Pub Date : 2017-12-28DOI: 10.17265/2161-6213/2017.11-12.007
Rabindra Chaulagain, R. Chalise, R. Khanal
For all practical applications of plasma, it has to be confined and in all such cases a sheath is formed at the material wall, which plays an important role in the properties of overall plasma wall transition region. The effect of ion temperature in a magnetized plasma sheath, which consists of two species of positive ions, has been studied using kinetic theory. The profile of ion densities, electron density, total charge density, potential is obtained by self-consistent solution to a non-neutral, collisionless, time independent plasma sheath. The physical parameters change slowly near the sheath entrance but exhibit steep gradient near the wall. The effect of applied magnetic field is more on ions whereas the electrons are almost non responsive and they are not influenced directly. In presence of magnetic field, the ion density is slightly lower compared to the case without magnetic field. The ion density increases on increasing ion temperature due to increase in their thermal velocity. On increasing the ion temperature, the total charge density at the wall increases and hence the potential decreases in magnitude. The result is useful in understanding and hence controlling the particles in plasma wall transition region especially in cases of two-ion species magnetized plasma sheath.
{"title":"Effect of Ion Temperature Variation in Two-Ion Species Magnetized Plasma Sheath","authors":"Rabindra Chaulagain, R. Chalise, R. Khanal","doi":"10.17265/2161-6213/2017.11-12.007","DOIUrl":"https://doi.org/10.17265/2161-6213/2017.11-12.007","url":null,"abstract":"For all practical applications of plasma, it has to be confined and in all such cases a sheath is formed at the material wall, which plays an important role in the properties of overall plasma wall transition region. The effect of ion temperature in a magnetized plasma sheath, which consists of two species of positive ions, has been studied using kinetic theory. The profile of ion densities, electron density, total charge density, potential is obtained by self-consistent solution to a non-neutral, collisionless, time independent plasma sheath. The physical parameters change slowly near the sheath entrance but exhibit steep gradient near the wall. The effect of applied magnetic field is more on ions whereas the electrons are almost non responsive and they are not influenced directly. In presence of magnetic field, the ion density is slightly lower compared to the case without magnetic field. The ion density increases on increasing ion temperature due to increase in their thermal velocity. On increasing the ion temperature, the total charge density at the wall increases and hence the potential decreases in magnitude. The result is useful in understanding and hence controlling the particles in plasma wall transition region especially in cases of two-ion species magnetized plasma sheath.","PeriodicalId":16171,"journal":{"name":"Journal of materials science & engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75969344","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}
Pub Date : 2017-12-28DOI: 10.17265/2161-6221/2017.11-12.006
S. Icli
: The photochemical reaction of carbon dioxide, nitrogen and water in at our atmosphere, production of amino acids, following protein molecular structures, finally creation of micro-living species, and the birth of plants, animals! These microscopic molecular structures (in rivers, lakes, seas) had given birth to moss on land, further all sorts of plants, animals and human beings, that are called as the Miracle of Universe. Human intelligence has created the Technologies simulating photosynthesis, named as Organic Photo-Electronic Technolojigies of OLED lamps, OFET transistors, OPV photovoltaics, that are now in our daily life. A distinct example is OLED-Organic LED lamps, in mobile phones, Lap-Top computers, colored TVs, and other electronics are now based on OLED technology. Advanced developments on Organic Photo Technologies, now overcome to the employment of inorganic materials of steel, iron etc. that creates huge pollution problems on Earth. The OLEDs, followed by the OPV-Organic Photo Voltaics and OFET-Organic Field Effect Transistors, with nature now entered into all of our electronic systems, capable us replace present inorganic technological systems-tools, and lower the pollution threat on our Earth.
{"title":"Photosynthesis: Miracle of Organic Life and Its Technologies","authors":"S. Icli","doi":"10.17265/2161-6221/2017.11-12.006","DOIUrl":"https://doi.org/10.17265/2161-6221/2017.11-12.006","url":null,"abstract":": The photochemical reaction of carbon dioxide, nitrogen and water in at our atmosphere, production of amino acids, following protein molecular structures, finally creation of micro-living species, and the birth of plants, animals! These microscopic molecular structures (in rivers, lakes, seas) had given birth to moss on land, further all sorts of plants, animals and human beings, that are called as the Miracle of Universe. Human intelligence has created the Technologies simulating photosynthesis, named as Organic Photo-Electronic Technolojigies of OLED lamps, OFET transistors, OPV photovoltaics, that are now in our daily life. A distinct example is OLED-Organic LED lamps, in mobile phones, Lap-Top computers, colored TVs, and other electronics are now based on OLED technology. Advanced developments on Organic Photo Technologies, now overcome to the employment of inorganic materials of steel, iron etc. that creates huge pollution problems on Earth. The OLEDs, followed by the OPV-Organic Photo Voltaics and OFET-Organic Field Effect Transistors, with nature now entered into all of our electronic systems, capable us replace present inorganic technological systems-tools, and lower the pollution threat on our Earth.","PeriodicalId":16171,"journal":{"name":"Journal of materials science & engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89854140","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}
Pub Date : 2017-12-28DOI: 10.17265/2161-6221/2017.11-12.001
Jong-Young Park, oung-Jae Kim, J. Noh, H. Honma
The recent appearance of mobile application processor now plays an important role in the semiconductor industry. Additionally, there have been endless demands for small form factor, thin profile, outstanding thermal, mechanical properties and electrical performances in the field of IC packages for mobile application processors. MIS (Molded Interconnect Substrate) can provide ideal and this solution in the mobile industry as it contains multiple solutions for the complicated requirement of the IC packages for application processors. Based on the embedded pattern technology, this solution can provide high I/O count, fine pattern for small form factor, and stable flip chip mounting methods. Other advantages of this solution include stable properties required for high-frequency transmission and high thermal dissipation rate as it is only composed of copper and epoxy mold compound materials. These core techniques for MIS technology can be divided into below major concepts. First, Cu pillar electrolytic plating technology electrically connects the inner and the outer layers using photo-lithography method, instead of laser method. The shape of Cu pillar and the plating thickness tolerance control are the key parameters. Second, grinding technology is to precisely grind the plated Cu pillars and applied mold epoxy. And deposition of Cu layer on top of grinded mold surface can construct fine pattern traces.
{"title":"Improvement of Cu-Pillar Structure Using Advanced Plating Method","authors":"Jong-Young Park, oung-Jae Kim, J. Noh, H. Honma","doi":"10.17265/2161-6221/2017.11-12.001","DOIUrl":"https://doi.org/10.17265/2161-6221/2017.11-12.001","url":null,"abstract":"The recent appearance of mobile application processor now plays an important role in the semiconductor industry. Additionally, there have been endless demands for small form factor, thin profile, outstanding thermal, mechanical properties and electrical performances in the field of IC packages for mobile application processors. MIS (Molded Interconnect Substrate) can provide ideal and this solution in the mobile industry as it contains multiple solutions for the complicated requirement of the IC packages for application processors. Based on the embedded pattern technology, this solution can provide high I/O count, fine pattern for small form factor, and stable flip chip mounting methods. Other advantages of this solution include stable properties required for high-frequency transmission and high thermal dissipation rate as it is only composed of copper and epoxy mold compound materials. These core techniques for MIS technology can be divided into below major concepts. First, Cu pillar electrolytic plating technology electrically connects the inner and the outer layers using photo-lithography method, instead of laser method. The shape of Cu pillar and the plating thickness tolerance control are the key parameters. Second, grinding technology is to precisely grind the plated Cu pillars and applied mold epoxy. And deposition of Cu layer on top of grinded mold surface can construct fine pattern traces.","PeriodicalId":16171,"journal":{"name":"Journal of materials science & engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83590993","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}
Pub Date : 2017-12-28DOI: 10.17265/2161-6221/2017.11-12.003
Tianjiao Liu, Xingdong Qiu, Z. Lu, Li-ming Dong
FEM (finite element method) simulation for estimating the cooling rate from 800 °C to 500 °C in welding cycle of plates with intermediate thickness is presented. Moving double ellipsoid heat sources were applied to simulate the thermal field of welding process, and the cooling rates were investigated with different welding parameters including plate thickness, heat input and preheating temperature according to the analysis of heat transfer characteristics. The critical condition for defining intermediate thickness of plates was determined through comparison between FEM results and calculation results from conventional analytical solutions of Rosenthal et al. and prediction equations of cooling rate in welding of plates with intermediate thickness were established based on regression analysis of FEM results using polynomial method. The feasible range of the equations with preheating temperature was discussed. The welding experiments with the same parameters were carried out to verify the effectiveness of the prediction equations. The compared results of thermal cycles and microstructures between experiment and FEM showed that a good agreement was obtained.
{"title":"Estimation of Cooling Rate from 800 °C to 500 °C in the Welding of Intermediate Thickness Plates Based on FEM Simulation","authors":"Tianjiao Liu, Xingdong Qiu, Z. Lu, Li-ming Dong","doi":"10.17265/2161-6221/2017.11-12.003","DOIUrl":"https://doi.org/10.17265/2161-6221/2017.11-12.003","url":null,"abstract":"FEM (finite element method) simulation for estimating the cooling rate from 800 °C to 500 °C in welding cycle of plates with intermediate thickness is presented. Moving double ellipsoid heat sources were applied to simulate the thermal field of welding process, and the cooling rates were investigated with different welding parameters including plate thickness, heat input and preheating temperature according to the analysis of heat transfer characteristics. The critical condition for defining intermediate thickness of plates was determined through comparison between FEM results and calculation results from conventional analytical solutions of Rosenthal et al. and prediction equations of cooling rate in welding of plates with intermediate thickness were established based on regression analysis of FEM results using polynomial method. The feasible range of the equations with preheating temperature was discussed. The welding experiments with the same parameters were carried out to verify the effectiveness of the prediction equations. The compared results of thermal cycles and microstructures between experiment and FEM showed that a good agreement was obtained.","PeriodicalId":16171,"journal":{"name":"Journal of materials science & engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86027063","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}
Pub Date : 2017-10-28DOI: 10.17265/2161-6221/2017.9-10.004
H. M. Mousa, M. Shabat, A. Ouda
In this paper, we investigate for the first time antireflection coating structure for silicon solar cell where CNPs (conductive nanoparticles) film layer is sandwiched between a semi-infinite glass cover layer and a semi-infinite silicon substrate. The transmission and reflection coefficients are derived by the transfer matrix method and simulated for values of unit cell sizes, gab widths in visible and near-infrared radiation. In addition, the absorption, reflection coefficients are examined for several angles of incidence of the TE (transverse electric) polarized guided waves. Numerical results provide an extremely high absorption, if nanoparticles are suitably located and sized. The absorptivity of the structure achieves 100% at gab width of 3.5 nm and CNP layer thickness of 150 nm.
{"title":"Anti-reflection Coating Solar Cell Structure Based on Conductive Nanoparticles","authors":"H. M. Mousa, M. Shabat, A. Ouda","doi":"10.17265/2161-6221/2017.9-10.004","DOIUrl":"https://doi.org/10.17265/2161-6221/2017.9-10.004","url":null,"abstract":"In this paper, we investigate for the first time antireflection coating structure for silicon solar cell where CNPs (conductive nanoparticles) film layer is sandwiched between a semi-infinite glass cover layer and a semi-infinite silicon substrate. The transmission and reflection coefficients are derived by the transfer matrix method and simulated for values of unit cell sizes, gab widths in visible and near-infrared radiation. In addition, the absorption, reflection coefficients are examined for several angles of incidence of the TE (transverse electric) polarized guided waves. Numerical results provide an extremely high absorption, if nanoparticles are suitably located and sized. The absorptivity of the structure achieves 100% at gab width of 3.5 nm and CNP layer thickness of 150 nm.","PeriodicalId":16171,"journal":{"name":"Journal of materials science & engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88189564","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}
Pub Date : 2017-10-28DOI: 10.17265/2161-6221/2017.9-10.003
K. Juhász, P. Schaul
In this article a macro synthetic fibre reinforced precast concrete track slab’s design process will be presented. The analysis was done with using advanced finite element software called ATENA (Cervenka et al. 2013). Beside the static loads, the precast slab was also checked for dynamic and fatigue loads. The structure was verified for early ages, for de-moulding, rotating, lifting and for transport as well. With the analysis a necessary fibre dosage was determined. After the design AECOM prepared a real scale test for two full slabs. During the test the displacements were measured on different places with using geophones. Finite element model of the test was made with all the details of the real scale test. The results from the tests and from the finite element models were close to each other in every checked case.
本文介绍了一种宏观合成纤维增强预制混凝土轨道板的设计过程。分析是使用名为ATENA的先进有限元软件完成的(Cervenka et al. 2013)。除了静荷载外，预制板还进行了动荷载和疲劳荷载的校核。该结构在早期，脱模，旋转，提升和运输方面都得到了验证。通过分析，确定了所需的纤维用量。设计完成后，AECOM准备了两个完整板的真实规模测试。在试验过程中，利用检波器对不同位置的位移进行了测量。该试验的有限元模型保留了实尺试验的所有细节。试验结果与有限元模型的计算结果在每个校核案例中都很接近。
{"title":"Finite Element Analysis of a Precast Fibre Reinforced Concrete Track Slab","authors":"K. Juhász, P. Schaul","doi":"10.17265/2161-6221/2017.9-10.003","DOIUrl":"https://doi.org/10.17265/2161-6221/2017.9-10.003","url":null,"abstract":"In this article a macro synthetic fibre reinforced precast concrete track slab’s design process will be presented. The analysis was done with using advanced finite element software called ATENA (Cervenka et al. 2013). Beside the static loads, the precast slab was also checked for dynamic and fatigue loads. The structure was verified for early ages, for de-moulding, rotating, lifting and for transport as well. With the analysis a necessary fibre dosage was determined. After the design AECOM prepared a real scale test for two full slabs. During the test the displacements were measured on different places with using geophones. Finite element model of the test was made with all the details of the real scale test. The results from the tests and from the finite element models were close to each other in every checked case.","PeriodicalId":16171,"journal":{"name":"Journal of materials science & engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81724742","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}
Pub Date : 2017-10-28DOI: 10.17265/2161-6213/2017.9-10.002
Matheus de Faria e Oliveira Barreto, P. Brandão
In Portland cement mortars it is of paramount importance to investigate the bond strength between mortar and masonry by means of the study of interfaces and surfaces that make up the system mortar/ceramic block. In this work the aim was to characterize the chemical compositions, microstructures, surfaces and interfaces of mortars applied on ceramic blocks. Therefore, two important characterization tools were used: field-effect gun (FEG) scanning electron microscope (SEM) FEI Quanta 200 with energy-dispersive (X-ray) spectrometer (EDS) and SEM system with EGF Nanofabrication FIB FEI Quanta 3D FEG also with an EDS coupled. To date the results obtained from the research show that the characterization of cementitious materials with high resolution SEM is an important tool in the detection and differentiation of hydrated calcium silicates (CSH), calcium hydroxide (Ca(OH)2), ettringite and calcium carbonate by means of morphological, topographical and chemical data, thus providing extremely reliable as well as qualitative data from the structure of cementitious materials.
{"title":"Nano and Microstructural Characterization of Phases and Interfaces of Portlant Cement Mortar Using High Resolution Microscopy","authors":"Matheus de Faria e Oliveira Barreto, P. Brandão","doi":"10.17265/2161-6213/2017.9-10.002","DOIUrl":"https://doi.org/10.17265/2161-6213/2017.9-10.002","url":null,"abstract":"In Portland cement mortars it is of paramount importance to investigate the bond strength between mortar and masonry by means of the study of interfaces and surfaces that make up the system mortar/ceramic block. In this work the aim was to characterize the chemical compositions, microstructures, surfaces and interfaces of mortars applied on ceramic blocks. Therefore, two important characterization tools were used: field-effect gun (FEG) scanning electron microscope (SEM) FEI Quanta 200 with energy-dispersive (X-ray) spectrometer (EDS) and SEM system with EGF Nanofabrication FIB FEI Quanta 3D FEG also with an EDS coupled. To date the results obtained from the research show that the characterization of cementitious materials with high resolution SEM is an important tool in the detection and differentiation of hydrated calcium silicates (CSH), calcium hydroxide (Ca(OH)2), ettringite and calcium carbonate by means of morphological, topographical and chemical data, thus providing extremely reliable as well as qualitative data from the structure of cementitious materials.","PeriodicalId":16171,"journal":{"name":"Journal of materials science & engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81101455","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}
Pub Date : 2017-10-28DOI: 10.17265/2161-6213/2017.9-10.005
W. Elghazaly, O. Elkady, S. Weiss, S. Elghazaly
Good combinations between strength and toughness are always the aim of all researchers working in the field of material science. Maraging steel grades (200-300) are one of the well known steel alloys proved to have good strength and toughness and are known as 18% Ni-Co-Mo steel family. Maraging steels production, import, and export by certain countries such as USA is closely monitored by international authorities because it is particularly suited for use in gas centrifuges used for uranium enrichment and in aviation technology. In this research an effort is paid to produce innovative carbon-free maraging steel alloy composites that can compete the well known 18% Ni-8% Co standard (250-300) maraging steel alloy with higher strength and superior toughness. The experimental maraging steel composites having different Ni (18-25%) and Al (0.5-1.5%) together with or without Ti and Mo contents are produced by consolidation from the nano-elemental powders. The mechanism of strengthening in IronNickelCobalt-Aluminum composite alloys is studied, however, the changes in microstructures after solution treatment and aging-heat treatment are emphasized using metallurgical microscopy and SEM-TEM aided with EDX analyzing unit. The effect of induced deformation on the properties of the as-sintered samples is also studied. Fracture toughness, impact toughness, hardness, and strength are measured for all alloy composites under investigation and compared with the standard nominal properties for conventional maraging series (250-300).
{"title":"Influence of Composition and Aging Heat Treatment on the Microstructure and Strength of Innovative-Carbon Free 10% Cobalt-Maraging Steel Powder Composites","authors":"W. Elghazaly, O. Elkady, S. Weiss, S. Elghazaly","doi":"10.17265/2161-6213/2017.9-10.005","DOIUrl":"https://doi.org/10.17265/2161-6213/2017.9-10.005","url":null,"abstract":"Good combinations between strength and toughness are always the aim of all researchers working in the field of material science. Maraging steel grades (200-300) are one of the well known steel alloys proved to have good strength and toughness and are known as 18% Ni-Co-Mo steel family. Maraging steels production, import, and export by certain countries such as USA is closely monitored by international authorities because it is particularly suited for use in gas centrifuges used for uranium enrichment and in aviation technology. In this research an effort is paid to produce innovative carbon-free maraging steel alloy composites that can compete the well known 18% Ni-8% Co standard (250-300) maraging steel alloy with higher strength and superior toughness. The experimental maraging steel composites having different Ni (18-25%) and Al (0.5-1.5%) together with or without Ti and Mo contents are produced by consolidation from the nano-elemental powders. The mechanism of strengthening in IronNickelCobalt-Aluminum composite alloys is studied, however, the changes in microstructures after solution treatment and aging-heat treatment are emphasized using metallurgical microscopy and SEM-TEM aided with EDX analyzing unit. The effect of induced deformation on the properties of the as-sintered samples is also studied. Fracture toughness, impact toughness, hardness, and strength are measured for all alloy composites under investigation and compared with the standard nominal properties for conventional maraging series (250-300).","PeriodicalId":16171,"journal":{"name":"Journal of materials science & engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86042243","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}
Pub Date : 2017-10-28DOI: 10.17265/2161-6221/2017.9-10.002
L. Legras, A. Volgin, B. Radiguet, P. Pareige, C. Pokor, B. Décamps, T. Couvant, N. Huin, R. Soulas
Even if temperature, pressure and chemistry of the cooling water are not very high and aggressive, materials used in PWRs (Pressurized Water Reactors) are exposed to different degradation mechanisms. One of the main goals of the research programs in this field is to develop physical model of the mechanisms down to the atomic scale. Such approach needs a clear description and understanding of the degradation mechanisms at the same small scale. This paper illustrates the benefits of different microscopies and of their last improvements up to the promising possibilities of monochromated and aberrations corrected TEM/STEM. A specific focus is placed on four different degradation mechanisms observed in austenitic stainless steel: irradiation ageing, corrosion fatigue, stress corrosion cracking and corrosion.
{"title":"Using Microscopy to Help with the Understanding of Degradation Mechanisms Observed in Materials of Pressurized Water Reactors","authors":"L. Legras, A. Volgin, B. Radiguet, P. Pareige, C. Pokor, B. Décamps, T. Couvant, N. Huin, R. Soulas","doi":"10.17265/2161-6221/2017.9-10.002","DOIUrl":"https://doi.org/10.17265/2161-6221/2017.9-10.002","url":null,"abstract":"Even if temperature, pressure and chemistry of the cooling water are not very high and aggressive, materials used in PWRs (Pressurized Water Reactors) are exposed to different degradation mechanisms. One of the main goals of the research programs in this field is to develop physical model of the mechanisms down to the atomic scale. Such approach needs a clear description and understanding of the degradation mechanisms at the same small scale. This paper illustrates the benefits of different microscopies and of their last improvements up to the promising possibilities of monochromated and aberrations corrected TEM/STEM. A specific focus is placed on four different degradation mechanisms observed in austenitic stainless steel: irradiation ageing, corrosion fatigue, stress corrosion cracking and corrosion.","PeriodicalId":16171,"journal":{"name":"Journal of materials science & engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89580128","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}
The electrical conductivity of trachyteandesite was measured in situ under conditions of pressure range from 0.5-2.0 GPa and temperature range from 773-1,323 K using a YJ-3000t multi-anvil press and a Solartron-1260 Impedance/Gain-phase Analyzer. The experimental results indicate that the electrical conductivity of trachyteandesite increases with increasing temperature and decreases with a rise in pressure. The relationship between the electrical conductivity (σ) and temperature (T) conforms to the Arrhenius equation within a certain temperature range. When the temperature rises to 923 K, the electrical conductivity of trachyandesite abruptly increases. This result demonstrates that trachyandesite begins to dehydrate at ~923 K and produces magnetite with a high-conductivity mineral phase after dehydration. The intergrowth of interconnected magnetite is the cause for the ~2 orders of magnitude increase in the electrical conductivity after dehydration. The interconnected high-conductivity mineral phase of magnetite in the dehydration product of the trachyandesite sample can be used to reasonably explain the high-conductivity anomalies in the South-Central Chilean subduction zone beneath the Andes.
{"title":"The Influence of Dehydration on the Electrical Conductivity of Trachyandesite at High Temperatures and High Pressures","authors":"Lidong Dai, Keshi Hui, Wenqing Sun, Haiying Hu, Heping Li, Jian-jun Jiang","doi":"10.17265/2161-6213/2017.9-10.001","DOIUrl":"https://doi.org/10.17265/2161-6213/2017.9-10.001","url":null,"abstract":"The electrical conductivity of trachyteandesite was measured in situ under conditions of pressure range from 0.5-2.0 GPa and temperature range from 773-1,323 K using a YJ-3000t multi-anvil press and a Solartron-1260 Impedance/Gain-phase Analyzer. The experimental results indicate that the electrical conductivity of trachyteandesite increases with increasing temperature and decreases with a rise in pressure. The relationship between the electrical conductivity (σ) and temperature (T) conforms to the Arrhenius equation within a certain temperature range. When the temperature rises to 923 K, the electrical conductivity of trachyandesite abruptly increases. This result demonstrates that trachyandesite begins to dehydrate at ~923 K and produces magnetite with a high-conductivity mineral phase after dehydration. The intergrowth of interconnected magnetite is the cause for the ~2 orders of magnitude increase in the electrical conductivity after dehydration. The interconnected high-conductivity mineral phase of magnetite in the dehydration product of the trachyandesite sample can be used to reasonably explain the high-conductivity anomalies in the South-Central Chilean subduction zone beneath the Andes.","PeriodicalId":16171,"journal":{"name":"Journal of materials science & engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90277380","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}
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