Pub Date : 2024-09-08DOI: 10.1016/j.mtcomm.2024.110375
Kaiyi Mao, Yanbin Du, Huajun Cao, Yunchuan Peng, Guohua He, Qiang Liang, Jian Tu
The application of laser cladding technology to prepare iron-based composite coatings has significant advantages in improving the surface properties of 12Cr13 stainless steel. 15–5PH composite coatings reinforced with CrC particles of different contents (0–25 wt%) were prepared on the 12Cr13 surface by the coaxial powder feeding laser cladding system. The microstructure, phase composition, element distribution, corrosion resistance and corrosion mechanism of the composite coatings were analyzed and studied by optical microscope, scanning electron microscope, X-ray energy dispersive spectrometer, X-ray diffractometer and electrochemical workstation. The results indicated that the CrC/15–5PH composite coatings exhibited good macroscopic morphology and dilution rate under appropriate laser cladding process parameters. The addition of CrC particles changed the main phase from -Fe to -Fe and formed new carbide phases (MC and CrC). The CrC/15–5PH composite coatings exhibited a typical microstructure with rapid solidification characteristics, and the addition of CrC significantly changed the grain size. The distribution of Fe, Ni, and Cr elements in the composite coatings was uniform, and the relative content of Cr elements increased and remained at high level. The 15-5PH composite coating with 15 wt% CrC exhibited a lower corrosion current density and higher impedance modulus values. The surface of this composite coating had no obvious corrosion pits, and the passive film effectively retarded the further corrosion by the Cl- ions on the surface during the electrochemical corrosion process. By preparing a 15–5PH composite coating with 15 wt% CrC on the surface of 12Cr13, the corrosion resistance of the surface can be effectively improved.
{"title":"Effects of Cr3C2 addition on microstructure and corrosion properties of Cr3C2/15–5PH composite coatings on 12Cr13 by laser cladding","authors":"Kaiyi Mao, Yanbin Du, Huajun Cao, Yunchuan Peng, Guohua He, Qiang Liang, Jian Tu","doi":"10.1016/j.mtcomm.2024.110375","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110375","url":null,"abstract":"The application of laser cladding technology to prepare iron-based composite coatings has significant advantages in improving the surface properties of 12Cr13 stainless steel. 15–5PH composite coatings reinforced with CrC particles of different contents (0–25 wt%) were prepared on the 12Cr13 surface by the coaxial powder feeding laser cladding system. The microstructure, phase composition, element distribution, corrosion resistance and corrosion mechanism of the composite coatings were analyzed and studied by optical microscope, scanning electron microscope, X-ray energy dispersive spectrometer, X-ray diffractometer and electrochemical workstation. The results indicated that the CrC/15–5PH composite coatings exhibited good macroscopic morphology and dilution rate under appropriate laser cladding process parameters. The addition of CrC particles changed the main phase from -Fe to -Fe and formed new carbide phases (MC and CrC). The CrC/15–5PH composite coatings exhibited a typical microstructure with rapid solidification characteristics, and the addition of CrC significantly changed the grain size. The distribution of Fe, Ni, and Cr elements in the composite coatings was uniform, and the relative content of Cr elements increased and remained at high level. The 15-5PH composite coating with 15 wt% CrC exhibited a lower corrosion current density and higher impedance modulus values. The surface of this composite coating had no obvious corrosion pits, and the passive film effectively retarded the further corrosion by the Cl- ions on the surface during the electrochemical corrosion process. By preparing a 15–5PH composite coating with 15 wt% CrC on the surface of 12Cr13, the corrosion resistance of the surface can be effectively improved.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"1 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268403","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 : 2024-09-08DOI: 10.1016/j.mtcomm.2024.110378
Guozheng Zhao, Dongfang Yang
This study explores the structural, molecular, and electronic responses of the ionic salt hydroxylammonium 3,3′-dinitro-bis-(1,2,4-triazole)-1,1′-diolate (HDBTD) crystal to external pressure. Utilizing Generalized Gradient Approximation (GGA) in both PBE and Perdew-Wang 91 (PW91) forms, alongside Local Spin Density Approximation (LDA) as per CA-PZ, we compared the computational results with experimental measurements to determine the most accurate method for analyzing the HDBTD crystal. The study reveals the anisotropic nature of the HDBTD crystal under varying pressures up to 200 GPa, with detailed observations on the behavior of lattice constants, unit cell volume, and molecular geometry including bond lengths, angles, and dihedral angles. External pressure was found to induce notable changes in molecular conformation, phase transitions, and the development of denser materials, altering molecular geometry significantly. The formation and breaking of covalent bonds under pressure were highlighted, showing complex effects on the crystal's molecular structure. Furthermore, the impact of pressure on the electronic structure of HDBTD was examined, showing a dynamic change in band gaps and density of states (DOS). The study provides a comprehensive analysis of the HDBTD crystal's response to external pressures, contributing valuable insights into its structural integrity, molecular dynamics, and electronic behavior, thereby enhancing the understanding of its potential applications and reactivity under high-pressure conditions.
{"title":"Pressure-induced structural and electronic transformations of energetic ionic salt hydroxylammonium 3,3′-dinitro-bis-(1,2,4-triazole)-1,1′-diolate","authors":"Guozheng Zhao, Dongfang Yang","doi":"10.1016/j.mtcomm.2024.110378","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110378","url":null,"abstract":"This study explores the structural, molecular, and electronic responses of the ionic salt hydroxylammonium 3,3′-dinitro-bis-(1,2,4-triazole)-1,1′-diolate (HDBTD) crystal to external pressure. Utilizing Generalized Gradient Approximation (GGA) in both PBE and Perdew-Wang 91 (PW91) forms, alongside Local Spin Density Approximation (LDA) as per CA-PZ, we compared the computational results with experimental measurements to determine the most accurate method for analyzing the HDBTD crystal. The study reveals the anisotropic nature of the HDBTD crystal under varying pressures up to 200 GPa, with detailed observations on the behavior of lattice constants, unit cell volume, and molecular geometry including bond lengths, angles, and dihedral angles. External pressure was found to induce notable changes in molecular conformation, phase transitions, and the development of denser materials, altering molecular geometry significantly. The formation and breaking of covalent bonds under pressure were highlighted, showing complex effects on the crystal's molecular structure. Furthermore, the impact of pressure on the electronic structure of HDBTD was examined, showing a dynamic change in band gaps and density of states (DOS). The study provides a comprehensive analysis of the HDBTD crystal's response to external pressures, contributing valuable insights into its structural integrity, molecular dynamics, and electronic behavior, thereby enhancing the understanding of its potential applications and reactivity under high-pressure conditions.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"20 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268401","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 : 2024-09-08DOI: 10.1016/j.mtcomm.2024.110382
Xinran Wang, Lin Zhang
Self-consistent charge density functional tight binding simulations were used to provide implications for the effect of S atoms’ doping on geometrical structures and electronic states in armchair graphene nanoribbons with different widths. The geometric configurations, energy, charge density differences, Mulliken charges, and molecular orbitals at HOMO and LUMO energy levels are characterized. Besides the changes of bond length and bond angles, the calculation results indicate that the band structures and bandgaps of the graphene nanoribbons is affected by the nanoribbon width as well as S doping positions, where the ribbons exhibit metallic or semiconductor properties. Doping S atoms result significant changes in the charge density differences and Mulliken charges on the atoms near the doped atom. At the same time, the HOMOs and LUMOs also present differences.
利用自洽电荷密度泛函紧密结合模拟提供了掺杂 S 原子对不同宽度的扶手石墨烯纳米带的几何结构和电子状态的影响。研究表征了 HOMO 和 LUMO 能级上的几何构型、能量、电荷密度差、Mulliken 电荷以及分子轨道。除了键长和键角的变化，计算结果还表明，石墨烯纳米带的带结构和带隙受纳米带宽度和 S 掺杂位置的影响，在这些位置上，纳米带表现出金属或半导体特性。掺杂 S 原子会导致掺杂原子附近原子的电荷密度差和 Mulliken 电荷发生显著变化。同时，HOMOs 和 LUMOs 也出现了差异。
{"title":"Implications for electronic structures of S-doped graphene nanoribbons from a DFTB algorithm at atomic scale","authors":"Xinran Wang, Lin Zhang","doi":"10.1016/j.mtcomm.2024.110382","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110382","url":null,"abstract":"Self-consistent charge density functional tight binding simulations were used to provide implications for the effect of S atoms’ doping on geometrical structures and electronic states in armchair graphene nanoribbons with different widths. The geometric configurations, energy, charge density differences, Mulliken charges, and molecular orbitals at HOMO and LUMO energy levels are characterized. Besides the changes of bond length and bond angles, the calculation results indicate that the band structures and bandgaps of the graphene nanoribbons is affected by the nanoribbon width as well as S doping positions, where the ribbons exhibit metallic or semiconductor properties. Doping S atoms result significant changes in the charge density differences and Mulliken charges on the atoms near the doped atom. At the same time, the HOMOs and LUMOs also present differences.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"33 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268281","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 ultrasonic vibration (UV) is applied during the laser cladding process of FeSiBCr (wt%) amorphous powders. The microstructure evolution and properties of the Fe-based crystal/amorphous composite coatings with and without UV were investigated in detail. The results reveal a significant decrease of 55.8 % in the average grain size within the UV coating, accompanied by a 35.9 % reduction in the length of columnar grains at the interface, which is primarily attributed to the acoustic streaming and cavitation effects of ultrasound. The average microhardness value of coatings rises from 659 33 HV to 873 48 HV. Meanwhile, the coatings with UV exhibit outstanding wear resistance, with a 38.2 % reduction in wear rate compared to normal coatings. The corrosion mechanism of the coatings is pitting corrosion and the corroded surface of the coating with UV displays a relatively smaller pitting area. The enhancement mechanism for properties by U V can be the cooperative effect of the fine-grain strengthening and the amorphous phase strengthening.
{"title":"Corrosion and wear resistance of ultrasonic vibration-assisted laser cladded Fe-based crystal/amorphous composite coatings","authors":"Lin Chen, Haolun Song, Chunhuan Guo, Shubang Wang, Fengchun Jiang, Mingying Xiao, Zhuhui Qiao","doi":"10.1016/j.mtcomm.2024.110377","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110377","url":null,"abstract":"The ultrasonic vibration (UV) is applied during the laser cladding process of FeSiBCr (wt%) amorphous powders. The microstructure evolution and properties of the Fe-based crystal/amorphous composite coatings with and without UV were investigated in detail. The results reveal a significant decrease of 55.8 % in the average grain size within the UV coating, accompanied by a 35.9 % reduction in the length of columnar grains at the interface, which is primarily attributed to the acoustic streaming and cavitation effects of ultrasound. The average microhardness value of coatings rises from 659 33 HV to 873 48 HV. Meanwhile, the coatings with UV exhibit outstanding wear resistance, with a 38.2 % reduction in wear rate compared to normal coatings. The corrosion mechanism of the coatings is pitting corrosion and the corroded surface of the coating with UV displays a relatively smaller pitting area. The enhancement mechanism for properties by U V can be the cooperative effect of the fine-grain strengthening and the amorphous phase strengthening.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"3 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268404","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 : 2024-09-08DOI: 10.1016/j.mtcomm.2024.110385
Mohammad Faisal Ahmed, William Granville
Density-graded cellular solids possess tailorable mechanical properties through variable localized densities, made possible with design freedom offered by additive manufacturing. In this paper, a novel design strategy is proposed to generate bidirectionally graded honeycombs where the gradient direction is both parallel and perpendicular to the loading direction. A gradient function is developed to design three density gradient honeycombs having three different thickness gradients. The graded honeycombs along with their uniform density regular honeycomb counterparts of similar relative density are manufactured using material extrusion process. In-plane compression tests are carried out to perform a comparative study of the honeycombs. Unlike the regular honeycombs, graded honeycombs show layer-by-layer deformation, in addition to cell-wise collapse in lateral direction. Graded honeycombs show better energy absorption characteristics in low and high energy compressions, and high strain regime. Also, graded honeycombs have similar or higher specific energy absorption, densification strain, mean crushing force, and peak crushing force. The compressive responses of the honeycombs are simulated with finite element analysis and the simulation results agree well with the experimental results. The results substantiate the significance of thickness gradient in controlling the density gradation, and effectively tailoring the load-bearing capacity, deformation behavior, and energy absorption characteristics of cellular structures.
{"title":"Bidirectionally graded honeycombs under quasi-static loading: Experimental and numerical study","authors":"Mohammad Faisal Ahmed, William Granville","doi":"10.1016/j.mtcomm.2024.110385","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110385","url":null,"abstract":"Density-graded cellular solids possess tailorable mechanical properties through variable localized densities, made possible with design freedom offered by additive manufacturing. In this paper, a novel design strategy is proposed to generate bidirectionally graded honeycombs where the gradient direction is both parallel and perpendicular to the loading direction. A gradient function is developed to design three density gradient honeycombs having three different thickness gradients. The graded honeycombs along with their uniform density regular honeycomb counterparts of similar relative density are manufactured using material extrusion process. In-plane compression tests are carried out to perform a comparative study of the honeycombs. Unlike the regular honeycombs, graded honeycombs show layer-by-layer deformation, in addition to cell-wise collapse in lateral direction. Graded honeycombs show better energy absorption characteristics in low and high energy compressions, and high strain regime. Also, graded honeycombs have similar or higher specific energy absorption, densification strain, mean crushing force, and peak crushing force. The compressive responses of the honeycombs are simulated with finite element analysis and the simulation results agree well with the experimental results. The results substantiate the significance of thickness gradient in controlling the density gradation, and effectively tailoring the load-bearing capacity, deformation behavior, and energy absorption characteristics of cellular structures.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"46 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268280","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 : 2024-09-08DOI: 10.1016/j.mtcomm.2024.110363
Y.G. Deng, Y. Li
This study investigates the impact of zinc phosphate-coated steel fibers on corrosion performance and bond strength within concrete subjected to corrosive environments. Results indicate that the coating enhanced corrosion resistance in various environments, including saturated Ca(OH), 10 % NaSO, and 3.5 % NaCl solutions. The zinc phosphate coating resulted in a more positive corrosion potential and a lower corrosion rate, likely due to galvanic coupling between the coating and the steel fiber matrix. Furthermore, the improved corrosion resistance in Ca(OH) solution may also be related to the formation of insoluble calcium phosphate compounds. The bond strength and pullout energy in the zinc phosphate-coated fiber-reinforced pre-corrosion specimens enhanced by 19.3 % and 90.92 %, respectively, compared to the bare fiber-reinforced ones. Upon exposure to a simulated seawater environment that induces corrosion, the interfacial bond strength and pullout energy of zinc phosphate-coated steel fibers and cement mortar experienced marginal decreases of 4.2 % and 4.6 %. Zinc phosphate coatings demonstrate considerable promise for extensive application in concrete structures exposed to highly corrosive environments.
{"title":"Evaluating the chemical stability and performance of zinc phosphate-coated steel fibers in concrete corrosion simulations","authors":"Y.G. Deng, Y. Li","doi":"10.1016/j.mtcomm.2024.110363","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110363","url":null,"abstract":"This study investigates the impact of zinc phosphate-coated steel fibers on corrosion performance and bond strength within concrete subjected to corrosive environments. Results indicate that the coating enhanced corrosion resistance in various environments, including saturated Ca(OH), 10 % NaSO, and 3.5 % NaCl solutions. The zinc phosphate coating resulted in a more positive corrosion potential and a lower corrosion rate, likely due to galvanic coupling between the coating and the steel fiber matrix. Furthermore, the improved corrosion resistance in Ca(OH) solution may also be related to the formation of insoluble calcium phosphate compounds. The bond strength and pullout energy in the zinc phosphate-coated fiber-reinforced pre-corrosion specimens enhanced by 19.3 % and 90.92 %, respectively, compared to the bare fiber-reinforced ones. Upon exposure to a simulated seawater environment that induces corrosion, the interfacial bond strength and pullout energy of zinc phosphate-coated steel fibers and cement mortar experienced marginal decreases of 4.2 % and 4.6 %. Zinc phosphate coatings demonstrate considerable promise for extensive application in concrete structures exposed to highly corrosive environments.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"26 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268405","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 : 2024-09-08DOI: 10.1016/j.mtcomm.2024.110345
Haixai Zheng, Yangyang Zhu, Bingjia Zhao, Yang Lin, Weixia Lan, Wei Shi, Bin Wei
We propose a face-sealed encapsulation solution with simple process and low cost. The polyisobutylene encapsulation patch mixed with calcium oxide particles is attached to the surface of the OLEDs that is exposed to the hygroscopic agent in a face-sealing manner. We find that this encapsulation scheme exhibited excellent waterproof performance. The encapsulated OLED has a long shelf lifetime in water under high temperature conditions, which is manifested in a long underwater shelf lifetime of T95 (luminance drops to 95 % of the initial luminance) of over 336 h at 60°C. We believe that this encapsulating technology can be applied to other organic optoelectronic devices, and the face-sealed encapsulating patch is flexible. This strategy can be extended to roll-to-roll processes to expand the application of flexible organic optoelectronic devices underwater.
{"title":"Temperature endurable face-sealing polyisobutylene film with contactable liquid desiccant for the encapsulation of OLEDs","authors":"Haixai Zheng, Yangyang Zhu, Bingjia Zhao, Yang Lin, Weixia Lan, Wei Shi, Bin Wei","doi":"10.1016/j.mtcomm.2024.110345","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110345","url":null,"abstract":"We propose a face-sealed encapsulation solution with simple process and low cost. The polyisobutylene encapsulation patch mixed with calcium oxide particles is attached to the surface of the OLEDs that is exposed to the hygroscopic agent in a face-sealing manner. We find that this encapsulation scheme exhibited excellent waterproof performance. The encapsulated OLED has a long shelf lifetime in water under high temperature conditions, which is manifested in a long underwater shelf lifetime of T95 (luminance drops to 95 % of the initial luminance) of over 336 h at 60°C. We believe that this encapsulating technology can be applied to other organic optoelectronic devices, and the face-sealed encapsulating patch is flexible. This strategy can be extended to roll-to-roll processes to expand the application of flexible organic optoelectronic devices underwater.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"33 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268406","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 recent development of high-entropy perovskites has demonstrated their tremendous promise for various applications. To meet the expanding needs for extreme environment applications, however, the critical properties of high-entropy perovskite at high pressure remain to be disclosed. In the present work, an A-site high-entropy perovskite (NdLiBaSrCa)TiO was synthesized. High-pressure investment on the phase stability, dielectric properties, and bandgap was conducted using diamond anvil cell combined with comprehensive in-situ measurements. The results reveal that (NdLiBaSrCa)TiO remains the perovskite structure at the pressure up to ∼15 GPa. The grain resistance exhibits an exponential decrease with the increasing pressure, whilst an unusual change of the grain boundary resistance was observed at ∼7 GPa. Furthermore, (NdLiBaSrCa)TiO shows a slight increase of the bandgap upon compression. Our multifaceted approach provides a comprehensive understanding of the high-pressure behavior of high-entropy perovskite, offering valuable insights for the design and optimization of advanced functional materials for high-pressure environments.
{"title":"Synthesis and high-pressure properties of (Nd0.2Li0.2Ba0.2Sr0.2Ca0.2)TiO3 high-entropy perovskite","authors":"Zhi Zheng, Junwei Li, Xinglong Deng, Mengjun Xiong, Weizhao Cai, Bingliang Liang, Kaihuai Yang, Shenghua Mei","doi":"10.1016/j.mtcomm.2024.110346","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110346","url":null,"abstract":"The recent development of high-entropy perovskites has demonstrated their tremendous promise for various applications. To meet the expanding needs for extreme environment applications, however, the critical properties of high-entropy perovskite at high pressure remain to be disclosed. In the present work, an A-site high-entropy perovskite (NdLiBaSrCa)TiO was synthesized. High-pressure investment on the phase stability, dielectric properties, and bandgap was conducted using diamond anvil cell combined with comprehensive in-situ measurements. The results reveal that (NdLiBaSrCa)TiO remains the perovskite structure at the pressure up to ∼15 GPa. The grain resistance exhibits an exponential decrease with the increasing pressure, whilst an unusual change of the grain boundary resistance was observed at ∼7 GPa. Furthermore, (NdLiBaSrCa)TiO shows a slight increase of the bandgap upon compression. Our multifaceted approach provides a comprehensive understanding of the high-pressure behavior of high-entropy perovskite, offering valuable insights for the design and optimization of advanced functional materials for high-pressure environments.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"41 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268173","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 : 2024-09-07DOI: 10.1016/j.mtcomm.2024.110376
Veerendra Kumar, S.K. Tiwari, Nitin Sharma
The present study has been designed to test the corrosion performance of epoxy based nano-composite coatings on Interstitial Free (IF) steel. PPy and PPy nano-composite powders were formed by polymerization of pyrrole using ferric chloride oxidant. PPy nano-composite powders were synthesized including Graphene oxide (GO) and Copper oxide (CuO) nano-particles. Four combinations have been undertaken in this study viz. pure PPy, PPy-GO (PG), PPy-CuO (PC) and PPy-GO-CuO (PGC). SEM/EDS and XRD results validated the uniform embedding of nano-particles in the pyrrole matrix during polymerization. Moreover, TGA analysis has also confirmed the enhancement of thermal stability of PPy with the incorporation of nano-particles. Further, epoxy (EP) powder was loaded with different concentration of synthesized composite powders to optimize the weight percent (wt%) of PPy, GO and CuO for testing the corrosion characteristics. The different coating configurations were applied on IF steel samples and electrochemical & salt spray testing have been conducted. It has been concluded that coating configuration EP/P2G0.5C1.0 has shown maximum corrosion protection efficiency () of approximately 99 %. Moreover, other three configurations EP/P2, EP/P2G0.5 and EP/P2C1.0 have also shown noteworthy results of of 85, 96 and 97 % respectively. SEM images for cross-sectional view of coatings have also confirmed the uniformity of coatings on to the IF steel. The suitability of these synthesized coatings has also been verified via adhesion test evidencing no significant change in adhesive strength.
{"title":"Corrosion characteristics of PPY/GO/CuO nano-composite powder reinforced epoxy coatings on IF steel","authors":"Veerendra Kumar, S.K. Tiwari, Nitin Sharma","doi":"10.1016/j.mtcomm.2024.110376","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110376","url":null,"abstract":"The present study has been designed to test the corrosion performance of epoxy based nano-composite coatings on Interstitial Free (IF) steel. PPy and PPy nano-composite powders were formed by polymerization of pyrrole using ferric chloride oxidant. PPy nano-composite powders were synthesized including Graphene oxide (GO) and Copper oxide (CuO) nano-particles. Four combinations have been undertaken in this study viz. pure PPy, PPy-GO (PG), PPy-CuO (PC) and PPy-GO-CuO (PGC). SEM/EDS and XRD results validated the uniform embedding of nano-particles in the pyrrole matrix during polymerization. Moreover, TGA analysis has also confirmed the enhancement of thermal stability of PPy with the incorporation of nano-particles. Further, epoxy (EP) powder was loaded with different concentration of synthesized composite powders to optimize the weight percent (wt%) of PPy, GO and CuO for testing the corrosion characteristics. The different coating configurations were applied on IF steel samples and electrochemical & salt spray testing have been conducted. It has been concluded that coating configuration EP/P2G0.5C1.0 has shown maximum corrosion protection efficiency () of approximately 99 %. Moreover, other three configurations EP/P2, EP/P2G0.5 and EP/P2C1.0 have also shown noteworthy results of of 85, 96 and 97 % respectively. SEM images for cross-sectional view of coatings have also confirmed the uniformity of coatings on to the IF steel. The suitability of these synthesized coatings has also been verified via adhesion test evidencing no significant change in adhesive strength.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"20 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268408","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}
Laser powder bed fusion (LPBF) is characterized by complicated non-equilibrium processing characteristics, involving extremely high temperature gradient and cooling rate within the mesoscopic dynamic molten pool, which brings great challenges to the forming of metal materials with high crack sensitivity (such as γ-TiAl alloy). In this paper, based on the LPBF forming process of Ti48Al2Cr2Nb alloy, a corresponding multi-track and multi-layer thermal-structure sequential coupled finite element model was constructed, and the influence of four different scanning strategies on the temperature and stress evolution behavior in the powder bed forming region was quantitatively studied, and the crack initiation criterion was also established according to the relationship between nodal flow stress and equivalent stress. It was found that island scanning strategy could induce the higher molten pool temperature and attendant larger molten pool size compared with the non-island linear scanning strategy. Besides, island scanning strategy was conducive to relieving the thermal stress inside the division region but also inducing the stress concentration in the sub-island overlap region. Specially, the strip island scanning strategy exhibited the lowest residual stress and most homogeneous stress distribution. By the experimental measurements, the strip island scanning strategy contributed to the lowest crack density of 0.33 mm/mm.
{"title":"Effect of scanning strategy on the thermo-structural coupling field and cracking behavior during laser powder bed fusion of Ti48Al2Cr2Nb alloys","authors":"Chenglong Ma, Zhuo Zhuo, Ziwen Xie, Quanlong Wang, Meiping Wu","doi":"10.1016/j.mtcomm.2024.110372","DOIUrl":"https://doi.org/10.1016/j.mtcomm.2024.110372","url":null,"abstract":"Laser powder bed fusion (LPBF) is characterized by complicated non-equilibrium processing characteristics, involving extremely high temperature gradient and cooling rate within the mesoscopic dynamic molten pool, which brings great challenges to the forming of metal materials with high crack sensitivity (such as γ-TiAl alloy). In this paper, based on the LPBF forming process of Ti48Al2Cr2Nb alloy, a corresponding multi-track and multi-layer thermal-structure sequential coupled finite element model was constructed, and the influence of four different scanning strategies on the temperature and stress evolution behavior in the powder bed forming region was quantitatively studied, and the crack initiation criterion was also established according to the relationship between nodal flow stress and equivalent stress. It was found that island scanning strategy could induce the higher molten pool temperature and attendant larger molten pool size compared with the non-island linear scanning strategy. Besides, island scanning strategy was conducive to relieving the thermal stress inside the division region but also inducing the stress concentration in the sub-island overlap region. Specially, the strip island scanning strategy exhibited the lowest residual stress and most homogeneous stress distribution. By the experimental measurements, the strip island scanning strategy contributed to the lowest crack density of 0.33 mm/mm.","PeriodicalId":18477,"journal":{"name":"Materials Today Communications","volume":"46 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268410","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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