IF 2.9 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materialia

Pub Date : 2026-01-24 DOI: 10.1016/j.mtla.2026.102673

J. Ribis

Oxide Dispersion Strengthened (ODS) materials are promising candidates for applications as core components for the next generation of nuclear power plants, including both GEN IV reactors and fusion reactors. These materials are characterized by a fine distribution of nano-oxides, which imparts excellent creep resistance. In this paper, a comprehensive characterization of the nano-oxides is proposed using Cs-corrected transmission electron microscopy. We show that three types of oxides exist within the ferritic matrix: nanoclusters with a structure identical to that of the matrix, pyrochlore-structured nano-oxides, and, for the first time, intermediate-sized nano-oxides exhibiting a structure in the process of transforming into the pyrochlore phase. We conclude that the formation of nano-oxides follows a precipitation sequence in which metastable nanoclusters act as precursors to the pyrochlore-like nano-oxides. Understanding this pathway is crucial, as it not only enables control over oxide distribution (in terms of size and density), but also provides insights into the formation of interface structure, which governs point defect and helium trapping. Moreover, it contributes to understanding the irradiation resistance of nano-oxides, since nanoclusters may be more resistant than pyrochlores, or vice versa.

氧化物弥散增强（ODS）材料是下一代核电站（包括GEN IV反应堆和聚变反应堆）核心部件的有希望的候选材料。这些材料的特点是纳米氧化物分布精细，具有优异的抗蠕变性能。本文采用cs校正透射电镜对纳米氧化物进行了全面表征。我们发现铁素体基体中存在三种类型的氧化物：具有与基体相同结构的纳米团簇，焦绿石结构的纳米氧化物，以及首次在向焦绿石相转变过程中表现出结构的中等尺寸纳米氧化物。我们得出结论，纳米氧化物的形成遵循沉淀顺序，其中亚稳纳米团簇作为焦绿石样纳米氧化物的前体。了解这一途径至关重要，因为它不仅可以控制氧化物的分布（在尺寸和密度方面），还可以深入了解控制点缺陷和氦捕获的界面结构的形成。此外，它有助于理解纳米氧化物的耐辐照性，因为纳米团簇可能比焦绿石更耐辐照，反之亦然。

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引用次数: 0

Effect of Ga additions as micro-alloying element to microstructure formation, thermal properties and mechanical properties of Sn-0.7Cu solder alloy 添加微量合金元素Ga对Sn-0.7Cu钎料合金显微组织形成、热性能和力学性能的影响

IF 2.9 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materialia

Pub Date : 2026-01-22 DOI: 10.1016/j.mtla.2026.102671

Sufian Firdaus Nazri , Mohd Arif Anuar Mohd Salleh , Nur Syahirah Mohamad Zaimi , Mohd Mustafa Al Bakri Abdullah , Mohd Sharizal Abdul Aziz , Somboon Otarawanna , Petrica Vizureanu , Andrei Victor Sandu

The present study investigates the effects of minor gallium (Ga) additions (0, 0.02, 0.05, 0.1, and 0.5 wt.%) on the microstructural, thermal, and mechanical properties of Sn-0.7Cu solder alloy. Cross-sectional microstructural analysis revealed that Ga is homogeneously distributed in the solder, forming a solid-solution structure and refining the bulk microstructure, with the most pronounced refinement observed at 0.1 wt.% Ga. This is evidenced by ∼16.9% reduction in the β-Sn area fraction region and the formation of finer, more uniformly dispersed Cu₆Sn₅ intermetallic compounds. At the solder/Cu interface, Ga reduces Cu₆Sn₅ scallop grooving and interfacial roughness, thereby limiting localized fast diffusion paths for Cu. The mechanical performance of Sn-0.7Cu-xGa solder joints results showed that Ga microalloying at 0.1 wt.% provided the best performance, increasing lap-shear strength by up to ∼43% and shifting the fracture surface toward dense, fine dimples, indicating enhanced plastic deformation and higher energy absorption. In contrast, excessive Ga addition (0.5 wt.%) reduced joint strength and promoted more brittle fracture features, likely due to the formation of Ga-rich phases that act as crack-initiation sites.

本研究研究了微量镓（Ga）添加量（0、0.02、0.05、0.1和0.5 wt.%）对Sn-0.7Cu钎料合金组织、热性能和力学性能的影响。横截面显微组织分析表明，Ga均匀分布在钎料中，形成固溶组织，并细化了钎料体组织，其中在0.1 wt.% Ga时细化最为明显。这可以通过β-Sn区分数区减少~ 16.9%和形成更精细、更均匀分散的Cu6Sn5金属间化合物来证明。在钎料/Cu界面处，Ga降低了Cu6Sn5的扇形沟槽和界面粗糙度，从而限制了Cu的局部快速扩散路径。Sn-0.7Cu-xGa焊点的力学性能结果表明，在0.1 wt.%的Ga微合金化时，焊点的力学性能最好，其拉剪强度提高了43%，断口表面转向致密、细小的韧窝，表明塑性变形增强，能量吸收更高。相反，过量的Ga添加量（0.5 wt.%）降低了接头强度，促进了更脆的断裂特征，这可能是由于形成了富Ga相作为裂纹起裂位点。

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引用次数: 0

Heterogeneous bending behavior of hot-rolled α-Titanium sheet via microstructure and texture evolution 热轧α-钛板微观组织与织构演化的非均匀弯曲行为

IF 2.9 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materialia

Pub Date : 2026-01-22 DOI: 10.1016/j.mtla.2026.102672

Sujit K Nayak, Jugal K Banikya, Devesh K Chouhan, Somjeet Biswas

This work investigates the heterogeneous bending behavior of hot-rolled

α

-Titanium (Ti) after

\sim 90^{\circ}

plane-strain bending at ambient temperature via microstructure and texture evolution. The through-thickness deformation heterogeneity in the bend portion could be microstructurally distinguished into three regions: the inner compressive region (ICR), the undeformed neutral region (NR), and the outer tensile region (OTR). The bend thickness of

α

-Ti sheets increased, and the NR shifts towards the OTR (instead of ICR, which usually occurs in the case of Steel, Al, and Cu). This phenomenon could be attributed to the hot-rolled split basal texture normal to the rolling direction (RD). For this texture,

α

-Ti is geometrically hard in tension with higher yield strength (∼275 MPa), lower ductility (∼0.25) and strain hardening exponent (

n

, ∼0.15) than compression (∼240 MPa, ∼0.69, and ∼0.3) along the rolling direction. Thus, larger plasticity was possible in ICR, accompanied with

{10 \bar{1} 2} 〈 10 \bar{1} 1 〉

extension twins (ET) evolution. Lesser deformation occurred in OTR with the formation of a few

{11 \bar{2} 2} 〈 11 \bar{2} \bar{3} 〉

contraction twins (CT). The ETs that developed in ICR followed Schmid's law, while the CTs in OTR didn't. After the springback, compressive residual stresses in both ICR and OTR resulted from balancing the elastic bending moment during unbending.

本研究通过显微组织和织构演变研究了热轧α-钛（Ti）在室温下经∼90°平面应变弯曲后的非均匀弯曲行为。在微观结构上，弯曲部分的全厚变形不均匀性可分为三个区域：内压缩区（ICR）、未变形中性区（NR）和外拉伸区（OTR）。α-Ti板的弯曲厚度增加，NR向OTR方向移动（而不是通常发生在钢、Al和Cu中的ICR）。这种现象可归因于与轧制方向垂直的热轧裂基底织构（RD）。对于该织构，α-Ti在拉伸状态下具有几何硬，沿轧制方向的屈服强度（~ 275 MPa）高于压缩（~ 240 MPa, ~ 0.69和~ 0.3），延展性（~ 0.25）和应变硬化指数（n, ~ 0.15）低于拉伸（~ 240 MPa, ~ 0.69和~ 0.3）。因此，ICR可能具有更大的可塑性，伴随着{101¯2}< 101¯1 >延伸孪晶（ET）演化。OTR变形较小，形成少量{112¯2}< 112¯3¯>收缩孪晶（CT）。ICR中开发的ETs遵循施密特定律，而OTR中的ct则没有。回弹后，ICR和OTR的残余压应力都是由平衡非弯曲过程中的弹性弯矩产生的。

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引用次数: 0

Characterization of the stress-induced martensitic transformation in a Ti-Zr-Nb-Sn biomedical alloy manufactured by laser powder bed fusion 激光粉末床熔合Ti-Zr-Nb-Sn生物医用合金应力诱导马氏体相变的表征

IF 2.9 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materialia

Pub Date : 2026-01-22 DOI: 10.1016/j.mtla.2026.102670

Hugo Schaal , Philippe Castany , Thierry Gloriant

A new potentially biocompatible Ti-22Zr-7Nb-2Sn (at.%) alloy was prepared by laser powder bed fusion (L-PBF) directly from pure elemental powders (in situ alloying). The manufactured alloy was characterized in its as-fabricated state by cyclic tensile tests, X-ray diffraction (XRD), transmission electron microscopy (TEM) observations and electron back-scattered diffraction (EBSD). The as-fabricated microstructure is dual-phased, composed of both β and α″ phases, with a majority of β phase. Cyclic tensile tests show high strain-hardening, with a maximum strain-hardening rate of approximately 14 GPa. The post deformation microstructure is studied to highlight the deformation mechanisms of the present alloy and exhibits a large fraction of stress-induced martensitic α″ phase, which formed from the parent β phase according to the standard orientation relationship (OR) during tensile test. The identification of the martensitic variants, their interfaces with the parent phase and the twinning relationships between them are reported in this study based on crystallographic investigations. In view of all these results, a deformation sequence of the Ti-22Zr-7Nb-2Sn (at.%) alloy is proposed.

以纯元素粉末（原位合金化）为原料，采用激光粉末床熔合（L-PBF）法制备了具有生物相容性的新型Ti-22Zr-7Nb-2Sn （at.%）合金。通过循环拉伸试验、x射线衍射（XRD）、透射电镜（TEM）和电子背散射衍射（EBSD）对制备的合金进行表征。制备后的微观结构为双相结构，由β相和α″相组成，以β相为主。循环拉伸试验显示高应变硬化，最大应变硬化速率约为14 GPa。变形后显微组织研究了合金的变形机制，发现合金中存在大量应力诱导的α″相，该相是由基体β相根据标准取向关系（OR）在拉伸试验中形成的。本文报道了基于晶体学研究的马氏体变异体的识别、与母相的界面以及它们之间的孪生关系。根据以上结果，提出了Ti-22Zr-7Nb-2Sn （at.%）合金的变形顺序。

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引用次数: 0

Porcine acellular dermal matrix facilitates hair follicle stem cells entering the hair cycle in C57/BL6 mice 猪脱细胞真皮基质促进毛囊干细胞进入C57/BL6小鼠毛发周期

IF 2.9 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materialia

Pub Date : 2026-01-19 DOI: 10.1016/j.mtla.2026.102669

Dar-Jen Hsieh , Srinivasan Periasamy , Ko-Chung Yen , Dur-Zong Hsu , Su-Shin Lee

Alopecia is a skin disease characterized by hair loss, which mainly distresses mental health and quality of life. A rise in the number of alopecia cases is evolving due to a variety of factors. We developed a porcine collagen acellular dermal matrix (ADM) using supercritical carbon dioxide (SCCO₂) extraction technology. We then cryo-ground the ADM into particles, ranging from 50–150 μm, named ADM scaffolds. In the present study, we used C57BL/6 mice injected with ADM scaffold and evaluated hair growth with and without mice Platelet-Rich Plasma (PRP), to evaluate its efficacy in hair regeneration. The combination of the ADM scaffold and mice PRP exhibited a synergistic effect. Hair growth was observed in ADM scaffold-treated mice in a time-dependent manner. Subdermal injection of the ADM scaffold enabled a serial cascade of stem cell differentiation markers for hair regeneration. ADM scaffold injected in the subdermal layer of the skin was found to modulate the CD34-positive stem cells and then followed by the expression of the hair cycle differentiation-related markers Sox9, Wnt3a, β-catenin, Ki67, and Lef-1, thereby modulating the hair cycle and increasing the hair follicles. To conclude, SCCO₂-derived porcine ADM scaffold increased hair follicles and hair density and might be a therapeutic solution for alopecia, without any adverse effects.

脱发是一种以脱发为特征的皮肤病，主要影响心理健康和生活质量。由于各种因素，脱发病例的数量正在不断增加。采用超临界二氧化碳（SCCO2）萃取技术制备猪胶原脱细胞真皮基质（ADM）。然后我们将ADM冷冻研磨成50-150 μm的颗粒，命名为ADM支架。本研究以C57BL/6小鼠为实验对象，注射ADM支架，观察其在添加和不添加富血小板血浆（PRP）的情况下毛发生长情况，以评价其对毛发再生的作用。ADM支架与小鼠PRP联合使用具有协同作用。ADM支架处理小鼠毛发生长呈时间依赖性。皮下注射ADM支架使一系列的干细胞分化标记物级联用于毛发再生。皮下注射ADM支架可调节cd34阳性干细胞，随后调节毛发周期分化相关标志物Sox9、Wnt3a、β-catenin、Ki67、Lef-1的表达，从而调节毛发周期，增加毛囊数量。综上所述，scco2衍生的猪ADM支架增加了毛囊和毛发密度，可能是一种治疗脱发的解决方案，没有任何不良反应。

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引用次数: 0

Nozzle clogging in cold spray of aluminum 6061 through 304 stainless steel split nozzles: Mechanisms, observations, and quantitative measurements 在铝6061通过304不锈钢分裂喷嘴冷喷涂喷嘴堵塞：机制，观察和定量测量

IF 2.9 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materialia

Pub Date : 2026-01-17 DOI: 10.1016/j.mtla.2026.102668

Anthony Naccarelli , Wyatt Auman , Justin Reiss , Jeremy Schreiber , Mala Sharma , Timothy Eden

Diverging section nozzle clogging is an issue in high pressure cold spray that can limit spray-ability and process parameter selection for certain powder-nozzle material combinations. This phenomenon is not well understood or well-characterized due to the difficulty and cost required for experimentation. An experimental framework for quantitative evaluation and analysis of nozzle clogging in cold spray is presented for aluminum 6061 powder particles in 304 stainless steel split nozzles. Backscatter scanning electron microscopy was used to characterize nozzle wall deposits at various locations in the diverging section of the split nozzles and compared for different particle size distributions, powder flow times, and for a misaligned injector tube. Experimental data are presented and mechanisms for initiation and progression of nozzle clogging in cold spray are proposed. Particles impact the nozzle wall which leaves residual particle material adhered to the nozzle wall. Subsequent impacts lead to additional transferred particle material and the formation of agglomerates on the nozzle wall. There was a measured difference where a particle size distribution of 20–37µ m showed less overall deposited material and different agglomerate geometry in the latter half of the diverging section when compared to distributions with larger particle sizes. A misaligned injector showed more overall deposited material near-throat. Average particle speeds were measured and analyzed. Dynamic impact models were built and loaded with gas-dynamics model predictions at three different diverging section locations and three different impact angles. The impact models were used to explain percent area results related to particle size and injector offset.

在高压冷喷涂中，分散段喷嘴堵塞是一个问题，它会限制某些粉末-喷嘴材料组合的喷涂能力和工艺参数的选择。由于实验的难度和成本，这种现象还没有被很好地理解或很好地表征。提出了一种用于304不锈钢分体式喷嘴中6061铝粉末颗粒冷喷涂时喷嘴堵塞定量评价与分析的实验框架。利用后向散射扫描电子显微镜对劈裂式喷嘴发散段不同位置的喷嘴壁沉积物进行了表征，并对不同粒径分布、粉末流动时间和未对准的注入管进行了比较。给出了实验数据，并提出了冷喷雾中喷嘴堵塞的发生和发展机理。颗粒撞击喷嘴壁，留下残留颗粒材料粘附在喷嘴壁上。随后的冲击会导致额外的颗粒物质转移，并在喷嘴壁上形成团块。与粒径较大的分布相比，粒径20-37µm的分布在发散剖面的后半部分显示出较少的总体沉积物质和不同的团聚体几何形状。一个未对准的注入器在喉部附近显示了更多的整体沉积物质。测量并分析了平均粒子速度。在三种不同的分流段位置和三种不同的冲击角度建立了动态冲击模型，并加载了气体动力学模型预测结果。用冲击模型来解释与颗粒大小和喷射器偏移有关的百分比面积结果。

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引用次数: 0

In-flight reduction of iron oxides from various sources by hydrogen plasma 氢等离子体在飞行中还原各种来源的氧化铁

IF 2.9 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materialia

Pub Date : 2026-01-15 DOI: 10.1016/j.mtla.2026.102658

Jordan N. Figueiredo, Bassam B. Dally, Deanna A. Lacoste

This study demonstrates in-flight reduction using a stable, elongated-arc hydrogen plasma for three iron-bearing feedstocks: pure hematite, combusted iron from the MC

^{2}

burner in TuE Eindhoven, and goethite. Despite not being designed for process performance, a high absolute reduction degree was achieved (71%–76% for hematite/combusted iron; 42% for aluminum-bearing goethite) at short residence times (18-30 ms) with an efficiency of 26.8 g

_{i r o n}

/kWh. SEM shows that in-flight melting modifies combustion-induced morphological defects in combusted iron particles (e.g., cracks and hollow-sphere structures), confirming technical feasibility for iron production and the iron-power cycle. Goethite-rich feed benefits from rapid dehydroxylation. However, even small gangue fractions, especially aluminum phases, promote iron–aluminum spinel formation that impedes fast reduction. Because gangues are not removed by this route, they must be managed separately. These results indicate clear paths towards practical application: enclosing the plasma–particle interaction zone, extending residence time, and systematically testing lower-grade ores with spinel formation mitigation strategies.

该研究演示了使用稳定的长弧氢等离子体对三种含铁原料进行飞行还原：纯赤铁矿、埃因霍温理工大学MC2燃烧器燃烧的铁和针铁矿。尽管没有针对工艺性能进行设计，但在短停留时间（18-30 ms）内，达到了很高的绝对还原度（赤铁矿/燃烧铁为71%-76%，含铝针铁矿为42%），效率为26.8吉隆/千瓦时。扫描电镜显示，飞行熔化改变了燃烧铁颗粒中由燃烧引起的形态缺陷（如裂纹和空心球体结构），证实了铁生产和铁动力循环的技术可行性。富含针铁矿的饲料受益于快速去羟基化。然而，即使是很小的脉石组分，特别是铝相，也会促进铁铝尖晶石的形成，阻碍快速还原。因为脉石不能通过这条路线移除，所以它们必须单独管理。这些结果为实际应用指明了明确的道路：封闭等离子体粒子相互作用区，延长停留时间，并系统地测试具有尖晶石形成减缓策略的低品位矿石。

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引用次数: 0

The decomposing crystallography of sandwich-like microstructure from deformed martensite in Ti-10V-2Fe-3Al alloy Ti-10V-2Fe-3Al合金中变形马氏体三明治状组织的分解结晶学

IF 2.9 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materialia

Pub Date : 2026-01-15 DOI: 10.1016/j.mtla.2026.102666

Tong Wang , Xinfu Gu , Ping Yang , Mengqi Yan , Fuzhi Dai

Crystal defects are critical in the microstructure control of titanium alloys, as they determine the precipitation characteristics of α phase. In this study, the decomposition of stress-induced martensite in Ti-10V-2Fe-3Al is investigated to understand the effect of martensite on α precipitation. The crystallography between α and β phases is analyzed using Electron Backscatter Diffraction (EBSD) and Transmission Electron Microscopy (TEM). During decomposition, the martensite is first transformed into α, and then to β_T, with a misorientation of 50°/<110> with matrix β_M. During further aging, α begins to precipitate at the β_M-β_T boundaries, and α phase exhibits two types of orientation relationships with β phase, i.e. Type I: one involving a double Burgers orientation relationship (BOR) and Type II: the other involving a single-sided BOR with β_T while the other side follows

(\bar{1} 10) β M \sim (\bar{1} 2 \bar{1} 3) α [\bar{1} \bar{1} 1] β M \sim [\bar{1} 010] α

with β_M. As for Type I, the selection of single α variant is due to the constraint of the β grains,

< 1 \bar{1} 1 >_{β T}

and

< 1 \bar{1} \bar{1} >_{β M}

are parallel to

{[\bar{1} 2 \bar{1} 0]}_{α}

and

{[\overline{11} 20]}_{α}

respectively and its habit plane {334} is close to β_M-β_T boundary. In Type II, the selected α variant, which has a {334} habit plane, also lies close to the β_M-β_T boundary. This finding indicates that the variant selection rule of the habit plane governs α precipitation during martensite decomposition.

晶体缺陷决定了钛合金α相的析出特性，是钛合金微观组织控制的关键。本研究研究了应力诱导马氏体在Ti-10V-2Fe-3Al中的分解，以了解马氏体对α析出的影响。利用电子背散射衍射（EBSD）和透射电镜（TEM）分析了α和β相之间的晶体学。在分解过程中，马氏体首先转变为α，然后转变为βT，与基体βM的取向偏差为50°/<；110>；在进一步时效过程中，α在β m -βT晶界处开始析出，α相与β相表现出两种取向关系，即ⅰ型为双Burgers取向关系（BOR），ⅱ型为单侧BOR与β t取向关系，另一侧为（1¯10）β m ~(1¯21¯3)α[1¯1¯1]β m ~[1¯010]α与β m取向关系。对于I型，单个α变体的选择是由于β晶粒的约束，<11¯1>；β t和<；11¯1¯>；β m分别平行于[1¯21¯0]α和[11¯20]α，其习惯面{334}靠近β m -βT边界。在II型中，选择的α变异体也位于βM-βT边界附近，具有{334}习惯面。这一发现表明马氏体分解过程中习惯面的变异选择规律支配着α的析出。

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引用次数: 0

Occurrence of DIFT in steel at high temperatures and its newly discovered intragranular nucleation mechanism 高温下钢中DIFT的发生及其新发现的晶内成核机制

IF 2.9 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materialia

Pub Date : 2026-01-15 DOI: 10.1016/j.mtla.2026.102667

Jingming Zhao , Sheng Gao , Dezhi Li , Yongpeng Zhang , Xinjun Shen , Jun Chen , Xiaonan Wang , Guodong Wang

To overcome the industrial limitation of conventional deformation-induced ferrite transformation (DIFT), which is typically restricted to temperatures below 810 °C, this study employed Al alloying in an Fe-0.06C-1.5Mn steel. The addition of 1.5 wt % Al reduced the Gibbs free energy difference for the austenite-to-ferrite transformation by approximately 140 J/mol. This reduction effectively lowered the activation barrier for DIFT, significantly destabilized austenite, and successfully induced DIFT within an elevated temperature range of 800–1100 °C. Rolling at 1100 °C yielded DIFT ferrite grains of approximately 5 μm with a maximum ferrite fraction of 83 %, while rolling at 800 °C with low strain rates produced ultrafine DIFT ferrite of ∼2.36 μm. The enrichment of C and Al elements at prior austenite grain boundaries enhances local stability, suppressing boundary nucleation and forcing intragranular nucleation. This new phenomenon can be termed the "Continuous DIFT". This work provides a novel pathway for achieving DIFT at high temperature through Al alloying and developing high-strength-toughness steels.

为了克服传统变形诱导铁素体相变（DIFT）的工业局限性（通常限制在810℃以下），本研究在Fe-0.06C-1.5Mn钢中采用了Al合金。添加1.5 wt % Al可使奥氏体向铁素体转变的吉布斯自由能差降低约140 J/mol。这种还原有效地降低了DIFT的激活势层，显著地破坏了奥氏体的稳定性，并在800-1100℃的高温范围内成功地诱导了DIFT。在1100℃下轧制得到的DIFT铁素体晶粒约为5 μm，最大铁素体分数为83%，而在800℃下低应变速率轧制得到的超细DIFT铁素体晶粒约为2.36 μm。C和Al元素在奥氏体晶界的富集增强了局部稳定性，抑制晶界成核，迫使晶内成核。这种新现象可以称为“连续DIFT”。本研究为通过铝合金化实现高温DIFT和开发高强度韧性钢提供了一条新的途径。

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引用次数: 0

Deformation mechanisms of dual-phase high entropy alloy with 9R structures at ambient and cryogenic temperatures 常温和低温下9R组织双相高熵合金的变形机理

IF 2.9 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materialia

Pub Date : 2026-01-14 DOI: 10.1016/j.mtla.2026.102663

Min Peng , Zhixue Cheng , Yeqing Cai , Yongjiang Jiang , Jingjing Zhao , Xi Zhu , Lixia Wang

The role of 9R structures in mediating phase transformations and mechanical properties of high-entropy alloys (HEAs) remains inadequately understood. This study investigates the tensile behavior of an Fe₄₀Mn₃₅Co₂₀Cr₅ HEA containing pre-existing 9R structures at both room temperature and 77 K. Results confirm the operation of a transformation-induced plasticity (TRIP) effect under both conditions. It is noteworthy that the low-temperature environment not only enables the stable existence of 9R structures but also promotes a massive phase transformation into a hexagonal close-packed (HCP) structure, consequently leading to the formation of a rarely reported HCP network structure at cryogenic temperatures. The synergistic interaction among the 9R structures, stacking faults, dislocations, and the HCP network enables the alloy to achieve significantly enhanced strength at 77 K without compromising ductility. A key finding is the crystallographic alignment between the 9R and the newly formed HCP structures, providing direct evidence for the role of 9R as a potent TRIP enhancer. Supported by a proposed crystallographic model for the 9R→HCP transformation, this work offers critical insights for designing advanced cryogenic structural materials leveraging 9R-phase engineering.

9R结构在高熵合金（HEAs）相变和力学性能中的调节作用尚不清楚。本文研究了含有9R结构的Fe40Mn35Co20Cr5 HEA在室温和77 K下的拉伸行为。结果证实，在这两种条件下，相变诱发塑性（TRIP）效应都在起作用。值得注意的是，低温环境不仅使9R结构稳定存在，而且促进了大量的相变向六边形紧密堆积（HCP）结构转变，从而导致在低温下形成罕见的HCP网络结构。9R组织、层错、位错和HCP网络之间的协同作用使合金在77 K时的强度显著提高，而塑性不受影响。一个关键的发现是9R和新形成的HCP结构之间的晶体排列，为9R作为一种有效的TRIP增强剂的作用提供了直接证据。在提出的9R→HCP相变晶体学模型的支持下，这项工作为利用9R相工程设计先进的低温结构材料提供了重要的见解。

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