temperature, thus the low-temperature strength was comparable to the room-temperature strength. These findings indicated that Cu-Cr-Ag and Cu-Cr-Ag-Si alloys would exhibit superior electrical and mechanical properties.

Cu-Cr合金的高温力学性能受到限制，而添加合金元素可以抑制Cr析出相的粗化，提高合金的高温力学性能。设计和制备了Cu-Cr-Ag和Cu-Cr-Ag- si合金，并对其组织和力学性能进行了研究，以实现高强高导电性铜合金。经两步冷轧时效处理的Cu-Cr-Ag合金抗拉强度为620 MPa，屈服强度为600 MPa，电导率为85.6%，延伸率为15.7%。添加Si提高了Cu-Cr-Ag合金的高温强度、室温伸长率和低温伸长率，但降低了合金的电导率、室温强度和高温伸长率。Cu-Cr-Ag合金中存在纳米级Cr颗粒，Cu-Cr-Ag- si合金中存在纳米级Cr和Cr3Si颗粒，其中Cr颗粒是主要的强化相。析出动力学曲线表明，Si的加入促进了Cu-Cr-Ag合金的析出。低温、室温和高温力学性能测量表明，强度变化取决于主要析出物的平均尺寸。高温强度的降低主要是由于Cr析出物的粗化所致。在低温下，析出相的平均尺寸与室温下基本相同，因此低温强度与室温强度相当。这些结果表明，Cu-Cr-Ag和Cu-Cr-Ag- si合金具有优异的电学和力学性能。

{"title":"Effect of Si addition on the microstructure and mechanical properties of a Cu-Cr-Ag alloy with high strength and electrical conductivity","authors":"Shuang Zhou , Qian Lei , Jie Yin , Wen Liu , Xiang Yan , Hailong Hu , Xinde Mo , Tiansheng Wei , Jinyi Wang","doi":"10.1016/j.msea.2025.148310","DOIUrl":"10.1016/j.msea.2025.148310","url":null,"abstract":"<div><div>The high-temperature mechanical properties of Cu-Cr alloys were limited, while adding alloying elements could inhibit the coarsening of Cr precipitates and improve the high-temperature mechanical properties. The Cu-Cr-Ag and Cu-Cr-Ag-Si alloys were designed and fabricated, and their microstructure and mechanical properties were investigated to achieve high-strength and high-electrical-conductivity copper alloys. The Cu-Cr-Ag alloy treated by two-step cold rolling and aging treatment achieved an ultimate tensile strength of 620 MPa, yield strength of 600 MPa, electrical conductivity of 85.6 % IACS, and elongation of 15.7 %. Adding Si increased the high-temperature strength, room-temperature elongation, and low-temperature elongation of the Cu-Cr-Ag alloy, while decreasing the electrical conductivity, room-temperature strength, and high-temperature elongation. Nanoscale Cr particles were detected in the Cu-Cr-Ag alloy, while nanoscale Cr and Cr<sub>3</sub>Si particles co-existed in the Cu-Cr-Ag-Si alloy, among which Cr particles were the main strengthening precipitates. The curves of precipitation kinetics indicated that adding Si promoted the precipitation in the Cu-Cr-Ag alloy. Low-, room-, and high-temperature mechanical properties measurements showed that the strength variation depended on the average size of the main precipitates. The decrease in the high-temperature strength was attributed to the coarsening of the Cr precipitates. At low temperature, the average size of the precipitates was essentially the same as that at room temperature, thus the low-temperature strength was comparable to the room-temperature strength. These findings indicated that Cu-Cr-Ag and Cu-Cr-Ag-Si alloys would exhibit superior electrical and mechanical properties.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"934 ","pages":"Article 148310"},"PeriodicalIF":6.1,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850790","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}

引用次数: 0

Microstructural evolution and mechanical enhancement of Co-free AlCrFeNi3 eutectic medium entropy alloy via heat treatment after selective laser melting AlCrFeNi3共晶中熵合金选择性激光熔化后热处理的显微组织演变及力学增强

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-08 DOI: 10.1016/j.msea.2025.148307

Yong Dong , Huimin Gu , Chenglin Hou , Qian Zhang , Dongmei Miao , Shougang Duan

The as-printed Co-free AlCrFeNi₃ eutectic medium entropy alloy (EMEA) was fabricated by selective laser melting (SLM). Heat treatment as a post processing was used to improve the mechanical properties of the as-printed samples, which were subjected to solid solution treatment at 400 °C–1200 °C for 1 h in this work. The microstructure and mechanical properties of the as-printed and heat-treated samples were examined in detail. No visible cracks and pores were found in the as-printed samples and the highest relative density is up to 99.57 %. The as-printed AlCrFeNi₃ EMEA is consisted of FCC, B2, and intergranular BCC phases, showing a typical fish scale-like structure with ultrafine cellular and columnar substructures. There are significantly preferred orientation and a strong texture in the molten pool, exhibiting obvious anisotropy, which affects the mechanical properties of the as-printed alloy in different directions. The ultimate tensile strength and elongation of the as-printed alloy with relatively optimal printing parameters are 1146.9 MPa and 7.6 %, respectively. Additionally, as the heat treatment temperature increases, the morphology of the matrix structure and intergranular BCC phases changed significantly, and the mechanical properties of the samples improved accordingly. When the solid solution temperature reaches 1000 °C, the intergranular BCC phases disappeared, and the second phases are uniformly distributed in the matrix, while the ultimate tensile strength and elongation of the sample are 1335.5 MPa and 12.3 %, respectively, demonstrating an 188.6 MPa increase in strength and 4.7 % increase in ductility compared to the as-printed alloy. Mechanical properties of the as-printed alloys are improved objectively due to grain refinement and second phase strengthening. Theoretical analysis and experimental guidance were provided in this work for the further application and performance improvement of printing alloys in additive manufacturing, such as aerospace, wear-resistant coatings, and energy applications.

采用选择性激光熔化法制备了无co AlCrFeNi3共晶介质熵合金（EMEA）。热处理作为后处理，用于改善打印样品的机械性能，在本工作中，样品在400°C - 1200°C下进行1小时的固溶处理。对打印后和热处理后样品的显微组织和力学性能进行了详细的研究。打印样品中未发现明显的裂纹和孔隙，最高相对密度可达99.57%。打印的AlCrFeNi3 EMEA由FCC相、B2相和晶间BCC相组成，呈典型的鱼鳞状结构，具有超细的细胞和柱状亚结构。熔池中存在明显的择优取向和较强的织构，表现出明显的各向异性，影响了不同方向打印合金的力学性能。相对较优的打印参数下，合金的抗拉强度和延伸率分别为1146.9 MPa和7.6%。此外，随着热处理温度的升高，基体组织和晶间BCC相的形貌发生了显著变化，试样的力学性能也随之提高。当固溶温度达到1000℃时，晶间BCC相消失，第二相在基体中均匀分布，试样的极限抗拉强度和延伸率分别为1335.5 MPa和12.3%，强度和塑性分别比打印时提高了188.6 MPa和4.7%。由于晶粒细化和第二相强化，在客观上提高了合金的力学性能。为打印合金在航空航天、耐磨涂层、能源等增材制造领域的进一步应用和性能提升提供理论分析和实验指导。

{"title":"Microstructural evolution and mechanical enhancement of Co-free AlCrFeNi3 eutectic medium entropy alloy via heat treatment after selective laser melting","authors":"Yong Dong , Huimin Gu , Chenglin Hou , Qian Zhang , Dongmei Miao , Shougang Duan","doi":"10.1016/j.msea.2025.148307","DOIUrl":"10.1016/j.msea.2025.148307","url":null,"abstract":"<div><div>The as-printed Co-free AlCrFeNi<sub>3</sub> eutectic medium entropy alloy (EMEA) was fabricated by selective laser melting (SLM). Heat treatment as a post processing was used to improve the mechanical properties of the as-printed samples, which were subjected to solid solution treatment at 400 °C–1200 °C for 1 h in this work. The microstructure and mechanical properties of the as-printed and heat-treated samples were examined in detail. No visible cracks and pores were found in the as-printed samples and the highest relative density is up to 99.57 %. The as-printed AlCrFeNi<sub>3</sub> EMEA is consisted of FCC, B2, and intergranular BCC phases, showing a typical fish scale-like structure with ultrafine cellular and columnar substructures. There are significantly preferred orientation and a strong texture in the molten pool, exhibiting obvious anisotropy, which affects the mechanical properties of the as-printed alloy in different directions. The ultimate tensile strength and elongation of the as-printed alloy with relatively optimal printing parameters are 1146.9 MPa and 7.6 %, respectively. Additionally, as the heat treatment temperature increases, the morphology of the matrix structure and intergranular BCC phases changed significantly, and the mechanical properties of the samples improved accordingly. When the solid solution temperature reaches 1000 °C, the intergranular BCC phases disappeared, and the second phases are uniformly distributed in the matrix, while the ultimate tensile strength and elongation of the sample are 1335.5 MPa and 12.3 %, respectively, demonstrating an 188.6 MPa increase in strength and 4.7 % increase in ductility compared to the as-printed alloy. Mechanical properties of the as-printed alloys are improved objectively due to grain refinement and second phase strengthening. Theoretical analysis and experimental guidance were provided in this work for the further application and performance improvement of printing alloys in additive manufacturing, such as aerospace, wear-resistant coatings, and energy applications.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"933 ","pages":"Article 148307"},"PeriodicalIF":6.1,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808651","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}

引用次数: 0

Investigation of Inhomogeneous Plastic Deformation Behavior of LDED TA15 Alloy Using In-Situ EBSD Tensile Technique 利用原位EBSD拉伸技术研究LDED TA15合金的非均匀塑性变形行为

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-07 DOI: 10.1016/j.msea.2025.148301

Rafi Ullah , Zhu Xiebin , Muhammad Rizwan , Jing Chen , Feng Dashun , Yuefei Zhang

Laser direct energy deposition (LDED) of titanium alloys often results in diverse grain structures, causing sequential or simultaneous deformation of multiple grains under dynamic loading. This microstructural diversity causes localized damage and deformation heterogeneity, leading to inconsistent mechanical properties and limiting the application of LDED TA15 titanium alloy in the aerospace industry. Real-time monitoring of these deformation mechanisms at the grain level is crucial for understanding the alloy's behavior. In this study, the grain deformation and texture evolution of LDED TA15 titanium alloy with a basketweave lamellar structure were examined using an in-situ SEM-EBSD tensile test conducted at 300°C. The results showed that the coarse grains accommodate more dislocations and exhibit lower deformation rates, while fine, thinner lamellar α grains fragment early due to geometrical constraints. Moreover, despite having a high Schmid factor (SF), coarse grains exhibited low intragranular misorientation at high deformation levels and maintained their morphology. Dislocations nucleated from low-angle boundaries, and the high dislocation density in neighboring grains caused boundary distortion. Microcracks formed along thin lamellar grain boundaries and prior α boundaries, eventually connecting and leading to fracture under increasing load.

钛合金的激光直接能量沉积（LDED）通常会产生多种晶粒结构，导致多个晶粒在动态加载下相继或同时变形。这种微结构多样性会造成局部损伤和变形异质性，导致机械性能不一致，限制了 LDED TA15 钛合金在航空航天工业中的应用。在晶粒层面实时监测这些变形机制对于了解合金的行为至关重要。在本研究中，利用在 300°C 下进行的原位 SEM-EBSD 拉伸试验，研究了具有篮织薄片结构的 LDED TA15 钛合金的晶粒变形和纹理演变。结果表明，粗晶粒可容纳更多的位错，并表现出较低的变形率，而细小、较薄的片状 α 晶粒则由于几何限制而较早破碎。此外，尽管具有较高的施密特因子（SF），粗晶粒在高变形水平下表现出较低的粒内错向，并保持了其形态。位错从低角度边界成核，相邻晶粒中的高位错密度导致了边界变形。微裂缝沿着薄层晶粒边界和先前的 α 边界形成，最终连接起来，并在载荷增加的情况下导致断裂。

{"title":"Investigation of Inhomogeneous Plastic Deformation Behavior of LDED TA15 Alloy Using In-Situ EBSD Tensile Technique","authors":"Rafi Ullah , Zhu Xiebin , Muhammad Rizwan , Jing Chen , Feng Dashun , Yuefei Zhang","doi":"10.1016/j.msea.2025.148301","DOIUrl":"10.1016/j.msea.2025.148301","url":null,"abstract":"<div><div>Laser direct energy deposition (LDED) of titanium alloys often results in diverse grain structures, causing sequential or simultaneous deformation of multiple grains under dynamic loading. This microstructural diversity causes localized damage and deformation heterogeneity, leading to inconsistent mechanical properties and limiting the application of LDED TA15 titanium alloy in the aerospace industry. Real-time monitoring of these deformation mechanisms at the grain level is crucial for understanding the alloy's behavior. In this study, the grain deformation and texture evolution of LDED TA15 titanium alloy with a basketweave lamellar structure were examined using an in-situ SEM-EBSD tensile test conducted at 300°C. The results showed that the coarse grains accommodate more dislocations and exhibit lower deformation rates, while fine, thinner lamellar α grains fragment early due to geometrical constraints. Moreover, despite having a high Schmid factor (SF), coarse grains exhibited low intragranular misorientation at high deformation levels and maintained their morphology. Dislocations nucleated from low-angle boundaries, and the high dislocation density in neighboring grains caused boundary distortion. Microcracks formed along thin lamellar grain boundaries and prior α boundaries, eventually connecting and leading to fracture under increasing load.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"934 ","pages":"Article 148301"},"PeriodicalIF":6.1,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820940","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}

引用次数: 0