Pub Date : 2024-11-02DOI: 10.1016/j.matchar.2024.114504
N. Swetha , V. Venkata Lakshmi , M. Mylarappa , S. Chandruvasan , K.S. Harisha
The present work determines the synthesis of cerium loaded silicon dioxide (Ce-SiO2/rGO) nanocomposite by using reflux method. The Ce-SiO2/rGO was confirmed by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive (EDAX) techniques. In photodecomposition investigation, Rose Bengal (RB) dye was degraded efficiently using Ce-SiO2/rGO nanocomposite (95 %) at 150 min with follows first order kinetics. The antioxidant property against 2,2-diphenyl-1-picrylhydrazyl (DPPH) was found to be 98 % performance with IC50 value of 488.35 mg/mL. The super capacitance value of Ce-SiO2/rGO was increased compared to that of rGO, SiO2 and SiO2/rGO respectively. The electrochemical reversibility () and diffusion coefficient (D) values were determined using 1 M KCl by cyclic voltammetry method. Ce-SiO2/rGO nanocomposite was used as an electrochemical sensor to detect bee pollen and cow urine. The produced material has superior dye purification, redox behavior, bio-molecule detection, and antioxidative capabilities.
{"title":"Development of rare earth doped SiO2/rGO from rice husk for antioxidant, photocatalysis, electrochemical and sensor studies","authors":"N. Swetha , V. Venkata Lakshmi , M. Mylarappa , S. Chandruvasan , K.S. Harisha","doi":"10.1016/j.matchar.2024.114504","DOIUrl":"10.1016/j.matchar.2024.114504","url":null,"abstract":"<div><div>The present work determines the synthesis of cerium loaded silicon dioxide (Ce-SiO<sub>2</sub>/rGO) nanocomposite by using reflux method. The Ce-SiO<sub>2</sub>/rGO was confirmed by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive (EDAX) techniques. In photodecomposition investigation, Rose Bengal (RB) dye was degraded efficiently using Ce-SiO<sub>2</sub>/rGO nanocomposite (95 %) at 150 min with follows first order kinetics. The antioxidant property against 2,2-diphenyl-1-picrylhydrazyl (DPPH) was found to be 98 % performance with IC<sub>50</sub> value of 488.35 mg/mL. The super capacitance value of Ce-SiO<sub>2</sub>/rGO was increased compared to that of rGO, SiO<sub>2</sub> and SiO<sub>2</sub>/rGO respectively. The electrochemical reversibility (<span><math><msub><mi>E</mi><mi>O</mi></msub><mo>−</mo><msub><mi>E</mi><mi>R</mi></msub></math></span><strong>) and</strong> diffusion coefficient (D) values were determined using 1 M KCl by cyclic voltammetry method. Ce-SiO<sub>2</sub>/rGO nanocomposite was used as an electrochemical sensor to detect bee pollen and cow urine. The produced material has superior dye purification, redox behavior, bio-molecule detection, and antioxidative capabilities.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114504"},"PeriodicalIF":4.8,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578822","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}
Pub Date : 2024-11-01DOI: 10.1016/j.matchar.2024.114509
Guy Molénat, Jean-Philippe Monchoux, Bénédicte Warot-Fonrose, Alain Couret
Transmission electron microscopy is used to study the structure and morphology of nanoprecipitates of ω-type phase located in the βo-phase of a TNM-TiAl alloy. Using conventional and high-resolution imaging techniques, it is demonstrated that this ω- precipitation takes the form of needle-shaped nanoprecipitates that have characteristic dimensions of a few nanometers. Analyses of electronic diffraction patterns show that these precipitates are of a metastable ω” phase.
Then, it is investigated how these nanoprecipitates affect the dislocation glide mechanism at room temperature in this βo-phase. For this purpose, quantitative measurements of densities of precipitates and of dislocation pinning points are developed. A comparison of these data indicates that only the largest precipitates serve as dislocations' pinning points.
{"title":"ω precipitation and its influence on the deformation mechanisms of a TNM Ti-Al alloy","authors":"Guy Molénat, Jean-Philippe Monchoux, Bénédicte Warot-Fonrose, Alain Couret","doi":"10.1016/j.matchar.2024.114509","DOIUrl":"10.1016/j.matchar.2024.114509","url":null,"abstract":"<div><div>Transmission electron microscopy is used to study the structure and morphology of nanoprecipitates of ω-type phase located in the β<sub>o</sub>-phase of a TNM-TiAl alloy. Using conventional and high-resolution imaging techniques, it is demonstrated that this ω- precipitation takes the form of needle-shaped nanoprecipitates that have characteristic dimensions of a few nanometers. Analyses of electronic diffraction patterns show that these precipitates are of a metastable ω” phase.</div><div>Then, it is investigated how these nanoprecipitates affect the dislocation glide mechanism at room temperature in this β<sub>o</sub>-phase. For this purpose, quantitative measurements of densities of precipitates and of dislocation pinning points are developed. A comparison of these data indicates that only the largest precipitates serve as dislocations' pinning points.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114509"},"PeriodicalIF":4.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656595","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}
Pub Date : 2024-11-01DOI: 10.1016/j.matchar.2024.114512
Xiang Yi , Xingwang Bai , Runyao Yu , Xiangman Zhou , Runsheng Li , Fazhi Li
To achieve the synergetic improvement of the strength and ductility of titanium matrix composites (TMCs), in this study, flux-cored wires were customized and combined with the wire arc additive manufacturing (WAAM) process to fabricate laminated Ti-TiBw/Ti composites. The diffusion behavior of the reinforcement during the WAAM deposition process was studied in detail. By optimizing the process parameters to regulate the distribution of the reinforcement, the composites presented a laminated structure on the macroscale and a non-uniform distributed network structure on the microscale. Compared with pure titanium, the ultimate tensile strengths and ductility of the laminated Ti-TiBw/Ti composites have both improved. The ultimate tensile strengths of the composites with 5 vol% and 10 vol% TiBw/Ti layers are 574 MPa and 663 MPa, respectively, and the fracture elongation are 27.74 % and 24.95 %, respectively. This heterogeneous structure of TMCs reconciles the contradiction between strength and ductility, mainly attributed to the strengthening effect of in-situ synthesized TiBw and the toughening effect of the laminated structure and the TiBw network structure.
{"title":"Microstructure and mechanical properties of laminated Ti-TiBw/Ti composites fabricated by wire arc additive manufacturing","authors":"Xiang Yi , Xingwang Bai , Runyao Yu , Xiangman Zhou , Runsheng Li , Fazhi Li","doi":"10.1016/j.matchar.2024.114512","DOIUrl":"10.1016/j.matchar.2024.114512","url":null,"abstract":"<div><div>To achieve the synergetic improvement of the strength and ductility of titanium matrix composites (TMCs), in this study, flux-cored wires were customized and combined with the wire arc additive manufacturing (WAAM) process to fabricate laminated Ti-TiBw/Ti composites. The diffusion behavior of the reinforcement during the WAAM deposition process was studied in detail. By optimizing the process parameters to regulate the distribution of the reinforcement, the composites presented a laminated structure on the macroscale and a non-uniform distributed network structure on the microscale. Compared with pure titanium, the ultimate tensile strengths and ductility of the laminated Ti-TiBw/Ti composites have both improved. The ultimate tensile strengths of the composites with 5 vol% and 10 vol% TiBw/Ti layers are 574 MPa and 663 MPa, respectively, and the fracture elongation are 27.74 % and 24.95 %, respectively. This heterogeneous structure of TMCs reconciles the contradiction between strength and ductility, mainly attributed to the strengthening effect of in-situ synthesized TiBw and the toughening effect of the laminated structure and the TiBw network structure.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114512"},"PeriodicalIF":4.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656810","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}
Pub Date : 2024-11-01DOI: 10.1016/j.matchar.2024.114510
Z.W. Yang, C.L. Shi, X.Z. Yao, H.J. Li, Z.Q. Ma, Y. Wang
Carbon alloying is a validated strategy for enhancing the mechanical properties of titanium alloys prepared by wire arc additive manufacturing (WAAM). However, achieving uniform carbon distribution, particularly nanocarbon, in the melt pool via the brushing method is challenging, which limits the improvement of mechanical properties. In this paper, nanocarbon was modified by nitric acid hydrothermal treatment and added into the Ti64 melt pool during the WAAM. The distribution of modified nanocarbon in the melt pool was characterized, and the microstructure and mechanical properties of the nanocarbon-alloyed titanium alloy deposits were studied. The findings revealed that the surface of modified nanocarbon generated oxygen-containing functional groups, which enhanced its dispersion in the melt pool. The addition of 0.1–0.3 wt% modified nanocarbon induced no pores in the deposits compared to unmodified ones. The tensile strength of the deposited alloys was continually enhanced with increasing modified nanocarbon content, while the elongation had a peak value. The Ti64 with 0.1 wt% nanocarbon exhibited a balanced comprehensive performance with an ultimate tensile strength (UTS) of 981 MPa coupled with an elongation of 8 %. The achievement of the balanced mechanical performances was attributed to the refinement of α-Ti and solid solution strengthening of nanocarbon. When 0.3 wt% nanocarbon was added, the UTS increased to 1012 MPa but the elongation sharply decreased to 4.5 % due to the precipitation of TiC.
{"title":"Tailoring the microstructure and mechanical properties of wire arc additively manufactured Ti6Al4V alloy by in-situ microalloying with modified nanocarbon","authors":"Z.W. Yang, C.L. Shi, X.Z. Yao, H.J. Li, Z.Q. Ma, Y. Wang","doi":"10.1016/j.matchar.2024.114510","DOIUrl":"10.1016/j.matchar.2024.114510","url":null,"abstract":"<div><div>Carbon alloying is a validated strategy for enhancing the mechanical properties of titanium alloys prepared by wire arc additive manufacturing (WAAM). However, achieving uniform carbon distribution, particularly nanocarbon, in the melt pool via the brushing method is challenging, which limits the improvement of mechanical properties. In this paper, nanocarbon was modified by nitric acid hydrothermal treatment and added into the Ti64 melt pool during the WAAM. The distribution of modified nanocarbon in the melt pool was characterized, and the microstructure and mechanical properties of the nanocarbon-alloyed titanium alloy deposits were studied. The findings revealed that the surface of modified nanocarbon generated oxygen-containing functional groups, which enhanced its dispersion in the melt pool. The addition of 0.1–0.3 wt% modified nanocarbon induced no pores in the deposits compared to unmodified ones. The tensile strength of the deposited alloys was continually enhanced with increasing modified nanocarbon content, while the elongation had a peak value. The Ti64 with 0.1 wt% nanocarbon exhibited a balanced comprehensive performance with an ultimate tensile strength (UTS) of 981 MPa coupled with an elongation of 8 %. The achievement of the balanced mechanical performances was attributed to the refinement of α-Ti and solid solution strengthening of nanocarbon. When 0.3 wt% nanocarbon was added, the UTS increased to 1012 MPa but the elongation sharply decreased to 4.5 % due to the precipitation of TiC.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114510"},"PeriodicalIF":4.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656819","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}
Pub Date : 2024-10-30DOI: 10.1016/j.matchar.2024.114506
Joseph Agyapong, Aleksander Czekanski, Solomon Boakye Yiadom
This study examines the microstructural evolution and high strain rate deformation response of Selective Laser Melted (SLM) CoCrFeMnNi high-entropy alloys (HEAs) after annealing and deep cryogenic treatment. Annealing treatment has traditionally improved the ductility of SLM materials. However, in this work, a significant improvement in strength was observed in the annealed SLM CoCrFeMnNi after high strain rate deformation testing. TEM/HRTEM investigations revealed the formation of refined oxides, generated from the processing chamber environment and constituent powder feedstock. These oxides were homogenously distributed within microstructure, reinforcing its structural integrity. Initial microstructural analysis of the as-printed samples showed Mn2O3 oxides sparsely distributed within a cellular dislocation structure and significant Mn segregation. Unique grain growth with a less prominent cellular dislocation structure was observed in the annealed specimen. Deep cryogenic treatment induced oriented cellular structures with higher dislocation density and rounded oxides that were 56 % smaller. High strain rate impact tests (up to 6500 s-1) demonstrated that the as-printed sample was sensitive to the strain rate and reached a yield strength of ∼920 MPa at 6000 s−1 and a strain deformation of ∼55 % making it desirable for high strain rate applications. Remarkably, up to 22 % higher strength and ∼10 % greater ductility were achieved after annealing. The strengthening mechanisms in the samples and their contributions to the overall material strength were thoroughly analyzed. It was determined that a substantial portion of the strength in the annealed samples was due to the contributions of the precipitates within the alloy. The observed increase in strength was primarily attributed to the presence of two distinct nano-precipitates in the annealed specimens. However, there was no change in ductility after the deep cryogenic treatment but ∼10 % higher yield strength values at equivalent strain rates also attributed to the increased dislocation density.
{"title":"Microstructural evolution and high strain rate deformation response of SLM-printed CoCrFeMnNi after annealing and deep-cryogenic treatment","authors":"Joseph Agyapong, Aleksander Czekanski, Solomon Boakye Yiadom","doi":"10.1016/j.matchar.2024.114506","DOIUrl":"10.1016/j.matchar.2024.114506","url":null,"abstract":"<div><div>This study examines the microstructural evolution and high strain rate deformation response of Selective Laser Melted (SLM) CoCrFeMnNi high-entropy alloys (HEAs) after annealing and deep cryogenic treatment. Annealing treatment has traditionally improved the ductility of SLM materials. However, in this work, a significant improvement in strength was observed in the annealed SLM CoCrFeMnNi after high strain rate deformation testing. TEM/HRTEM investigations revealed the formation of refined oxides, generated from the processing chamber environment and constituent powder feedstock. These oxides were homogenously distributed within microstructure, reinforcing its structural integrity. Initial microstructural analysis of the as-printed samples showed Mn<sub>2</sub>O<sub>3</sub> oxides sparsely distributed within a cellular dislocation structure and significant Mn segregation. Unique grain growth with a less prominent cellular dislocation structure was observed in the annealed specimen. Deep cryogenic treatment induced oriented cellular structures with higher dislocation density and rounded oxides that were 56 % smaller. High strain rate impact tests (up to 6500 s-1) demonstrated that the as-printed sample was sensitive to the strain rate and reached a yield strength of ∼920 MPa at 6000 s<sup>−1</sup> and a strain deformation of ∼55 % making it desirable for high strain rate applications. Remarkably, up to 22 % higher strength and ∼10 % greater ductility were achieved after annealing. The strengthening mechanisms in the samples and their contributions to the overall material strength were thoroughly analyzed. It was determined that a substantial portion of the strength in the annealed samples was due to the contributions of the precipitates within the alloy. The observed increase in strength was primarily attributed to the presence of two distinct nano-precipitates in the annealed specimens. However, there was no change in ductility after the deep cryogenic treatment but ∼10 % higher yield strength values at equivalent strain rates also attributed to the increased dislocation density.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114506"},"PeriodicalIF":4.8,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586920","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}
Pub Date : 2024-10-30DOI: 10.1016/j.matchar.2024.114493
Zheng-Dong Qi , Zhong Yang , Xian-Fang Meng , Qiao-Qin Guo , Shi-Xing Huang , Xi-Gang Yang
Gd-rich austenitic stainless steel as a low-cost neutron shielding structural-functional integrated material is considered the most promising material to replace boron neutron shielding materials. However, as-cast Gd-rich austenitic stainless steel neutron shielding materials are affected by high hardness, low melting point, net-like, brittle intermetallic compound (Fe,Ni,Cr)3Gd, and its hot workability and mechanical properties are very poor. In this paper, Gd-rich 316 L austenitic stainless steel neutron shielding material hot deformation behavior was revealed, and the constitutive equation and hot processing maps were established and verified. On this basis, the effects of hot rolling on material microstructure and properties were studied, mainly discussing the effects of rolling temperature and subsequent solution treatment on the microstructure, recrystallization, mechanical properties, and neutron shielding properties. Studies have shown that Gd-rich 316 L austenitic stainless steel neutron shielding material has good hot workability at deformation temperatures of 950 ∼ 1050 °C and strain rates of 0.01 ∼ 0.1 s−1. Compared with before hot rolling, the strength, elongation and neutron shielding properties of 1050 °C hot-rolled 316 L-2.5wt%Gd neutron shielding material are increased by 1.79 times, 1.96 times and 1.31 times, respectively. After solution treatment at 1100 °C × 60 min, the elongation further increased to 39.53 %, which was 4.32 times than before hot rolling. This study provides valuable insights for high Gd content austenitic stainless steel neutron shielding materials thermo-mechanical processing and improving the strength and plasticity.
富钆奥氏体不锈钢作为一种低成本的中子屏蔽结构功能集成材料，被认为是最有希望取代硼中子屏蔽材料的材料。然而，铸态富钆奥氏体不锈钢中子屏蔽材料受高硬度、低熔点、网状、脆性金属间化合物（Fe,Ni,Cr）3Gd 的影响，热加工性能和力学性能很差。本文揭示了富含 Gd 的 316 L 奥氏体不锈钢中子屏蔽材料的热变形行为，建立并验证了构成方程和热加工图。在此基础上，研究了热轧对材料显微组织和性能的影响，主要讨论了轧制温度和后续固溶处理对显微组织、再结晶、力学性能和中子屏蔽性能的影响。研究表明，富钆 316 L 奥氏体不锈钢中子屏蔽材料在变形温度为 950 ∼ 1050 °C 和应变速率为 0.01 ∼ 0.1 s-1 时具有良好的热加工性能。与热轧前相比，1050 °C 热轧 316 L-2.5wt%Gd 中子屏蔽材料的强度、伸长率和中子屏蔽性能分别提高了 1.79 倍、1.96 倍和 1.31 倍。在 1100 °C × 60 分钟固溶处理后，伸长率进一步增加到 39.53 %，是热轧前的 4.32 倍。这项研究为高钆含量奥氏体不锈钢中子屏蔽材料的热机械加工以及提高强度和塑性提供了有价值的见解。
{"title":"Hot deformation behavior and hot rolled properties of Gd-rich 316 L austenitic stainless steel neutron shielding material for spent nuclear fuel storage and transportation","authors":"Zheng-Dong Qi , Zhong Yang , Xian-Fang Meng , Qiao-Qin Guo , Shi-Xing Huang , Xi-Gang Yang","doi":"10.1016/j.matchar.2024.114493","DOIUrl":"10.1016/j.matchar.2024.114493","url":null,"abstract":"<div><div>Gd-rich austenitic stainless steel as a low-cost neutron shielding structural-functional integrated material is considered the most promising material to replace boron neutron shielding materials. However, as-cast Gd-rich austenitic stainless steel neutron shielding materials are affected by high hardness, low melting point, net-like, brittle intermetallic compound (Fe,Ni,Cr)<sub>3</sub>Gd, and its hot workability and mechanical properties are very poor. In this paper, Gd-rich 316 L austenitic stainless steel neutron shielding material hot deformation behavior was revealed, and the constitutive equation and hot processing maps were established and verified. On this basis, the effects of hot rolling on material microstructure and properties were studied, mainly discussing the effects of rolling temperature and subsequent solution treatment on the microstructure, recrystallization, mechanical properties, and neutron shielding properties. Studies have shown that Gd-rich 316 L austenitic stainless steel neutron shielding material has good hot workability at deformation temperatures of 950 ∼ 1050 °C and strain rates of 0.01 ∼ 0.1 s<sup>−1</sup>. Compared with before hot rolling, the strength, elongation and neutron shielding properties of 1050 °C hot-rolled 316 L-2.5wt%Gd neutron shielding material are increased by 1.79 times, 1.96 times and 1.31 times, respectively. After solution treatment at 1100 °C × 60 min, the elongation further increased to 39.53 %, which was 4.32 times than before hot rolling. This study provides valuable insights for high Gd content austenitic stainless steel neutron shielding materials thermo-mechanical processing and improving the strength and plasticity.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114493"},"PeriodicalIF":4.8,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656811","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}
Pub Date : 2024-10-29DOI: 10.1016/j.matchar.2024.114505
Qingyan Peng , Xiaodong Tan , Zbigniew Stempień , Mohanapriya Venkataraman , Jiri Militky , Pavel Kejzlar , Ewa Korzeniewska
This study developed a silver/graphene flexible composite electrode using inkjet printing technology for high-performance supercapacitor. A rGO active layer was in-situ printed and reduced on the polypropylene non-woven fabric, and silver nanoparticles were simultaneously inserted and reduced to increase the interlayer spacing of the rGO active layer. This effectively reduced the self-stacking effect of rGO and improved the overall electrochemical performance. The successful in-situ reduction of GO and silver nitrate to rGO and silver nanoparticles was confirmed through morphological, structural, and surface chemical characterization. The 4Ag/rGO composite exhibits superior electrical conductivity, with a sheet resistance of 57.39 kΩ/sq., making it suitable for direct use as an electrode. In a three-electrode setup, these flexible composite electrodes demonstrated outstanding super capacitive performance, achieving a maximum specific capacitance of 800.30 F/g, excellent bendability, and remarkable cycle stability, with a capacitance retention of 104.9 % after over 2000 charge/discharge cycles at a current density of 0.25 mA/cm2. Furthermore, the composite electrodes exhibited a high energy density of up to 70.9 Wh/kg at a current density of 0.25 mA/cm2. The promising capacitive behavior and straightforward manufacturing process position the Ag/rGO hybrid electrodes as a potential material for future applications in next-generation flexible and wearable electronics.
{"title":"Inkjet printing of silver/graphene flexible composite electrodes for high-performance supercapacitors","authors":"Qingyan Peng , Xiaodong Tan , Zbigniew Stempień , Mohanapriya Venkataraman , Jiri Militky , Pavel Kejzlar , Ewa Korzeniewska","doi":"10.1016/j.matchar.2024.114505","DOIUrl":"10.1016/j.matchar.2024.114505","url":null,"abstract":"<div><div>This study developed a silver/graphene flexible composite electrode using inkjet printing technology for high-performance supercapacitor. A rGO active layer was in-situ printed and reduced on the polypropylene non-woven fabric, and silver nanoparticles were simultaneously inserted and reduced to increase the interlayer spacing of the rGO active layer. This effectively reduced the self-stacking effect of rGO and improved the overall electrochemical performance. The successful in-situ reduction of GO and silver nitrate to rGO and silver nanoparticles was confirmed through morphological, structural, and surface chemical characterization. The 4Ag/rGO composite exhibits superior electrical conductivity, with a sheet resistance of 57.39 kΩ/sq., making it suitable for direct use as an electrode. In a three-electrode setup, these flexible composite electrodes demonstrated outstanding super capacitive performance, achieving a maximum specific capacitance of 800.30 F/g, excellent bendability, and remarkable cycle stability, with a capacitance retention of 104.9 % after over 2000 charge/discharge cycles at a current density of 0.25 mA/cm<sup>2</sup>. Furthermore, the composite electrodes exhibited a high energy density of up to 70.9 Wh/kg at a current density of 0.25 mA/cm<sup>2</sup>. The promising capacitive behavior and straightforward manufacturing process position the Ag/rGO hybrid electrodes as a potential material for future applications in next-generation flexible and wearable electronics.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114505"},"PeriodicalIF":4.8,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573077","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}
Pub Date : 2024-10-29DOI: 10.1016/j.matchar.2024.114501
Ashoktaru Chakraborty, Shibayan Roy
Shear localization and shear band formation in metals, alloys and composites is an important deformation phenomenon most commonly associated with high strain rate deformation. It generally occurs as a thermo-mechanical instability where thermal softening due to adiabatic heating subdues strain hardening. The review presents different facets of strain localization and eventual shear band formation in various materials primarily including pure metals, alloys and composites. It starts with the dependence of shear band formation on materials parameters (e.g. crystal structure, stacking fault energy, c/a ratio, twining and TRIP effect etc.) and process variables (strain rate, stress states etc.) are presented. Effect of microstructural heterogeneities like twinning, grain boundary, phase boundary, particulates etc. are then discussed along with orientation variables (micro- and bulk texture etc.). Various aspects of microstructure and texture evolution due to strain localization in and around the shear bands are further demonstrated e.g. heat accumulation leading to dynamic recrystallization, phase transformation amorphization, evolution of Brass type texture due to shear banding etc. Theoretical simulations and modeling efforts pertaining to shear band formation, mostly crystal plasticity finite element based and resulting texture evolution is presented. Finally, an extensive review is carried out about the shear location and shear band formation for various metallic nanolayered composites. The present review therefore should be useful in understanding the root causes of shear localization and shear band formation e.g. during fabricating components for fracture-critical applications.
{"title":"Shear localization and shear banding: A review about the complex interplay between material, microstructural and process variables","authors":"Ashoktaru Chakraborty, Shibayan Roy","doi":"10.1016/j.matchar.2024.114501","DOIUrl":"10.1016/j.matchar.2024.114501","url":null,"abstract":"<div><div>Shear localization and shear band formation in metals, alloys and composites is an important deformation phenomenon most commonly associated with high strain rate deformation. It generally occurs as a thermo-mechanical instability where thermal softening due to adiabatic heating subdues strain hardening. The review presents different facets of strain localization and eventual shear band formation in various materials primarily including pure metals, alloys and composites. It starts with the dependence of shear band formation on materials parameters (e.g. crystal structure, stacking fault energy, c/a ratio, <strong>twining and TRIP effect</strong> etc.) and process variables (strain rate, stress states etc.) are presented. Effect of microstructural heterogeneities like twinning, grain boundary, phase boundary, particulates etc. are then discussed along with orientation variables (micro- and bulk texture etc.). Various aspects of microstructure and texture evolution due to strain localization in and around the shear bands are further demonstrated e.g. heat accumulation leading to dynamic recrystallization, phase transformation amorphization, evolution of Brass type texture due to shear banding etc. Theoretical simulations and modeling efforts pertaining to shear band formation, mostly crystal plasticity finite element based and resulting texture evolution is presented. Finally, an extensive review is carried out about the shear location and shear band formation for various metallic nanolayered composites. The present review therefore should be useful in understanding the root causes of shear localization and shear band formation e.g. during fabricating components for fracture-critical applications.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114501"},"PeriodicalIF":4.8,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656594","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}
The effect of equal-channel-angular pressing (ECAP) on the microstructure and precipitation of an Al-4.7Cu-0.74 Mg-0.51Si-0.48Mn-0.10Cr-0.09Ti-0.02Fe (all wt%) has been studied using aberration-corrected scanning transmission electron microscopy. The ECAP followed by a short-term aging provides a superior combination of strength and ductility in the present alloy. The ECAPed alloy shows a substantially different precipitation behavior in the deformation bands (DBs) compared to extended regions (ERs) during aging. The relatively coarse particles of the equilibrium θ (Al2Cu) and β (Mg2Si) phases were found to form along deformation-induced grain/subgrain boundaries within the DBs after short-term aging. In the present alloy after ECAP and aging, the phases continuously decorating dislocation lines or forming the discrete particles in the ERs are similar to those in the bulk matrix after conventional aging. The macroscopic strengths have been estimated for the ERs and DBs in the samples after ECAP and aging. The former, i.e., ERs, with predominant strengthening contributions originating from solid solution, precipitation and dislocations, is likely have a higher YS than the latter with the relatively coarse equilibrium particles and mainly strengthened by only grain boundaries and dislocations.
使用畸变校正扫描透射电子显微镜研究了等沟道角压（ECAP）对 Al-4.7Cu-0.74Mg-0.51Si-0.48Mn-0.10Cr-0.09Ti-0.02Fe（所有重量百分比）的微观结构和析出的影响。经过 ECAP 和短期时效处理后，该合金的强度和延展性得到了很好的结合。在老化过程中，ECAP 合金在变形带（DBs）和扩展区（ERs）的析出行为大不相同。在短期时效后，发现平衡θ（Al2Cu）和β（Mg2Si）相的相对较粗颗粒沿着变形引起的晶粒/亚晶粒边界在 DBs 内形成。在本合金中，经过 ECAP 和时效后，ERs 中不断装饰位错线或形成离散颗粒的相与常规时效后的块状基体中的相类似。对经过 ECAP 和时效处理的样品中的 ER 和 DB 进行了宏观强度估算。前者（即ERs）的主要强化作用来自固溶体、沉淀和位错，其YS值可能高于后者（后者的平衡颗粒相对较粗，主要强化作用仅来自晶界和位错）。
{"title":"Effect of ECAP and aging on microstructure of an Al-Cu-Mg-Si alloy","authors":"M.R. Gazizov , S.Yu. Mironov , R. Holmestad , M.Yu. Gazizova , R.O. Kaibyshev","doi":"10.1016/j.matchar.2024.114500","DOIUrl":"10.1016/j.matchar.2024.114500","url":null,"abstract":"<div><div>The effect of equal-channel-angular pressing (ECAP) on the microstructure and precipitation of an Al-4.7Cu-0.74 Mg-0.51Si-0.48Mn-0.10Cr-0.09Ti-0.02Fe (all wt%) has been studied using aberration-corrected scanning transmission electron microscopy. The ECAP followed by a short-term aging provides a superior combination of strength and ductility in the present alloy. The ECAPed alloy shows a substantially different precipitation behavior in the deformation bands (DBs) compared to extended regions (ERs) during aging. The relatively coarse particles of the equilibrium θ (Al<sub>2</sub>Cu) and β (Mg<sub>2</sub>Si) phases were found to form along deformation-induced grain/subgrain boundaries within the DBs after short-term aging. In the present alloy after ECAP and aging, the phases continuously decorating dislocation lines or forming the discrete particles in the ERs are similar to those in the bulk matrix after conventional aging. The macroscopic strengths have been estimated for the ERs and DBs in the samples after ECAP and aging. The former, i.e., ERs, with predominant strengthening contributions originating from solid solution, precipitation and dislocations, is likely have a higher YS than the latter with the relatively coarse equilibrium particles and mainly strengthened by only grain boundaries and dislocations.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114500"},"PeriodicalIF":4.8,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656681","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}
Pub Date : 2024-10-29DOI: 10.1016/j.matchar.2024.114502
Jinhua Lu , Wenqi Liu , Binyao Cao , Zhaofan Zhou , Yi Cao , Ruoxi Zhang , Shouyang Zhang , Ruimei Yuan , Hejun Li
C/C composites possess both lightweight and high-strength properties, and joining them with superalloys can reduce the mass of the joints and construct ultra-high heat flux lightweight cooling components, which are widely used in the hot end of a nuclear reactor. Nonetheless, significant residual stress caused by thermal mismatch is the counterpart when brazing C/C composites and metals. This increases the initiation of the joint cracks. In this study, a new method of deposition pyrolytic carbon (PyC) on the Mo-Ni skeleton to help braze C/C composites and nickel-based superalloys was proposed. With the protection of a uniformly distributed PyC layer, the corrosion and dissolution of the metal skeleton by the brazing material can be effectively mitigated. The low coefficient of thermal expansion (CTE) of the PyC layer mitigates the thermal mismatch of the joint, while the high plastic deformation capacity of the skeleton effectively mitigates the residual stresses. The two mechanisms cooperate to increase joint strength. To enhance the chemical bonding of the joint, a modification of Ti powder was implemented. The synergistic reinforcement of PyC-modified Mo-Ni foam (C-MN) and Ti powder-modified brazing material was utilized to effectively enhance the shear strength of the joint to ∼41 MPa, a 163 % improvement over unmodified joints. This work can provide a new idea for the preparation of high-performance C/C composites and joining materials for metals.
{"title":"Mo-Ni foam interlayer deposited pyrolytic carbon for brazing C/C and nickel-based superalloy","authors":"Jinhua Lu , Wenqi Liu , Binyao Cao , Zhaofan Zhou , Yi Cao , Ruoxi Zhang , Shouyang Zhang , Ruimei Yuan , Hejun Li","doi":"10.1016/j.matchar.2024.114502","DOIUrl":"10.1016/j.matchar.2024.114502","url":null,"abstract":"<div><div>C/C composites possess both lightweight and high-strength properties, and joining them with superalloys can reduce the mass of the joints and construct ultra-high heat flux lightweight cooling components, which are widely used in the hot end of a nuclear reactor. Nonetheless, significant residual stress caused by thermal mismatch is the counterpart when brazing C/C composites and metals. This increases the initiation of the joint cracks. In this study, a new method of deposition pyrolytic carbon (PyC) on the Mo-Ni skeleton to help braze C/C composites and nickel-based superalloys was proposed. With the protection of a uniformly distributed PyC layer, the corrosion and dissolution of the metal skeleton by the brazing material can be effectively mitigated. The low coefficient of thermal expansion (CTE) of the PyC layer mitigates the thermal mismatch of the joint, while the high plastic deformation capacity of the skeleton effectively mitigates the residual stresses. The two mechanisms cooperate to increase joint strength. To enhance the chemical bonding of the joint, a modification of Ti powder was implemented. The synergistic reinforcement of PyC-modified Mo-Ni foam (C-MN) and Ti powder-modified brazing material was utilized to effectively enhance the shear strength of the joint to ∼41 MPa, a 163 % improvement over unmodified joints. This work can provide a new idea for the preparation of high-performance C/C composites and joining materials for metals.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114502"},"PeriodicalIF":4.8,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573408","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}
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