Materials Characterization最新文献

{"title":"Analysis of damage mechanisms in an AlSi10Fe0.7 model casting alloy based on a “digital twin”","authors":"T. Ickler , D. Jüngst , A. Brückner-Foit , M. Fehlbier","doi":"10.1016/j.matchar.2025.115506","DOIUrl":"10.1016/j.matchar.2025.115506","url":null,"abstract":"<div><div>Brittle phases have a major influence on the mechanical behavior of cast aluminum alloys. Among these, silicon precipitates are nearly omnipresent, as Si is a common alloying element. In secondary alloys, <span><math><mi>Fe</mi></math></span>-containing phases are generally unavoidable and tend to degrade the mechanical properties. This study investigates the interaction between the silicon phase and the failure-critical intermetallic phase β-<span><math><msub><mi>Al</mi><mn>4.5</mn></msub><mtext>FeSi</mtext></math></span> in the <span><math><mi>Al</mi></math></span>-<span><math><mi>Si</mi></math></span>-<span><math><mi>Fe</mi></math></span> phase system by a combined computational and experimental approach. A model alloy <span><math><mi>Al</mi><mn>10</mn><mi>Si</mi><mn>0.7</mn><mi>Fe</mi></math></span> was defined, which is composed of a large-grained <span><math><mi>Al</mi></math></span>-matrix, <span><math><mi>Si</mi></math></span>-precipitates and the plate-like β-<span><math><msub><mi>Al</mi><mn>4.5</mn></msub><mtext>FeSi</mtext></math></span> phase. The “digital twin” of a micro specimen cast with this model alloy was set up combining electron backscatter diffraction (EBSD) and computer tomography (μCT). EBSD provided the crystallographic orientation of the phases, while the μCT delivered the morphology and 3D distribution. Elastic-anisotropic, plastic-isotropic and crystal-plastic material models were used in the simulation. The study aimed at identifying “hot spots” in the microstructure where cracks might initiate under mechanical loading. The experimental tool was a deformation analysis via digital image correlation in the SEM (SEM-DIC). The experimental analysis is shown in (Ickler et al., 2024 [<span><span>1</span></span>]) in detail. In addition to the “real” tensile tests in the SEM, a “virtual” tensile test was performed with the “digital twin” using boundary conditions determined from the SEM-DIC experiment. The SEM-DIC results and simulations show that the deformation field is governed by the elastic incompatibility of the microstructural constituents. Crack initiation occurs because of the detachment of the <span><math><mi>Si</mi></math></span>+β-<span><math><msub><mi>Al</mi><mn>4.5</mn></msub><mtext>FeSi</mtext></math></span> phase boundary from the matrix (Ickler et al., 2024 [<span><span>1</span></span>]). The simulation provided a view in the subsurface domain, revealing that the deformation processes within the <span><math><mi>Al</mi></math></span>-matrix are closely linked to the orientation of the plate-like phases relative to the crystal orientation and load direction. When platelets are aligned with a suitable slip plane of the <span><math><mi>Al</mi></math></span>-matrix, significant shearing without rotational deformation along the inclusions can be observed even at low loads. When platelets are not aligned with a suitable slip plane, dislocations can accumulate at phase triple points, further increasing the","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"229 ","pages":"Article 115506"},"PeriodicalIF":5.5,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907238","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 ultrasonic vibration on microstructure, texture and mechanical characteristics of Inconel 625 additively manufactured through continuous and pulsed laser directed energy deposition","authors":"Saurav Misra,&nbsp;Saikat Nandi,&nbsp;Prasenjit Patra,&nbsp;Ipsita Mohanty,&nbsp;Partha Saha,&nbsp;Cheruvu Siva Kumar","doi":"10.1016/j.matchar.2025.115504","DOIUrl":"10.1016/j.matchar.2025.115504","url":null,"abstract":"<div><div>The present study investigated the influence of hybridizing external ultrasonic vibration with continuous and pulsed wave laser for directed energy deposition of Inconel 625. A comparative analysis of the microstructural and mechanical characteristics was undertaken under four different conditions: unassisted continuous wave mode, unassisted pulsed wave mode, ultrasonic-wave-assisted continuous wave mode, and ultrasonic-assisted pulsed wave mode. The investigation revealed that the combination of laser pulsation and ultrasonic agitation produced higher level of microstructural refinement, resulting in the formation of smaller, near-equiaxed grains. The synergistic impact of ultrasonication and laser pulsation also helped control the extent of elemental segregation, resulting in greater chemical homogeneity. The refined microstructure, along with reduced elemental segregation and increased dislocation densities due to ultrasonic-vibration-assisted pulsed wave mode, contributed to a greater strengthening effect. Additionally, a significant reduction in internal porosity was achieved in samples subjected to external ultrasonic agitation. The study also reflected an increase in the degree of grain misorientation with a considerable presence of coincidence site lattice in the samples fabricated under vibration-assisted pulsed laser-DED. The results indicated a weak mixed-texture evolution in samples fabricated using only pulsed wave mode and in those produced with a combination of ultrasonication and PW laser input. Moreover, the synergistic effect of ultrasonication and pulsed wave laser irradiation also led to an improvement in microhardness, nano-hardness, and load-carrying capacity. Additionally, an enhancement in tensile strength was observed when pulsed laser irradiation was paired with ultrasonic vibration. However, there was a slight reduction in elongation characteristics compared to samples made using only PW and continuous wave modes.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"229 ","pages":"Article 115504"},"PeriodicalIF":5.5,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144904198","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":"Flash synthesis of high-entropy alloy nanoparticles on carbon nanotubes: Synergistic lattice distortion and chemical reconfiguration for superior oxygen evolution catalysis","authors":"Wenwen Chen ,&nbsp;Xiaoyan Liu ,&nbsp;Xirong Yang ,&nbsp;Linxiao Gou ,&nbsp;Gengjie Wang","doi":"10.1016/j.matchar.2025.115508","DOIUrl":"10.1016/j.matchar.2025.115508","url":null,"abstract":"<div><div>Transition metal-based catalysts hold promise as alternatives to precious metals for water electrolysis, yet their conventional synthesis faces challenges such as lengthy processes and structural instability. In this work, ternary, quaternary medium-entropy alloys nanoparticles (MEA NPs) and FeCoNiCrMn high-entropy alloy nanoparticles (HEA NPs) are successfully synthesized anchored on carbon nanotube films (CNTs), The size is approximately 30–60 nm. ICP results show that the elemental composition complies with HEA standards (5 %–35 %). The incorporation of Cr and Mn induces lattice distortion and enhances the oxidation states of Fe/Co/Ni, synergistically optimizing d-p orbital overlaps between metals and adsorbed oxygen species. This electronic reconfiguration enables the quinary FeCoNiCrMn/CNTs catalyst to achieve a low oxygen evolution reaction (OER) overpotential of 260 mV at 10 mA cm⁻² and a reduced Tafel slope of 65.31 mV dec⁻¹, outperforming commercial RuO₂ (330 mV). The subsequent analysis of the results further reveals that the generated hydroxide/carbide phase during the OER process could dynamically regulate the electron transfer at the metal-support interface, thus inhibiting the dissolution of the active components. In addition, the HEA catalysts demonstrate satisfactory catalytic stability. This study provides a new idea for the regulation of the electrocatalytic performance of HEA NPs.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"229 ","pages":"Article 115508"},"PeriodicalIF":5.5,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144931627","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":"Quantification of nanoscale Al3Zr-dispersoids in 7xxx aluminium alloys using low energy backscattered electron microscopy","authors":"Aurel Arnoldt ,&nbsp;Patrick Ortner ,&nbsp;Andreas Schiffl ,&nbsp;Johannes A. Österreicher ,&nbsp;Heinz-Werner Höppel","doi":"10.1016/j.matchar.2025.115505","DOIUrl":"10.1016/j.matchar.2025.115505","url":null,"abstract":"<div><div>High strength 7xxx series aluminium alloys are commonly used in the aerospace industry and hold significant promise for advancing weight reduction efforts in automobiles. These alloys contain nanoscale phases, known as dispersoids, which precipitate during homogenization. Dispersoids have a major impact on processability and final product properties. Dispersoids are commonly analysed by transmission electron microscopy (TEM), especially in the case of Al₃Zr-dispersoids with typical sizes &lt; 50 nm. However, TEM foil preparation is rather time-consuming, and TEM operating costs are high. In contrast, scanning electron microscopy (SEM) is less expensive, and sample preparation is much easier and faster. However, resolution is limited in comparison to TEM.</div><div>The focus of this work is the SEM analysis of Al₃Zr-dispersoid size distributions in aluminium alloys. A specialized low accelerating voltage (≤ 5 kV) backscattered electron detector is employed, greatly improving the attainable resolution compared to standard SEM conditions. The method is validated using two variants of alloy AA7108A with different dispersoid size distributions. The obtained size distributions are compared to those acquired using TEM, and good agreement is found.</div><div>Low-energy backscattered SEM using dedicated detectors allows for fast quantification of nanoscale Al₃Zr-dispersoids in aluminium alloys, offering the potential to accelerate alloy and process development, particularly in contexts where optimizing dispersoid size distributions is critical.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"229 ","pages":"Article 115505"},"PeriodicalIF":5.5,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144918104","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":"On the high-temperature tensile deformation mechanisms of the IN738LC superalloy fabricated by laser powder bed fusion","authors":"Mohammad Hafezi ,&nbsp;Ahmad Kermanpur ,&nbsp;Ahmad Rezaeian ,&nbsp;Fatemeh Heydari ,&nbsp;Hossein Rabieifar ,&nbsp;Giulio Marchese ,&nbsp;Emilio Bassini ,&nbsp;Daniele Ugues ,&nbsp;Sara Biamino","doi":"10.1016/j.matchar.2025.115510","DOIUrl":"10.1016/j.matchar.2025.115510","url":null,"abstract":"<div><div>The high-temperature tensile properties of the IN738LC alloy fabricated by laser powder bed fusion (LPBF) process was evaluated in terms of strengthening mechanisms and factors influencing alloy deformation in two post-processing conditions: standard heat treatment (HT), and hot isostatic pressing followed by standard heat treatment (HIPHT). The microstructure of both types of samples consisted of γ matrix, γ' precipitates, and carbides; however, the amount and distribution of these features varied depending on the type of heat treatment. It was found that cracking in both HT and HIPHT specimens was initially caused in regions where adjacent grains exhibited heterogeneous deformation. The contribution of various deformation and strengthening mechanisms was determined through microstructural evaluations by transmission electron microscopy along with calculation of critical resolved shear stress. Mechanisms such as precipitate shearing, Orowan looping, and multiple structural interactions between matrix, precipitates, carbides, and dislocations, contribute to the high-temperature tensile deformation and strengthening of the LPBF-fabricated alloy. Microstructural characterization indicated that the coherency between the γ and γ' phases has the most significant impact on high-temperature tensile strength.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"229 ","pages":"Article 115510"},"PeriodicalIF":5.5,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907233","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 stabilization heat treatment on hot deformation behavior of GH4706 alloy","authors":"Jialiang Huang ,&nbsp;Xiangyi Hou ,&nbsp;Chong Wang ,&nbsp;Ran Duan ,&nbsp;Xintong Lian ,&nbsp;Shuo Huang","doi":"10.1016/j.matchar.2025.115490","DOIUrl":"10.1016/j.matchar.2025.115490","url":null,"abstract":"<div><div>Stabilization heat treatment is an effective method for refining and homogenizing the grain structure of GH4706 superalloy. In this study, the influence of stabilization heat treatment on the microstructural evolution of GH4706 forged bars was investigated using the Gleeble-3500 thermal simulation system, with particular emphasis on the role of the η-phase in dislocation accumulation and dynamic recrystallization (DRX) behavior. Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analyses reveal that the promotion of DRX nucleation by the η-phase primarily results from its Zener pinning effect, which enhances dislocation accumulation due to its low stacking fault energy, as well as the local strain gradients induced by its distribution. Three-dimensional atom probe (3DAP) results show that Ti segregates at grain boundaries to promote η-phase precipitation, while Nb enriches within grains, which hinders dislocation motion and facilitates discontinuous dynamic recrystallization (DDRX). In stabilized compression specimens, the DRX grain fraction increased significantly, reaching 46.55 % at 50 % strain, compared to 14.31 % in untreated specimens, and the proportion of low-angle grain boundaries (LAGBs) decreased from 57 % to 30 %. This phenomenon is closely associated with the η-phase, which facilitates DDRX nucleation via grain boundary bulging. In contrast, untreated specimens exhibit limited dynamic recovery (DRV) and lower DRX efficiency. Furthermore, the presence of the η-phase enhances grain boundary stability, suppresses grain coarsening, and further improves microstructural homogeneity. This study reveals the dominant role of the η-phase in DDRX during the hot deformation of GH4706 alloy.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"229 ","pages":"Article 115490"},"PeriodicalIF":5.5,"publicationDate":"2025-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144904188","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":"Investigation on the effect of sigma phase on the brittle fracture behavior and fracture mechanism of super ferritic stainless steel via quasi-in-situ tensile testing","authors":"Fei Yang ,&nbsp;Yujin Nie ,&nbsp;Lixin Meng ,&nbsp;Liuwei Zheng ,&nbsp;Wei Liang ,&nbsp;Quanxin Shi ,&nbsp;Lei Yan","doi":"10.1016/j.matchar.2025.115497","DOIUrl":"10.1016/j.matchar.2025.115497","url":null,"abstract":"<div><div>The precipitation behavior of brittle phases and their detrimental effects on the mechanical properties of hot-rolled S44660 super ferritic stainless steel (SFSS) during aging at 800 °C were examined. The influence of the sigma phase on deformation fracture behavior and the brittle fracture mechanism was elucidated through quasi-in-situ tensile tests. The fibrous deformed structure resulting from hot rolling, characterized by high-density dislocations and sub-grain boundaries, provided preferred nucleation sites for the Laves and sigma phases and facilitated the diffusion of Cr, Mo, and Nb elements, thereby promoting the precipition of those phases. During aging, the nanoscale Laves phase precipitated preferentially at dislocations and grain boundaries, followed by the growth of the massive σ phase. The precipitation of these brittle phases significantly reduced the material's plasticity and toughness, with the sigma phase being the primary cause of brittle fracture. Quasi-in-situ tensile tests revealed that while the ferrite matrix exhibited a relatively high Schmid factor (SF ≈ 0.44–0.46) due to active slip systems, plastic deformation was limited by dislocation and precipitates, as indicated by an increase in the average KAM value from 0.77° to 1.51°. The sigma phase, despite having a high SF value (≈0.439), exhibited minimal deformation due to its high critical resolved shear stress, with the KAM value increasing only slightly from 0.46° to 0.89°. This disparity in deformation capacity led to stress concentration at the phase interface, inducing microcrack initiation in the sigma phase perpendicular to the applied force. Crack propagation and penetration through the ferrite matrix ultimately resulted in material brittle fracture.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"229 ","pages":"Article 115497"},"PeriodicalIF":5.5,"publicationDate":"2025-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144931630","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":"The effect of B4C addition on hot cracking suppression mechanism and mechanical properties of IN718 superalloy prepared by LDED","authors":"Xu Zhang ,&nbsp;Changyu Zhou ,&nbsp;Zhixue Wang ,&nbsp;Yajie Chu ,&nbsp;Dong Wu ,&nbsp;Liyi Wang","doi":"10.1016/j.matchar.2025.115498","DOIUrl":"10.1016/j.matchar.2025.115498","url":null,"abstract":"<div><div>The effect of the B₄C particles addition on the microstructure evolution, hot cracking suppression mechanism, and mechanical properties of the Inconel 718 (IN718) superalloy fabricated by the laser-directed energy deposition (LDED) was investigated. The results indicated that the LDED IN718 superalloy has a high hot cracking sensitivity and the addition of the B₄C particles could significantly inhibit the initiation and propagation of the hot cracking. B₄C has high thermal conductivity, and the addition of B₄C particles enhanced the heat dissipation of the molten pool and altered the growth behaviors of the columnar dendrites. This improvement led to an increase in the proportion of the low-angle grain boundaries (LAGBs) from 26.8 % to 57.3 %. Furthermore, B₄C reacted chemically with the elements in IN718 superalloy at high temperatures. The precipitation of borides and carbides in the interdendritic region was promoted, while the formation of low melting point Laves phase was suppressed. The synergistic effect of the LAGBs formation, borides and carbides precipitation, and the reduction of the Laves phase may result in the improvement of the hot cracking resistance of the LDED IN718 superalloy. Mechanical property tests showed that the addition of 2 wt% B₄C particles to the LDED IN718 superalloy result in increased hardness, enhanced wear resistance, and a simultaneous improvement in both tensile strength and plasticity. This study provides new insights into the additive manufacturing of high-performance, crack-free Ni-based superalloy.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"229 ","pages":"Article 115498"},"PeriodicalIF":5.5,"publicationDate":"2025-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144913859","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":"On the high cycle fatigue behavior of a deep drawable dual-phase steel for car body","authors":"Gaurav Pandey ,&nbsp;Basudev Bhattacharya ,&nbsp;Somjeet Biswas","doi":"10.1016/j.matchar.2025.115501","DOIUrl":"10.1016/j.matchar.2025.115501","url":null,"abstract":"<div><div>This work deals with the high cycle fatigue (HCF) behavior of a cold-rolled (CR) and heat-treated <span><math><mn>0.05</mn><mi>wt</mi><mo>%</mo></math></span> carbon micro-alloyed (<span><math><mo>&lt;</mo><mn>4</mn><mi>wt</mi><mo>%</mo></math></span>) ferrite-martensite (FM) dual-phase (DP) steel sheet having high strength, ductility, and deep-drawing combination required for car structural parts. The heat treatment was done by inter-critical annealing (<span><math><msup><mn>800</mn><mo>°</mo></msup><mi>C</mi></math></span>, <span><math><mn>5</mn><mi>min</mi></math></span>) and quenching. An exceptionally high endurance limit <span><math><mo>∼</mo><mn>485</mn><mi>MPa</mi></math></span>, greater than the yield strength, was achieved. This could be attributed to (i) uniformly distributed fine ferrite grains with finer <span><math><mo>∼</mo><mn>0.30</mn></math></span> fraction of interconnected island martensite (IM), (ii) fully recovered microstructure with very low statistically stored dislocations (SSD), (iii) interconnecting geometrically necessary boundaries (GNB) and ferrite-martensite (FM) interface, coincidental site lattice boundaries (CSLB), and (iv) strong <span><math><mi>γ</mi></math></span>-fiber texture with <span><math><mfenced><mn>111</mn></mfenced></math></span> along the thickness for geometric strengthening. The <span><math><mi>γ</mi></math></span>-fiber weakens during HCF at high stress amplitudes (<span><math><msub><mi>S</mi><mi>A</mi></msub></math></span>). Additionally, the γ-fiber shifts towards the <span><math><mi>β</mi></math></span>-fiber position with the increase in <span><math><msub><mi>S</mi><mi>A</mi></msub></math></span>. The geometrically softer grains formed are more susceptible to deformation, increasing the dislocation density and stored energy during HCF. Thus resulting in fractures in a lower number of cycles with higher <span><math><msub><mi>S</mi><mi>A</mi></msub></math></span>. Furthermore, the damage mechanism indicate that the cracks initiate from the surface through the persistent slip bands (PSB) in ferrite and propagate along the FM interface and IM into the specimen interior. The fracture surface of a failed HCF specimen revealed the formation of fatigue failure, transition, and overload failure zones.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"229 ","pages":"Article 115501"},"PeriodicalIF":5.5,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907236","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":"Synergy of solidification cooling rate and Cr addition to promote the recyclability of a near-eutectic AlSi alloy with high Fe impurity","authors":"R. Kakitani ,&nbsp;A.V. Rodrigues ,&nbsp;C. Silva ,&nbsp;Amauri Garcia ,&nbsp;Noé Cheung","doi":"10.1016/j.matchar.2025.115494","DOIUrl":"10.1016/j.matchar.2025.115494","url":null,"abstract":"<div><div>Adding strategic elements to Fe-contaminated Al<img>Si alloys offers a viable recycling route by suppressing the formation of harmful Fe-rich intermetallic compounds (IMCs) or modifying their morphology to less detrimental forms. Chromium is one of such elements, known to transform β-AlFeSi into α-Al(<em>Fe</em>,<em>Cr</em>)Si, altering its morphology from needle-like to Chinese script or fishbone shapes. This study investigates the combined effects of Cr additions (0.2, 0.4, and 0.6 wt%) and cooling rate on an Al-12 %Si-1 %Fe alloy solidified under non-equilibrium conditions. A comprehensive analysis explores the interrelationships between solidification cooling rate, microstructure, and mechanical properties. X-Ray Diffraction results showed that 0.2 wt% Cr was insufficient to fully suppress β-AlFeSi formation, whereas 0.4 wt% and 0.6 wt% Cr effectively promoted the formation of α-Al(<em>Fe</em>,<em>Cr</em>)Si with Chinese script and fishbone morphologies. Shape factors — circularity and aspect ratio — of the Fe-rich IMCs were evaluated across high (15 °C/s), moderate (6 °C/s) and low (3 °C/s) solidification cooling rates. Primary, secondary, and tertiary dendritic arm spacings were also measured to determine growth laws in relation to the cooling rate. Tensile testing and fractography were conducted to assess mechanical behavior as a function of IMC morphology and the dendritic matrix. Finally, radar charts were proposed to correlate mechanical performance with alloy Cr content and cooling rate, offering guidance for alloy design and casting process optimization.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"229 ","pages":"Article 115494"},"PeriodicalIF":5.5,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893428","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}