材料科学与应用期刊(英文)最新文献_第10页

Effect of Repainting Process on Atmospheric Corrosion Behavior of Perforated Panel 复涂工艺对多孔板大气腐蚀性能的影响

材料科学与应用期刊(英文) Pub Date : 2021-01-01 DOI: 10.4236/msa.2021.1211035

Motoki Kuratani, K. Yamakawa, Ryuji Kurono, Yuma Kano, Takato Sasaki, Yutaka Yamada, O. Sakurada

{"title":"Effect of Repainting Process on Atmospheric Corrosion Behavior of Perforated Panel","authors":"Motoki Kuratani, K. Yamakawa, Ryuji Kurono, Yuma Kano, Takato Sasaki, Yutaka Yamada, O. Sakurada","doi":"10.4236/msa.2021.1211035","DOIUrl":"https://doi.org/10.4236/msa.2021.1211035","url":null,"abstract":"Steel structures are often painted to protect against corrosion. Repainting is one of the most important factors in maintaining the corrosion protection function of the coating. Various factors affect the life of the coating film, such as the surface preparation, the type of coating, and the number of coats. Surface preparation is important for the life of the coating film. However, appropriate surface treatment is difficult due to the complex shape of perforated panels, and it has been confirmed that corrosion progresses from the machined area. Therefore, appropriate pretreatment of the machined area is important for corrosion prevention. In this study, we investigated the effects of the repainting process on the atmospheric corrosion behavior of perforated panels. To reproduce the repainting process, a number of pretreatments were performed, such as salt spraying, blasting, and zinc phosphate treatment. In the salt spray test after pretreatment and painting, the corrosion progressed in cases with no zinc phosphate treatment and those left untreated for 48 h before painting. In addition, the coating film on the processed area was confirmed to be thin. These results suggested that appropriate pretreatment and sufficient thickness of the coating on the machined area would affect the occurrence of corrosion.","PeriodicalId":68376,"journal":{"name":"材料科学与应用期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70512649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structural and Mechanical Properties of Alumina-Zirconia (ZTA) Composites with Unstabilized Zirconia Modulation 不稳定氧化锆调制下氧化铝-氧化锆复合材料的结构和力学性能

材料科学与应用期刊(英文) Pub Date : 2021-01-01 DOI: 10.4236/msa.2021.1211036

M. Gafur, M. Al-Amin, Md. Saifur Rahman Sarker, M. Alam

{"title":"Structural and Mechanical Properties of Alumina-Zirconia (ZTA) Composites with Unstabilized Zirconia Modulation","authors":"M. Gafur, M. Al-Amin, Md. Saifur Rahman Sarker, M. Alam","doi":"10.4236/msa.2021.1211036","DOIUrl":"https://doi.org/10.4236/msa.2021.1211036","url":null,"abstract":"Zirconia toughened alumina (ZTA) ceramics are very promising materials for structural and biomedical applications due to their high hardness, fracture toughness, strength, corrosion and abrasion resistance and excellent biocompa-tibility. The effect of unstabilized ZrO 2 on the density, fracture toughness, microhardness, flexural strength and microstructure of some Zirconia-toughened alumina (ZTA) samples was investigated in this work. The volume percentage of unstabilized ZrO 2 was varied from 0% - 20% whereas sintering time and sintering temperature were kept constant at 2 hours and 1580˚C. The samples were fabricated from nanometer-sized (α-Al 2 O 3 : 150 nm, monoclinic ZrO 2 : 30 - 60 nm) powder raw materials by the conventional mechanical mixing process. Using a small amount of sintering aid (0.2 wt% MgO) almost 99.2% of theoretical density, 8.54 MPam ½ fracture toughness, 17.35 GPa Vickers microhardness and 495.67 MPa flexural strength were found. It was observed that the maximum flexural strength and fracture toughness was obtained for 10 vol% monoclinic ZrO 2 but maximum Vickers microhardness was achieved for 5 vol% ZrO 2 although the maximum density was found for 20 vol% ZrO 2 . It is assumed that this was happened due to addition of denser component, phase transformation of monoclinic ZrO 2 and the changes of grain size of α-Al 2 O 3 and ZrO 2","PeriodicalId":68376,"journal":{"name":"材料科学与应用期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70512659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Carbon Nanotubes and Resistance to Freeze-Thaw Cycles 碳纳米管与抗冻融循环

材料科学与应用期刊(英文) Pub Date : 2021-01-01 DOI: 10.4236/MSA.2021.125016

S. P. Hounkpe, Valéry K. Doko, S. O. Kotchoni, Hui Li, Abbas Tiambo Datchossa

引用次数: 0

Solvent Composition Effect on PDMS Composite Dielectric Elastomer Actuator 溶剂组成对PDMS复合介质弹性体致动器的影响

材料科学与应用期刊(英文) Pub Date : 2021-01-01 DOI: 10.4236/msa.2021.1211033

S. Tamura, R. Kiyono, Toshihiro Hirai

{"title":"Solvent Composition Effect on PDMS Composite Dielectric Elastomer Actuator","authors":"S. Tamura, R. Kiyono, Toshihiro Hirai","doi":"10.4236/msa.2021.1211033","DOIUrl":"https://doi.org/10.4236/msa.2021.1211033","url":null,"abstract":"Polydimethylsiloxane (PDMS) is inactive to electric fields, but when combined with ferroelectric cyanoethyl sucrose (CR-U), it becomes an electrically active actuator material. The PDMS/CR-U composites were prepared by casting method using tetrahydrofuran (THF) and acetone (ACT) as solvents. The effect of a mixed solvent composition was investigated. The viscosity of the PDMS/CR-U/solvent solution decreased as the THF composition increased. The composite film obtained by evaporation of the solvent and cross-linkage of PDMS showed a phase-separated structure. Spherical CR-U dispersed in the PDMS matrix with a skin layer on one surface side. Electrical resistance, dielectric constant, space-charge distribution, and electrically induced bending deformation behavior were investigated for these composite films. The composite films prepared from a THF-rich solvent exhibited lower surface resistivity than those prepared from a THF-poor solvent. Applying an electric field to the composite film resulted in an asymmetric space-charge distribution with charge accumulation in the skin layer. THF content decreased the viscosity of the solution, meaning the decrease of the apparent size of PDMS chain aggregates. It allows the dispersion of CR-U in the PDMS matrix and also results in the decline of resistivity, the increase of permittivity, and the increase of charge injection. The results explained the structure formation of the composite film and the electric field response as an actuator. A casting solvent of THF content of 87.5 wt% or more is essential for the function of the PDMS/CR-U composite.","PeriodicalId":68376,"journal":{"name":"材料科学与应用期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70513084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermophysical and Mechanical Characterization of Poto-Poto Compressed Blocks for Use as Fill Material 用作填充材料的Poto-Poto压缩块的热物理和力学特性

材料科学与应用期刊(英文) Pub Date : 2021-01-01 DOI: 10.4236/msa.2021.1210029

KO Eric, J. Damfeu, Pettang J. Ursulala, J. Ducourneau, P. Woafo, Chispin Pettang

{"title":"Thermophysical and Mechanical Characterization of Poto-Poto Compressed Blocks for Use as Fill Material","authors":"KO Eric, J. Damfeu, Pettang J. Ursulala, J. Ducourneau, P. Woafo, Chispin Pettang","doi":"10.4236/msa.2021.1210029","DOIUrl":"https://doi.org/10.4236/msa.2021.1210029","url":null,"abstract":"This article is devoted to the thermophysical and mechanical study of an eco-material, poto-poto. The objective is to study the influence of the addition of bamboo fibers on the thermophysical properties of the material, while verifying that it complies with the mechanical standards in Cameroon. A double study is therefore carried out: a mechanical characterization whose objective is to determine the mechanical properties (compressive strength, flexural strength and Young’s modulus) and a thermophysical characterization whose objective is to determine the thermal conductivity. For the thermophysical characterization, the asymmetric hot plane experimental setup based on 1D quadrupole modelling was developed and simulated for the estimation of thermal effusivity E and volume heat capacity ρC p . The obtained experimental results show that the apparent thermal conductivity of the developed materials decreases with increasing fibers. Although the reference material (0% fibers) has a much higher conductivity than the ordinary sand block (1.15 Wm −1 K −1 ), the addition of fibers, already at 2%, contributes to decrease this conductivity (0.95 Wm −1 K −1 ). From the point of view of thermal insulation and energy savings, the thermal conductivity results obtained show that the use of these materials with a maximum fibercontent of 6% would be a better thermal insulator than sand block or compressed earth brick. The compressive strength obtained is such that R c > 0.6 MPa. All the materials developed meet the design standards when used as infill.","PeriodicalId":68376,"journal":{"name":"材料科学与应用期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70512977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Comparative Study of Structural, Optical and Electrical Properties of SnO2 Thin Film Growth via CBD, Drop-Cast and Dip-Coating Methods CBD法、滴铸法和浸涂法生长SnO2薄膜的结构、光学和电学性能的比较研究

材料科学与应用期刊(英文) Pub Date : 2021-01-01 DOI: 10.4236/msa.2021.1212038

Md Tareq Rahman, Z. Ahmed, M. Islam, . Kamaruzzaman, Mst. Toma Khatun, M. Gafur, Md. Shahriar Bashar, Md. Monjarul Alam

{"title":"Comparative Study of Structural, Optical and Electrical Properties of SnO2 Thin Film Growth via CBD, Drop-Cast and Dip-Coating Methods","authors":"Md Tareq Rahman, Z. Ahmed, M. Islam, . Kamaruzzaman, Mst. Toma Khatun, M. Gafur, Md. Shahriar Bashar, Md. Monjarul Alam","doi":"10.4236/msa.2021.1212038","DOIUrl":"https://doi.org/10.4236/msa.2021.1212038","url":null,"abstract":"Tin oxide (SnO 2 ) thin films were deposited on glass substrate by Chemical Bath Deposition (CBD), Drop-Cast and Dip-Coating method. The thin films were post-annealed at 500˚C for 2 hours. The structural, optical, and electrical properties of the SnO 2 thin films were investigated by using XRD, FTIR, SEM, EDX, UV-Vis spectroscopy, and Electrometer experiment. The XRD patterns of SnO 2 thin films deposited on glass substrate by CBD method, Drop-Cast method and Dip-Coating method showed cubic, tetragonal and amorphous structures respectively. The FTIR spectrum exhibited the strong presence of SnO 2 with the characteristic vibrational mode of Sn-O-Sn. The SEM analysis was observed that the surface morphology of the thin films toughly depends on the deposition methods of the SnO 2 thin films. EDX measurement confirmed that the thin films are the composition of Tin (Sn) and Oxygen (O 2 ). The optical band gap of SnO 2 thin films deposited by CBD method, Drop-Cast method and Dip-Coating method is found to be 3.12 eV, 3.14 eV and 3.16 eV respectively. Thin films deposited by Dip-Coating method showed the highest band gap. The electrical results confirmed that the SnO 2 thin films are good conductors and pursued Ohm’s Law. These properties of the SnO 2 thin films brand are appropriate for application in solar cell assembly, gas sensor devices and transparent electrodes of panel displays.","PeriodicalId":68376,"journal":{"name":"材料科学与应用期刊(英文)","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70512802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Effect of Improving the Slip Properties of the Organic Materials on the Inorganic Filler in Heat Dissipated Pad 改善有机材料的滑移性能对散热垫中无机填料的影响

材料科学与应用期刊(英文) Pub Date : 2021-01-01 DOI: 10.4236/msa.2021.1212039

M. Oh, Y. Yoon, Dong-Bin Moon, Eunjin Jang

引用次数: 0

Simulation of Polyhedral Crystal Growth Based on the Estimated Surface Energy of Crystallographic Planes 基于晶体面表面能的多面体晶体生长模拟

材料科学与应用期刊(英文) Pub Date : 2021-01-01 DOI: 10.4236/msa.2021.1211034

T. Uehara

{"title":"Simulation of Polyhedral Crystal Growth Based on the Estimated Surface Energy of Crystallographic Planes","authors":"T. Uehara","doi":"10.4236/msa.2021.1211034","DOIUrl":"https://doi.org/10.4236/msa.2021.1211034","url":null,"abstract":"Polyhedral shapes can be found in crystalline materials ranging from macroscopic natural mineral solids to microscopic or nanoscopic particles. These shapes originate from the crystallographic properties of the constituting material, and the outer shape depends on several unique habit planes. In this study, polyhedral crystal growth was simulated considering the surface energy and crystallographic characteristics. A series of polyhedrons, including cube, truncated hexahedron, cuboctahedron, truncated octahedron, and regular octahedron, was targeted. First, the polyhedron’s static surface energy and dynamic energy variation during crystal growth were computed. Then, the crystal-growth process was simulated based on the energy minimization policy. Interestingly, when the simulation began with truncated hexahedral nucleus, the shape changed to a cuboctahedron; however, a certain type of truncated octahedron was obtained when starting with different types of truncated octahedrons. In addition, once converged cuboctahedron abruptly changed the shape to a truncated octahedron as the crystal became larger. These results were supported by the static and dynamic energy curves. Furthermore, the method was applied to different materials by assuming virtual parameters, yielding various morphologies.","PeriodicalId":68376,"journal":{"name":"材料科学与应用期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70512641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Dynamic Flexural Modulus and Low-Velocity Impact Response of SupercompositeTM Laminates with Vertical Z-Axis Milled Carbon Fiber Reinforcement 纵向z轴铣削碳纤维增强超复合材料etm层合板动态弯曲模量及低速冲击响应

材料科学与应用期刊(英文) Pub Date : 2021-01-01 DOI: 10.4236/MSA.2021.124010

Suman Babu Ukyam, R. Mantena, Damian Stoddard, A. Rajendran, R. Moser

引用次数: 1

Influence of Annealing Atmosphere on Varistor Property of TiO2-Nb2O5-SrCO3 Ceramics 退火气氛对TiO2-Nb2O5-SrCO3陶瓷压敏电阻性能的影响

材料科学与应用期刊(英文) Pub Date : 2021-01-01 DOI: 10.4236/msa.2021.1211030

Kunyong Kang, Haodong Zhu, Gang Zhu, S. Deng

{"title":"Influence of Annealing Atmosphere on Varistor Property of TiO2-Nb2O5-SrCO3 Ceramics","authors":"Kunyong Kang, Haodong Zhu, Gang Zhu, S. Deng","doi":"10.4236/msa.2021.1211030","DOIUrl":"https://doi.org/10.4236/msa.2021.1211030","url":null,"abstract":"Varistor ceramics are typical electronic ceramics, which are widely used in circuits of overvoltage protection, high voltage stabilization and high energy surge absorption. TiO 2 varistor ceramics has the advantages of low varistor voltage and good dielectric properties, but their low nonlinearity limited the application. The influence of annealing on the varistor properties of TiO 2 -Nb 2 O 5 -SrCO 3 ceramics was investigated in this paper. TiO 2 -Nb 2 O 5 -SrCO 3 varistor ceramics were prepared by the traditional method of ball grind-ing-forming-sintering and they were annealed in oxygen and nitrogen, respec-tively. The nonlinear coefficient α and the breakdown voltage E B of the samples were tested using the varistor dc parameter meter. The microstructure of samples was analyzed by XRD, SEM, STEM-EDAX and SAEDP. The results show that during annealing, Sr 2+ ions with a larger radius obtain the kinetic energy and are segregated to grain boundaries, which increases the acceptor density of the grain boundaries and improves α. Annealing in an oxygen atmosphere, the enrichment of oxygen at grain boundaries is also helpful to increase the density of acceptor states and the height of the potential barrier, so as to further increase α. Meanwhile, annealing makes crystalline grains grow properly, which results in even grain size, reduces the porosity and increases the density of grains. So E B tends to reduce. As the doping concentration of Nb 2 O 5 and SrCO 3 is 0.15 mol%, respectively, and sintering temperature is 1300˚C, TiO 2 -Nb 2 O 5 -SrCO 3 varistor ceramics annealed in oxygen for 3 h at 750˚C achieved the highest nonlinear coefficient α = 8.9 and the lowest breakdown voltage E B = 19.1 V∙mm −1 , which annealed in nitrogen achieved α = 8.4, E B = 20.6 V∙mm −1 , both superior to unannealed samples.","PeriodicalId":68376,"journal":{"name":"材料科学与应用期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70513018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2