Nanocrystalline AlCoCrCuFeNi high entropy alloy with 1 at. % Y was prepared by mechanical alloying and its microstructural stability was examined up to 1173 K (0.75 Tm). The lattice parameter analysis of the as-milled alloys shows a dual-phase structure, where Cu and Cr are identified as the host lattices for the FCC (0.362 nm) and BCC (0.288 nm) phases, respectively. The effect of Y addition on the microstructural evolution during annealing was studied by X-ray diffraction (XRD), and transmission electron microscopy (TEM). Molecular dynamics (MD) simulation was incorporated to track the atomistic behaviour of Y. Microhardness measurement was utilized to study the ability to retain strength after high temperature exposure. The FCC phase fraction is found to increase monotonically with increase in the annealing temperature. The Y addition helps in stabilizing an average grain size of ∼31 nm after annealing at 1173 K, along with retaining 82 % of the hardness (∼8.56 ± 0.3 GPa) observed for the ball-milled base alloy. The theoretical framework corroborated with the MD simulation elicited that the “thermodynamic” stabilization mechanism controls the superior coarsening resistance of the alloy. The strength predicted by the Hall-Petch analysis is in good agreement with the experimental result, further substantiating the stabilization of the nanocrystalline microstructure in the alloy annealed at 1173 K.
通过机械合金化方法制备了含 1 at.通过机械合金化方法制备了含 1% Y 的纳米晶铝铜铁镍高熵合金，并对其在 1173 K (0.75 Tm) 下的微观结构稳定性进行了检测。研磨合金的晶格参数分析表明其具有双相结构，其中铜和铬分别被确定为 FCC（0.362 nm）和 BCC（0.288 nm）相的主晶格。通过 X 射线衍射 (XRD) 和透射电子显微镜 (TEM) 研究了退火过程中添加 Y 对微观结构演变的影响。分子动力学（MD）模拟用于跟踪 Y 的原子行为。微硬度测量用于研究高温暴露后的强度保持能力。结果发现，随着退火温度的升高，FCC 相分数单调增加。在 1173 K 退火后，Y 的加入有助于稳定 31 nm 的平均晶粒大小，同时保留了球磨基础合金 82% 的硬度（8.56 ± 0.3 GPa）。理论框架与 MD 模拟证实，"热力学 "稳定机制控制着合金的优异抗粗化性能。霍尔-佩奇分析预测的强度与实验结果十分吻合，进一步证实了在 1173 K 下退火的合金中纳米晶微观结构的稳定性。
{"title":"Influence of Y (yttrium) doping on thermal stability of nanocrystalline AlCoCrCuFeNi high entropy alloy","authors":"Koushik Sikdar , Avik Mahata , Chinmoy Chattopadhyay , Debdas Roy , Rahul Mitra","doi":"10.1016/j.intermet.2025.108638","DOIUrl":"10.1016/j.intermet.2025.108638","url":null,"abstract":"<div><div>Nanocrystalline AlCoCrCuFeNi high entropy alloy with 1 at. % Y was prepared by mechanical alloying and its microstructural stability was examined up to 1173 K (0.75 T<sub>m</sub>). The lattice parameter analysis of the as-milled alloys shows a dual-phase structure, where Cu and Cr are identified as the host lattices for the FCC (0.362 nm) and BCC (0.288 nm) phases, respectively. The effect of Y addition on the microstructural evolution during annealing was studied by X-ray diffraction (XRD), and transmission electron microscopy (TEM). Molecular dynamics (MD) simulation was incorporated to track the atomistic behaviour of Y. Microhardness measurement was utilized to study the ability to retain strength after high temperature exposure. The FCC phase fraction is found to increase monotonically with increase in the annealing temperature. The Y addition helps in stabilizing an average grain size of ∼31 nm after annealing at 1173 K, along with retaining 82 % of the hardness (∼8.56 ± 0.3 GPa) observed for the ball-milled base alloy. The theoretical framework corroborated with the MD simulation elicited that the “<em>thermodynamic</em>” stabilization mechanism controls the superior coarsening resistance of the alloy. The strength predicted by the Hall-Petch analysis is in good agreement with the experimental result, further substantiating the stabilization of the nanocrystalline microstructure in the alloy annealed at 1173 K.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"179 ","pages":"Article 108638"},"PeriodicalIF":4.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181227","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 : 2025-01-14DOI: 10.1016/j.intermet.2025.108652
Dongyao Zhang , Yun Tian , Xingye Mao , Yuxin Wang , Yanqi Zhao , Chunli Qiu , Keping Geng , Yanchun Dong , Yong Yang , Hongjian Zhao
To study the corrosion behavior of high-entropy alloy coatings in alkaline solutions, FeCoNiCrMnAl0.5 and FeCoNiCrMnAl1.0 powders were prepared by mechanical alloying, and their coatings were coated on the surface of 316L stainless steel by plasma spraying technology. The corrosion resistance of the coatings in 1.0 mol/L NaOH solution was tested using an electrochemical workstation. The FeCoNiCrMnAl0.5 coating consists of a dual phase of FCC phase and Al2O3 phase, and the FeCoNiCrMnAl1.0 coating consists of FCC phase, BCC phase, and Al2O3 phase. In 1.0 mol/L NaOH solution, both coatings showed an obvious passivation phenomenon. The corrosion current densities of FeCoNiCrMnAl0.5 coating and FeCoNiCrMnAl1.0 coating were 1.006 × 10−5 A/cm2 and 7.051 × 10−6 A/cm2, respectively, and the corrosion potentials were −0.5277V and −0.5116V, respectively, which were higher than that of the corrosion potential of 316L stainless steel of −0.6572 V. The corrosion rates were 0.529 mg/(cm2/h) and 0.671 mg/(cm2/h), respectively, both lower than the corrosion rate of 316L stainless steel of 0.878 mg/(cm2/h).
{"title":"Analysis of the microstructure and corrosion behavior of FeCoNiCrMnAlX high-entropy alloy coatings","authors":"Dongyao Zhang , Yun Tian , Xingye Mao , Yuxin Wang , Yanqi Zhao , Chunli Qiu , Keping Geng , Yanchun Dong , Yong Yang , Hongjian Zhao","doi":"10.1016/j.intermet.2025.108652","DOIUrl":"10.1016/j.intermet.2025.108652","url":null,"abstract":"<div><div>To study the corrosion behavior of high-entropy alloy coatings in alkaline solutions, FeCoNiCrMnAl<sub>0.5</sub> and FeCoNiCrMnAl<sub>1.0</sub> powders were prepared by mechanical alloying, and their coatings were coated on the surface of 316L stainless steel by plasma spraying technology. The corrosion resistance of the coatings in 1.0 mol/L NaOH solution was tested using an electrochemical workstation. The FeCoNiCrMnAl<sub>0.5</sub> coating consists of a dual phase of FCC phase and Al<sub>2</sub>O<sub>3</sub> phase, and the FeCoNiCrMnAl<sub>1.0</sub> coating consists of FCC phase, BCC phase, and Al<sub>2</sub>O<sub>3</sub> phase. In 1.0 mol/L NaOH solution, both coatings showed an obvious passivation phenomenon. The corrosion current densities of FeCoNiCrMnAl<sub>0.5</sub> coating and FeCoNiCrMnAl<sub>1.0</sub> coating were 1.006 × 10<sup>−5</sup> A/cm<sup>2</sup> and 7.051 × 10<sup>−6</sup> A/cm<sup>2</sup>, respectively, and the corrosion potentials were −0.5277V and −0.5116V, respectively, which were higher than that of the corrosion potential of 316L stainless steel of −0.6572 V. The corrosion rates were 0.529 mg/(cm<sup>2</sup>/h) and 0.671 mg/(cm<sup>2</sup>/h), respectively, both lower than the corrosion rate of 316L stainless steel of 0.878 mg/(cm<sup>2</sup>/h).</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"179 ","pages":"Article 108652"},"PeriodicalIF":4.3,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182230","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 : 2025-01-11DOI: 10.1016/j.intermet.2025.108639
Ivan A. Ditenberg, Ivan V. Smirnov, Denis A. Osipov, Konstantin V. Grinyaev
The results of a study of the features of the structural-phase state of the surfacing formed by remelting of a multicomponent precursor with an electric arc with a non-consumable tungsten electrode in a protective argon environment on a steel substrate are presented. A non-equiatomic mixture of refractory metal powders W-Ta-Mo-Nb-Cr-Zr-Ti after high-energy ball milling was used. It has been established that the resulting structural state is represented by several multicomponent phases that differ in elemental composition, type of crystal lattice, morphology and defect structure and can be described as a complex structural-phase composite. A smooth nature of the change in microhardness values was discovered as one moved from the lower part of the substrate to the upper boundary of the surfacing, which indicates the gradient nature of the structural-phase state. It is assumed that a decrease in the size of structural elements of dendrites in areas with a high density of high-strength phases is a consequence of the formation of a high density of nuclei during phase formation, the competing growth of which limits the size of these structural elements.
{"title":"Structural-phase state and microhardness of the surfacing formed on a steel substrate by pulsed argon tungsten arc remelting of Cu-tube containing W-Ta-Mo-Nb-Zr-Cr-Ti powder mixture","authors":"Ivan A. Ditenberg, Ivan V. Smirnov, Denis A. Osipov, Konstantin V. Grinyaev","doi":"10.1016/j.intermet.2025.108639","DOIUrl":"10.1016/j.intermet.2025.108639","url":null,"abstract":"<div><div>The results of a study of the features of the structural-phase state of the surfacing formed by remelting of a multicomponent precursor with an electric arc with a non-consumable tungsten electrode in a protective argon environment on a steel substrate are presented. A non-equiatomic mixture of refractory metal powders W-Ta-Mo-Nb-Cr-Zr-Ti after high-energy ball milling was used. It has been established that the resulting structural state is represented by several multicomponent phases that differ in elemental composition, type of crystal lattice, morphology and defect structure and can be described as a complex structural-phase composite. A smooth nature of the change in microhardness values was discovered as one moved from the lower part of the substrate to the upper boundary of the surfacing, which indicates the gradient nature of the structural-phase state. It is assumed that a decrease in the size of structural elements of dendrites in areas with a high density of high-strength phases is a consequence of the formation of a high density of nuclei during phase formation, the competing growth of which limits the size of these structural elements.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"179 ","pages":"Article 108639"},"PeriodicalIF":4.3,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143180808","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 : 2025-01-10DOI: 10.1016/j.intermet.2025.108650
Jiachen Yu
Despite the growing interest in dual-phase high-entropy alloys (HEAs) for their unique combination of strength and ductility, some hypoeutectic HEAs still exhibit inadequate mechanical properties under tension. This study proposes a novel design strategy to enhance the mechanical performance of a specific hypoeutectic HEA (Al16.596Cr12.048Co15.060Fe15.060Ni37.650V3.012Si0.461C0.065B0.048). This approach leverages local inhomogeneity in powder mixing and the benefits of gradual printing and rapid solidification in additive manufacturing (AM). Unlike the traditional method of simply mixing pure elemental powders, the hypoeutectic HEA composition is divided into two components: one containing Al and having a face-centered cubic (FCC) structure, and the other being an Al-rich alloy. These pre-alloyed powders are mixed and remelted using the laser powder bed fusion (LPBF) technique to fabricate bulk samples, which leads to a heterogeneous distribution of phase types and grain sizes. The LPBF-fabricated HEA samples do not exhibit the typical hypoeutectic microstructure but instead display a dual-phase structure. Specifically, the refined FCC grains contain fine B2 phases, while the refined body-centered cubic (BCC) grains incorporate small FCC crystals. These microstructural transitions significantly enhance the mechanical properties of the samples. The Vickers hardness increases to 458 ± 5 HV, the yield strength reaches 1028 ± 10 MPa, and the ultimate tensile strength attains 1377 ± 10 MPa while maintaining comparable elongation. These improvements are primarily attributed to the refined grain structure and the presence of fine B2 phases within the FCC grains, as well as small FCC crystals within the BCC grains. The complex heterogeneous microstructure also induces significant back stress, which ensures stable strain-hardening rates during deformation. This study demonstrates a promising approach to improving the mechanical properties of hypoeutectic HEAs through compositional engineering and AM techniques.
{"title":"Enhancing mechanical properties of hypoeutectic high-entropy alloys via composition engineering and laser powder bed fusion technique","authors":"Jiachen Yu","doi":"10.1016/j.intermet.2025.108650","DOIUrl":"10.1016/j.intermet.2025.108650","url":null,"abstract":"<div><div>Despite the growing interest in dual-phase high-entropy alloys (HEAs) for their unique combination of strength and ductility, some hypoeutectic HEAs still exhibit inadequate mechanical properties under tension. This study proposes a novel design strategy to enhance the mechanical performance of a specific hypoeutectic HEA (Al<sub>16.596</sub>Cr<sub>12.048</sub>Co<sub>15.060</sub>Fe<sub>15.060</sub>Ni<sub>37.650</sub>V<sub>3.012</sub>Si<sub>0.461</sub>C<sub>0.065</sub>B<sub>0.048</sub>). This approach leverages local inhomogeneity in powder mixing and the benefits of gradual printing and rapid solidification in additive manufacturing (AM). Unlike the traditional method of simply mixing pure elemental powders, the hypoeutectic HEA composition is divided into two components: one containing Al and having a face-centered cubic (FCC) structure, and the other being an Al-rich alloy. These pre-alloyed powders are mixed and remelted using the laser powder bed fusion (LPBF) technique to fabricate bulk samples, which leads to a heterogeneous distribution of phase types and grain sizes. The LPBF-fabricated HEA samples do not exhibit the typical hypoeutectic microstructure but instead display a dual-phase structure. Specifically, the refined FCC grains contain fine B2 phases, while the refined body-centered cubic (BCC) grains incorporate small FCC crystals. These microstructural transitions significantly enhance the mechanical properties of the samples. The Vickers hardness increases to 458 ± 5 HV, the yield strength reaches 1028 ± 10 MPa, and the ultimate tensile strength attains 1377 ± 10 MPa while maintaining comparable elongation. These improvements are primarily attributed to the refined grain structure and the presence of fine B2 phases within the FCC grains, as well as small FCC crystals within the BCC grains. The complex heterogeneous microstructure also induces significant back stress, which ensures stable strain-hardening rates during deformation. This study demonstrates a promising approach to improving the mechanical properties of hypoeutectic HEAs through compositional engineering and AM techniques.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"179 ","pages":"Article 108650"},"PeriodicalIF":4.3,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182221","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 : 2025-01-10DOI: 10.1016/j.intermet.2025.108648
Zedong Liu, Jieren Yang, Yunlu Ma, Jinwen Ye, Ying Liu
This study investigates the impact of columnar and equiaxed microstructures of γ-TiAl alloy on tensile properties at 900 °C, as well as the corresponding high-temperature deformation microstructure. The characterization of twin and dislocation morphologies is conducted using scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). The dislocation and twinning behavior of γM and γL following high-temperature stretching is the primary focus of this investigation. The findings reveal that the columnar structure, characterized by reduced transverse grain boundaries, demonstrates enhanced high-temperature performance during the tensile process at 900 °C. This results in improved high-temperature strength and greater capacity for permanent deformation after necking. During high-temperature deformation, γM forms dislocation walls comprising superdislocations and triggers numerous <110] true twins, potentially originating from the dissociation of stacking faults. Concurrently, a broad spectrum of dislocation cross-slip activities is observed in γL, involving ordinary dislocations, as well as and superdislocations, along with some <011] true twins in γL facilitating additional strain adjustment. Furthermore, the study identifies that micro-holes and micro-cracks tend to develop at the interface of γM and the interface of (α2+γ) lamellar colonies. These results offer valuable insights for enhancing the comprehension of the benefits associated with the high-temperature mechanical properties of α columnar crystal structures characterized by a high aspect ratio, as well as the alterations in micro/nano structures that occur during high-temperature deformation.
{"title":"The impact of directional annealing on the microstructure and 900 °C tensile properties of γ-TiAl alloy","authors":"Zedong Liu, Jieren Yang, Yunlu Ma, Jinwen Ye, Ying Liu","doi":"10.1016/j.intermet.2025.108648","DOIUrl":"10.1016/j.intermet.2025.108648","url":null,"abstract":"<div><div>This study investigates the impact of columnar and equiaxed microstructures of γ-TiAl alloy on tensile properties at 900 °C, as well as the corresponding high-temperature deformation microstructure. The characterization of twin and dislocation morphologies is conducted using scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). The dislocation and twinning behavior of γ<sub>M</sub> and γ<sub>L</sub> following high-temperature stretching is the primary focus of this investigation. The findings reveal that the columnar structure, characterized by reduced transverse grain boundaries, demonstrates enhanced high-temperature performance during the tensile process at 900 °C. This results in improved high-temperature strength and greater capacity for permanent deformation after necking. During high-temperature deformation, γ<sub>M</sub> forms dislocation walls comprising <span><math><mrow><mrow><mrow><mo>⟨</mo><mn>0</mn></mrow><mover><mn>1</mn><mo>‾</mo></mover><mn>1</mn></mrow><mo>]</mo></mrow></math></span> superdislocations and triggers numerous <110] true twins, potentially originating from the dissociation of <span><math><mrow><mrow><mrow><mo>⟨</mo><mn>0</mn></mrow><mover><mn>1</mn><mo>‾</mo></mover><mn>1</mn></mrow><mo>]</mo></mrow></math></span> stacking faults. Concurrently, a broad spectrum of dislocation cross-slip activities is observed in γ<sub>L</sub>, involving <span><math><mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn><mrow><mo>⟨</mo><mn>1</mn></mrow><mover><mn>1</mn><mo>‾</mo></mover><mn>0</mn></mrow><mo>]</mo></mrow></math></span> ordinary dislocations, as well as <span><math><mrow><mrow><mrow><mo>⟨</mo><mn>0</mn></mrow><mover><mn>1</mn><mo>‾</mo></mover><mn>1</mn></mrow><mo>]</mo></mrow></math></span> and <span><math><mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn><mrow><mo>⟨</mo><mn>1</mn></mrow><mn>1</mn><mover><mn>2</mn><mo>‾</mo></mover></mrow><mo>]</mo></mrow></math></span> superdislocations, along with some <011] true twins in γ<sub>L</sub> facilitating additional strain adjustment. Furthermore, the study identifies that micro-holes and micro-cracks tend to develop at the interface of γ<sub>M</sub> and the interface of (α<sub>2</sub>+γ) lamellar colonies. These results offer valuable insights for enhancing the comprehension of the benefits associated with the high-temperature mechanical properties of α columnar crystal structures characterized by a high aspect ratio, as well as the alterations in micro/nano structures that occur during high-temperature deformation.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"179 ","pages":"Article 108648"},"PeriodicalIF":4.3,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182223","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 : 2025-01-08DOI: 10.1016/j.intermet.2025.108636
Ying Wang , Ruiping Wang , Zeming Wang , Zonglin Xiao , Shiyu Niu , Xu Yang , Zhenwen Yang
The zirconium alloy was thermo-hydrogen processed with 0.02 wt% and 0.2 wt% hydrogen, and the impact of hydrogen content on the microstructure and mechanical properties of the alloy was investigated. The hydrides in the hydrogen-treated alloys were identified as δ-ZrH1.66, which exhibit a semi-coherent boundary with the α-Zr matrix and an orientation relationship of (0001)α-Zr//(111)δ. The hydride platelets tend to align in lines parallel to the rolling direction (RD) and transverse direction (TD) at a slow cooling rate after thermo-hydrogenation. Thermo-hydrogen processing introduced additional intragranular secondary phases characterized as larger-sized ZrFe2 compared to those present in the raw alloy. The tensile strength and elongation of the zirconium alloys decrease with increasing hydrogen content due to the elevated hardness and brittleness of the hydrides. Specifically, the tensile strength decreases from 476 MPa without hydrogen to 449 MPa with 200 ppm hydrogen and 433 MPa with 2000 ppm hydrogen. The elongation of specimens without hydrogen was 38.4 %, whereas specimens with 200 ppm and 2000 ppm hydrogen exhibited reductions of 6.3 % and 42.7 %, respectively. Specimens with 2000 ppm hydrogen exhibited significantly low elongation due to the increased quantity and size of hydride lines.
{"title":"Effect of hydrogenation on microstructure and mechanical properties of new zirconium alloy","authors":"Ying Wang , Ruiping Wang , Zeming Wang , Zonglin Xiao , Shiyu Niu , Xu Yang , Zhenwen Yang","doi":"10.1016/j.intermet.2025.108636","DOIUrl":"10.1016/j.intermet.2025.108636","url":null,"abstract":"<div><div>The zirconium alloy was thermo-hydrogen processed with 0.02 wt% and 0.2 wt% hydrogen, and the impact of hydrogen content on the microstructure and mechanical properties of the alloy was investigated. The hydrides in the hydrogen-treated alloys were identified as δ-ZrH<sub>1.66</sub>, which exhibit a semi-coherent boundary with the α-Zr matrix and an orientation relationship of (0001)<sub>α-Zr</sub>//(111)<sub>δ</sub>. The hydride platelets tend to align in lines parallel to the rolling direction (RD) and transverse direction (TD) at a slow cooling rate after thermo-hydrogenation. Thermo-hydrogen processing introduced additional intragranular secondary phases characterized as larger-sized ZrFe<sub>2</sub> compared to those present in the raw alloy. The tensile strength and elongation of the zirconium alloys decrease with increasing hydrogen content due to the elevated hardness and brittleness of the hydrides. Specifically, the tensile strength decreases from 476 MPa without hydrogen to 449 MPa with 200 ppm hydrogen and 433 MPa with 2000 ppm hydrogen. The elongation of specimens without hydrogen was 38.4 %, whereas specimens with 200 ppm and 2000 ppm hydrogen exhibited reductions of 6.3 % and 42.7 %, respectively. Specimens with 2000 ppm hydrogen exhibited significantly low elongation due to the increased quantity and size of hydride lines.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"178 ","pages":"Article 108636"},"PeriodicalIF":4.3,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153722","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 : 2025-01-08DOI: 10.1016/j.intermet.2025.108645
Zhanming Zhou, Xincheng Yan, Yi Dai
The microstructure, mechanical properties, and damping properties of a (FeCrCoNi)95Ti5 high-entropy alloy after a series of aging treatments were studied. The alloy had a face-centered cubic (FCC) structure, and its microstructure was characterized by typically equiaxed grains. The effects of the γ′ precipitates and lamellar η on the mechanical and damping properties of the alloy were studied. In addition, the mechanisms of strengthening and deformation were explored. Owing to the precipitation strengthening of the γ′ precipitates, the yield strength of the alloy after aging at 873 K was 513 MPa, which was 52 % higher than that before the treatment (337 MPa). Meanwhile, the elongation was 53 %; only a 5 % reduction in elongation was achieved. After aging at 973K and 1073K, the lamellar η phase significantly increases the yield strength of the alloy to 755 MPa and 818 MPa, but the elongation decreases to 36 % and 25 %, respectively. After the deformation, a large number of dislocations piled up in the η phase and formed high-density dislocation walls. In the γ′ phase, a large number of cross-stacking faults were generated, which formed Lomer–Cottrell locks. With an increase in the aging temperature, the microstructure changed, and the deformation mechanism began to change from the stacking-fault control mode to the dislocation-stacking fault co-dominant mode. The damping mechanism of the alloy satisfied the G-L dislocation model, and the damping parameter of the solid solution alloy was approximately 0.035. Following aging at 873 K, the γ′ precipitates acted as weak pinning points in the alloy. When the dislocation approached the interface, it continued to pass through the interface and consumed energy, which further improved the damping capacity of the alloy. The value reached approximately 0.045, and the η precipitation of the phase reduced the value further. The values of the alloys aging at 973 K and 1073 K were 0.038 and 0.036, respectively.
{"title":"Effect of precipitation on the mechanical and damping properties of (FeCrCoNi)95Ti5 high-entropy alloy","authors":"Zhanming Zhou, Xincheng Yan, Yi Dai","doi":"10.1016/j.intermet.2025.108645","DOIUrl":"10.1016/j.intermet.2025.108645","url":null,"abstract":"<div><div>The microstructure, mechanical properties, and damping properties of a (FeCrCoNi)<sub>95</sub>Ti<sub>5</sub> high-entropy alloy after a series of aging treatments were studied. The alloy had a face-centered cubic (FCC) structure, and its microstructure was characterized by typically equiaxed grains. The effects of the γ′ precipitates and lamellar η on the mechanical and damping properties of the alloy were studied. In addition, the mechanisms of strengthening and deformation were explored. Owing to the precipitation strengthening of the γ′ precipitates, the yield strength of the alloy after aging at 873 K was 513 MPa, which was 52 % higher than that before the treatment (337 MPa). Meanwhile, the elongation was 53 %; only a 5 % reduction in elongation was achieved. After aging at 973K and 1073K, the lamellar η phase significantly increases the yield strength of the alloy to 755 MPa and 818 MPa, but the elongation decreases to 36 % and 25 %, respectively. After the deformation, a large number of dislocations piled up in the η phase and formed high-density dislocation walls. In the γ′ phase, a large number of cross-stacking faults were generated, which formed Lomer–Cottrell locks. With an increase in the aging temperature, the microstructure changed, and the deformation mechanism began to change from the stacking-fault control mode to the dislocation-stacking fault co-dominant mode. The damping mechanism of the alloy satisfied the G-L dislocation model, and the damping parameter <span><math><mrow><msup><mi>Q</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span> of the solid solution alloy was approximately 0.035. Following aging at 873 K, the γ′ precipitates acted as weak pinning points in the alloy. When the dislocation approached the interface, it continued to pass through the interface and consumed energy, which further improved the damping capacity of the alloy. The <span><math><mrow><msup><mi>Q</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span> value reached approximately 0.045, and the η precipitation of the phase reduced the value further. The <span><math><mrow><msup><mi>Q</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span> values of the alloys aging at 973 K and 1073 K were 0.038 and 0.036, respectively.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"178 ","pages":"Article 108645"},"PeriodicalIF":4.3,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153723","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 : 2025-01-08DOI: 10.1016/j.intermet.2025.108640
Zhanxing Chen , Zhe Deng , Yupeng Wang , Tengfei Ma , Xinfang Zhang , Guoju Li
To address the inherent trade-off between strength and ductility in TiAl alloys, multi-component TiB2-Ti2AlN reinforced TiAl composite was designed by tailoring Al content and prepared using metallurgical techniques. The solidification behavior of TixAl2Cr2Nb-0.5BN composites were influenced by Al contents, exhibiting varied solidification path. An increase in Al content from 44 to 50 at.% leaded to a rise in the volume fraction of Ti2AlN precipitates, shifting from 0.34 % to 2.05 %. Notably, the minimum lamellar colony size of 44 μm was produced with an Al content of 48 at.%. Simultaneously, both the γ-phase and the lamellar spacing underwent expansion as the Al content increased. A duplex microstructure was achieved at an Al content of 50 at.%. The Ti48Al2Cr2Nb-0.5BN composite exhibited an ultimate compressive strength of 2263 MPa, representing an enhancement of 47 % compared to the Ti44Al2Cr2Nb-0.5BN composite. Additionally, this composite displayed the highest compressive strain, marking an improvement of 115 %. The dominant fracture mechanisms of TiAl composites were revealed, including grain boundary fracture, crack deflection, inter-lamellar fracture, and the pull-out of reinforcing phases.
{"title":"Solidification behavior of TiB2-Ti2AlN reinforced TiAl composites with variation Al content","authors":"Zhanxing Chen , Zhe Deng , Yupeng Wang , Tengfei Ma , Xinfang Zhang , Guoju Li","doi":"10.1016/j.intermet.2025.108640","DOIUrl":"10.1016/j.intermet.2025.108640","url":null,"abstract":"<div><div>To address the inherent trade-off between strength and ductility in TiAl alloys, multi-component TiB<sub>2</sub>-Ti<sub>2</sub>AlN reinforced TiAl composite was designed by tailoring Al content and prepared using metallurgical techniques. The solidification behavior of TixAl2Cr2Nb-0.5BN composites were influenced by Al contents, exhibiting varied solidification path. An increase in Al content from 44 to 50 at.% leaded to a rise in the volume fraction of Ti<sub>2</sub>AlN precipitates, shifting from 0.34 % to 2.05 %. Notably, the minimum lamellar colony size of 44 μm was produced with an Al content of 48 at.%. Simultaneously, both the γ-phase and the lamellar spacing underwent expansion as the Al content increased. A duplex microstructure was achieved at an Al content of 50 at.%. The Ti48Al2Cr2Nb-0.5BN composite exhibited an ultimate compressive strength of 2263 MPa, representing an enhancement of 47 % compared to the Ti44Al2Cr2Nb-0.5BN composite. Additionally, this composite displayed the highest compressive strain, marking an improvement of 115 %. The dominant fracture mechanisms of TiAl composites were revealed, including grain boundary fracture, crack deflection, inter-lamellar fracture, and the pull-out of reinforcing phases.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"178 ","pages":"Article 108640"},"PeriodicalIF":4.3,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153721","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 : 2025-01-07DOI: 10.1016/j.intermet.2025.108647
Ning Zhou , Qilong Guan , Shengli Li , Lin Wu , Xiaojiu Tang , Jian Guo , Chunjin Hang , Wei Zhang
Solid-liquid interdiffusion bonding (SLID) acts as a promising stacking process for three-dimensional integrated circuit (3D IC) tacking, but nevertheless is plagued with low throughput. In this work, a new speed solid-liquid interdiffusion bonding process is proposed to improve the bonding reliability. Different from the homogeneous bonding temperature, a temperature gradient superposition is applied across the joint in the new process. Firstly, the new method is 5–7 times faster than that of the traditional bonding process, depending on the bonding temperatures and times. On the other hand, the asymmetric dissolution of Cu/Sn-3.0Ag-0.5Cu/Cu (Cu/SAC305/Cu) solder joints induced by large temperature gradient (0.1 °C/μm) leads the asymmetric growth of intermetallic compounds (IMCs) at the cold end. Besides, the morphologies of IMCs layer transforms from scallop-like grains to columnary grains at the cold end. In addition, the shear property of the solder joints obviously increases with the extension of the bonding times. The bonding mechanism of the solder joints is provided and experimentally confirmed in this work.
{"title":"Thermal gradient-induced full intermetallic joints formation for chip bonding","authors":"Ning Zhou , Qilong Guan , Shengli Li , Lin Wu , Xiaojiu Tang , Jian Guo , Chunjin Hang , Wei Zhang","doi":"10.1016/j.intermet.2025.108647","DOIUrl":"10.1016/j.intermet.2025.108647","url":null,"abstract":"<div><div>Solid-liquid interdiffusion bonding (SLID) acts as a promising stacking process for three-dimensional integrated circuit (3D IC) tacking, but nevertheless is plagued with low throughput. In this work, a new speed solid-liquid interdiffusion bonding process is proposed to improve the bonding reliability. Different from the homogeneous bonding temperature, a temperature gradient superposition is applied across the joint in the new process. Firstly, the new method is 5–7 times faster than that of the traditional bonding process, depending on the bonding temperatures and times. On the other hand, the asymmetric dissolution of Cu/Sn-3.0Ag-0.5Cu/Cu (Cu/SAC305/Cu) solder joints induced by large temperature gradient (0.1 °C/μm) leads the asymmetric growth of intermetallic compounds (IMCs) at the cold end. Besides, the morphologies of IMCs layer transforms from scallop-like grains to columnary grains at the cold end. In addition, the shear property of the solder joints obviously increases with the extension of the bonding times. The bonding mechanism of the solder joints is provided and experimentally confirmed in this work.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"178 ","pages":"Article 108647"},"PeriodicalIF":4.3,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153148","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 : 2025-01-07DOI: 10.1016/j.intermet.2025.108642
Dong Lu , Chao Wang , Jianhong Peng
To improve the properties of TC4 alloy, NbMoTaVTi refractory high-entropy alloy coating without defects was successfully prepared on the surface of TC4 alloy by laser cladding method. Phase compositions and properties were investigated through various characterization methods. The coating exhibited a dual-phase structure of BCC and HCP. SEM and EDS showed that the coating formed an excellent metallurgical bond with the TC4 substrate and had a small heat-affected zone. The microhardness of the coating was 600.62 HV, which was 57.63 % higher than the microhardness of the substrate. High-temperature experiments at 1000 °C, 1100 °C, 1200 °C revealed that the coating had better oxidation resistance at high temperatures. An electrochemical experiment in 3.5 wt% NaCl solution showed that the passive film's stability on the coating's surface was improved. The corrosion rates of the substrate and coating were 258.10 × 10−3 mpy and 87.79 × 10−3 mpy, respectively, indicating that the coating had better corrosion resistance.
{"title":"Phase compositions and properties of NbMoTaVTi refractory high-entropy alloy coating on Ti-6Al-4V alloy","authors":"Dong Lu , Chao Wang , Jianhong Peng","doi":"10.1016/j.intermet.2025.108642","DOIUrl":"10.1016/j.intermet.2025.108642","url":null,"abstract":"<div><div>To improve the properties of TC4 alloy, NbMoTaVTi refractory high-entropy alloy coating without defects was successfully prepared on the surface of TC4 alloy by laser cladding method. Phase compositions and properties were investigated through various characterization methods. The coating exhibited a dual-phase structure of BCC and HCP. SEM and EDS showed that the coating formed an excellent metallurgical bond with the TC4 substrate and had a small heat-affected zone. The microhardness of the coating was 600.62 HV, which was 57.63 % higher than the microhardness of the substrate. High-temperature experiments at 1000 °C, 1100 °C, 1200 °C revealed that the coating had better oxidation resistance at high temperatures. An electrochemical experiment in 3.5 wt% NaCl solution showed that the passive film's stability on the coating's surface was improved. The corrosion rates of the substrate and coating were 258.10 × 10<sup>−3</sup> mpy and 87.79 × 10<sup>−3</sup> mpy, respectively, indicating that the coating had better corrosion resistance.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"178 ","pages":"Article 108642"},"PeriodicalIF":4.3,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153149","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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