Materials Characterization最新文献

{"title":"An X-ray computed tomography study of three-dimensional microstructure evolution for undercooled SiNi three-phase peritectic-type alloys","authors":"Yuhao Wu ,&nbsp;Mingchen Du ,&nbsp;Zhiming Gao ,&nbsp;Rengeng Li ,&nbsp;Zhaoqi Hou ,&nbsp;Peipei Wang ,&nbsp;Juzhong Duan ,&nbsp;Jinyan Wang ,&nbsp;Yiting Xu ,&nbsp;Xi Chen","doi":"10.1016/j.matchar.2025.114904","DOIUrl":"10.1016/j.matchar.2025.114904","url":null,"abstract":"<div><div>Most of previous investigations on microstructure evolutions of undercooled peritectic alloys mainly performed on two-dimensional sections, and three-dimensional (3D) microstructure explorations of undercooled peritectic alloys contribute to understanding the crystal growth characteristics and spatial distribution features of constituted phases in 3D space geometry. In this work, 3D microstructure evolutions of undercooled Si<img>Ni peritectic-type alloys were investigated based on glass fluxing experiments assisted by the characterization of X-ray computed tomography. In experimental undercooling range, undercooled Si<img>Ni alloys appeared as primary Si phase surrounded by peritectic NiSi₂ phase plus the eutectic (NiSi+NiSi₂) phase inside the interdendritic gap. Primary Si and peritectic NiSi₂ phases with the major characteristics of plate-like structures became more with a rise in the undercooling. Meanwhile, plate-like Si phase shrank in the spatial direction of its maximum size, whereas peritectic phase thickened in three dimensions. With increasing the undercooling beyond a threshold value, lamellar eutectic evolved into anomalous eutectic. The volume-fraction reduction and microstructure refinement of eutectic phase happened under a higher undercooling. Owing to the upward movement of Si phase with a smaller density, the farther away from the sample bottom the more the primary Si phase and peritectic NiSi₂ phase, and the less the eutectic phase. Because of the relatively higher undercooling in the outside shell region of the sample, plate-like Si phase within the outside shell region was smaller and primary and peritectic phases were more than those inside the internal spherical regions of the sample, whereas the volume fraction of eutectic phase in the center of the sample was relatively higher.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114904"},"PeriodicalIF":4.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549755","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":"Morphological and crystallographic features of Laves phase in advanced 9 % Cr creep-resistant steel","authors":"E. Tkachev,&nbsp;Yu. Tkacheva,&nbsp;A. Belyakov,&nbsp;R. Kaibyshev","doi":"10.1016/j.matchar.2025.114907","DOIUrl":"10.1016/j.matchar.2025.114907","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The precipitation behavior of the Laves phase in a 9 % Cr martensitic steel during creep at 650 °C was investigated by means of transmission electron microscopy (TEM). The ideal stacking sequence of the Laves phase is interrupted by various defects, including basal, prismatic, and pyramidal planar faults. The high density of coexisting planar defects significantly affects the crystal structure of the C14 Laves phase, leading to the appearance of a five-fold symmetry structure with characteristics of quasicrystalline ordering. The preferred nucleation sites for the Laves phase particles were determined to be the ferrite (α) grain boundaries and the α/M&lt;sub&gt;23&lt;/sub&gt;C&lt;sub&gt;6&lt;/sub&gt; (M = Cr, Fe) interphase boundaries. Selected area electron diffraction and high-resolution TEM of extracted carbon replicas were employed to reveal the orientation relationships between the phases. In the case of interfacial precipitation, the lattice mismatch between the Laves phase and the α-matrix is discussed with respect to the adoption of two distinct orientation relationships with M&lt;sub&gt;23&lt;/sub&gt;C&lt;sub&gt;6&lt;/sub&gt; carbide: namely, &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mn&gt;01&lt;/mn&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;mi&gt;Laves&lt;/mi&gt;&lt;/msub&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;‖&lt;/mo&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mfenced&gt;&lt;mn&gt;110&lt;/mn&gt;&lt;/mfenced&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;‖&lt;/mo&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;mi&gt;α&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mfenced&gt;&lt;mn&gt;0001&lt;/mn&gt;&lt;/mfenced&gt;&lt;mtext&gt;Laves&lt;/mtext&gt;&lt;/msub&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;‖&lt;/mo&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;‖&lt;/mo&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mfenced&gt;&lt;mn&gt;011&lt;/mn&gt;&lt;/mfenced&gt;&lt;mi&gt;α&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, and &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mfenced&gt;&lt;mn&gt;0001&lt;/mn&gt;&lt;/mfenced&gt;&lt;mtext&gt;Laves&lt;/mtext&gt;&lt;/msub&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;‖&lt;/mo&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mfenced&gt;&lt;mn&gt;110&lt;/mn&gt;&lt;/mfenced&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;‖&lt;/mo&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;mi&gt;α&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mn&gt;01&lt;/mn&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;mtext&gt;Laves&lt;/mtext&gt;&lt;/msub&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;‖&lt;/mo&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/msub&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;‖&lt;/mo&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mn&gt;12&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;mi&gt;α&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, taking into account that M&lt;sub&gt;23&lt;","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114907"},"PeriodicalIF":4.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549756","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":"Structural, defect, and photoelectric characterization of CdTe-based single crystals grown by a vertical Bridgman method","authors":"Boyang Wang ,&nbsp;Pengfei Yu ,&nbsp;Yuting Li ,&nbsp;Qingyang Xu ,&nbsp;Yize Zhang ,&nbsp;Wanqi Jie","doi":"10.1016/j.matchar.2025.114899","DOIUrl":"10.1016/j.matchar.2025.114899","url":null,"abstract":"<div><div>This study presents a comparative characterization of CdZnTe, CdMnTe, and CdMgTe single crystals, grown via a modified vertical Bridgman method, focusing on their structural, defect, optical, and electrical properties for room-temperature radiation detection applications. XRD analysis confirmed the sphalerite structure of all three crystals, with distinct preferred orientations influenced by spontaneous nucleation. CdMgTe crystal featured a lower density of Te inclusions (approximately 10³ cm⁻²) compared to CdZnTe and CdMnTe. TEM analysis revealed all three crystals contained nanoscale Te precipitates, contributing to lattice distortion and dislocations. Compared to CdZnTe crystal, CdMnTe and CdMgTe exhibit better compositional uniformity. CdZnTe demonstrated superior crystal quality, with an average infrared transmittance of 62 % and a distinct free exciton peak in the photoluminescence spectrum. The resistivity of all three crystals met the specifications for room-temperature radiation detectors, with CdZnTe, exhibiting a resistivity of up to 7.09 × 10¹⁰ Ω·cm, showing the best detector performance.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114899"},"PeriodicalIF":4.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549750","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":"Experimental validation of the efficacy of X-ray computed tomography for the in-situ time-resolved observation of the aqueous degradation of uranium carbide","authors":"D. Samaras,&nbsp;C.P. Jones,&nbsp;J. Wąsik,&nbsp;A. Banos,&nbsp;R.S. Springell,&nbsp;T.B. Scott","doi":"10.1016/j.matchar.2025.114872","DOIUrl":"10.1016/j.matchar.2025.114872","url":null,"abstract":"<div><div>Researching the aqueous degradation of uranium carbide (UC) is important for understanding and predicting the behaviour of carbide-based spent nuclear fuels during interim storage and subsequent geological disposal. UC has historically been tested in fast-neutron test reactors, and it is currently one of the fuel forms being considered in some advanced nuclear reactor concepts. If carbide fuel is to be used more widely in the future, it is important to understand and predict how the material degrades as a waste along with understanding its in-reactor fuel performance. However, because UC is documented as reacting readily with oxygen and water vapour, corrosion studies which simulate real-world storage and/or disposal conditions are challenging. This work provides experimental validation of the use of X-ray tomography (XRT) for the in-situ and time-resolved study of UC degradation in an aqueous environment. Three samples of UC were submerged in aqueous media and their subsequent degradation was monitored, in situ, using XRT. The first experiment, in pure MilliQ water, was monitored using time-resolved radiography through one single scanning sequence. This radiography sequence was compiled to produce a high-quality video of the corrosion process, whilst verifying the timescale for reaction and analysis conditions. The second experiment, involving immersion in a 1 M sodium carbonate groundwater simulant solution (pH = 12) revealed the existence of an induction period, estimated at approximately 8–10 h prior to the onset of visible degradation. The third sample (again in a sodium carbonate solution) demonstrated an influence of the surface area-to-volume ratio on the corrosion properties of the uranium carbide. This experimental work demonstrates that XRT is a viable technical approach for studying degradation of reactive nuclear materials held in encapsulated or enclosed environments, where physically intervening with the systems to make in-situ measurements would otherwise disrupt or invalidate the reaction conditions.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114872"},"PeriodicalIF":4.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577133","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":"Effects of laser power and Y2O3/Ti contents on microstructure and hardness of ODS-CrFeNi medium entropy alloys by additive manufacturing","authors":"Lu Wang ,&nbsp;Shang Gao ,&nbsp;Hui Li,&nbsp;Xiaolong Li,&nbsp;Dingbo Sun,&nbsp;Feng Jin,&nbsp;Zheng Lu","doi":"10.1016/j.matchar.2025.114897","DOIUrl":"10.1016/j.matchar.2025.114897","url":null,"abstract":"<div><div>Oxide dispersion strengthened (ODS)-CrFeNi medium entropy alloys (MEAs) were prepared by laser engineering near-net forming. The effects of varying laser power (1800 W, 2000 W, 2200 W and 2400 W) and Y₂O₃/Ti contents (0.5 wt%, 1 wt% and 1.5 wt%) on the microstructure and hardness of the alloys were investigated. The results showed that the ODS-CrFeNi MEA is mainly composed of FCC-structured FeNi-rich matrix, plate-like FeCr-rich σ phase and Cr-rich phase with a BCC structure. The volume fractions of the Cr-rich phase and the σ phase are found to be closely related to the laser power and the oxide content. With the increasing laser power, the volume fraction of the Cr-rich phase decreases while that of the σ phase increases. The addition of Y₂O₃/Ti effectively refines the solidification microstructure. With the increasing Y₂O₃/Ti content, the volume fraction of Cr-rich phases increases and the σ phase decreases. The alloy with an optimized laser power of 2000 W and a Y₂O₃/Ti content of 1 wt% exhibits the lowest porosity, the highest density and hardness. Its hardness reaches 629 HV. The mechanism by which laser powder and Y₂O₃/Ti additions affect the microstructure and hardness has been elucidated.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114897"},"PeriodicalIF":4.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549751","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 nanolaminated structure design to produce high-strength Cu alloys with enhanced electrical conductivity and thermal stability","authors":"Longfei Zeng,&nbsp;Xu Lu,&nbsp;Shaoyu Li,&nbsp;Jinghui Zhang","doi":"10.1016/j.matchar.2025.114883","DOIUrl":"10.1016/j.matchar.2025.114883","url":null,"abstract":"<div><div>Nanocrystalline Cu has the merit of high strength but usually suffer from poor electrical conductivity and rapid grain coarsening, limiting its practical application. Here, we demonstrate that this challenge can be overcome by architecting a unique nanolaminated grain structure (NGS) with an ultra-thin lamellae boundary spacing of ∼55 nm, featuring pronounced Ag atoms segregation at high angle lamellae boundaries and very few defects inside the lamellae interiors, in a Cu-5wt.%Ag alloy. Benefiting from the synergistic contributions from the NGS, pronounced Ag atoms segregation at lamellae boundaries and continuous electron transport channels as well as a low electron scattering within the lamellae interiors, the resultant NGSed Cu-5wt.%Ag alloy achieves an ultrahigh tensile yield strength (YS) of 895<!--> <!-->MPa, together with an excellent electrical conductivity of ∼83 % IACS (International Annealed Copper Standard) and a good thermal stability of 400 °C (∼0.4 Tm). The structure design strategy reported here, via nanolamellar grain structure combined with solute atoms decoration at lamellae boundaries, represents a promising approach that may be widely applicable to develop high strength, conductivity, and thermally stable nanostructured Cu-based materials for future structural and functional applications.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114883"},"PeriodicalIF":4.8,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549860","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":"Corrosion mechanism of electron beam remelted layer of eutectic high-entropy alloy AlCoCrFeNi2.1","authors":"Daochen Feng ,&nbsp;Yifei Zheng ,&nbsp;Wenjian Zheng ,&nbsp;Zhihui Cai ,&nbsp;Zhangmin Jin ,&nbsp;Yinghe Ma ,&nbsp;Sendong Ren ,&nbsp;Shiyi Bao ,&nbsp;Dapeng Tan ,&nbsp;Jianguo Yang","doi":"10.1016/j.matchar.2025.114882","DOIUrl":"10.1016/j.matchar.2025.114882","url":null,"abstract":"<div><div>Electron beam remelting technology was used to improve the microstructure of the high-entropy alloy (HEA) AlCoCrFeNi_2.1. The results of electrochemical experiments show that the corrosion resistance of the remelted layer on the sample surface is the best under the process conditions of 6 mA + 400 mm/min (remelting parameters). The surface corrosion morphology of the remelted layer of AlCoCrFeNi_2.1 shows body-centered cubic (BCC/B2) selective corrosion and face-centered cubic (FCC) phase pitting corrosion characteristics. Additionally, Cl⁻ promotes the dissolution of matrix alloy atoms, leading to pitting corrosion nucleation. As the corrosion time increases, the passivation film on the BCC phase surface becomes thinner preferentially. After remelting, the alloy grains are significantly refined, the grain boundary density is increased, and the alloy elements are more evenly distributed, which is the fundamental reason for the improved corrosion resistance.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114882"},"PeriodicalIF":4.8,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143561908","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":"Yttrium-induced morphological evolution of primary MC carbides in a second-generation Ni-based single crystal superalloys","authors":"Nan Wang ,&nbsp;Jide Liu ,&nbsp;Zhandong Xi ,&nbsp;Shulin Yang ,&nbsp;Wei Xu ,&nbsp;Jinguo Li","doi":"10.1016/j.matchar.2025.114880","DOIUrl":"10.1016/j.matchar.2025.114880","url":null,"abstract":"<div><div>Evolution of the morphology of primary MC carbides with the doping of yttrium with different content from 0 to 0.5 wt% in a typical second-generation nickel based SX superalloys (DD5) was investigated in this work. The deep-etched samples indicate that the morphology of MC carbides evolves from script-like to faceted octahedral block with the increase of yttrium content to 0.5 wt%. Meanwhile, STEM analyses demonstrated that yttrium significantly disturbed the orientation relationship between primary MC carbides and matrix. These phenomena were attributed to the ultra-low surface tension property of yttrium, which has a spontaneous segregation propensity at the phase interface during solidification process, and utterly alters compositional and temperature fields in the liquid at the front of carbide/matrix interface.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114880"},"PeriodicalIF":4.8,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549753","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 ultra-high strength, good toughness and cost reduction in secondary hardening steel via dual precipitation","authors":"Haofei Zhu ,&nbsp;Zhiping Xiong ,&nbsp;Jianwen Mao ,&nbsp;Xingwang Cheng","doi":"10.1016/j.matchar.2025.114869","DOIUrl":"10.1016/j.matchar.2025.114869","url":null,"abstract":"<div><div>The dual precipitation of NiAl particles and M₂C carbides during ageing plays a critical role in achieving an optimal balance of strength and toughness in low-cobalt secondary hardening steel, yet this remains scarcely investigated. This work investigates the evolution of NiAl and M₂C during ageing at 482 °C for durations ranging from 1 h to 150 h, focusing on their influence on the strength and impact toughness of martensitic steel. It was found that after 5 h of ageing, NiAl particles nucleate rapidly with high number density and nearly reaches saturation, suppressing dislocation recovery. This leads to a high yield strength of 1875 MPa. When the ageing time is extended to 32 h, the NiAl particles coarsen and the volume fraction of M₂C carbides increases, while the dislocation recovery remains minimal. Consequently, the yield strength increases slightly to 1895 MPa. Notably, the impact toughness improves from 17 J at 5 h to 28 J at 32 h, reflecting to a 65 % improvement. This is predominantly due to the reduction in the number density of brittle NiAl particles which can induce cracks and due to the formation of film-like reversed austenite which can deflect cracks. After 32 h of ageing, the yield strength and impact toughness of the secondary hardening steel are comparable to those of commercial AerMet310 steel. Notably, the cobalt content is reduced from 15.0 wt% to 5.0 wt%, resulting in an approximate 36 % reduction in raw material costs.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114869"},"PeriodicalIF":4.8,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488827","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":"Refining the identification methodology for describing heterogeneous Fe-Si materials using the viscoplastic self-consistent approach","authors":"Laura Herard ,&nbsp;Yann Charles ,&nbsp;Mihaela Teodorescu ,&nbsp;Sohrab Masteri Farahani ,&nbsp;Brigitte Bacroix ,&nbsp;Carlos Tomé","doi":"10.1016/j.matchar.2025.114877","DOIUrl":"10.1016/j.matchar.2025.114877","url":null,"abstract":"<div><div>Electrical steels stand as the predominant soft ferromagnetic materials in the power transmission industry. The magnetic properties of these steels are linked to a very specific crystallographic texture composed of centimeter-sized grains oriented along the Goss component. The formation of this texture is known to be directly linked with recrystallization mechanisms, abnormal grain growth during the high temperature annealing, as well as the texture evolution during cold rolling. Because of the complexity and heterogeneity of the deformed state, the key controlling parameters of the recrystallization mechanisms and then abnormal grain growth are not yet fully identified. In that context, to get a better understanding of the link between deformation and subsequent recrystallization mechanisms, the cold rolling stage is modelled in the present work as a first step. A viscoplastic self-consistent approach is used, to capture both texture and hardening evolution. The objective is to provide a qualitative and quantitative prediction of the microstructure and mechanical behavior resulting from the rolling process-induced cold deformation. It is thus necessary to establish a representative description of the heterogeneous Fe-Si material before this step: a novel identification methodology is introduced with that aim. Mechanical tests, consisting of tensile and simple shear at varying angles with respect to the rolling direction, were conducted for the sake of parameters identification and validation. Especially, a dislocation-based hardening model integrated in a viscoplastic self-consistent polycrystal framework is used. Required parameters, such as grain morphology, strain rate sensitivity, and microstructure heterogeneity, are discussed to enhance alignment with experimental data.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114877"},"PeriodicalIF":4.8,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}