Abstract In shielded metal arc welding, the major factors influencing hydrogen uptake into the weld metal are (i) the hydrogen content of the base metal, (ii) hydrogen input by the welding consumable, and (iii) the hydrogen introduced by the atmosphere surrounding the arc process. In this study, the relative contribution of these factors is investigated and compared to each other for the case of underwater wet shielded metal arc welding. To assess the influence of the stick electrode’s moisture (capillary introduced water during handling operations) on the diffusible hydrogen in wet welded samples, wet and dry electrodes were welded at four different water depths. The moisture was absorbed through the sharpened electrode tip only, to ensure close to service conditions. The results show that the moist stick electrode coatings lead to 22.6% higher average diffusible hydrogen content in the weld metal (0.5 m water depth an average). However, the effect disappears with increasing water depths (no difference in 60 m water depth).
{"title":"Influence of Stick Electrode Coating’s Moisture Content on the Diffusible Hydrogen in Underwater Wet Shielded Metal Arc Welding","authors":"J. Klett, T. Hassel","doi":"10.2478/adms-2020-0020","DOIUrl":"https://doi.org/10.2478/adms-2020-0020","url":null,"abstract":"Abstract In shielded metal arc welding, the major factors influencing hydrogen uptake into the weld metal are (i) the hydrogen content of the base metal, (ii) hydrogen input by the welding consumable, and (iii) the hydrogen introduced by the atmosphere surrounding the arc process. In this study, the relative contribution of these factors is investigated and compared to each other for the case of underwater wet shielded metal arc welding. To assess the influence of the stick electrode’s moisture (capillary introduced water during handling operations) on the diffusible hydrogen in wet welded samples, wet and dry electrodes were welded at four different water depths. The moisture was absorbed through the sharpened electrode tip only, to ensure close to service conditions. The results show that the moist stick electrode coatings lead to 22.6% higher average diffusible hydrogen content in the weld metal (0.5 m water depth an average). However, the effect disappears with increasing water depths (no difference in 60 m water depth).","PeriodicalId":7327,"journal":{"name":"Advances in Materials Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77847551","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 : 2020-11-24DOI: 10.11648/J.AM.20200904.11
Moustapha Sawadogo, M. Seynou, L. Zerbo, B. Sorgho, G. Lecomte‐Nana, P. Blanchart, R. Ouedraogo
Refractory materials from kaolinitic clays and clay chamotte or quartz were studied to increase the refractoriness under load at temperature above 1300°C. Two different clays mined in Burkina Faso were used and chamotte grains were obtained by preliminary firing a local clay. Fired materials at 1350-1400°C present a typical granular composite microstructure where large grains of chamotte or quartz are embedded in the clay matrix phase. Under load at high temperature, the behavior of material is influenced by the nature of the clay matrix phase that progressively melt at high temperature, the type of chamotte or quartz grains, the grain sizes of different phases and the sequence of the thermal transformations during firing. Kinetics of creep under a constant load were characterized against temperature and time. It gives the typical temperatures at fixed creep strains, that’s a well-recognized method for the refractoriness quantification. It’s shown that the kinetic of creep change with the variation of viscosity with temperature of the melted clay matrix phase, that’s related to both the chemical composition and the extend of the micro-composite nature of the heat transformed clays. Results also indicated that values of activation energy for creep are correlated to the refractoriness of materials.
{"title":"Formulation of Clay Refractory Bricks: Influence of the Nature of Chamotte and the Alumina Content in the Clay","authors":"Moustapha Sawadogo, M. Seynou, L. Zerbo, B. Sorgho, G. Lecomte‐Nana, P. Blanchart, R. Ouedraogo","doi":"10.11648/J.AM.20200904.11","DOIUrl":"https://doi.org/10.11648/J.AM.20200904.11","url":null,"abstract":"Refractory materials from kaolinitic clays and clay chamotte or quartz were studied to increase the refractoriness under load at temperature above 1300°C. Two different clays mined in Burkina Faso were used and chamotte grains were obtained by preliminary firing a local clay. Fired materials at 1350-1400°C present a typical granular composite microstructure where large grains of chamotte or quartz are embedded in the clay matrix phase. Under load at high temperature, the behavior of material is influenced by the nature of the clay matrix phase that progressively melt at high temperature, the type of chamotte or quartz grains, the grain sizes of different phases and the sequence of the thermal transformations during firing. Kinetics of creep under a constant load were characterized against temperature and time. It gives the typical temperatures at fixed creep strains, that’s a well-recognized method for the refractoriness quantification. It’s shown that the kinetic of creep change with the variation of viscosity with temperature of the melted clay matrix phase, that’s related to both the chemical composition and the extend of the micro-composite nature of the heat transformed clays. Results also indicated that values of activation energy for creep are correlated to the refractoriness of materials.","PeriodicalId":7327,"journal":{"name":"Advances in Materials Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87879667","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}
B. Maaoui, Y. Aoun, S. Benramache, A. Nid, R. Far, A. Touati
Abstract In this work, nickel oxide was deposited on a glass substrate at by spray deposition technique; the structural, optical and electrical properties were studied at different NiO concentrations (0.05, 0.10 and 0.15 mol.l−1). Polycrystalline NiO films with a cubic structure with a strong (111) preferred orientation were observed at all sprayed films with minimum crystallite size of 11.97 nm was attained of deposited film at 0.1 mol.l−1. However, α-Ni(OH)2 was observed at 0.15 mol.l−1. The NiO thin films have good transparency in the visible region, the band gap energy varies from 3.54 to 376 eV was affected by NiO concentration, it is shown that the NiO thin film prepared at 0.05 mol.l−1 has less disorder with few defects. The NiO film deposited at 0.15 mol.l−1 has the electrical conductivity was 0.169 (Ω.cm)−1.
{"title":"Synthesis and Characterization of Physical Properties of the NiO Thin Films by Various Concentrations","authors":"B. Maaoui, Y. Aoun, S. Benramache, A. Nid, R. Far, A. Touati","doi":"10.2478/adms-2020-0017","DOIUrl":"https://doi.org/10.2478/adms-2020-0017","url":null,"abstract":"Abstract In this work, nickel oxide was deposited on a glass substrate at by spray deposition technique; the structural, optical and electrical properties were studied at different NiO concentrations (0.05, 0.10 and 0.15 mol.l−1). Polycrystalline NiO films with a cubic structure with a strong (111) preferred orientation were observed at all sprayed films with minimum crystallite size of 11.97 nm was attained of deposited film at 0.1 mol.l−1. However, α-Ni(OH)2 was observed at 0.15 mol.l−1. The NiO thin films have good transparency in the visible region, the band gap energy varies from 3.54 to 376 eV was affected by NiO concentration, it is shown that the NiO thin film prepared at 0.05 mol.l−1 has less disorder with few defects. The NiO film deposited at 0.15 mol.l−1 has the electrical conductivity was 0.169 (Ω.cm)−1.","PeriodicalId":7327,"journal":{"name":"Advances in Materials Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73490482","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}
Abstract The purpose of this study is to elucidate the flow features of the dissimilar Al-Cu welded plates. The welding method used is Bobbin Friction Stir Welding (BFSW), and the joint is between two dissimilar materials, aluminium alloy (AA6082-T6) and pure copper. Weld samples were cut from along the weld line, and the cross-sections were polished and observed under an optical microscope (OM). Particular regions of interest were examined under a scanning electron microscope (SEM) and analysed with Energy Dispersive X-ray Spectroscopy (EDS) using the AZtec software from Oxford Instruments. The results and images attained were compared to other similar studies. The reason for fracture was mainly attributed to the welding parameters used; a higher rotational speed may be required to achieve a successful BFSW between these two materials. The impact of welding parameters on the Al-Cu flow bonding and evolution of the intermetallic compounds were identified by studying the interfacial microstructure at the location of the tool action. The work makes an original contribution to identifying the solid-phase hybrid bonding in Al-Cu joints to improve the understanding of the flow behaviours during the BFSW welding process. The microstructural evolution of the dissimilar weld has made it possible to develop a physical model proposed for the flow failure mechanism.
{"title":"Characterization of Dissimilar Al-Cu BFSW Welds; Interfacial Microstructure, Flow Mechanism and Intermetallics Formation","authors":"A. Tamadon, M. Abdali, D. Pons, D. Clucas","doi":"10.2478/adms-2020-0016","DOIUrl":"https://doi.org/10.2478/adms-2020-0016","url":null,"abstract":"Abstract The purpose of this study is to elucidate the flow features of the dissimilar Al-Cu welded plates. The welding method used is Bobbin Friction Stir Welding (BFSW), and the joint is between two dissimilar materials, aluminium alloy (AA6082-T6) and pure copper. Weld samples were cut from along the weld line, and the cross-sections were polished and observed under an optical microscope (OM). Particular regions of interest were examined under a scanning electron microscope (SEM) and analysed with Energy Dispersive X-ray Spectroscopy (EDS) using the AZtec software from Oxford Instruments. The results and images attained were compared to other similar studies. The reason for fracture was mainly attributed to the welding parameters used; a higher rotational speed may be required to achieve a successful BFSW between these two materials. The impact of welding parameters on the Al-Cu flow bonding and evolution of the intermetallic compounds were identified by studying the interfacial microstructure at the location of the tool action. The work makes an original contribution to identifying the solid-phase hybrid bonding in Al-Cu joints to improve the understanding of the flow behaviours during the BFSW welding process. The microstructural evolution of the dissimilar weld has made it possible to develop a physical model proposed for the flow failure mechanism.","PeriodicalId":7327,"journal":{"name":"Advances in Materials Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74068546","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}
Abstract Ba0.85(La,Y)0.15Fe12O19 hexaferrite magnets were produced using the powder metallurgy method. The phase analysis of the ferrite magnets was carried out by X-ray diffraction (XRD) technique. A single hexaferrite phase was present in both samples as revealed by XRD patterns. The microstructural evolution in the hexaferrite samples was examined using Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-Ray Spectroscopy (EDS). The grain morphology altered with the sintering temperature. Room temperature ferrimagnetic hysteresis curves were obtained by Vibrating Sample Magnetometer (VSM). The crystallite size and the lattice parameters (a,c) were also calculated after sintering at 1150ºC and 1250ºC. Saturation magnetizations, Ms were determined to be 48.60 emu/g and 52.95 emu/g for the samples sintered at 1150ºC and 1250ºC, respectively whereas the remanent magnetizations, Mr were 29.26 emu/g and 31.17 emu/g. The coercivity, Hc decreased from 3.95 kOe to the value of 2.44 kOe with the sintering temperature due to the increase of the crystallite size. The squareness ratios (Mr/Ms) of the ferrimagnetic samples were different because the uniaxial anisotropies altered after sintering at 1150ºC and 1250ºC. The maximum energy product, (BH)max dropped from 35.81 kJ/m3 to 27.38 kJ/m3 when the sintering temperature increased. This result can be attributed to a combination of higher magnetization and the lower coercivity.
{"title":"Effect of Rare-Earth Co-Doping on the Microstructural and Magnetic Properties of BaFe12O19","authors":"P. Güler, B. Ertuğ, N. İ. Işıkcı, A. Kara","doi":"10.2478/adms-2020-0014","DOIUrl":"https://doi.org/10.2478/adms-2020-0014","url":null,"abstract":"Abstract Ba0.85(La,Y)0.15Fe12O19 hexaferrite magnets were produced using the powder metallurgy method. The phase analysis of the ferrite magnets was carried out by X-ray diffraction (XRD) technique. A single hexaferrite phase was present in both samples as revealed by XRD patterns. The microstructural evolution in the hexaferrite samples was examined using Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-Ray Spectroscopy (EDS). The grain morphology altered with the sintering temperature. Room temperature ferrimagnetic hysteresis curves were obtained by Vibrating Sample Magnetometer (VSM). The crystallite size and the lattice parameters (a,c) were also calculated after sintering at 1150ºC and 1250ºC. Saturation magnetizations, Ms were determined to be 48.60 emu/g and 52.95 emu/g for the samples sintered at 1150ºC and 1250ºC, respectively whereas the remanent magnetizations, Mr were 29.26 emu/g and 31.17 emu/g. The coercivity, Hc decreased from 3.95 kOe to the value of 2.44 kOe with the sintering temperature due to the increase of the crystallite size. The squareness ratios (Mr/Ms) of the ferrimagnetic samples were different because the uniaxial anisotropies altered after sintering at 1150ºC and 1250ºC. The maximum energy product, (BH)max dropped from 35.81 kJ/m3 to 27.38 kJ/m3 when the sintering temperature increased. This result can be attributed to a combination of higher magnetization and the lower coercivity.","PeriodicalId":7327,"journal":{"name":"Advances in Materials Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79919242","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}
Abstract Poly(vinyl alcohol) (PVA) has been considered as an important commercial synthetic thermoplastic polymer. PVA is a low cost, reasonably processable, optically transmitting, heat stable, and mechanically robust plastic. PVA-based nanomaterials usually comprise of the nanocomposites (PVA/graphene, PVA/carbon nanotube, PVA/nanodiamond, PVA/metal nanoparticle) and nanofibers. The structural, optical, mechanical, and electrical properties of the PVA-based nanomaterials have been enhanced with nanofiller addition or nanostructuring. This review offers fundamentals and advanced aspects of poly(vinyl alcohol) and the derived nanomaterials. It highlights recent advances in PVA nanocomposites and nanofibers for potential applications. The PVA-based nanomaterials have been successfully employed in fuel cells, sensors, batteries, membranes, electronics, and drug delivery relevances. The challenges and opportunities to strengthen the research fields of PVA-based nanomaterials have also been presented.
{"title":"Innovations in Poly(Vinyl Alcohol) Derived Nanomaterials","authors":"Ayesha Kausar","doi":"10.2478/adms-2020-0013","DOIUrl":"https://doi.org/10.2478/adms-2020-0013","url":null,"abstract":"Abstract Poly(vinyl alcohol) (PVA) has been considered as an important commercial synthetic thermoplastic polymer. PVA is a low cost, reasonably processable, optically transmitting, heat stable, and mechanically robust plastic. PVA-based nanomaterials usually comprise of the nanocomposites (PVA/graphene, PVA/carbon nanotube, PVA/nanodiamond, PVA/metal nanoparticle) and nanofibers. The structural, optical, mechanical, and electrical properties of the PVA-based nanomaterials have been enhanced with nanofiller addition or nanostructuring. This review offers fundamentals and advanced aspects of poly(vinyl alcohol) and the derived nanomaterials. It highlights recent advances in PVA nanocomposites and nanofibers for potential applications. The PVA-based nanomaterials have been successfully employed in fuel cells, sensors, batteries, membranes, electronics, and drug delivery relevances. The challenges and opportunities to strengthen the research fields of PVA-based nanomaterials have also been presented.","PeriodicalId":7327,"journal":{"name":"Advances in Materials Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77549810","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}
A. Gahtar, S. Benramache, C. Zaouche, A. Boukacham, A. Sayah
Abstract In this work, we have prepared new materials of the nickel sulfide thin films by using the spray pyrolysis technique for promising co-catalyst to improve the photocatalytic performance or superconductivity. The effect of deposition temperature (523, 573 and 623 K) on structural, optical and electrical properties was investigated. The XRD diffraction shows that the prepared nickel sulfide at 523, 573 and 623 K having an orthorhombic, hexagonal and hexagonal structure, which were Ni3S2, Ni17S18 and NiS2, respectively. The minimum value of crystallite size (45,9 nm) was measured of deposited film at 573K. The thin films prepared at 523 and 573 K have an average transmittance is about 20 %. The prepared Ni1S2 thin film at T=623 K has the lowest calculated optical band gap and Urbach energy. The Ni1S2 thin film also has the best calculated of the refractive index and the extinction coefficient. The FTIR spectrums of the nickel sulfide have various bands such as Ni-S, C-H, O-H, N–H and C-S. The maximum electrical conductivity is 4,29x105 (Ω.cm)−1 was obtained at 573K of the Ni17S18. The nickel sulfide thin films sprayed at 573K have good structural, optical and electrical properties.
{"title":"Effect of Temperature on the Properties of Nickel Sulfide Films Performed by Spray Pyrolysis Technique","authors":"A. Gahtar, S. Benramache, C. Zaouche, A. Boukacham, A. Sayah","doi":"10.2478/adms-2020-0015","DOIUrl":"https://doi.org/10.2478/adms-2020-0015","url":null,"abstract":"Abstract In this work, we have prepared new materials of the nickel sulfide thin films by using the spray pyrolysis technique for promising co-catalyst to improve the photocatalytic performance or superconductivity. The effect of deposition temperature (523, 573 and 623 K) on structural, optical and electrical properties was investigated. The XRD diffraction shows that the prepared nickel sulfide at 523, 573 and 623 K having an orthorhombic, hexagonal and hexagonal structure, which were Ni3S2, Ni17S18 and NiS2, respectively. The minimum value of crystallite size (45,9 nm) was measured of deposited film at 573K. The thin films prepared at 523 and 573 K have an average transmittance is about 20 %. The prepared Ni1S2 thin film at T=623 K has the lowest calculated optical band gap and Urbach energy. The Ni1S2 thin film also has the best calculated of the refractive index and the extinction coefficient. The FTIR spectrums of the nickel sulfide have various bands such as Ni-S, C-H, O-H, N–H and C-S. The maximum electrical conductivity is 4,29x105 (Ω.cm)−1 was obtained at 573K of the Ni17S18. The nickel sulfide thin films sprayed at 573K have good structural, optical and electrical properties.","PeriodicalId":7327,"journal":{"name":"Advances in Materials Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90450916","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 : 2020-07-23DOI: 10.11648/j.am.20200902.13
D. Armand, Adamon Gildas David, Houngbeme Carlos, H. Aristide, Houehanou C. Ernesto, Vianou Antoine
This work concerns the thermophysical characterization of a bio-eco-material made from cow dung and the macerate of nere pods. To achieve this, chemical tests based on tannin concentration determination of four different solutions of nere pods (60 g.l-1; 120 g.l-1; 180 g.l-1 and 240 g.l-1) were prepared at 100°C, then brought to the boil for 5 minutes. After three different maceration times (6 h; 24 h and 48 h), the analysis of the solutions obtained using a spectrometer made it possible to select the solutions of 120 g.l-1 and 180 g.l-1 which offer best tannin concentrations in 24 hours, necessary for making test pieces. Thermal tests based on thermal effusivity and thermal conductivity measurements were then carried out in transient mode, with hot strip method. In order to compare the thermal performance of developed eco-material with that of ordinary insulators, the thermophysical properties of plywood and plaster were also measured. The results obtained showed that for the two dosages of 120 g.l-1 and 180 g.l-1, the thermal effusivity of eco-insulator varies from 247.732 J.K-1.m-2.s-0,5 to 270.732 J.K-1.m-2.s-0,5 respectively and the thermal conductivity from 0.082 W.m-1.K-1 to 0.080 W.m-1.K-1. For the same dosages, the thermal diffusivity varies from 1.106.10-7 m².s-¹ to 0.881.10-7 m².s-¹ respectively. A comparative study has shown that the eco-material developed and tested offers better insulating power due to its relatively weak thermophysical properties compared to ordinary insulating materials, namely plaster and plywood.
这项工作涉及由牛粪和神经豆荚浸渍制成的生物生态材料的热物理特性。为了实现这一目标，基于单宁浓度测定的四种不同的神经豆荚溶液(60 g.l-1;120 g.l-1;分别取180 g.l-1和240 g.l-1)，在100℃下煮沸5分钟。经过三次不同的浸渍时间(6 h;24小时和48小时)，用光谱仪对得到的溶液进行分析，可以选择120 g.l-1和180 g.l-1的溶液，在24小时内提供最佳的单宁浓度，这是制作试样所必需的。然后在瞬态模式下用热带法进行了基于热渗透率和导热系数测量的热测试。为了比较开发的生态材料与普通绝缘体的热性能，还测量了胶合板和石膏的热物理性能。结果表明，在120 g.l-1和180 g.l-1两种剂量下，生态绝缘子的热溢率为247.732 j . k . 1.m-2。s-0,5至270.732 j.k -1 - m-2s-0,5，导热系数0.082 w - m-1。K-1至0.080 w - m-1 K-1。对于相同剂量，热扩散系数在1.106.10-7 m²之间变化。S -¹到0.881.10-7 m²。s -¹分别。一项对比研究表明，开发和测试的生态材料与普通绝缘材料(即石膏和胶合板)相比，其热物理性能相对较弱，因此具有更好的绝缘能力。
{"title":"Thermophysical Characterization of an Insulating Bio-material Based on the Macerate of ''Néré'' (Parkiabiglobosa) Pods and Cow Dung","authors":"D. Armand, Adamon Gildas David, Houngbeme Carlos, H. Aristide, Houehanou C. Ernesto, Vianou Antoine","doi":"10.11648/j.am.20200902.13","DOIUrl":"https://doi.org/10.11648/j.am.20200902.13","url":null,"abstract":"This work concerns the thermophysical characterization of a bio-eco-material made from cow dung and the macerate of nere pods. To achieve this, chemical tests based on tannin concentration determination of four different solutions of nere pods (60 g.l-1; 120 g.l-1; 180 g.l-1 and 240 g.l-1) were prepared at 100°C, then brought to the boil for 5 minutes. After three different maceration times (6 h; 24 h and 48 h), the analysis of the solutions obtained using a spectrometer made it possible to select the solutions of 120 g.l-1 and 180 g.l-1 which offer best tannin concentrations in 24 hours, necessary for making test pieces. Thermal tests based on thermal effusivity and thermal conductivity measurements were then carried out in transient mode, with hot strip method. In order to compare the thermal performance of developed eco-material with that of ordinary insulators, the thermophysical properties of plywood and plaster were also measured. The results obtained showed that for the two dosages of 120 g.l-1 and 180 g.l-1, the thermal effusivity of eco-insulator varies from 247.732 J.K-1.m-2.s-0,5 to 270.732 J.K-1.m-2.s-0,5 respectively and the thermal conductivity from 0.082 W.m-1.K-1 to 0.080 W.m-1.K-1. For the same dosages, the thermal diffusivity varies from 1.106.10-7 m².s-¹ to 0.881.10-7 m².s-¹ respectively. A comparative study has shown that the eco-material developed and tested offers better insulating power due to its relatively weak thermophysical properties compared to ordinary insulating materials, namely plaster and plywood.","PeriodicalId":7327,"journal":{"name":"Advances in Materials Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79227283","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}
Abstract The paper discusses the problem of possibility of the detecting surface defects in carbon fibre reinforced plastics (CFRP) materials on the basis of the milling time series. First, the special defects in the hole-shaped with various depth were made. Next, the cutting forces are measured during the milling machining. Finally, the recurrence plot and quantification analysis was applied. The obtained results show that the depth defect influences the selected recurrence quantifications, which can be used as the simple defect indicators. The conducted research allow to determine the percentage share of the detectable defects. The novelty of the work and an unresolved problem is the selection of recurrence quantifications with the simultaneous use of them to detect the size of defects in carbon fibre reinforced plastics.
{"title":"Effect of Depth Surface Defects in Carbon Fibre Reinforced Composite Material on the Selected Recurrence Quantifications","authors":"K. Ciecieląg, K. Kęcik, K. Zaleski","doi":"10.2478/adms-2020-0011","DOIUrl":"https://doi.org/10.2478/adms-2020-0011","url":null,"abstract":"Abstract The paper discusses the problem of possibility of the detecting surface defects in carbon fibre reinforced plastics (CFRP) materials on the basis of the milling time series. First, the special defects in the hole-shaped with various depth were made. Next, the cutting forces are measured during the milling machining. Finally, the recurrence plot and quantification analysis was applied. The obtained results show that the depth defect influences the selected recurrence quantifications, which can be used as the simple defect indicators. The conducted research allow to determine the percentage share of the detectable defects. The novelty of the work and an unresolved problem is the selection of recurrence quantifications with the simultaneous use of them to detect the size of defects in carbon fibre reinforced plastics.","PeriodicalId":7327,"journal":{"name":"Advances in Materials Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73119074","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}
S. S. Yusuf, M. N. Islam, M. H. Ali, M. Akram, M. Siddique
Abstract This paper presents an investigation of impact strength of sponge gourd, coir, and jute fibers reinforced epoxy resin-based composites. Impact strength of specimens, made of composites with various proportions of wt% ratio of resin and hardener, wt% of resin and hardener, wt% ratio of sponge gourd and jute, wt% ratio of sponge gourd and coir, was measured. Design of experiment was done by Taguchi method using four control factors with three levels. Effect of the above control factors on impact strength was examined and the best combinations of control factors are advised. Confirmation test was performed by using this combination and the percentage of contribution of the above factors on impact strength was investigated by Analysis of Variance (ANOVA). Contour and interaction plots provide helpfully examines to explore the combined influences of different control factors on output characteristics. The regression equation represents a mathematical model that relates control factors with impact strength.
{"title":"Towards the Optimization of Process Parameters for Impact Strength of Natural Fiber Reinforced Composites: Taguchi Method","authors":"S. S. Yusuf, M. N. Islam, M. H. Ali, M. Akram, M. Siddique","doi":"10.2478/adms-2020-0010","DOIUrl":"https://doi.org/10.2478/adms-2020-0010","url":null,"abstract":"Abstract This paper presents an investigation of impact strength of sponge gourd, coir, and jute fibers reinforced epoxy resin-based composites. Impact strength of specimens, made of composites with various proportions of wt% ratio of resin and hardener, wt% of resin and hardener, wt% ratio of sponge gourd and jute, wt% ratio of sponge gourd and coir, was measured. Design of experiment was done by Taguchi method using four control factors with three levels. Effect of the above control factors on impact strength was examined and the best combinations of control factors are advised. Confirmation test was performed by using this combination and the percentage of contribution of the above factors on impact strength was investigated by Analysis of Variance (ANOVA). Contour and interaction plots provide helpfully examines to explore the combined influences of different control factors on output characteristics. The regression equation represents a mathematical model that relates control factors with impact strength.","PeriodicalId":7327,"journal":{"name":"Advances in Materials Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86863872","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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