Materials Science and Engineering: A最新文献_第5页

Improving the hydrogen embrittlement resistance of high-strength fastener steels 提高高强度紧固件钢的抗氢脆性能

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-12-03 DOI: 10.1016/j.msea.2025.149560

Marjolein Weyns , Vsevolod Razumovskiy , Matthew Galler , Kim Verbeken , Tom Depover

High-strength fasteners play a crucial role in maintaining the structural integrity in various applications. Unfortunately, they are highly sensitive to hydrogen embrittlement (HE). This research aims to improve the HE resistance of steel grade 32CrB4 by adding the carbide-forming elements titanium and vanadium. Three alloys are considered: alloy A (32CrB4), B (alloy A + Ti), and C (alloy B + V). The hydrogen-assisted mechanical degradation is evaluated by performing slow strain rate tensile (SSRT) tests with both ex- and in-situ hydrogen charging. The influence of hydrogen on the mechanical properties is typically quantified by using a hydrogen embrittlement index (HEI). When using the relative reduction of area (RRA), a clear discrepancy was observed between the results obtained for ex- and in-situ testing. For the former, alloys B and C showed a clear improvement in behaviour, whereas no improvement was observed for the latter. More appropriate HEI's were defined directly related to the impact of the charging method on the fracture mechanism, indicating a higher HE resistance for alloys B and C in both cases. For ex-situ testing, the improved behaviour is linked to a preserved fracture pattern called radial cracking, also observed in air reference testing for all materials, yet only present in H conditions for alloys B and C. For in-situ testing, by combining SSRT and thermal desorption spectroscopy (TDS), it was demonstrated that additional hydrogen trapping occurs in alloys B and C during tensile testing, as compared to charging without mechanical loading, explaining their improved behaviour.

在各种应用中，高强度紧固件在保持结构完整性方面起着至关重要的作用。不幸的是，它们对氢脆（HE）非常敏感。本研究旨在通过添加碳化物形成元素钛和钒来提高钢级32CrB4的抗HE性能。考虑三种合金：合金A (32CrB4)，合金B（合金A + Ti）和合金C（合金B + V）。氢气辅助的机械降解是通过进行慢应变速率拉伸（SSRT）试验来评估的，同时进行了前充氢和原位充氢。氢对力学性能的影响通常用氢脆指数（HEI）来量化。当使用相对面积收缩率（RRA）时，在现场测试和现场测试中得到的结果有明显的差异。对于前者，合金B和C表现出明显的性能改善，而对于后者则没有观察到任何改善。更合适的HEI被定义为直接与充注方式对断裂机制的影响相关，表明合金B和C在两种情况下都具有更高的HE电阻。对于非原位测试，性能的改善与被称为径向开裂的断裂模式有关，这在所有材料的空气参考测试中也观察到，但只存在于H条件下的合金B和C。对于原位测试，通过结合SSRT和热解吸光谱（TDS），证明了在拉伸测试期间，与没有机械载荷的加载相比，合金B和C中出现了额外的氢捕获，解释了它们性能的改善。

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引用次数: 0

Achieving exceptional ductility in an ultra-high strength heterostructured lightweight steel through regulated microstructural engineering 通过规范的微结构工程实现超高强度异质轻钢的卓越延展性

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-12-03 DOI: 10.1016/j.msea.2025.149572

Qian Cheng , Chao Zhang , Bo Yang , Zihao Feng , Xianghui Zheng , Qingyuan Wang , Wenquan Cao , Chongxiang Huang

Achieving ultra-high strength (>1.5 GPa) within lightweight steels necessitates the introduction of structures with high dislocation density, while how to tailor these structures to maintain an exceptional ductility? In this study, a dual-phase regulated heterostructured lightweight steel with dispersed deformed substructures (with the sizes of several hundred nanometers and an average spacing less than 1 μm) is prepared through critical annealing followed by pre-straining (ε = 18 %), contrasting it with the rolling-rested, and banded partially recrystallized counterpart fabricated solely by the truncated annealing. The regulated microstructure achieves an ultra-high strength (∼1.67 GPa), coupled with a substantially improved ductility of 18.6 %, twice that of the banded partially recrystallized counterpart. Deformation analysis reveals notable strain partitioning, where austenite grains undertake primary applied strains, evidenced by intense slip bands, dislocation pile-ups, and minor stacking faults, suppressing crack initiation and propagation. Ultra-high strength stems from heterogeneous-deformation induced (HDI) strengthening, dislocation strengthening, and intrinsic strengthening of austenite and B2 phases. Pronounced dual-synergistic deformation, operating at intergranular and intragranular scales, promotes the exceptional ductility. Fracture resistance is notably enhanced via restructuring failure pathways, enabled by stable interfacial cohesion and effective constraints from ductile constituents. This work provides insights into microstructural design of ultra-high-strength lightweight steel possessing exceptional ductility.

在轻钢中实现超高强度（>1.5 GPa）需要引入具有高位错密度的结构，而如何定制这些结构以保持卓越的延展性？本研究通过临界退火和预应变（ε = 18%）制备了具有分散变形子结构（尺寸为几百纳米，平均间距小于1 μm）的双相调节异质轻钢，并与仅通过截断退火制备的滚动休息带状部分再结晶的异质轻钢进行了对比。调节后的微观结构实现了超高强度（约1.67 GPa），同时延展性大幅提高，达到18.6%，是带状部分再结晶合金的两倍。变形分析揭示了显著的应变分配，其中奥氏体晶粒承担主要的施加应变，表现为强烈的滑移带、位错堆积和较小的层错，抑制了裂纹的萌生和扩展。超高强度源于非均质变形诱导（HDI）强化、位错强化以及奥氏体和B2相的本征强化。明显的双协同变形，作用于晶间和晶内，促进了特殊的延展性。通过重构断裂路径，通过稳定的界面内聚和延性成分的有效约束，显著增强了抗断裂能力。这项工作为具有特殊延展性的超高强度轻钢的微观结构设计提供了见解。

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引用次数: 0

Outstanding mechanical and electrical properties of CoCrFeMnNi high entropy alloy with partial substitution of Mn by Si Si部分取代Mn的CoCrFeMnNi高熵合金具有优异的力学和电学性能

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-12-02 DOI: 10.1016/j.msea.2025.149571

Jiaqi Tang , Hui Yang , Yalin Xue , Wenjuan Jia , Yang Wang , Yunjia Shi , Hai Huang , Guopeng Zhang

Face-centered cubic (FCC)-structured high entropy alloys (HEAs) with high plasticity and resistivity are promising candidates for the integration and miniaturization of electrothermal devices. Further improving their mechanical and electrical properties remains a key challenge. Here, partial substitution of Mn by Si is employed to modify the CoCrFeMnNi HEA (Cantor alloy), a representative FCC-structured HEA. A Co₂₀Cr₂₀Fe₂₀Ni₂₀Mn₁₀Si₁₀ (Si10) HEA with a high negative mixing enthalpy was fabricated by hot-pressing sintering of gas-atomized powder. The microstructure and the mechanical and electrical properties were investigated. The as-sintered Si10 alloy consisted of an equiaxed FCC major phase and a monoclinic minor phase. After solutionization at 1250 °C for 12 h, the minor phase dissolved, and the mechanical properties were significantly improved. The yield strength, ultimate strength, and elongation of the as-solutionized Si10 reached 289.6 MPa, 791.1 MPa, and 79.5 %, respectively. This strong strength–ductility combination was likely related to the extremely fine deformation-twin thickness, which produced a dynamic Hall–Petch effect and stable strain-hardening rate. Moreover, the as-solutionized Si10 alloy exhibited a high electrical resistivity of 153.0 μΩ cm and a low temperature coefficient of resistivity of 5.2 × 10⁻⁴ °C⁻¹, both significantly improved relative to the Cantor alloy. Si substitution enhanced the mechanical and electrical properties simultaneously, providing useful guidance for developing high-performance electrical resistance HEAs.

面心立方结构高熵合金（FCC）具有较高的塑性和电阻率，是电热器件集成化和小型化的理想材料。进一步提高其机械和电气性能仍然是一个关键的挑战。本文采用Si部分取代Mn来修饰CoCrFeMnNi HEA （Cantor合金），这是一种典型的fcc结构HEA。采用气体雾化粉末热压烧结法制备了具有高负混合焓的Co20Cr20Fe20Ni20Mn10Si10 (Si10) HEA。对其显微组织和力学性能进行了研究。烧结Si10合金由等轴FCC主相和单斜次相组成。1250℃固溶12 h后，小相溶解，力学性能显著提高。固溶态Si10的屈服强度、极限强度和延伸率分别达到289.6 MPa、791.1 MPa和79.5%。这种强大的强度-塑性组合可能与极细的变形孪晶厚度有关，从而产生了动态的Hall-Petch效应和稳定的应变硬化速率。固溶态Si10合金的电阻率为153.0 μΩ cm，低温电阻率系数为5.2 × 10−4°C−1，均较Cantor合金有显著提高。硅取代同时提高了材料的力学性能和电学性能，为开发高性能电阻HEAs提供了有益的指导。

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引用次数: 0

The effect of prior austenite grain size on hierarchical structures of lath martensite in a 22MnB5 steel 奥氏体晶粒尺寸对22MnB5钢板条马氏体分层组织的影响

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-12-02 DOI: 10.1016/j.msea.2025.149544

Chien-Yu Tseng , Ming-Yi Cheng , Tzu-Ching Tsao , Po-Han Chiu , Yu-An Chen , Chu-Jen Chen , R.D.K. Misra , Yo-Lun Yang , Te-Cheng Su , Chih-Yuan Chen , Jer-Ren Yang

Electron backscatter diffraction (EBSD) has been extensively employed to characterize the lath martensite structure; however, systematic investigations of substructures across entire prior-austenite grains, particularly the spatial distributions of lath sub-units observed along specific zone axes, remain limited. In this study, samples of 22MnB5 steel (Fe-0.22C-1.17Mn-0.17Si-0.25Cr-0.0021B, wt%) were subjected to austenitization at 1000 °C or 1200 °C for 5 min, followed by rapid quenching to room temperature. The treatments produced small (∼8 μm, SG) and large (∼60 μm, LG) prior-austenite grains, respectively. The resulting lath martensite substructures within the full prior-austenite grains in SG and LG samples were analyzed, with emphasis on the crystallography of sub-units along three prior-austenite orientations: [001]_γ,

{(0 \bar{1} 1)}_{γ}

and [111]_γ. The hierarchical organization of lath martensite was clearly resolved in the LG sample, where 24 Kurdjumov–Sachs (K–S) variants were distinctly identified, particularly along [001]_γ. The systematic comparison of SG and LG samples provides detailed insights into the hierarchical features of lath martensite across entire prior-austenite grains with specific orientations.

电子背散射衍射（EBSD）被广泛用于板条马氏体结构的表征；然而，对整个奥氏体晶粒的亚结构的系统研究，特别是沿特定带轴观察到的板条亚单元的空间分布，仍然有限。在本研究中，将22MnB5钢（Fe-0.22C-1.17Mn-0.17Si-0.25Cr-0.0021B, wt%）样品在1000℃或1200℃下进行奥氏体化5 min，然后快速淬火至室温。这两种处理分别产生小的（~ 8 μm， SG）和大的（~ 60 μm， LG）奥氏体晶粒。分析了SG和LG样品中完整奥氏体晶粒内的板条马氏体亚结构，重点研究了三个奥氏体取向：[001]γ、01¯1γ和[111]γ的亚基结晶学。在LG样品中，板条马氏体的分层组织被清楚地解决了，其中24个Kurdjumov-Sachs （K-S）变体被清楚地识别出来，特别是沿着[001]γ。SG和LG样品的系统比较提供了详细的见解，板条马氏体的层次特征，跨越整个具有特定取向的奥氏体晶粒。

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引用次数: 0

Plasma wire arc additive manufacturing (PWAAM) of high-strength steel on a high-carbon steel, consideration and characterization of the transition area 等离子丝电弧增材制造（PWAAM）高强钢对高碳钢过渡区的考虑与表征

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-12-02 DOI: 10.1016/j.msea.2025.149543

Matthias Moschinger , Ruogu Hou , Junya Inoue , Verena Maier-Kiener , Peter Zok , Saskia Siegert , Fernando Warchomicka , Norbert Enzinger

In hybrid metal structures where high-strength steel (10NiMnMoCr8-7-6) is added onto a high-carbon (C55E) steel substrate using plasma wire arc additive manufacturing (PWAAM), the transition area remains critical due to the complex interactions between the alloys and their thermal histories.

This study uses a combination of high-resolution characterization methods to investigate the local mechanical properties and microstructural gradients in the unaffected substrate, the heat-affected zone (HAZ), the dilution zone (DZ), and the all-weld metal (AWM). Carbon content and microstructure were systematically characterized and linked to the respective microstructural zones of the transition area to evaluate the differences in microstructure and mechanical properties.

In addition to micro-tensile tests and hardness measurements, nanoindentation and indentation plastometry-based imprint testing (IPIT) were applied to capture local mechanical properties at a high resolution across the transition area.

The different carbon content in combination with the altering thermal history establishes a complex microstructure gradient, correlating with local mechanical properties — a relationship that was clearly revealed by the combined characterization methods.

在混合金属结构中，使用等离子电弧增材制造（PWAAM）将高强度钢（10NiMnMoCr8-7-6）添加到高碳（C55E）钢基体上，由于合金及其热历史之间复杂的相互作用，过渡区域仍然是关键。本研究结合高分辨率表征方法，研究了未受影响的基体、热影响区（HAZ）、稀释区（DZ）和全焊金属（AWM）的局部力学性能和微观结构梯度。系统地表征了碳含量和微观组织，并将其与过渡区各自的微观组织区联系起来，以评估微观组织和力学性能的差异。除了微拉伸测试和硬度测量外，还应用了纳米压痕和基于压痕塑性测量的压痕测试（IPIT），以高分辨率捕获整个过渡区域的局部力学性能。不同的碳含量与改变的热历史相结合，建立了复杂的微观结构梯度，与局部力学性能相关-这种关系通过组合表征方法清楚地揭示出来。

{"title":"Plasma wire arc additive manufacturing (PWAAM) of high-strength steel on a high-carbon steel, consideration and characterization of the transition area","authors":"Matthias Moschinger , Ruogu Hou , Junya Inoue , Verena Maier-Kiener , Peter Zok , Saskia Siegert , Fernando Warchomicka , Norbert Enzinger","doi":"10.1016/j.msea.2025.149543","DOIUrl":"10.1016/j.msea.2025.149543","url":null,"abstract":"<div><div>In hybrid metal structures where high-strength steel (10NiMnMoCr8-7-6) is added onto a high-carbon (C55E) steel substrate using plasma wire arc additive manufacturing (PWAAM), the transition area remains critical due to the complex interactions between the alloys and their thermal histories.</div><div>This study uses a combination of high-resolution characterization methods to investigate the local mechanical properties and microstructural gradients in the unaffected substrate, the heat-affected zone (HAZ), the dilution zone (DZ), and the all-weld metal (AWM). Carbon content and microstructure were systematically characterized and linked to the respective microstructural zones of the transition area to evaluate the differences in microstructure and mechanical properties.</div><div>In addition to micro-tensile tests and hardness measurements, nanoindentation and indentation plastometry-based imprint testing (IPIT) were applied to capture local mechanical properties at a high resolution across the transition area.</div><div>The different carbon content in combination with the altering thermal history establishes a complex microstructure gradient, correlating with local mechanical properties — a relationship that was clearly revealed by the combined characterization methods.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"951 ","pages":"Article 149543"},"PeriodicalIF":7.0,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747573","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

Mechanisms governing synergistic enhancement of strength-plasticity and α2 thermal stability in TiAl alloys fabricated via selective electron beam melting 选择性电子束熔化制备TiAl合金的强度塑性和α2热稳定性协同增强机制

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-12-02 DOI: 10.1016/j.msea.2025.149561

Qingchao Li , Shulong Xiao , Zhenquan Liang , Guo Jiang , Yifan Wang , Ye Tian , Xicheng Wang , Fuyang Cao , Yuyong Chen , Lijuan Xu

The incoordination of strength-plasticity and the low thermal stability of α₂ phases seriously restrict the development of TiAl alloys. To overcome these shortcomings, Ti-48Al-2Cr-2Nb (at.%) alloys with superior mechanical performance and high thermal stability of α₂ phases were prepared by reasonably optimizing the printing strategy of selective electron beam melting (SEBM) in this work. The alloys exhibit the room-temperature compressive strength of 2716.08 MPa with 58.71 % fracture strain, and maintain compressive strength of 749.43 MPa at 850 °C. The improvement of strength-toughness and enhanced α₂-phase thermal stability are mainly attributed to the influence of long-period stacking ordered (LPSO) structures introduced via SEBM. High temperature and stress will induce the generation of high density 9R-type LPSO structures, and 9R structures can promote the orientation transformation of γ phases. Abundant 9R structures and deformation twins play a key role in enhancing strength and toughness. Furthermore, this study reveals the transformation mechanism of 9R-type and 6H-type LPSO structures and first proposes three reaction pathways for the transformation from γ to α₂ phases, with 6H phases serving as the intermediate structures. The three reaction processes are γ→6H→α₂, γ→9R→6H→α₂ and γ→γ_T→6H→α₂, in which 9R and twin structures can transform into 6H configurations, promoting the transformation of γ to α₂ phases. Due to γ→α₂ transformation induced by LPSO structures, the conventional decomposition reaction of α₂ phase is effectively inhibited, thus improving the stability of α₂ phases.

α2相的强度塑性不协调和较低的热稳定性严重制约了TiAl合金的发展。为了克服这些缺点，本文通过合理优化选择性电子束熔化（SEBM）的打印策略，制备了具有优异力学性能和α2相热稳定性的Ti-48Al-2Cr-2Nb （at.%）合金。合金的室温抗压强度为2716.08 MPa，断裂应变为58.71%，850℃时抗压强度为749.43 MPa。强韧性的提高和α2相热稳定性的增强主要是由于通过SEBM引入长周期有序堆积（LPSO）结构的影响。高温和应力会诱导生成高密度的9R型LPSO结构，9R结构能促进γ相的取向转变。丰富的9R组织和变形孪晶是提高材料强度和韧性的关键。此外，本研究揭示了9r型和6H型LPSO结构的转化机理，并首次提出了以6H相为中间结构的γ向α2相转化的三种反应途径。三个反应过程分别为γ→6H→α2、γ→9R→6H→α2和γ→γ t→6H→α2，其中9R和孪晶结构转变为6H构型，促进γ向α2相转变。由于LPSO结构诱导γ→α2转变，有效抑制了α2相的常规分解反应，从而提高了α2相的稳定性。

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引用次数: 0

Phase stability, microstructure, and mechanical properties of the ultra-strong lightweight eutectic AlCr1.3TiNi2 alloy 超高轻质共晶AlCr1.3TiNi2合金的相稳定性、显微组织和力学性能

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-12-02 DOI: 10.1016/j.msea.2025.149536

Nadeem Fayaz Lone , Frank Czerwinski , Daolun Chen

Thermal stability of the newly developed AlCr_1.3TiNi₂ lightweight complex concentrated alloy (CCA) was assessed through a retention study of the phase composition, microstructure and mechanical properties after thermal exposures up to 1100 °C. The as-cast alloy with a density of 6.42 g/cm³, hardness of 669 HV, yield stress, ultimate compressive strength, and fracture strain of 1364 MPa, 2384 MPa and 19 %, respectively, displayed a near eutectic predominantly lamellar structure consisting of the Heusler-like L2₁ phase rich in Ni, Al, and Ti, and BCC phase rich in Cr. Although there was a partial change from lamellar to rod-like morphology during heating with some spheroidization, the overall coarsening of the lamellae was limited, and the initial lamellae width of 200–250 nm still remained below 500 nm after 10 h exposure at 1100 °C. The phase and microstructural stability was accompanied by the high retention rate of mechanical properties where the alloy retained about 95 % of its initial hardness, 94 % of yield stress and 66 % of ultimate compressive strength after exposures up to 1100 °C. Despite the anomaly of strength retention, the specific properties of this alloy are advantageous than that for conventional superalloys, high entropy alloys and CCAs designed for high temperature service.

通过对AlCr1.3TiNi2轻质复合浓缩合金（CCA）在1100℃高温下的相组成、显微组织和力学性能的保留研究，对其热稳定性进行了评价。铸态合金的密度为6.42克/立方厘米,硬度669高压,屈服应力、极限抗压强度,断裂应变1364 MPa, 2384 MPa和19%,分别显示近共晶组成的层状结构为主Heusler-like L21阶段丰富的镍、铝、钛,和BCC阶段丰富的Cr。尽管有部分改变从片状、棒状形态在加热一些球状化处理,整体的粗化薄片是有限的,在1100℃下曝光10 h后，初始片宽200 ~ 250 nm仍低于500 nm。在1100℃的高温下，相和显微组织的稳定性伴随着较高的力学性能保留率，合金保留了95%的初始硬度，94%的屈服应力和66%的极限抗压强度。尽管强度保持异常，但该合金的特定性能优于常规高温合金、高熵合金和专为高温服务而设计的cca。

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引用次数: 0

Investigation on crystal plasticity of dual-phase NiTiNb shape memory alloy during intermediate temperature compression 双相NiTiNb形状记忆合金中温压缩晶体塑性研究

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-12-02 DOI: 10.1016/j.msea.2025.149562

Dezhen Zhang , Shuyong Jiang , Xiaoqian Duan , Lingyu Meng , Bingyao Yan , Dong Sun , Peng Lin , Yanqiu Zhang

The present study develops crystal plasticity finite element method (CPFEM) model of a dual-phase NiTiNb alloy based on intermediate temperature compression experiments, which incorporates slip systems, statistically stored dislocation (SSD) density and geometrically necessary dislocation (GND) density. The developed CPFEM model can effectively simulate evolution of texture during plastic deformation of NiTiNb alloy. Both B2 austenite phase and β-Nb phase exhibit similar types of texture, where a pronounced <111> fiber texture gradually is generated with increasing plastic deformation. Plastic deformation of NiTiNb alloy is considerably associated with activation of slip systems, where {110}<100> slip system family plays a predominant role in plastic deformation of B2 austenite phase, whereas {112}<111> slip system family is dominant in plastic deformation of β-Nb phases. Evolution of GND density and SSD density is elucidated during plastic deformation of NiTiNb sample. As plastic strain increases, SSD density increases gradually, whereas GND density decreases dramatically. Furthermore, SSD density presents a significant difference between β-Nb grains and NiTi ones, whereas GND density exhibits relatively little difference between β-Nb grains and NiTi ones. The interaction mechanism between β-Nb phase and NiTi matrix is further revealed, where formation of deformation bands results from deformation localization, which is validated by experimental observation.

本研究基于中温压缩实验，建立了包含滑移系统、统计存储位错（SSD）密度和几何必要位错（GND）密度的双相NiTiNb合金晶体塑性有限元模型。所建立的CPFEM模型能够有效地模拟NiTiNb合金塑性变形过程中织构的演变。B2奥氏体相与β-Nb相织构类型相似，随着塑性变形的增大，逐渐产生明显的<；111>；纤维织构。NiTiNb合金的塑性变形与滑移系统的激活密切相关，其中{110}<；100>；滑移系统族在B2奥氏体相的塑性变形中起主导作用，而{112}<；111>；滑移系统族在β-Nb相的塑性变形中起主导作用。研究了钛矿试样在塑性变形过程中GND密度和SSD密度的变化规律。随着塑性应变的增大，SSD密度逐渐增大，而GND密度急剧减小。β-Nb晶粒与NiTi晶粒的SSD密度差异显著，而GND密度差异相对较小。进一步揭示了β-Nb相与NiTi基体的相互作用机制，其中变形带的形成是变形局部化的结果，实验观察证实了这一点。

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引用次数: 0

Tailoring boride formation and strength–toughness balance in dissimilar superalloy joints with Ni–Pd-based brazing filler metals 用镍钯基钎料钎焊不同高温合金接头中硼化物形成和强度-韧性平衡的调整

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-12-02 DOI: 10.1016/j.msea.2025.149540

Zilong Guo , Qiying Li , Jiankang Zhang , Rui Hu , Xian Luo , Yanli Lu

The excessive formation of borides in brazed joints deteriorates the base metal and restricts joint performance. To address this issue, a Ni-Pd-based brazing filler metal (BFM) was developed using Ni-40Pd as the primary alloy system, while Si and B were rationally adjusted to suppress boride precipitation. The resulting Inconel 718/NP-BFM/Inconel 625 joints exhibited reduced boride content with a dispersed distribution. The strength degradation in the DAZ was limited to less than 15 %, significantly lower than the observed in conventional BNi-2 joints (>40 %). Interface defects were eliminated, and the joints demonstrated excellent forming quality, achieving a tensile shear strength of 443 MPa and an elongation of 18 % at room temperature. The formation and failure mechanisms of the joints were elucidated. Comparative analysis with high-Si and B BFMs highlighted the superior microstructural control and performance of the NP-BFM. The relationship between Si content and B diffusion rate was quantified, revealing the fundamental reason for the suppressed boride formation. Furthermore, the influence of boride types on strength enhancement and toughness degradation was modeled, clarifying the relative contributions of various boride types to overall joint performance.

钎焊接头中过量硼化物的形成使母材劣化，制约了接头的性能。为了解决这一问题，以Ni-40Pd为一次合金体系，合理调整Si和B抑制硼化物析出，研制了一种ni - pd基钎焊填充金属（BFM）。得到的Inconel 718/NP-BFM/Inconel 625接头的硼化物含量降低，且分布分散。DAZ的强度退化被限制在15%以下，显著低于传统BNi-2关节（40%）。消除了界面缺陷，接头具有良好的成形质量，室温拉伸剪切强度为443 MPa，伸长率为18%。阐明了接头的形成和破坏机制。与高si和B bfm的对比分析突出了NP-BFM优越的微观结构控制和性能。量化了Si含量与B扩散速率之间的关系，揭示了抑制硼化物形成的根本原因。此外，建立了不同硼化物类型对接头强度增强和韧性降低的影响模型，明确了不同硼化物类型对接头整体性能的相对贡献。

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引用次数: 0

Deformation-induced martensitic transformation in fused filament fabrication austenitic stainless steels during tension at wide range of temperatures (77 K, RT) 大范围温度（77 K， RT）下熔丝制造奥氏体不锈钢变形诱发马氏体相变

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-12-01 DOI: 10.1016/j.msea.2025.149552

J. Tabin , J. Kawałko , D. Schob , R. Roszak , A. Brodecki , P. Bała , Ph Maasch , Z. Kowalewski , M. Ziegenhorn

This study investigates the mechanical behaviour of fused filament fabrication (FFF) of 316L austenitic stainless steel compared to conventional 316L at room temperature and 77 K, focusing on deformation-induced martensitic transformation (DIMT). Results reveal that the Lüders-like effect, present in conventional 316L at 77 K, is absent in FFF 316L due to porosities that hinder martensitic front propagation. At room temperature, uniform strain distribution and DIMT were observed in conventional 316L, whereas in FFF 316L, martensitic nucleation occurred around pores, serving as a localized strengthening mechanism. Microstructural analysis identified Fe-δ islands along grain boundaries in FFF 316L, which contribute to its multiphase nature. Although FFF 316L demonstrates lower yield stress and elongation compared to conventional 316L, this study does not establish design allowables. The present findings are limited to monotonic tensile behaviour, fatigue performance and corrosion resistance under cryogenic conditions were not assessed. Further optimization of fabrication parameters to minimize ferrite content and porosities is suggested to enhance mechanical performance.

本研究研究了316L奥氏体不锈钢在室温和77 K下与传统316L相比较的熔丝制造（FFF）的力学行为，重点研究了变形诱发马氏体相变（DIMT）。结果表明，在77 K时，传统316L中存在的l德尔效应在FFF 316L中不存在，这是由于孔隙阻碍了马氏体前缘的扩展。室温下，常规316L的应变分布均匀，且存在DIMT，而FFF 316L的强化机制是在气孔周围形成马氏体形核。显微组织分析表明，FFF 316L晶界上存在铁δ岛，这是其多相性质的主要原因。虽然与传统的316L相比，FFF 316L表现出更低的屈服应力和延伸率，但本研究没有建立设计允许值。目前的研究结果仅限于单调拉伸行为，未评估低温条件下的疲劳性能和耐腐蚀性。建议进一步优化工艺参数，以减少铁素体含量和孔隙率，以提高力学性能。

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