Pub Date : 2024-09-14DOI: 10.1016/j.mtcomm.2024.110421
Yihe Liu, Yufei Gao, Guanzheng Li, Zhenyu Shi
2.5D C/SiC composite materials are widely used in aerospace high-temperature components, optical system structural components and other fields due to their excellent performance. For the cutting of 2.5D C/SiC composites, diamond wire saw cutting process has great potential for application. In this study, experiments were conducted on cutting 2.5D C/SiC composites with diamond wire saw along different fiber orientations (P0°, P90°, V90°) and different process parameters. The effects of fiber orientation, feed speed, and wire speed on the surface morphology, surface waviness profile, and roughness of the as-sawn surface were analyzed. The results show that fiber orientation significantly affects the fiber damage mode and surface quality of the as-sawn surface, with the surface quality of the slices ranked as V90°>P0°>P0°. The surface morphology and surface roughness improves with decreasing feed speed and increasing wire speed. However, surface waviness profile peak-valley (PV) values increases with increasing the feed speed and wire speed. The study provides experimental references for process optimization and quality improvement in diamond wire saw cutting of 2.5D C/SiC composite materials.
{"title":"Influences of fiber orientation and process parameters on diamond wire sawn surface characteristics of 2.5D Cf/SiC composites","authors":"Yihe Liu, Yufei Gao, Guanzheng Li, Zhenyu Shi","doi":"10.1016/j.mtcomm.2024.110421","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110421","url":null,"abstract":"2.5D C/SiC composite materials are widely used in aerospace high-temperature components, optical system structural components and other fields due to their excellent performance. For the cutting of 2.5D C/SiC composites, diamond wire saw cutting process has great potential for application. In this study, experiments were conducted on cutting 2.5D C/SiC composites with diamond wire saw along different fiber orientations (P0°, P90°, V90°) and different process parameters. The effects of fiber orientation, feed speed, and wire speed on the surface morphology, surface waviness profile, and roughness of the as-sawn surface were analyzed. The results show that fiber orientation significantly affects the fiber damage mode and surface quality of the as-sawn surface, with the surface quality of the slices ranked as V90°>P0°>P0°. The surface morphology and surface roughness improves with decreasing feed speed and increasing wire speed. However, surface waviness profile peak-valley (PV) values increases with increasing the feed speed and wire speed. The study provides experimental references for process optimization and quality improvement in diamond wire saw cutting of 2.5D C/SiC composite materials.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"105 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, the effects of Fe doping on phase stability, martensitic transformation, and magnetic properties of NiMnTiFe ( = 3.125, 6.25, 9.375) all--metal Heusler alloys were systematically investigated by first-principles calculations. The results indicate a tendency for doped Fe atoms to aggregate within the NiMnTiFe alloys. As Fe concentration increases, a gradual reduction in both lattice constants and phase stability of austenite and martensite is observed. In the absence or presence of minimal Fe doping, both austenite and martensite exhibit antiferromagnetic behavior. However, at = 9.375, a transition to a ferromagnetic state is observed in the austenite phase. This transition is attributed to the activation of the ferromagnetic coupling effect in the austenite phase induced by Fe doping in the Ni-Mn-Ti alloy. In contrast, the martensite phase maintains its antiferromagnetic characteristics throughout the doping range. A comprehensive analysis of the electronic structure elucidates the underlying physical mechanisms responsible for the martensitic transformation and magnetic property changes.
{"title":"Insights into effects of Fe doping on phase stability, martensitic transformation, and magnetic properties in Ni-Mn-Ti-Fe all-d-metal Heusler alloys","authors":"Jiaxin Xu, Jing Bai, Yu Zhang, Keliang Guo, Qingshuang Ma, Xinjun Jiang, Jianglong Gu, Qiuzhi Gao, Liang Zuo","doi":"10.1016/j.mtcomm.2024.110415","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110415","url":null,"abstract":"In this work, the effects of Fe doping on phase stability, martensitic transformation, and magnetic properties of NiMnTiFe ( = 3.125, 6.25, 9.375) all--metal Heusler alloys were systematically investigated by first-principles calculations. The results indicate a tendency for doped Fe atoms to aggregate within the NiMnTiFe alloys. As Fe concentration increases, a gradual reduction in both lattice constants and phase stability of austenite and martensite is observed. In the absence or presence of minimal Fe doping, both austenite and martensite exhibit antiferromagnetic behavior. However, at = 9.375, a transition to a ferromagnetic state is observed in the austenite phase. This transition is attributed to the activation of the ferromagnetic coupling effect in the austenite phase induced by Fe doping in the Ni-Mn-Ti alloy. In contrast, the martensite phase maintains its antiferromagnetic characteristics throughout the doping range. A comprehensive analysis of the electronic structure elucidates the underlying physical mechanisms responsible for the martensitic transformation and magnetic property changes.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"108 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
SiCp/Al composites have excellent material properties and are increasingly being used in the aerospace, military, and electronic packaging industries. However, the inhomogeneity and non-conductivity of conventional turning (CT) results in poor material surface quality and high cutting forces, which seriously hinder the application of particlereinforced metal matrix composites. The thermal softening property of laser-assisted turning (LAT) and the intermittent cutting property of two-dimensional (2D) ultrasonic elliptical vibratory turning (UEVT) offer unique advantages in improving material surface quality. Therefore, a novel laser ultrasonic elliptical vibratory turning (LUEVT) machining technique is proposed to improve the machining of SiCp/Al composites with two different volume fractions. The effect of highfrequency intermittent machining on material processing was further investigated by adjusting the pulsed laser power. Finite element modelling was used to predict the machining state, surface roughness, and chip morphology between the workpiece and the PCD tool. The effects of varying the machining parameters during the experiment on the two composites were analysed. The results showed that the LUEVT of 25 % and 45 % SiCp/Al composites were reduced by 39.3 % and 30.7 % respectively compared to the CT cutting forces. The experiments verified the consistency of the surface roughness and chip morphology with the finite element simulation results. The stability of the cutting force during the cutting process is also improved, as the material removal process mainly takes the form of small particle fragmentation and matrix encapsulation.
{"title":"Finite element analysis and experimental study on the cutting mechanism of SiCp/Al composite in laser ultrasonic elliptic vibration turning","authors":"Chenyang Xia, Jieqiong Lin, Mingming Lu, Xuejian Zhang, Shuang Chen","doi":"10.1016/j.mtcomm.2024.110389","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110389","url":null,"abstract":"SiCp/Al composites have excellent material properties and are increasingly being used in the aerospace, military, and electronic packaging industries. However, the inhomogeneity and non-conductivity of conventional turning (CT) results in poor material surface quality and high cutting forces, which seriously hinder the application of particlereinforced metal matrix composites. The thermal softening property of laser-assisted turning (LAT) and the intermittent cutting property of two-dimensional (2D) ultrasonic elliptical vibratory turning (UEVT) offer unique advantages in improving material surface quality. Therefore, a novel laser ultrasonic elliptical vibratory turning (LUEVT) machining technique is proposed to improve the machining of SiCp/Al composites with two different volume fractions. The effect of highfrequency intermittent machining on material processing was further investigated by adjusting the pulsed laser power. Finite element modelling was used to predict the machining state, surface roughness, and chip morphology between the workpiece and the PCD tool. The effects of varying the machining parameters during the experiment on the two composites were analysed. The results showed that the LUEVT of 25 % and 45 % SiCp/Al composites were reduced by 39.3 % and 30.7 % respectively compared to the CT cutting forces. The experiments verified the consistency of the surface roughness and chip morphology with the finite element simulation results. The stability of the cutting force during the cutting process is also improved, as the material removal process mainly takes the form of small particle fragmentation and matrix encapsulation.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"20 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1016/j.mtcomm.2024.110417
Suqing Qin, Jin Chen, Xiaofeng Yang, XinLe Wang, Huiqi Zheng, Yuzhao Ma, Yanjun Li
Magnetic CoFeO nanoparticles have received considerable attention as an activator for peroxymonosulfate (PMS) in the degradation of tetracycline. However, it is still challenging to construct CoFeO composites with good dispersion and highly exposed reactive sites. Herein, the KOH fiber-functionalized MXene matrix decorated by cobalt ferrite nanoparticles (denoted as CoFeO@Alk-MXene) was developed by electrostatic self-assembly method. The layered fibrotic structure effectively disperses and fixes cobalt ferrite nanoparticles, increasing the exposure of reactive sites. The as-prepared CoFeO@Alk-MXene material exhibited rapid removal of 100% tetracycline hydrochloride (TC-HCl) within 10 minutes by activating PMS, leveraging the excellent conductivity of alkalized MXene and the efficient activation of transition metal atoms. The experimental and theoretical analysis revealed that the electron transfer process of Ti/Ti, Co/Co and Fe/Fe, as well as the free radical and non-free radical attack behaviors produced by the adsorption of PMS by the composite, are the primary mechanisms for achieving rapid removal of pollutants. A comprehensive degradation mechanism and potential pathways were proposed based on these findings. Overall, CoFeO@Alk-MXene/PMS emerges as a promising catalytic system for TC removal.
{"title":"Efficient degradation of tetracycline by cobalt ferrite modified alkaline solution nanofibrous Ti3C2Tx MXene activated peroxymonosulfate system: Mechanism analysis and pathway","authors":"Suqing Qin, Jin Chen, Xiaofeng Yang, XinLe Wang, Huiqi Zheng, Yuzhao Ma, Yanjun Li","doi":"10.1016/j.mtcomm.2024.110417","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110417","url":null,"abstract":"Magnetic CoFeO nanoparticles have received considerable attention as an activator for peroxymonosulfate (PMS) in the degradation of tetracycline. However, it is still challenging to construct CoFeO composites with good dispersion and highly exposed reactive sites. Herein, the KOH fiber-functionalized MXene matrix decorated by cobalt ferrite nanoparticles (denoted as CoFeO@Alk-MXene) was developed by electrostatic self-assembly method. The layered fibrotic structure effectively disperses and fixes cobalt ferrite nanoparticles, increasing the exposure of reactive sites. The as-prepared CoFeO@Alk-MXene material exhibited rapid removal of 100% tetracycline hydrochloride (TC-HCl) within 10 minutes by activating PMS, leveraging the excellent conductivity of alkalized MXene and the efficient activation of transition metal atoms. The experimental and theoretical analysis revealed that the electron transfer process of Ti/Ti, Co/Co and Fe/Fe, as well as the free radical and non-free radical attack behaviors produced by the adsorption of PMS by the composite, are the primary mechanisms for achieving rapid removal of pollutants. A comprehensive degradation mechanism and potential pathways were proposed based on these findings. Overall, CoFeO@Alk-MXene/PMS emerges as a promising catalytic system for TC removal.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"1 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1016/j.mtcomm.2024.110388
Xirui Gao, Kangyi Deng, Hengqing Li, Ping Zhu, Xiumin Yang, Lei Zhang, Yangzhen Liu
Copper (Cu) matrix composites are the most attractive materials in rail transit, aerospace and other fields because of their excellent electrical conductivity and strength. The aim of this study was to determine the effect of milling time on the microstructure and mechanical properties of the (Graphtie-TiB)/Cu composites. The composites were prepared using rapid hot pressing sintering at the milling time of 4, 6, 8, 10 and 12. The structural, physical and mechanical properties of the composites was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and compression test. The results revealed that the particles size decreased with an increase in milling time, especially the particles size drop sharply during the first 4 h of milling, and the particles size directly decreased from 44.3 μm to about 13.2 μm. The full width at half maximum of diffraction peak increased gradually with an increase in milling time. The relative density, hardness, elastic modulus, electrical conductivity and compressive strength of the composites reached the maximum at 6 h, which were 99.1 %, 86.6 HV, 137.1 GPa, 45.6 %IACS, and 228.8 MPa, respectively. Compared with 12 h, the hardness, electrical conductivity and compressive strength at 6 h were increased by 5.7 %, 79.4 % and 56.9 %, respectively. Finally, the fracture mechanism of the composites was analyzed by observing the fracture morphology.
{"title":"On microstructures and mechanical properties of automotive (Graphtie-TiB2)/Cu composites with different milling times","authors":"Xirui Gao, Kangyi Deng, Hengqing Li, Ping Zhu, Xiumin Yang, Lei Zhang, Yangzhen Liu","doi":"10.1016/j.mtcomm.2024.110388","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110388","url":null,"abstract":"Copper (Cu) matrix composites are the most attractive materials in rail transit, aerospace and other fields because of their excellent electrical conductivity and strength. The aim of this study was to determine the effect of milling time on the microstructure and mechanical properties of the (Graphtie-TiB)/Cu composites. The composites were prepared using rapid hot pressing sintering at the milling time of 4, 6, 8, 10 and 12. The structural, physical and mechanical properties of the composites was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and compression test. The results revealed that the particles size decreased with an increase in milling time, especially the particles size drop sharply during the first 4 h of milling, and the particles size directly decreased from 44.3 μm to about 13.2 μm. The full width at half maximum of diffraction peak increased gradually with an increase in milling time. The relative density, hardness, elastic modulus, electrical conductivity and compressive strength of the composites reached the maximum at 6 h, which were 99.1 %, 86.6 HV, 137.1 GPa, 45.6 %IACS, and 228.8 MPa, respectively. Compared with 12 h, the hardness, electrical conductivity and compressive strength at 6 h were increased by 5.7 %, 79.4 % and 56.9 %, respectively. Finally, the fracture mechanism of the composites was analyzed by observing the fracture morphology.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"26 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The production of contrasted polymer-coated cardboards is necessary to establish the structure/properties relationships and produce the « just necessary » packaging materials. For that purpose, the impact of the processing parameters on the resulting structure of polymer-coated cardboards was modeled using a statistical Design of Experiment (DOE) approach. Five independent factors were considered: three numeric continuous factors, the pressure, the temperature, and the duration of thermocompression, one numeric discrete factor, the initial polymer film thickness, and one categorical factor, the cardboard type. Four responses were considered: the thicknesses of each of the three layers constituting polymer-coated cardboards (i.e., the free polymer, the impregnated, and the free cardboard) and the material’s curvature. The choice of the adequate DOE was first assessed using a Scoping Design and coupled with the characterization of the used polymer, i.e., poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV). The I-optimal DOE was found to be the most suitable and was therefore implemented. To validate the model, the DOE was then used to produce two targeted structures, one with no impregnation of the polymer and another one with a complete impregnation of the cardboard. The values of thicknesses and curvature were not significantly different from the model predictions, therefore verifying the model.
生产对比聚合物涂层纸板是建立结构/性能关系和生产 "刚需 "包装材料的必要条件。为此，我们采用统计实验设计（DOE）方法模拟了加工参数对聚合物涂层纸板最终结构的影响。实验中考虑了五个独立因素：三个连续数值因素，即压力、温度和热压持续时间；一个离散数值因素，即初始聚合物膜厚度；以及一个分类因素，即纸板类型。考虑了四个响应：构成聚合物涂层纸板（即游离聚合物、浸渍纸板和游离纸板）的三层中每一层的厚度以及材料的曲率。首先使用范围设计评估了适当 DOE 的选择，并结合了所用聚合物（即聚 3-羟基丁酸-3-羟基戊酸（PHBV））的特性。I-optimal DOE 被认为是最合适的，因此得以实施。为了验证该模型，我们使用 DOE 制作了两种目标结构，一种是未浸渍聚合物的结构，另一种是完全浸渍纸板的结构。厚度和曲率值与模型预测值相差不大，因此验证了模型。
{"title":"Prediction of the structure of polymer-coated cardboards produced by thermocompression using I-optimal design of experiment","authors":"Allison Vercasson, Luc Choisnard, Elsa Lamberet, Sébastien Gaucel, Valérie Guillard, Hélène Angellier-Coussy","doi":"10.1016/j.mtcomm.2024.110411","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110411","url":null,"abstract":"The production of contrasted polymer-coated cardboards is necessary to establish the structure/properties relationships and produce the « just necessary » packaging materials. For that purpose, the impact of the processing parameters on the resulting structure of polymer-coated cardboards was modeled using a statistical Design of Experiment (DOE) approach. Five independent factors were considered: three numeric continuous factors, the pressure, the temperature, and the duration of thermocompression, one numeric discrete factor, the initial polymer film thickness, and one categorical factor, the cardboard type. Four responses were considered: the thicknesses of each of the three layers constituting polymer-coated cardboards (i.e., the free polymer, the impregnated, and the free cardboard) and the material’s curvature. The choice of the adequate DOE was first assessed using a Scoping Design and coupled with the characterization of the used polymer, i.e., poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV). The I-optimal DOE was found to be the most suitable and was therefore implemented. To validate the model, the DOE was then used to produce two targeted structures, one with no impregnation of the polymer and another one with a complete impregnation of the cardboard. The values of thicknesses and curvature were not significantly different from the model predictions, therefore verifying the model.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"33 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1016/j.mtcomm.2024.110401
Zhihang Wang, Erlei Bai, Biao Ren, Yuhang Du, Chaojia Liu
In order to explore the cross-scale synergistic modification effect of carbon fiber (CF) and carbon nanofiber (CNF) on the mechanical properties of concrete, based on CNF modified concrete (NCFC, with CNF volume content of 0.3 %), four kinds of micro-nano carbon fiber modified concrete (MNCFMC, with CNF volume content of 0.3 % and CF volume content of 0.1∼0.4 %) are prepared. For comparison, four kinds of CF modified concrete (CFMC, with CF volume content of 0.1∼0.4 %) are also prepared. The compressive, flexural and splitting tensile strength of concrete are tested, and the cross-scale synergistic modification mechanism is analyzed by SEM and MIP tests. The results show that CF and CNF have cross-scale synergistic improvement effect on the mechanical properties of concrete. The mechanical properties of concrete can be further improved by adding CF with appropriate content on the basis of the addition of CNF. With the increase of CF content, the compressive, flexural and splitting tensile strength of MNCFMC first increase and then decrease. The mechanical properties of MNCFMC are the best when the CF content is 0.2 %, the compressive, flexural and splitting tensile strength of MNCFMC increase by 14.12 %, 19.69 % and 30.32 %, respectively. Compared with CFMC, the mechanical properties of MNCFMC with the same CF content are better. The physical bond between CF and concrete matrix is poor, CNF can enhance the physical bond between CF and concrete matrix by attracting the deposition of cement hydration product crystals. When CF and CNF are added together, the pore size refinement and pore structure optimization effects of fiber on concrete are the best. When the CF content is 0.2 %, the average pore size and total pore volume of MNCFMC decrease by 30.66 % and 16.86 % compared with CFMC, respectively.
{"title":"Mechanical properties and cross-scale synergistic modification mechanism of micro-nano carbon fiber modified concrete","authors":"Zhihang Wang, Erlei Bai, Biao Ren, Yuhang Du, Chaojia Liu","doi":"10.1016/j.mtcomm.2024.110401","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110401","url":null,"abstract":"In order to explore the cross-scale synergistic modification effect of carbon fiber (CF) and carbon nanofiber (CNF) on the mechanical properties of concrete, based on CNF modified concrete (NCFC, with CNF volume content of 0.3 %), four kinds of micro-nano carbon fiber modified concrete (MNCFMC, with CNF volume content of 0.3 % and CF volume content of 0.1∼0.4 %) are prepared. For comparison, four kinds of CF modified concrete (CFMC, with CF volume content of 0.1∼0.4 %) are also prepared. The compressive, flexural and splitting tensile strength of concrete are tested, and the cross-scale synergistic modification mechanism is analyzed by SEM and MIP tests. The results show that CF and CNF have cross-scale synergistic improvement effect on the mechanical properties of concrete. The mechanical properties of concrete can be further improved by adding CF with appropriate content on the basis of the addition of CNF. With the increase of CF content, the compressive, flexural and splitting tensile strength of MNCFMC first increase and then decrease. The mechanical properties of MNCFMC are the best when the CF content is 0.2 %, the compressive, flexural and splitting tensile strength of MNCFMC increase by 14.12 %, 19.69 % and 30.32 %, respectively. Compared with CFMC, the mechanical properties of MNCFMC with the same CF content are better. The physical bond between CF and concrete matrix is poor, CNF can enhance the physical bond between CF and concrete matrix by attracting the deposition of cement hydration product crystals. When CF and CNF are added together, the pore size refinement and pore structure optimization effects of fiber on concrete are the best. When the CF content is 0.2 %, the average pore size and total pore volume of MNCFMC decrease by 30.66 % and 16.86 % compared with CFMC, respectively.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"11 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Commercializing perovskite solar cells (PSCs) necessitates achieving high performance and reproducibility. One effective strategy for this is the precise regulation of raw powder components in the precursor solution to create high-quality perovskite films. In this study, explored the impact of various precursor solutions on the crystallinity and photovoltaic performance of α-phase (FAPbI)(MAPbBr) perovskite systems. A synthesis method utilizing a mixed powder (FAPbI)(MAPbBr), designated as P2, was developed to address reproducibility issues in PSCs arising from unbalanced stoichiometric ratios. The resulting P2-based perovskite film exhibited large grain size and minimal defects, leading to PSCs with an impressive power conversion efficiency (PCE) of 21.36 % and an open-circuit voltage () of 1.142 V. Encouragingly, the P2-based PSCs demonstrated outstanding reproducibility and storage stability, with PCE decay limited to 2.1 % at room temperature over a 21-day period.
{"title":"Pure α-phase (FAPbI3)0.83(MAPbBr3)0.17 powder for efficient perovskite solar cells with enhancing reproducibility","authors":"Tianxiang Zhao, Yanchun Guo, Xia Yang, Qiu Xiong, Peng Gao, Lingyi Meng, Zhihua Xiong","doi":"10.1016/j.mtcomm.2024.110398","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110398","url":null,"abstract":"Commercializing perovskite solar cells (PSCs) necessitates achieving high performance and reproducibility. One effective strategy for this is the precise regulation of raw powder components in the precursor solution to create high-quality perovskite films. In this study, explored the impact of various precursor solutions on the crystallinity and photovoltaic performance of α-phase (FAPbI)(MAPbBr) perovskite systems. A synthesis method utilizing a mixed powder (FAPbI)(MAPbBr), designated as P2, was developed to address reproducibility issues in PSCs arising from unbalanced stoichiometric ratios. The resulting P2-based perovskite film exhibited large grain size and minimal defects, leading to PSCs with an impressive power conversion efficiency (PCE) of 21.36 % and an open-circuit voltage () of 1.142 V. Encouragingly, the P2-based PSCs demonstrated outstanding reproducibility and storage stability, with PCE decay limited to 2.1 % at room temperature over a 21-day period.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"6 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1016/j.mtcomm.2024.110368
Wen Li, Shaojie Li, Yang Nan, Xuepiao Bai, Weiping Li
T-shaped joints of high-strength aluminum alloy welded by friction stir welding (FSW) are expected to replace the traditional riveting structures. However, the popularization of FSW in aerospace industry is still hindered by the corrosion of T-joint. Herein, T-joints of 2A12 and 2A97 aluminum alloys are prepared and studied via structural characterization and corrosion tests. The microstructures and constituents of different micro zones in T-joints before and after corrosion tests are characterized and analyzed particularly. The internal relationship between different micro zones in T-joints and their corrosion behaviors are clarified, which provides theoretical basis for improving welding process and surface protection after welding.
采用搅拌摩擦焊（FSW）焊接的高强度铝合金 T 形接头有望取代传统的铆接结构。然而，由于 T 形接头的腐蚀问题，搅拌摩擦焊在航空航天工业中的推广仍受到阻碍。本文制备了 2A12 和 2A97 铝合金的 T 形接头，并通过结构表征和腐蚀试验对其进行了研究。特别对腐蚀试验前后 T 形接头中不同微区的微观结构和成分进行了表征和分析。阐明了 T 型接头中不同微区的内部关系及其腐蚀行为，为改进焊接工艺和焊后表面保护提供了理论依据。
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Pub Date : 2024-09-12DOI: 10.1016/j.mtcomm.2024.110414
Jiayi He, Zikai Wu, Chen Wang, Yuandong Peng, Ning Wu, Fenghua Luo
Ni–Co alloy coating is applied to crystallizer surface to enhance its wear resistance for continuous steel casting. This study investigated the effects of heating temperature on the hardness, strength, and elongation of Ni–21 wt% Co coatings obtained by electroplating. The evolution of microstructure was analyzed by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results indicated that the as-deposited coating had a mixed structure of nanocrystals and microcrystals, containing numerous nanotwins and stacking faults. Its hardness, tensile strength, yield strength, and elongation were 371 HV, 1170 MPa, 1117 MPa, and 13.8 %, respectively. After low-temperature heating, the number of nanocrystals decreased, whereas the fraction of microcrystals increased. At heating temperatures of 100–200 °C, a reverse Hall–Petch phenomenon occurred owing to the formation of annealing twins and the transformation of dislocation-emission mechanisms, resulting in a stable hardness and tensile strength. As the heating temperature was further increased, the grains continuously grew, thereby decreasing the hardness and tensile strength. After annealed at 400 °C, the elongation reached 32.5 %, whereas the hardness, tensile strength, and yield strength decreased to 200 HV, 662 MPa, and 577 MPa, respectively.
镍钴合金镀层被应用于结晶器表面，以提高其耐磨性，用于连续铸钢。本研究探讨了加热温度对电镀法获得的镍-21 wt% Co 涂层的硬度、强度和伸长率的影响。通过扫描电子显微镜、透射电子显微镜和 X 射线衍射分析了微观结构的演变。结果表明，沉积后的涂层具有纳米晶体和微晶的混合结构，含有大量纳米孪晶和堆积断层。其硬度、抗拉强度、屈服强度和伸长率分别为 371 HV、1170 MPa、1117 MPa 和 13.8%。低温加热后，纳米晶体的数量减少，而微晶的比例增加。在加热温度为 100-200 ℃时，由于退火孪晶的形成和位错发射机制的转变，出现了反向霍尔-佩奇现象，从而使硬度和抗拉强度趋于稳定。随着加热温度的进一步升高，晶粒不断长大，从而降低了硬度和抗拉强度。在 400 °C 退火后，伸长率达到 32.5%，而硬度、抗拉强度和屈服强度则分别降至 200 HV、662 MPa 和 577 MPa。
{"title":"Evolution of microstructure and mechanical properties of electroplated nanocrystalline Ni–Co coating during heating","authors":"Jiayi He, Zikai Wu, Chen Wang, Yuandong Peng, Ning Wu, Fenghua Luo","doi":"10.1016/j.mtcomm.2024.110414","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110414","url":null,"abstract":"Ni–Co alloy coating is applied to crystallizer surface to enhance its wear resistance for continuous steel casting. This study investigated the effects of heating temperature on the hardness, strength, and elongation of Ni–21 wt% Co coatings obtained by electroplating. The evolution of microstructure was analyzed by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results indicated that the as-deposited coating had a mixed structure of nanocrystals and microcrystals, containing numerous nanotwins and stacking faults. Its hardness, tensile strength, yield strength, and elongation were 371 HV, 1170 MPa, 1117 MPa, and 13.8 %, respectively. After low-temperature heating, the number of nanocrystals decreased, whereas the fraction of microcrystals increased. At heating temperatures of 100–200 °C, a reverse Hall–Petch phenomenon occurred owing to the formation of annealing twins and the transformation of dislocation-emission mechanisms, resulting in a stable hardness and tensile strength. As the heating temperature was further increased, the grains continuously grew, thereby decreasing the hardness and tensile strength. After annealed at 400 °C, the elongation reached 32.5 %, whereas the hardness, tensile strength, and yield strength decreased to 200 HV, 662 MPa, and 577 MPa, respectively.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"2 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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