Materials Characterization最新文献

{"title":"Instance segmentation and microstructure characterization based on powder microscopic image data","authors":"Shuangmei He ,&nbsp;Jiahao Tu ,&nbsp;Yanlin Zhu ,&nbsp;Weifu Li ,&nbsp;Liming Tan ,&nbsp;Zi Wang","doi":"10.1016/j.matchar.2026.116051","DOIUrl":"10.1016/j.matchar.2026.116051","url":null,"abstract":"<div><div>Metal powders, as the medium in metal additive manufacturing, have their particle size, shape, and distribution characteristics directly influencing the quality of the final product. Addressing the limitations of traditional image analysis methods in terms of precision and real-time monitoring for measuring powder microstructural features, this study proposes a deep learning-based approach for powder instance segmentation and microstructural characterization. The study employs algorithms such as Mask R-CNN based on the Detectron2 framework and YOLO series algorithms based on the Ultralytics framework to perform instance segmentation on IN718 nickel-based superalloy powder data. Experimental results show that the YOLOv9-seg algorithm achieves an F1 score above 0.95 across all datasets. Furthermore, six parameters, including area and aspect ratio, are selected for the quantitative characterization of the powder's particle size and shape. Based on the precise segmentation provided by the YOLOv9-seg model, an analysis of these parameters reveals that larger powder particles may exhibit more regular shapes. These findings have significant theoretical and practical implications for powder parameter performance evaluation and shape control in additive manufacturing.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116051"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146196839","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 aging precipitation behavior of nuclear-grade N-strengthened austenitic stainless steel","authors":"Cui Chen ,&nbsp;Yong Wang ,&nbsp;Weijuan Li ,&nbsp;Dazheng Zhang ,&nbsp;Zongxu Pang ,&nbsp;Qihang Pang","doi":"10.1016/j.matchar.2026.116143","DOIUrl":"10.1016/j.matchar.2026.116143","url":null,"abstract":"<div><div>This study systematically investigates the degree of recrystallization, precipitation behavior, and their relationship with the hardening mechanisms in hot-rolled nuclear-grade N-strengthened austenitic stainless steel aged at various temperatures. The characterization techniques employed include microstructural analysis, thermodynamic phase diagram calculations, and hardness testing. The results indicated that both the rolled and aged states of the experimental steel comprised large deformed grains, recrystallized fine grains, and a limited number of precipitates. An increase in aging temperature resulted in a gradual rise in the proportion of high-angle grain boundaries and a decrease in the full width at half maximum (FWHM) of the (220) and (311) diffraction peaks, signifying enhanced recovery and recrystallization. Micron-scale precipitates in both states were predominantly strip-like Laves phase, while nano-precipitates primarily consisted of granular <em>Z</em>-phase, pearl-string Nb(C, N), and block M₂₃C₆. Laves phase, Z-phase, and Nb(C, N) precipitated both at grain boundaries and within grains. In contrast, M₂₃C₆ precipitated exclusively along grain boundaries at the 800 °C aging temperature. Aging at 650 °C increased the quantity of all types of precipitates. Within highly deformed grains, the size of <em>Z</em>-phase precipitates decreased, while within highly recrystallized grains, the sizes of both Nb(C, N) and Z-phase precipitates increased. As the aging temperature increased, the precipitation of the Laves phase gradually diminished, while the number of <em>Z</em>-phase precipitates increased. The number of Nb(C, N) precipitates initially increased before decreasing, and the sizes of both Z-phase and Nb(C, N) precipitates gradually increased. Additionally, the macro hardness of the experimental steel varied with aging temperature, peaking at 285 HV at 800 °C. The dominant hardening mechanism evolved with increasing aging temperature, transitioning from dislocation hardening to a combination of precipitation hardening and fine-grain hardening, and ultimately to fine-grain hardening. This study elucidates the aging precipitation behavior and hardening mechanisms in N-strengthened austenitic stainless steel, providing a theoretical foundation for optimizing the heat treatment process for steels within this compositional system.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116143"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146196893","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":"Investigating microstructure and mechanical properties of gradient joints between GH3230 and 316 L dissimilar alloys fabricated by directed energy deposition","authors":"Ling Wang ,&nbsp;Wenhao Liu ,&nbsp;Xiaojiang Long ,&nbsp;Shilei Li ,&nbsp;Qungang Kong ,&nbsp;Yulin Qin ,&nbsp;Jun Zhu ,&nbsp;Xiaoyi Wang ,&nbsp;Longqing Chen ,&nbsp;Yanjun Hao ,&nbsp;Xiaochong Liang ,&nbsp;Ming Yin","doi":"10.1016/j.matchar.2026.116188","DOIUrl":"10.1016/j.matchar.2026.116188","url":null,"abstract":"<div><div>This study addresses interfacial failure caused by thermomechanical incompatibility in nuclear components by fabricating a GH3230/316 L functionally graded material (FGM) via directed energy deposition (DED). A quasi-linear compositional gradient and a uniform FCC matrix were achieved without forming brittle intermetallic compounds. Microstructural analysis revealed a continuous transition from dendritic to cellular morphology governed by constitutional supercooling. Interlayer cooling was applied during fabrication, which promoted the formation of a distinct interfacial architecture with recrystallized fine grains sandwiched between columnar regions. The FGM exhibits excellent mechanical stability up to 950 °C, while room-temperature tensile failure occurs within the gradient zone due to synergistic effects of fine grains, nano-precipitates, and twins. These findings provide valuable insights for designing high-performance graded materials under extreme thermomechanical conditions.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116188"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386538","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 grain size distribution on dislocation slip mechanisms during cyclic deformation of brass alloy","authors":"P.S.M. Jena ,&nbsp;J.K. Sahu ,&nbsp;K.L. Sahoo","doi":"10.1016/j.matchar.2026.116182","DOIUrl":"10.1016/j.matchar.2026.116182","url":null,"abstract":"<div><div>The role of grain size distribution in governing dislocation slip mechanisms during cyclic deformation of a Cu-37 wt% Zn brass alloy was investigated through strain-controlled low cycle fatigue (LCF) testing, complemented by detailed microstructural characterization. The alloy was 35–40% cold rolled and subsequently annealed at 500 °C to obtain two distinct grain structures: a bimodal distribution (1-h annealing) comprising ∼90% fine recrystallized grains (∼6 μm) with ∼10% coarse grains (∼50 μm), and a unimodal distribution (3-h annealing) with uniform fine grains (∼6 μm). Low cycle fatigue tests revealed that the bimodal specimen exhibited nearly twice the fatigue life compared to the unimodal counterpart across all applied strain amplitudes. Analysis of mid-life hysteresis loops and Coffin-Manson (CM) plots indicated that the unimodal specimen accumulated more plastic strain per cycle. Microstructural characterization by SEM and TEM analyses revealed a fundamental shift in failure mechanisms: transgranular slip band cracking dominated in the bimodal structure, while the unimodal specimen failed predominantly by intergranular cracking. Further TEM and EBSD analysis revealed that in the bimodal grain size distribution, slip bands were more likely to transmit/nucleate at neighboring grains due to a smaller difference in Schmid factors between grains (0.03 for bimodal compared to 0.08 in the unimodal structure). This reduces strain localization at grain boundaries and hence, enhances LCF life in bimodal grain size distribution specimens. These findings establish microstructural heterogeneity, through bimodal grain size design, enhances fatigue resistance by enabling efficient slip transfer, mitigating grain boundary stress concentration, and delaying crack initiation.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116182"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386698","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":"Additive manufacturing of biomimetic layered periodic heterogeneous structures: Achieving synergistic improvement of strength and ductility in 316L stainless steel","authors":"Shuai Guo ,&nbsp;Wenlu Yang ,&nbsp;Shang Sui ,&nbsp;Anfu Guo ,&nbsp;Junjie Ni ,&nbsp;Yufan Zhao ,&nbsp;Meng Wang ,&nbsp;Xin Lin","doi":"10.1016/j.matchar.2026.116236","DOIUrl":"10.1016/j.matchar.2026.116236","url":null,"abstract":"<div><div>The inherent strength-ductility trade-off in metallic materials restricts their applications in high-end manufacturing. Inspired by nacre, this study fabricated a biomimetic layered periodic heterogeneous structure via laser powder bed fusion by alternately depositing ductile 316L stainless steel (316L SS) and high-strength 316L SS-xTi6Al4V (x = 0.5, 1, 2 wt%) layers. Notably, trace oxygen was intentionally introduced during powder preparation to promote the in-situ formation of nanoparticles. These nanoparticles, acting as potent nucleation sites, work synergistically with α stabilizing elements to facilitate α phase precipitation and trigger the columnar-to-equiaxed transition, establishing a three-level grain hierarchy (coarse, fine, and ultrafine grains). Compared with monolithic 316L SS, the layered periodic heterogeneous structure achieves a synergistic enhancement in strength and ductility. This is primarily attributed to back stress strengthening at heterogeneous interfaces and nanoparticle reinforcement involving both shearing and Orowan bypassing mechanisms. By systematically integrating phase heterogeneity, grain hierarchy, in-situ nanoparticle reinforcement, and active compositional modulation, this work achieves a four-in-one synergistic effect. This study provides a new paradigm for the active design of high-performance metallic materials through the construction of layered periodic heterostructures.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116236"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386751","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":"Enhancing the oxidation resistance of ZrB2-SiC based ultra-high temperature ceramic coatings through ZrB2-ZrSi2 alloying modification","authors":"Huiqun Liu ,&nbsp;Chengshan Ji ,&nbsp;Xiang Ji ,&nbsp;Jiaping Chen ,&nbsp;Zhichao Shang ,&nbsp;Peipei Wang ,&nbsp;Yi Sun ,&nbsp;Xueqin Kang ,&nbsp;Baojing Zhang ,&nbsp;Junfei Peng ,&nbsp;Junfeng Wang ,&nbsp;Xuanru Ren ,&nbsp;Peizhong Feng","doi":"10.1016/j.matchar.2026.116155","DOIUrl":"10.1016/j.matchar.2026.116155","url":null,"abstract":"<div><div>To mitigate the degradation of oxidation protection performance in ZrB₂-SiC-based ultra-high-temperature ceramic coatings caused by porosity and loosening of the oxygen-barrier structure during service at 1700 °C in an oxygen-rich environment, alloying modification using ZrB₂-ZrSi₂-based powders was employed to enhance the self-healing efficiency of the in-situ generated glass layer in loosened regions. The research revealed that alloying with ZrB₂-ZrSi₂ powder shortened the repair pathway of the in-situ formed glass layer produced by silicide oxidation in loosened areas, thereby improving the oxidation resistance of ZrB₂-ZrSi₂-based coatings under ultra-high-temperature conditions. ZrB₂ powder modified with 10 vol% ZrSi₂ exhibited optimal self-healing performance, reducing oxygen permeability by 4.25%, decreasing the structural factor by 26.20%, and lowering the passivation factor by 57.43% and achieving a cumulative protection efficiency of 96.36%. When the ZrSi₂ content exceeded 10 vol%, excess ZrSi₂ acted as a corrosion phase at high temperatures, accelerating ZrB₂ oxidation and weakening its self-healing capability. This effect is primarily ascribed to the excessive generation of ZrO₂, which disrupts the structural stability of the SiO₂ glass matrix, leading to localized volume contraction and an increase in the thermal expansion coefficient. Consequently, oxide segregation and accumulation occur within the protective layer, degrading its oxidation resistance. Additionally, the ZrB₂-ZrSi₂-SiC-based composite coating modified with 10 vol% ZrSi₂ markedly improved oxidation resistance; relative to the unmodified ZrB₂-SiC coating, its structural factor decreased by 43.94%, and its passivation factor decreased by 12.31% and its cumulative protection efficiency reached 98.62%. This study provides a novel methodology for enhancing the oxygen barrier protection performance of ultra-high-temperature ceramic coatings.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116155"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386461","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":"Strengthening C/C-GH5188 joints by surface modification and in-situ TiC reinforcements","authors":"Yonglei Wang ,&nbsp;Meng Wang ,&nbsp;Zhenqian Lang ,&nbsp;Danqing Yin ,&nbsp;Wanli Wang ,&nbsp;Jiachen Zhou ,&nbsp;Minglei Song","doi":"10.1016/j.matchar.2026.116218","DOIUrl":"10.1016/j.matchar.2026.116218","url":null,"abstract":"<div><div>This study presents a novel approach to joining carbon‑carbon (C/C) composite and GH5188 superalloy by integrating surface modification and particle-reinforced interlayer. Eutectic Co-Fe-B powders and (Co-Fe-B) + Ti mixed powders were applied to bond chromium carbide-modified C/C (denoted as C/C_m) and GH5188 superalloy. A coherent chromium carbide-modified layer consisting of Cr₃C₂ and Cr₂₃C₆ was fabricated on the C/C composite surface via the embedding technique. The chromium carbide-modified layer significantly enhanced the wettability of the molten filler on the C/C surface. The C/C_m/interlayer interface was predominantly composed of a ductile (Co) solid solution with dispersed carbides, effectively mitigating interface embrittlement. The reduction in boron (B) content and the shift in eutectic composition facilitated rapid isothermal solidification of the Co-Fe-B matrix. The introduction of Ti powders led to the in-situ formation of TiC reinforcements through reaction with carbon atoms, which played a critical role in alleviating tensile stress at the C/C/interlayer interface. The C/C_m-(Co-Fe-B) + Ti-GH5188 joint achieved a maximum shear strength of 55.7 ± 4.9 MPa, representing a 14.8% improvement over that of the C/C_m-(Co-Fe-B)-GH5188 joint and a 21.9% enhancement compared with the joint bonded with the unmodified C/C composite.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116218"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386573","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 Cu addition on the microstructure and the mechanical properties of austenitic low-density steel","authors":"Chuguang Tong ,&nbsp;Chunguang Shen ,&nbsp;Lingling Zhang ,&nbsp;Yu Qi ,&nbsp;Chi Zhang ,&nbsp;Shijian Zheng","doi":"10.1016/j.matchar.2026.116185","DOIUrl":"10.1016/j.matchar.2026.116185","url":null,"abstract":"<div><div>In this study, austenitic low-density steels with 0, 1, and 3 wt% Cu additions were subjected to various solid-solution and aging treatments to examine their microstructural evolution and mechanical properties. After solution treatment at 950–1050 °C, all steels exhibited a single-phase austenitic structure. The addition of 3 wt% Cu caused the austenite softening, but it could effectively inhibit grain growth during the increase of solution treatment temperature, thereby enhancing grain boundary strengthening. In the aged state, high-density intragranular κ-carbides precipitated in all steels, while only a small amount of intergranular Cu-rich particles was observed in the Cu-containing steels. Furthermore, the addition of 3 wt% Cu promoted the formation and growth of κ-carbides, leading to an enhanced precipitation strengthening and a significant improvement in strength. The predominant deformation mechanism was dislocation glide in all steels. Strain hardening was attributed to dynamic slip band refinement, and Cu alloying contributed to reducing the spacing of slip bands. As a result, the Cu-containing steels achieved a higher work hardening rate and greater fracture elongation.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116185"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386601","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-guided revelation of Detwinning-dominated cryogenic plasticity in Nano-twinned Cu-Ag alloys","authors":"Pengtao Li ,&nbsp;Chenke Ding ,&nbsp;Yutong Song ,&nbsp;Yihui Jiang ,&nbsp;Fei Cao ,&nbsp;Yanfang Wang ,&nbsp;Zhongyi Ding ,&nbsp;Yuanxi Liu ,&nbsp;Ruihan Zhang ,&nbsp;Yong Gao","doi":"10.1016/j.matchar.2026.116226","DOIUrl":"10.1016/j.matchar.2026.116226","url":null,"abstract":"<div><div>High-strength high-conductivity (HSHC) copper alloys are urgently needed for cryogenic applications such as superconducting cables and pulsed magnets operating at liquid-nitrogen temperature and below. By integrating large-scale molecular dynamics simulations containing 472,689 datasets with interpretable machine learning, we reveal that detwinning-induced grain boundary migration rather than conventional dislocation - twin boundary interactions dominate plastic deformation below 150 K in nano-twinned Cu-18 wt% Ag alloys. Cryorolling followed by low-temperature annealing produces dense nanotwins with mean spacing of 5.2 nm, as confirmed by TEM. Atomistic simulations show that Ag segregation dramatically reduces the critical detwinning stress from 800 MPa (pure Cu) to 220 MPa, resulting in a pronounced Hall-Petch plateau below λ = 7.0 nm. SHAP analysis quantitatively demonstrates that detwinning accounts for &gt;72% of plastic strain at <em>T</em> &lt; 150 K. A random forest-derived (R² = 99.4%) temperature–twin spacing phase diagram identifies a cryogenic service window (T &lt; 150 K, λ = 3.0–12.0 nm) where flow stress stabilizes at 5.1 ± 0.2 GPa. These findings provide explicit design guidelines for next-generation HSHC copper alloys in extreme cryogenic environments.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116226"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386689","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":"Superlattice phase precipitation in Ti-Fe-Mo-Al alloys","authors":"A.M.L. Andersson,&nbsp;R.F.L. Mellor,&nbsp;J.M. Hogg,&nbsp;H.C. Cole,&nbsp;G.I. Lampronti,&nbsp;N.L. Church,&nbsp;O.S. Houghton,&nbsp;N.G. Jones,&nbsp;H.J. Stone","doi":"10.1016/j.matchar.2026.116139","DOIUrl":"10.1016/j.matchar.2026.116139","url":null,"abstract":"<div><div>Ti-Fe-Al and Ti-Fe-Mo alloys containing B2 superlattice precipitates within an A2 matrix have attracted interest for structural applications. However, few studies have considered alloys derived from the quaternary Ti-Fe-Mo-Al system. In this work, six Ti-Fe-Mo-Al compositions with 70<!--> <!-->at.% Ti have been aged for 1000<!--> <!-->h at <span><math><mrow><mn>600</mn></mrow></math></span>, <span><math><mrow><mn>800</mn></mrow></math></span>, and 1000<!--> <!-->°C to assess their equilibrium phases. A2+B2 phase microstructures formed in two of the alloys considered: Ti-20Fe-5Mo-5Al at both <span><math><mrow><mn>800</mn></mrow></math></span> <!--> <!-->and 1000<!--> <!-->°C, and Ti-15Fe-10Mo-5Al at 800<!--> <!-->°C. A2+B2 microstructures were not observed in the other alloys investigated. At high temperatures, most alloys were single-phase A2, while at lower temperatures A3 and D0₁₉ phases were widely observed.</div><div>Studying continuous cooling of Ti-20Fe-5Mo-5Al from the solid solution showed a change in precipitation behaviour with cooling rate. Intermediate cooling rates permitted discontinuous B2 precipitation. The slowest cooling rate led to continuous B2 precipitation and the observation of the D8<span><math><msub><mrow></mrow><mrow><mtext>a</mtext></mrow></msub></math></span> G-phase. This transition in precipitation mechanism was attributed to the relative rates of bulk and grain boundary diffusion at varying temperatures.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"234 ","pages":"Article 116139"},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386695","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}