Journal of Alloys and Compounds最新文献

{"title":"Influence of Ho3+ and Yb3+ Concentration Distributions on Ce3+-Fine-Tuned Upconversion Luminescence in Highly Doped Core–Multi-Shell Upconversion Nanoparticles","authors":"Ye Kuang, Junhao Xu, Guangli Shi, Tengbo Hu, Xian Wang, Bo Li, Yu Liang, Panpan Qin, Wen Zeng, Hao Wang, Longhai Shen, Yiwei Wang","doi":"10.1016/j.jallcom.2025.181927","DOIUrl":"https://doi.org/10.1016/j.jallcom.2025.181927","url":null,"abstract":"Although widely used for Ho-based upconversion luminescence (UCL) fine-tuning of upconversion nanoparticles (UCNPs), Ce<ce:sup loc=\"post\">3+</ce:sup> doping has lacked comprehensive investigation in core–multi-shell and highly doped structures. Herein, a series of highly doped core–multi-shell UCNPs with Ce<ce:sup loc=\"post\">3+</ce:sup> doping were synthesised via oleate-based methods. The structures and morphologies were characterised by X-ray diffraction (XRD), transmission emission microscopy (TEM) and elemental mapping, while UCL properties were assessed using emission spectra, decay curves and pump power measurements. The distributions of Ho<ce:sup loc=\"post\">3+</ce:sup> and Yb<ce:sup loc=\"post\">3+</ce:sup> concentrations were systematically varied to explore, for the first time, their distinct effects on Ce<ce:sup loc=\"post\">3+</ce:sup>-mediated UCL fine-tuning. These effects arose from different energy mechanisms and varied with the number of shell layers. A deficiency in phonon energy was found to reduce the efficiency of both Yb<ce:sup loc=\"post\">3+</ce:sup>–Ho<ce:sup loc=\"post\">3+</ce:sup> energy transfer and Ho<ce:sup loc=\"post\">3+</ce:sup>–Ce<ce:sup loc=\"post\">3+</ce:sup> cross-relaxation while also exacerbating surface energy quenching. Beyond mitigating the phonon energy shortage and providing greater shielding for surrounding Ho<ce:sup loc=\"post\">3+</ce:sup> ions, a low Ho<ce:sup loc=\"post\">3+</ce:sup> concentration in the core and a high concentration in the first shell (S<ce:inf loc=\"post\">1</ce:inf>) were found to reduce the overall distance between Yb<ce:sup loc=\"post\">3+</ce:sup> and activated Ho<ce:sup loc=\"post\">3+</ce:sup> ions, enhancing energy transfer but increasing surface quenching. A high Yb<ce:sup loc=\"post\">3+</ce:sup> concentration in the second shell (S<ce:inf loc=\"post\">2</ce:inf>) and a low concentration in the third shell helped to promote inward sensitising energy transfer and suppress surface quenching, though this configuration partially intensified the phonon energy shortage. UCNPs with the composition NaHoF<ce:inf loc=\"post\">4</ce:inf>:10%Ce<ce:sup loc=\"post\">3+</ce:sup>,40%Gd<ce:sup loc=\"post\">3+</ce:sup>@NaHoF<ce:inf loc=\"post\">4</ce:inf>:10%Ce<ce:sup loc=\"post\">3+</ce:sup>@NaGdF<ce:inf loc=\"post\">4</ce:inf>:10%Ce<ce:sup loc=\"post\">3+</ce:sup>,60%Yb<ce:sup loc=\"post\">3+</ce:sup>@NaGdF<ce:inf loc=\"post\">4</ce:inf>:20%Yb<ce:sup loc=\"post\">3+</ce:sup> demonstrated optimal performance, exhibiting a red UCL decay time of 164.97 μs, a green-to-red intensity ratio of 0.43 and a quantum yield of 1.23%. Both metrics declined when Ce<ce:sup loc=\"post\">3+</ce:sup> dopants were confined only to S<ce:inf loc=\"post\">2</ce:inf>. Multi-layer Ce<ce:sup loc=\"post\">3+</ce:sup> doping outperformed configurations with doping limited to the core or S<ce:inf loc=\"post\">1</ce:inf>. Moreover, the emission colour of Ce<ce:sup loc=\"post\">3+</ce:sup>-doped UCNPs remained tunable with variations in pump power. These findings provide","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"39 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515756","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}

{"title":"Tailoring the tensile deformation modes in the Ni-Cr-Fe-base superalloy GH4070T at 750 ℃ by adjusting Fe content","authors":"Z.Z. Dou, P. Zhang, S. Wang, Y. Yuan, J.B. Yan, W.Z. Diao, L.H. Huang, Y.L. Nan","doi":"10.1016/j.jallcom.2025.181900","DOIUrl":"https://doi.org/10.1016/j.jallcom.2025.181900","url":null,"abstract":"A novel Ni-Cr-Fe-base superalloy GH4070T containing around 25<ce:hsp sp=\"0.25\"></ce:hsp>wt.% of iron has recently been developed and evaluated as a candidate material of superheater/reheater tubes in the boiler of 700 °C-class advanced ultra-supercritical power plants. In order to determine the optimum addition of iron, the impact of Fe element on the tensile properties and deformation modes of the alloy at 750 °C is investigated by adjusting the Fe content from 15<ce:hsp sp=\"0.25\"></ce:hsp>wt.% to around 35<ce:hsp sp=\"0.25\"></ce:hsp>wt.%. We found that the yield strength and ultimate tensile strength decrease monotonically with increasing the addition of iron, but the tensile plasticity has an optimum value when the concentration of iron is at 25<ce:hsp sp=\"0.25\"></ce:hsp>wt.%. Microstructural observations reveal that the γ′ volume fraction decreases with the Fe content, but without obvious changes in the grain sizes and particle sizes of γ′ precipitates. Meanwhile, it is also found that the primary deformation mode transits from dislocations cutting through γ′ precipitates to dislocations striding over them via Orowan looping and cross-slip/climb with enlarging the concentration of iron, but all the experimental alloys display the mixed-mode fracture. Simulation calculations disclose that the stacking fault energy of the matrix increases with the Fe content, whereas the anti-phase boundary energy of the γ′ phase shows an opposite changing tendency. Given these results, it is deemed that the changes in the microstructural features with the Fe content are responsible for variations in deformation modes and fracture mechanisms as well as tensile properties for GH4070T.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"89 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515760","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}

{"title":"On the merit of solute segregation and low angle grain boundary for thermal stability and thermal expansion of cold-sprayed CuCrZr","authors":"Abhijith Vijay V, M.P. Sreerag, S. Varalakshmi, K. Santhy, Reeti Singh, Jan Kondás, Surendra Kumar Makineni, B. Rajasekaran","doi":"10.1016/j.jallcom.2025.181937","DOIUrl":"https://doi.org/10.1016/j.jallcom.2025.181937","url":null,"abstract":"The precipitation hardenable CuCrZr alloy is a potential alternative to copper for inner liners in rocket thrust engines. Cold spray manufacturing has been seen as a promising processing route to manufacture bulk additive structure of CuCrZr. This work reveals that the cold-sprayed as-deposited Cu-Cr-Zr alloy, in its inherent non-equilibrium state, is highly stable up to 950 °C and exhibits lower thermal expansion than the equilibrium Cu-Cr-Zr alloy, deduced using HT-XRD and Thermo-Calc. Atomic-scale compositional and diffraction analysis using Atom Probe Tomography (APT) and Electron Backscatter Diffraction (EBSD) support the Zener pinning effect of Cr segregation near the grain boundaries, along with a large fraction of low-angle grain boundaries (LAGBs), that contribute to the high thermal stability and controlled thermal expansion of the deposit. Cold spray deposition naturally yields microstructural features that are conducive to high thermal stability and controlled thermal expansion, features which are comparable to the self-organized microstructures observed in Segregation engineering (SE).","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"57 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515750","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}

{"title":"Phase Diagram Investigation in the Al-Ce-Ti System: Focusing on the Aluminum-Rich Region","authors":"Taowen Zheng, Dongsheng Liu, Yuchuan Wang, Dandan Huang, Xinpeng Wang","doi":"10.1016/j.jallcom.2025.181945","DOIUrl":"https://doi.org/10.1016/j.jallcom.2025.181945","url":null,"abstract":"This work provides a comprehensive analysis of solidification behavior and phase equilibria at 773<ce:hsp sp=\"0.25\"></ce:hsp>K in the Al-rich region of the Al-Ce-Ti system. Using nineteen as-cast and nine annealed alloys, the investigation characterizes phase equilibria and microstructural evolution through scanning electron microscopy, electron probe microanalysis, X-ray diffraction, and differential scanning calorimetry. Six ternary-phase regions were delineated at 773<ce:hsp sp=\"0.25\"></ce:hsp>K, revealing nine distinct primary solidification phases: γ-TiAl, ζ-Ti<ce:inf loc=\"post\">2+x</ce:inf>Al<ce:inf loc=\"post\">5-x</ce:inf>, Al<ce:inf loc=\"post\">2</ce:inf>Ce, ε(ht)-TiAl<ce:inf loc=\"post\">3</ce:inf>, ε(rt)-TiAl<ce:inf loc=\"post\">3</ce:inf>, τ(Al<ce:inf loc=\"post\">20</ce:inf>Ti<ce:inf loc=\"post\">2</ce:inf>Ce), α-Al<ce:inf loc=\"post\">11</ce:inf>Ce<ce:inf loc=\"post\">3</ce:inf>, β-Al<ce:inf loc=\"post\">11</ce:inf>Ce<ce:inf loc=\"post\">3</ce:inf> and (Al). Proposed phase transformations include one type I, six type II and one III ternary invariant reactions. The resultant liquidus projection and isothermal section at 773<ce:hsp sp=\"0.25\"></ce:hsp>K in the Al-rich region provide essential experimental benchmarks for advancing thermodynamic assessments and predictive modeling of the Al-Ce-Ti system. This work lays a solid foundation for further research and development in the field of aluminum alloys, particularly for applications in industries such as aerospace and automotive manufacturing, where lightweight and high-strength materials are in high demand. Future work could focus on exploring the relationships between microstructure and mechanical properties in more depth, as well as investigating the performance of these alloys under different service conditions. Additionally, the methodologies and insights gained from this work could be applied to other alloy systems.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"56 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515626","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}

{"title":"Precipitation Mechanisms and Crystallographic Study of Co-precipitation Carbides in Super Austenitic Stainless Steel","authors":"Yulin Gao, Min Zhang, Jingyuan Li, Rui Wang, Zhengyuan Yuan, Zhunli Tan, Wenbo Yu","doi":"10.1016/j.jallcom.2025.181942","DOIUrl":"https://doi.org/10.1016/j.jallcom.2025.181942","url":null,"abstract":"This study focuses on the microstructural evolution mechanisms of co-precipitated M<ce:inf loc=\"post\">23</ce:inf>C<ce:inf loc=\"post\">6</ce:inf> and M<ce:inf loc=\"post\">6</ce:inf>C carbides in S32654 super austenitic stainless steel. It is found that the crystallographic characteristics of carbides largely determine their morphology, which has an important influence on the properties of stainless steel. Therefore, an accurate description of the crystallographic characteristics of carbides is essential for an in-depth understanding of their effects on material properties. The orientation relationships between the matrix γ, M<ce:inf loc=\"post\">23</ce:inf>C<ce:inf loc=\"post\">6</ce:inf>, and M<ce:inf loc=\"post\">6</ce:inf>C phases were determined as [-1 1 0]<ce:inf loc=\"post\">γ</ce:inf>//[-1 1 0]<ce:inf loc=\"post\">M23C6</ce:inf>//[-1 1 0]<ce:inf loc=\"post\">M6C</ce:inf> and (1 1 1)<ce:inf loc=\"post\">γ</ce:inf>//(1 1 1)<ce:inf loc=\"post\">M23C6</ce:inf>//(1 1 1)<ce:inf loc=\"post\">M6C</ce:inf>. The M<ce:inf loc=\"post\">23</ce:inf>C<ce:inf loc=\"post\">6</ce:inf>/γ interface provided favorable sites for the nucleation of M<ce:inf loc=\"post\">6</ce:inf>C, and M<ce:inf loc=\"post\">6</ce:inf>C/γ exhibited identical orientation relationships and interface orientation as M<ce:inf loc=\"post\">23</ce:inf>C<ce:inf loc=\"post\">6</ce:inf>/γ. Due to the structural similarity between M<ce:inf loc=\"post\">23</ce:inf>C<ce:inf loc=\"post\">6</ce:inf> and M<ce:inf loc=\"post\">6</ce:inf>C, the lattices matched well at all orientations, and no repeated habit plane was observed. Based on STEM-EDS analysis, the chemical formula of M<ce:inf loc=\"post\">23</ce:inf>C<ce:inf loc=\"post\">6</ce:inf> was confirmed as (Cr<ce:inf loc=\"post\">17</ce:inf>Mo<ce:inf loc=\"post\">3</ce:inf>Fe<ce:inf loc=\"post\">3</ce:inf>)C<ce:inf loc=\"post\">6</ce:inf>. An appropriate increase in Mo content enhanced the stability of M<ce:inf loc=\"post\">23</ce:inf>C<ce:inf loc=\"post\">6</ce:inf>, but when exceeding a specific threshold, M<ce:inf loc=\"post\">23</ce:inf>C<ce:inf loc=\"post\">6</ce:inf> will gradually transform to M<ce:inf loc=\"post\">6</ce:inf>C. First-principles calculation verified the feasibility of this transformation process in terms of the system energy. This work promotes the understanding of the precipitation mechanism of multiple carbides in super austenitic stainless steel.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"6 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515627","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}

{"title":"Achieving high yield strength in a directly cast eutectic high entropy alloy via introducing κ′ nano-precipitates","authors":"Xiaoyu Liang, Jian Chen, Rengen Ding, Yuhong Yao, Weili Wang, Tao Zhang, Jiahua He, Yunzi Liu, Jiangnan Liu","doi":"10.1016/j.jallcom.2025.181935","DOIUrl":"https://doi.org/10.1016/j.jallcom.2025.181935","url":null,"abstract":"Eutectic high entropy alloy (EHEA) with excellent mechanical properties has attained significant attention in science and engineering fields. However, achieving high tensile yield strength is encountering serious challenges via conventional casting. Here, we report a novel approach to overcome this difficulty via introducing κ′ phase into FCC phase in EHEA. As a proof, (Al<ce:inf loc=\"post\">19</ce:inf>Co<ce:inf loc=\"post\">20</ce:inf>Fe<ce:inf loc=\"post\">20</ce:inf>Ni<ce:inf loc=\"post\">41</ce:inf>)<ce:inf loc=\"post\">100-x</ce:inf>C<ce:inf loc=\"post\">x</ce:inf> (x = 0.5, 1 and 2, denoted as Cx alloys hereafter) EHEAs were produced by conventional vacuum arc-melting. Their eutectic structures and mechanical properties were investigated in detail. Experimental results confirm that C element plays a key role in forming κ′ phase and that the κ′ phase provides an excellent strengthening effect. Among three κ′-strengthened EHEAs, the C1 alloy exhibits a relatively optimal combination of yield strength and ductility, with a yield strength close to 1<ce:hsp sp=\"0.25\"></ce:hsp>GPa and a good fracture elongation of approximately 7%. The yield strength was increased by nearly 50% as compared with the base alloy, which is mainly attributed to the ordering strengthening of κ′ phase. Our results would provide an innovative and viable route to improve the tensile properties of directly cast eutectic high-entropy alloy and expend the application of eutectic high-entropy alloy.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"67 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515752","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}

{"title":"Synergistic Strategy of Homologous Lattice Doping and Phonon Engineering Enables Deep-Red Narrow-Band High-Efficiency Luminescence and Dynamic Anti-Counterfeiting Applications","authors":"Rujia Chen, Fanming Zeng, Chun Li, Weiling Yang, Lina Liu, Hai Lin, Shasha Li","doi":"10.1016/j.jallcom.2025.181925","DOIUrl":"https://doi.org/10.1016/j.jallcom.2025.181925","url":null,"abstract":"To address the urgent demand for high-quantum-yield and low-thermal-quenching materials in WLED and dynamic anti-counterfeiting applications, this study innovatively proposes a homologous lattice doping coupled with phonon engineering strategy. By precisely substituting Y<ce:sup loc=\"post\">3+</ce:sup> sites in the garnet lattice with Gd<ce:sup loc=\"post\">3+</ce:sup>, we overcome the luminescence limitations of conventional rare-earth materials, achieving the first controllable tunable 706<ce:hsp sp=\"0.25\"></ce:hsp>nm far-red narrow-band emission. The optimized Ca<ce:inf loc=\"post\">3</ce:inf>Y<ce:inf loc=\"post\">1.4</ce:inf>Ge<ce:inf loc=\"post\">3</ce:inf>O<ce:inf loc=\"post\">12</ce:inf>: 0.6Eu<ce:sup loc=\"post\">3+</ce:sup> phosphor exhibits exceptionally strong <ce:sup loc=\"post\">5</ce:sup>D<ce:inf loc=\"post\">0</ce:inf>→<ce:sup loc=\"post\">7</ce:sup>F<ce:inf loc=\"post\">4</ce:inf> far-red transitions and disruptive optical performance: an internal quantum efficiency of 97%, external quantum efficiency of 38%, and absorption efficiency of 41%, significantly surpassing commercial Y<ce:inf loc=\"post\">2</ce:inf>O<ce:inf loc=\"post\">3</ce:inf>: Eu<ce:sup loc=\"post\">3+</ce:sup> and CaAlSiN<ce:inf loc=\"post\">3</ce:inf>: Eu<ce:sup loc=\"post\">3+</ce:sup> benchmarks. Its thermal stability is remarkable, retaining 94.54% luminescence intensity at 150 °C (423<ce:hsp sp=\"0.25\"></ce:hsp>K) and 90% at 210 °C, outperforming the thermal tolerance limits of KSF: Mn<ce:sup loc=\"post\">4+</ce:sup>. Through groundbreaking phonon engineering theory, establishing a phonon-assisted lattice vibration model to decode electron-phonon coupling dynamics, revealing that the enlarged local phonon density at the Eu<ce:sup loc=\"post\">3+</ce:sup>-centered oxygen octahedron accelerates energy exchange between excited electrons and phonons, fundamentally explaining its high absorption and quantum efficiencies. The fabricated WLED device demonstrates superior performance with correlated color temperature (4805<ce:hsp sp=\"0.25\"></ce:hsp>K), color rendering index (93.5). Furthermore, three advanced applications of plant growth, screen printing anti-counterfeiting and information encryption are also explored, demonstrating excellent capabilities in anti-counterfeiting and information security. This work establishes a phonon-lattice-transition ternary engineering paradigm for high-stability deep-red luminescent materials and provides versatile solutions for next-generation optoelectronic systems.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"5 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515767","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}

{"title":"A novel heat treatment combining cryogenic and aging treatment for enhanced mechanical properties of extruded Mg-8Gd-3Y-0.4Zr alloy","authors":"Haoran Pang, Liwei Lu, Xingjie Liang, Gongjii Yang, Gang Liu, Lifei Wang, Hua Zhang, Yujuan Wu","doi":"10.1016/j.jallcom.2025.181919","DOIUrl":"https://doi.org/10.1016/j.jallcom.2025.181919","url":null,"abstract":"In this study, a novel heat treatment consisting of aging treatment and cryogenic treatment was conducted to process extruded Mg-8Gd-3Y-0.4Zr alloy. The microstructure characteristics were systematically investigated using scanning electron microscopy (SEM), Optical microstructure (OM), electron back-scatter diffraction (EBSD), X-Ray diffraction (XRD) and transmission electron microscope (TEM) to study their correlation with the mechanical properties. The results show that the combination of cryogenic treatment and aging treatment significantly enhances mechanical properties. The sample subjected to 1<ce:hsp sp=\"0.25\"></ce:hsp>h cryogenic treatment followed by aging treatment demonstrated the highest strength (435.5<ce:hsp sp=\"0.25\"></ce:hsp>MPa) among all tested specimens, exhibiting a strength improvement exceeding 100<ce:hsp sp=\"0.25\"></ce:hsp>MPa compared to that treated solely with 1<ce:hsp sp=\"0.25\"></ce:hsp>h cryogenic treatment. However, this was accompanied by a 12.8% reduction in ductility. This phenomenon can be attributed to the aging process, which promotes the nucleation and growth of fine Mg<ce:inf loc=\"post\">3</ce:inf>(Gd,Y) and Mg<ce:inf loc=\"post\">24</ce:inf>(Gd,Y)<ce:inf loc=\"post\">5</ce:inf> precipitates, thereby enhancing second-phase strengthening effects. Conversely, these precipitates may induce stress concentration, leading to decreased plasticity. In addition, the aging treatment following cryogenic treatment can alter grain orientation and reduce dislocation density. Samples subjected solely to cryogenic treatment exhibited more frequent activation of both prismatic &lt;c&gt; slip and pyramidal &lt;c+a&gt; slip systems, which significantly enhanced plasticity. Notably, prolonged cryogenic treatment duration may reduce strength.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"70 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144504005","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}

{"title":"Modification mechanism of eutectic Si phases in Al-Si-Mg series alloys with Sc addition","authors":"Yaohua Wang, Xueping Zhao, Fei Liu, Xiaohuo Hou, Pucun Bai, Xiaoming Cui","doi":"10.1016/j.jallcom.2025.181912","DOIUrl":"https://doi.org/10.1016/j.jallcom.2025.181912","url":null,"abstract":"The modification mechanism of Sc additions to the eutectic Si phase in Al-7.0Si-0.3Mg alloys was investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The results indicated that the element Sc was able to modify the morphology of eutectic Si phase in the experimental alloys from a coarse plate-like shape to highly branched fibrous structures, inducing the formation of twinned branches at angles of 35.25° and 54.75°. In addition, a large number of twins, stacking faults, and Al-Si-Sc nanoclusters were observed in the modified Si phase. These nanoclusters are firstly preferentially segregated at the 70.5° twin intersections and twin fronts in the Si phase, demonstrating the applicability of the impurity-induced twinning (IIT) mechanism. And secondly, they are linearly aligned along the &lt;112&gt; growth direction of Si, supporting the poisoning of twin plane re-entrant edge (TPRE) mechanism was also applicable. Notably, this study found that the segregation of the nanoclusters in the Si phase was the key factor in inducing its modification effect, and these clusters only induced the formation of micro-twins or stacking faults of a few atomic layers thickness in the Si phase. This was different from the IIT mechanism and the poisoning of TPRE mechanism, which proposed that the modifier atomic themselves are adsorbed in the Si, inducing the formation of overall twins to achieve the modification effect.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"46 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515773","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}

{"title":"2.86-kV Vertical Cu2O/Ga2O3 Heterojunction Diodes with Stepped Double-layer Structure","authors":"XiaoHui Wang, MuJun Li, Yang Jiang, KangYao Wen, ChuYing Tang, FangZhou Du, Chun-Zhang Chen, ChenKai Deng, Yi Zhang, HongHao Lu, YiFan Cui, Qing Wang, HongYu Yu","doi":"10.1016/j.jallcom.2025.181672","DOIUrl":"https://doi.org/10.1016/j.jallcom.2025.181672","url":null,"abstract":"High-performance Cu<ce:inf loc=\"post\">2</ce:inf>O/β-Ga<ce:inf loc=\"post\">2</ce:inf>O<ce:inf loc=\"post\">3</ce:inf> heterojunction diodes (HJDs) with a notable breakdown voltage of 2860<ce:hsp sp=\"0.25\"></ce:hsp>V were achieved by employing a stepped double-layer (SDL) structure of Cu<ce:inf loc=\"post\">2</ce:inf>O. The device exhibits a turn-on voltage of 1.2<ce:hsp sp=\"0.25\"></ce:hsp>V, a specific on-resistance of 8.1 mΩ·cm<ce:sup loc=\"post\">2</ce:sup>, and a power figure-of-merit exceeding 1.0<ce:hsp sp=\"0.25\"></ce:hsp>GW/cm<ce:sup loc=\"post\">2</ce:sup>. Additionally, the HJD-SDL demonstrates consistent thermal stability, operating normally at temperatures up to 473<ce:hsp sp=\"0.25\"></ce:hsp>K. Simulation results indicate that the SDL structure, consisting of a p<ce:sup loc=\"post\">+</ce:sup> Cu<ce:inf loc=\"post\">2</ce:inf>O/p<ce:sup loc=\"post\">-</ce:sup> Cu<ce:inf loc=\"post\">2</ce:inf>O structure, significantly enhances breakdown performance by effectively suppressing the peak electric field and redistributing it within the device bulk. The temperature-dependent I–V analysis reveals the variations in electrical performance parameters underlying the forward conduction mechanism. The interface trap density at Cu<ce:inf loc=\"post\">2</ce:inf>O/Ga<ce:inf loc=\"post\">2</ce:inf>O<ce:inf loc=\"post\">3</ce:inf> heterojunction is determined through frequency-dependent capacitance and conductance measurements. These findings provide a promising and effective strategy for the development of Ga<ce:inf loc=\"post\">2</ce:inf>O<ce:inf loc=\"post\">3</ce:inf> bipolar power electronics.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"10 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144504003","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}