Materials Characterization最新文献

{"title":"Coaxial laser directed energy deposition of high‑nitrogen steel: Nitrogen escape suppression mechanism, microstructural evolution, and superior strength-ductility synergy","authors":"Wei Zhang,&nbsp;Mengwei Duan,&nbsp;Jianxiang Ding,&nbsp;Yuan Cheng,&nbsp;Pengfei Gao,&nbsp;Jian Kong,&nbsp;Kehong Wang,&nbsp;Yong Peng","doi":"10.1016/j.matchar.2026.117114","DOIUrl":"10.1016/j.matchar.2026.117114","url":null,"abstract":"<div><div>High‑nitrogen steel (HNS) exhibits substantial application potential in high-end equipment due to its excellent combination of strength, toughness, and corrosion resistance. However, in conventional additive manufacturing processes, severe nitrogen escape and porosity defects readily occur, resulting in a sharp deterioration of forming quality and mechanical properties. To address this challenge, the present study proposes the fabrication of large-scale high‑nitrogen steel components using coaxial laser wire directed energy deposition (CLW-DED). The nitrogen loss suppression behavior, microstructural evolution, and synergistic mechanisms governing mechanical properties during the rapid laser melting and solidification process were systematically investigated. The results indicate that an appropriate linear energy input during CLW-DED produces a small, short-lived melt pool that limits nitrogen diffusion, aggregation, and escape at elevated temperatures, restricting nitrogen loss to 5.6–9.9%. Meanwhile, the shortened bubble flotation distance and brief but sufficient liquid-state lifetime facilitate the escape of the few N₂ bubbles formed. The resulting components exhibit a high relative density of 99.7%, with porosities of only 0.081–0.306%, demonstrating a favorable combination of low porosity and high nitrogen retention.The microstructure exhibits a typical AF solidification mode, dominated by columnar austenite grains with a strong 〈001〉 preferred orientation.Benefiting from the multiple strengthening mechanisms—including solid-solution strengthening by high nitrogen content, grain refinement strengthening, and high-density dislocation strengthening—the as-deposited high‑nitrogen steel displays superior strength-ductility synergy, with an ultimate tensile strength of 1073 ± 14 MPa and a maximum elongation of 53 ± 5%. This study not only elucidates the intrinsic physical relationships among laser heat input, molten pool nitrogen escape, and microstructural evolution, but also provides a novel theoretical foundation and technical paradigm for the additive manufacturing of large-scale, complex-structured high-performance high‑nitrogen steel components.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117114"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199354","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":"Dual roles of dense dislocations on martensitic transformation in a FeNiAl high-strength steel","authors":"Xiedong Sun,&nbsp;Weipeng Li,&nbsp;Guanchen Zhou,&nbsp;Haicheng Zhang,&nbsp;Zhongyang Yao,&nbsp;Binbin He","doi":"10.1016/j.matchar.2026.117122","DOIUrl":"10.1016/j.matchar.2026.117122","url":null,"abstract":"<div><div>Dislocation strengthening is an effective approach to enhance steel strength, often at the cost of ductility. In this research, a severely cold-rolled FeNiAl high-strength steel with high dislocation density was investigated, with the aim of improving its ductility through high-temperature annealing. The as-received steel exhibited an ultra-high yield strength of ∼1726 MPa, primarily attributed to the dense dislocation entanglement. Annealing significantly altered the dislocation structure via recovery and recrystallization, thereby influencing the deformation behavior of the proposed steel. The specimen annealed at 700 °C for 10 min displayed rapid martensitic transformation after a low-strain stage (<em>ε</em>_<em>t</em> &gt; 0.05), leading to a pronounced work-hardening rate (WHR) but a limited total elongation of ∼21%. In contrast, the specimen annealed at 800 °C exhibited sustained and gradual martensitic transformation over a strain range more than twice that of the 700 °C-annealed specimen, resulting in enhanced ductility with elevated WHR. Microstructural analysis further revealed a dual role of dislocations in martensitic transformation: high-density entangled dislocations inhibit transformation, whereas ordered and mobile screw dislocations, formed via thermally activated rearrangement, alleviate this inhibition. These findings elucidate the intrinsic relationship between dislocation configurations and martensitic transformation, offering new insights into the processing-microstructure-property relationship of dislocation-rich steels, highlighting the critical role of coupled deformation mechanisms in optimizing their mechanical performance.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117122"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199435","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":"Machine learning-driven composition design and synergistic strengthening mechanisms in dual-microalloyed Cu-Ni-Sn alloy","authors":"Ziqiang Sun,&nbsp;Fei Tan,&nbsp;Bairui Qi,&nbsp;Zhaoliang Ling,&nbsp;Ziqian Zhao,&nbsp;Zhu Xiao,&nbsp;Linghui He,&nbsp;Yanlin Jia,&nbsp;Zhou Li","doi":"10.1016/j.matchar.2026.117063","DOIUrl":"10.1016/j.matchar.2026.117063","url":null,"abstract":"<div><div>This study presents a machine learning (ML)-driven strategy for the dual microalloying design of Cu-Ni-Sn alloys. Leveraging Gaussian-noise-based data augmentation to extract compositional alloy features and integrating algorithmic performance evaluation, a Support Vector Regression (SVR) model was established to predict key alloy properties. High-throughput screening via this model identified Cu-15Ni-8Sn-0.1In-0.1Zr (wt%) as the selected Pareto-optimal candidate. Experimental validation demonstrated that the alloy aged at 375 °C for 90 min achieved an exceptional balance of mechanical and electrical properties, with a tensile strength of 1416 MPa, a peak hardness of 424 HV, and an electrical conductivity of 8.8%IACS. The relative errors between the ML predictions and experimental results were tightly controlled at 4.9% for hardness and 6.4% for conductivity, respectively. Comprehensive microstructural characterization revealed that the synergistic performance enhancement originated from the cooperative effects of In and Zr microalloying. The close agreement between data-driven predictions and experimental outcomes highlighted the effectiveness of ML paradigms in accelerating the development of advanced high-performance copper alloys.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117063"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199438","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":"Ultrasonic additive manufacturing of layered CNTs reinforced cu matrix composites: interface behavior and multi-performance enhancement","authors":"Rongmao Du,&nbsp;Ruihan Zhao,&nbsp;Siheng Tan,&nbsp;Yanlong Fan,&nbsp;Junlin Pan,&nbsp;Yu Sun,&nbsp;Hongtao Zhang","doi":"10.1016/j.matchar.2026.117110","DOIUrl":"10.1016/j.matchar.2026.117110","url":null,"abstract":"<div><div>In response to the demand for high strength and high thermal conductivity Cu matrix composites as well as the efficient processing technology in fields such as high-power chip heat dissipation, this paper reports a technology for preparing layered CNTs reinforced Cu matrix composites through ultrasonic additive manufacturing. Under the action of thermo-mechanical coupling, a synergistic strengthening structure composed of fine grain transition zones, high-density geometrically necessary dislocations, and multi-level transition phases was formed at the interface of the composites. Compared with the pure Cu matrix, the tensile strength of the composites increased by 49.3% to 331.00 MPa, and the thermal conductivity increased by 19.4% to 463.039 W/(m·K). This study provides theoretical basis and technical support for the rapid manufacturing and free shaping of high-performance CNTs/Cu composites.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117110"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199432","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":"Elucidating the distinct mechanisms of Er and Y in elevating the creep resistance of Al-Cu-Mg alloys","authors":"Chuanhai Li,&nbsp;Zhimin Mo,&nbsp;Guihao Sun,&nbsp;Yuxiu Zhang","doi":"10.1016/j.matchar.2026.117136","DOIUrl":"10.1016/j.matchar.2026.117136","url":null,"abstract":"<div><div>The effects of Er and Y microalloying on the creep behavior of Al-Cu-Mg alloys were comparatively investigated in this work. Three T6-treated alloys, including Al-4Cu-0.25 Mg (as-received alloy), Al-4Cu-0.25 Mg-0.1Er (Er-modified alloy) and Al-4Cu-0.25 Mg-0.1Y (Y-modified alloy), were crept at 270 °C under applied stresses ranging from 100 MPa to 120 MPa. Both Er and Y significantly reduced the steady creep rate, with the Er-modified alloy exhibiting the greatest creep resistance, followed by the Y-modified alloy and then the as-received alloy. Microstructural analysis revealed that θ’-Al₂Cu and S′-Al₂CuMg precipitates significantly coarsened during creep, but the coarsening degree depended on alloy composition. Specifically, the Er-modified alloy exhibited the lowest coarsening rate, which was attributed to local Er enrichment at precipitates. The retained fine precipitates effectively hindered dislocation motion and sub-grain boundary migration, which contributed to the reduced steady creep rate. In contrast, Y was predominantly distributed in the Al matrix and offered inferior suppression of precipitate coarsening compared with Er. Thus, segregation strengthening is more conducive than solution strengthening, and Er microalloying is a more effective choice than Y for enhancing the high-temperature creep resistance of Al-Cu-Mg alloys.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117136"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199351","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":"Erratum to “Curvature-driven quantification of 2D SEM fracture morphology across metallic materials” [Materials Characterization 235 (2026) 116319]","authors":"Jingsi Jiao","doi":"10.1016/j.matchar.2026.116673","DOIUrl":"10.1016/j.matchar.2026.116673","url":null,"abstract":"","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"238 ","pages":"Article 116673"},"PeriodicalIF":6.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148729982","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}

{"title":"Designing TiAl/Ni laminated metal-matrix composites (LMC) with enhanced damping capacity via interfacial reaction engineering","authors":"Kun Zhang ,&nbsp;Yunzhu Li ,&nbsp;Hongliang Sun ,&nbsp;Xiaosong Jiang ,&nbsp;Rui Shu ,&nbsp;Yihao Li","doi":"10.1016/j.matchar.2026.116595","DOIUrl":"10.1016/j.matchar.2026.116595","url":null,"abstract":"<div><div>In this study, a TiAl/Ni laminated metal-matrix composite (LMC) was successfully fabricated using vacuum hot pressing and stacking processes. The effects of Ni introduction methods (laminated LMC versus non-laminated MC) and the orientation of the layer interface on the microstructure, mechanical properties, and damping behavior were systematically investigated. The results indicate that intense mutual diffusion occurs at the interface between the TiAl and Ni layers in the LMC, forming a multi-layer reaction zone containing NiTi and Ni₃(Ti, Al). The overall hardness of the LMC is significantly higher than that of pure TiAl and MC. The compressive properties exhibited anisotropy. For the sample with the layer interface perpendicular to the loading direction (LMC 1–1), the compressive strength reached 1595.4 MPa and the fracture strain was 38.5%, demonstrating the best comprehensive mechanical properties. Moreover, all LMCs exhibited excellent damping performance. LMC 1–1 achieved a peak damping coefficient of 0.0251 at room temperature, far exceeding the predictions of the rule-of-mixture (ROM) and those of the reference samples. This enhanced damping stems from the synergistic effects of interfacial damping, dislocation damping, and NiTi phase-transition damping. This study provides new insights into the synergistic optimization of high strength and high damping in TiAl-based composites.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"238 ","pages":"Article 116595"},"PeriodicalIF":5.5,"publicationDate":"2026-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148170506","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":"Influence of residual segregation on γ’ precipitate and creep performance in novel nickel-based single-crystal superalloy","authors":"Abbas Jafri ,&nbsp;Zhaoyang Liang ,&nbsp;Zihao Tan ,&nbsp;Xipeng Tao ,&nbsp;Yanfei Liu ,&nbsp;Xinguang Wang ,&nbsp;Chuanyong Cui ,&nbsp;Jinguo Li ,&nbsp;Yizhou Zhou ,&nbsp;Xiaofeng Sun","doi":"10.1016/j.matchar.2026.116198","DOIUrl":"10.1016/j.matchar.2026.116198","url":null,"abstract":"<div><div>A series of solution heat treatment (SHT) processes was applied to investigate the creep behaviour at 1140 °C / 137 MPa of a novel nickel-based single-crystal superalloy. The γ/γ’ microstructure, including the γ’ size and volume fraction, was compared after each SHT. The SEM results reveal that a γ’ size gradient emerges between interdendritic and dendritic regions (DR), depending on the SHT process, as a result of remaining segregation of elements. WDS-EPMA quantification of residual segregation validated the microstructure differences observed via SEM, emphasising the impact of SHT on phase distribution. The creep response at ultra-high temperature, low stress was found to be correlated with the dimensions of the γ’ precipitates. The specimen featuring the smallest γ’ size in DR manifested a remarkable 67% increase in creep life compared to those with larger γ’ size. Post-creep microstructure analysis revealed that fine and highly uniform raft formation is attributed to the robust strengthening effect originating from small-size γ’ precipitates. These precipitates also facilitate a more equitable distribution of refractory elements, thereby reducing the propensity for the nucleation of topologically closed-packed phases. The underlying mechanisms for the enhanced creep resistance properties have been discussed.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116198"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386691","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":"Effect of recrystallization on plastic deformation of LPBF-Inconel 718 superalloy: The role of annealing twins","authors":"Dongqing Jia,&nbsp;Xiaopeng Cheng,&nbsp;Junxia Lu","doi":"10.1016/j.matchar.2026.116199","DOIUrl":"10.1016/j.matchar.2026.116199","url":null,"abstract":"<div><div>Laser powder bed fused (L-PBFed) Inconel 718 alloy shows anisotropic microstructure and mechanical properties. Recrystallization offers an effective method to enhance the microstructural homogeneity, thereby improving the mechanical properties. In this study, two heat treatments (1020-HSA and 1100-HSA) were applied to obtain samples with different degrees of recrystallization, and their deformation behaviors were investigated by using in-situ electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analyses. The results showed that recrystallization by heat treatment effectively eliminated cellular subgrains and decreased dislocation density. Meanwhile, recrystallization also promotes the formation of high-density annealing twins. These twins acted as barriers and storage sites for dislocations, which enhanced strain-hardening and deformation compatibility. Moreover, twin boundaries facilitated dislocation transmission and could transform into random high angle grain boundaries, which promoted uniform plastic deformation. Compared with the unrecrystallized specimen (1020-HSA), the 1100-HSA specimen exhibited improved ductility and stable strength, which achieved a favorable strength–ductility synergy. This study elucidated the underlying mechanisms by which recrystallization coordinated plastic deformation, guiding the design of heat treatment in L-PBFed Inconel 718.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116199"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386692","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":"Microstructural evolution and recrystallization mechanisms in a Cu-Ni-Co-Si alloy subjected to multi-step drawing and aging","authors":"Longjian Li ,&nbsp;Kai Zhao ,&nbsp;Hongrui Yu ,&nbsp;Gaojie Liu ,&nbsp;Zeyuan Chen ,&nbsp;Enlang Feng ,&nbsp;Huijun Kang ,&nbsp;Jinchuan Jie ,&nbsp;Zongning Chen ,&nbsp;Enyu Guo ,&nbsp;Tongmin Wang","doi":"10.1016/j.matchar.2026.116202","DOIUrl":"10.1016/j.matchar.2026.116202","url":null,"abstract":"<div><div>The synergistic optimization of strength and electrical conductivity continues to pose a considerable challenge in the development of precipitation-strengthened copper alloys, particularly in Cu-Ni-Co-Si systems, where the interactions between deformation and aging processes remain not yet fully understood. In this work, a multi-step cold-drawing strategy incorporating intermediate aging was designed to regulate recrystallization and precipitation behavior of a Cu-Ni-Co-Si-Mg-Ti alloy. Cold drawing induced a high density of dislocations and a pronounced fiber texture, which provided abundant heterogeneous nucleation sites for subsequent precipitate formation. Compared with conventional single-step drawing, the multi-step drawing process effectively inhibited recrystallization during aging, maintained subgrain stability, and retained a high dislocation density. This stabilized deformation framework promoted the uniform precipitation of nanoscale δ-(Ni, Co)₂Si particles and enhanced interactions between precipitates and dislocations, thereby improving both precipitation and dislocation strengthening. Concurrently, the progressive depletion of solute during aging decreased electron scattering, promoting a rapid recovery of electrical conductivity. Consequently, the alloy subjected to the optimized multi-step drawing and aging process achieved an outstanding combination of properties, including a yield strength of 905.5 MPa, an ultimate tensile strength of 977.1 MPa, and an electrical conductivity of 49.1% IACS. Quantitative analysis indicated that precipitation and dislocation strengthening contributed collectively to over 80% of the yield strength. These findings demonstrate that the synergistic regulation of recrystallization and precipitation through multi-step drawing and aging offers an effective and scalable strategy for the development of high-performance copper wire materials.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116202"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386693","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}