Pub Date : 2022-01-01DOI: 10.3934/matersci.2022047
Hung-Nguyen Manh, Oanh Le Thi Mai, Chung Pham Do, Mai Vu Thanh, Anh Nguyen Thi Diep, Dao La Bich, Hang Lam Thi, Duyen Pham Thi, Minh Nguyen Van
Ag3PO4 was prepared by the precipitation method using monobasic/dibasic phosphate salts (K2HPO4, KH2PO4, Na2HPO4, NaH2PO4) as a precipitating agent. The environment created by the precursor salts strong affected on the crystallinity and the morphology of Ag3PO4. Ag3PO4 synthesized from dibasic phosphate salts exhibited pseudospherical morphology and small particle size while monobasic phosphate salts promoted crystallization, resulting in a large grain size and a very diverse grain morphology. Ag3PO4 prepared from dibasic phosphate salts (K2HPO4 and Na2HPO4) exhibited superior photocatalytic ability, completely degrading rhodamine B (RhB) in 8 min and 10 min under Xenon lamp irradiation, respectively. This result once again confirms the necessity of particle size reduction in the production of photocatalysts.
{"title":"Effect of monobasic/dibasic phosphate salts on the crystallinity, physical properties and photocatalytic performance of Ag3PO4 material","authors":"Hung-Nguyen Manh, Oanh Le Thi Mai, Chung Pham Do, Mai Vu Thanh, Anh Nguyen Thi Diep, Dao La Bich, Hang Lam Thi, Duyen Pham Thi, Minh Nguyen Van","doi":"10.3934/matersci.2022047","DOIUrl":"https://doi.org/10.3934/matersci.2022047","url":null,"abstract":"<abstract> <p>Ag<sub>3</sub>PO<sub>4</sub> was prepared by the precipitation method using monobasic/dibasic phosphate salts (K<sub>2</sub>HPO<sub>4</sub>, KH<sub>2</sub>PO<sub>4</sub>, Na<sub>2</sub>HPO<sub>4</sub>, NaH<sub>2</sub>PO<sub>4</sub>) as a precipitating agent. The environment created by the precursor salts strong affected on the crystallinity and the morphology of Ag<sub>3</sub>PO<sub>4</sub>. Ag<sub>3</sub>PO<sub>4</sub> synthesized from dibasic phosphate salts exhibited pseudospherical morphology and small particle size while monobasic phosphate salts promoted crystallization, resulting in a large grain size and a very diverse grain morphology. Ag<sub>3</sub>PO<sub>4</sub> prepared from dibasic phosphate salts (K<sub>2</sub>HPO<sub>4</sub> and Na<sub>2</sub>HPO<sub>4</sub>) exhibited superior photocatalytic ability, completely degrading rhodamine B (RhB) in 8 min and 10 min under Xenon lamp irradiation, respectively. This result once again confirms the necessity of particle size reduction in the production of photocatalysts.</p> </abstract>","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70089045","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 : 2022-01-01DOI: 10.3934/matersci.2022019
I. Chaves, R. Melchers, Barbara Jardim do Nascimento, J. Philips, M. Masia
An important structural component for cavity brick and masonry-veneer construction are wall ties. Typically, they are galvanized steel, sufficiently strong to provide continuity for transmission of direct and shear forces. However, field observations show they are prone to long-term corrosion and this can have serious structural implications under extreme events such as earthquakes. Opportunistic observations show corrosion occurs largely to the internal masonry interface zone even though conventional Code requirements specify corrosion testing for the whole tie. To throw light on the issue electrochemical test for 2 grades of galvanized ties and 316 stainless steels combined with three different mortar compositions are reported. Most severe corrosion occurred at the masonry interface and sometimes within the masonry itself. Structural capacity tests showed galvanized ties performed better than stainless steel ties in lieu of stainless steel R4 class ties presenting significantly greater relative losses of yield strength, ultimate tensile strength and elongation structural capacity compared to R2 low galvanized and R3 heavy galvanized tie classes.
{"title":"Effects of inter-cavity corrosion on metallic wall ties in masonry structures","authors":"I. Chaves, R. Melchers, Barbara Jardim do Nascimento, J. Philips, M. Masia","doi":"10.3934/matersci.2022019","DOIUrl":"https://doi.org/10.3934/matersci.2022019","url":null,"abstract":"An important structural component for cavity brick and masonry-veneer construction are wall ties. Typically, they are galvanized steel, sufficiently strong to provide continuity for transmission of direct and shear forces. However, field observations show they are prone to long-term corrosion and this can have serious structural implications under extreme events such as earthquakes. Opportunistic observations show corrosion occurs largely to the internal masonry interface zone even though conventional Code requirements specify corrosion testing for the whole tie. To throw light on the issue electrochemical test for 2 grades of galvanized ties and 316 stainless steels combined with three different mortar compositions are reported. Most severe corrosion occurred at the masonry interface and sometimes within the masonry itself. Structural capacity tests showed galvanized ties performed better than stainless steel ties in lieu of stainless steel R4 class ties presenting significantly greater relative losses of yield strength, ultimate tensile strength and elongation structural capacity compared to R2 low galvanized and R3 heavy galvanized tie classes.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088110","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 : 2022-01-01DOI: 10.3934/matersci.2022015
V. Flores-Alés, F. J. Alejandre, F. Blasco-López, M. Torres-González, J. M. Alducin-Ochoa
This study analyses the façades of a white concrete building located in Cádiz (Spain). Numerous sections of the concrete cladding on the façades have become detached and there are clear signs of reinforcement corrosion. For the purposes of this study, the arrangement of the reinforcement was evaluated by georadar (GPR). Cylindrical concrete cores measuring 10 cm in diameter by 15–18 cm in depth were extracted and their carbonation front was evaluated. Samples were characterized by physical properties determination; chemical and mineralogical analysis and the chloride penetration profiles. According to the results obtained, the concrete used can be considered permeable and porous (16.5–19.7%). Only two sampling points fulfilled the minimum reinforcement coating requirements for this type of environmental exposure, in accordance with current Spanish legislation. The carbonation fronts have reached the reinforcements, causing their depassivation. Depending on the orientation of the façade, the penetration of chlorides from marine spray was observed with a maximum value of 0.250% by weight of cement, without reaching the limit states of durability.
{"title":"Analysis of alterations presented in a white-concrete façade exposed to a marine environment——A case study in Cádiz (Spain)","authors":"V. Flores-Alés, F. J. Alejandre, F. Blasco-López, M. Torres-González, J. M. Alducin-Ochoa","doi":"10.3934/matersci.2022015","DOIUrl":"https://doi.org/10.3934/matersci.2022015","url":null,"abstract":"This study analyses the façades of a white concrete building located in Cádiz (Spain). Numerous sections of the concrete cladding on the façades have become detached and there are clear signs of reinforcement corrosion. For the purposes of this study, the arrangement of the reinforcement was evaluated by georadar (GPR). Cylindrical concrete cores measuring 10 cm in diameter by 15–18 cm in depth were extracted and their carbonation front was evaluated. Samples were characterized by physical properties determination; chemical and mineralogical analysis and the chloride penetration profiles. According to the results obtained, the concrete used can be considered permeable and porous (16.5–19.7%). Only two sampling points fulfilled the minimum reinforcement coating requirements for this type of environmental exposure, in accordance with current Spanish legislation. The carbonation fronts have reached the reinforcements, causing their depassivation. Depending on the orientation of the façade, the penetration of chlorides from marine spray was observed with a maximum value of 0.250% by weight of cement, without reaching the limit states of durability.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088398","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 : 2022-01-01DOI: 10.3934/matersci.2022027
H. O. Psihoyos, G. Lampeas
Laser Powder Bed Fusion (LPBF) process is one of the advanced Additive Manufacturing (AM) processes, which is employed for the fabrication of complex metallic components. One of the major drawbacks of the LPBF is the development of residual stresses due to the high temperature gradients developed during the process thermal cycles. Reliable models for the prediction of residual strain and stress at part scale are required to support the LPBF process optimization. Due to the computational cost of the LPBF simulation, the current modelling methodology utilizes assumptions to make feasible the prediction of residual stresses at parts or component level. To this scope, a thermomechanical modelling approach for the simulation of LPBF process is presented with focus to residual stress and strain prediction. The modelling efficiency of the proposed approach was tested on a series on cases for which experimental data were available. The good comparison between the predicted and experimental data validated the modelling method. The efficiency of the thermomechanical modelling method is demonstrated by the reduced computational time required.
{"title":"Efficient thermomechanical modelling of Laser Powder Bed Fusion additive manufacturing process with emphasis on parts residual stress fields","authors":"H. O. Psihoyos, G. Lampeas","doi":"10.3934/matersci.2022027","DOIUrl":"https://doi.org/10.3934/matersci.2022027","url":null,"abstract":"Laser Powder Bed Fusion (LPBF) process is one of the advanced Additive Manufacturing (AM) processes, which is employed for the fabrication of complex metallic components. One of the major drawbacks of the LPBF is the development of residual stresses due to the high temperature gradients developed during the process thermal cycles. Reliable models for the prediction of residual strain and stress at part scale are required to support the LPBF process optimization. Due to the computational cost of the LPBF simulation, the current modelling methodology utilizes assumptions to make feasible the prediction of residual stresses at parts or component level. To this scope, a thermomechanical modelling approach for the simulation of LPBF process is presented with focus to residual stress and strain prediction. The modelling efficiency of the proposed approach was tested on a series on cases for which experimental data were available. The good comparison between the predicted and experimental data validated the modelling method. The efficiency of the thermomechanical modelling method is demonstrated by the reduced computational time required.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088634","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 : 2022-01-01DOI: 10.3934/matersci.2022029
P. Kah, P. Layus, B. Ndiwe
The paper focuses on the submerged arc welding (SAW) process in application to structures for Arctic conditions. One of the technical challenges for modern Arctic structures is to produce high-quality welds since a weld is usually the weakest part of any structure. Welding is especially difficult for the high strength steels (HSS), which are used in structures for weight-reduction purposes. The objective of the study is to explore the usability, development possibilities and parameters of SAW process for welding of thick cold-resistant HSS plates. Meeting this objective required in-depth understanding of the welding and material science background, which includes the quality requirements of weld joints intended for Arctic service as described in various standards, properties of cold-resistant HSS and description of testing methods used to validate welding joints for low temperature conditions. The study describes experimental findings that improve understanding of SAW process of thick quenched and tempered (QT) and thermo-mechanically processed (TMCP) HSS plates. Experiments were conducted to develop SAW procedures to weld several thick (exceeding 25 mm) high strengths (580–650 MPa tensile strength) cold-resistant (intended operational temperature at least −40 ℃) steel grades. The welds were evaluated by a wide range of industrial tests: analyses of chemical, microstructural and mechanical properties; hardness tests; and cold resistance evaluation tests: the Charpy V-notch impact test and the Crack tip opening displacement (CTOD) test. Acceptable welding parameters and recommendations were developed, and the results of the experiments show that high quality welds can be obtained using heat input up to 3.5 kJ/mm.
{"title":"Submerged arc welding process peculiarities in application for Arctic structures","authors":"P. Kah, P. Layus, B. Ndiwe","doi":"10.3934/matersci.2022029","DOIUrl":"https://doi.org/10.3934/matersci.2022029","url":null,"abstract":"The paper focuses on the submerged arc welding (SAW) process in application to structures for Arctic conditions. One of the technical challenges for modern Arctic structures is to produce high-quality welds since a weld is usually the weakest part of any structure. Welding is especially difficult for the high strength steels (HSS), which are used in structures for weight-reduction purposes. The objective of the study is to explore the usability, development possibilities and parameters of SAW process for welding of thick cold-resistant HSS plates. Meeting this objective required in-depth understanding of the welding and material science background, which includes the quality requirements of weld joints intended for Arctic service as described in various standards, properties of cold-resistant HSS and description of testing methods used to validate welding joints for low temperature conditions. The study describes experimental findings that improve understanding of SAW process of thick quenched and tempered (QT) and thermo-mechanically processed (TMCP) HSS plates. Experiments were conducted to develop SAW procedures to weld several thick (exceeding 25 mm) high strengths (580–650 MPa tensile strength) cold-resistant (intended operational temperature at least −40 ℃) steel grades. The welds were evaluated by a wide range of industrial tests: analyses of chemical, microstructural and mechanical properties; hardness tests; and cold resistance evaluation tests: the Charpy V-notch impact test and the Crack tip opening displacement (CTOD) test. Acceptable welding parameters and recommendations were developed, and the results of the experiments show that high quality welds can be obtained using heat input up to 3.5 kJ/mm.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088799","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 : 2022-01-01DOI: 10.3934/matersci.2022034
M. Konieczny
Laminated Mg-intermetallic composites were successfully fabricated by reaction synthesis in vacuum using 1 mm thick magnesium sheets and 0.25 mm thick copper foils. The final microstructure consisted of alternating layers of a hypoeutectic alloy containing crystals of CuMg2 and eutectic mixture of CuMg2 and solid solution of copper in magnesium and unreacted magnesium. The mechanical properties and fracture behavior of the fabricated composites were examined under different loading directions through compression, three-point bending and impact tests. The results indicated that the composites exhibited anisotropic features. The specimens compressed in the parallel direction failed by cracking along the layers of intermetallics and buckling of magnesium layers. The specimens compressed in the perpendicular direction failed by transverse cracking in the intermetallic layers and fallowing catastrophic cracking inclined about 45° to the interface of both intermetallic and magnesium layers. The flexural strength of the composites was higher in perpendicular than in parallel direction. When the load parallel to the layers was applied, the failure occurred by cleavage mode showing limited plastic deformation. When the load perpendicular to the layers was applied, the failure occurred by transverse cracking of the intermetallic layers and gradual cracking of the Mg layers. The Charpy-tested samples showed the same fracture behavior as the bend-tested specimens, which indicated that the same mechanisms operated at both high impact rate and low bending-test rate.
{"title":"Mechanical properties and failure analysis of laminated magnesium-intermetallic composites","authors":"M. Konieczny","doi":"10.3934/matersci.2022034","DOIUrl":"https://doi.org/10.3934/matersci.2022034","url":null,"abstract":"Laminated Mg-intermetallic composites were successfully fabricated by reaction synthesis in vacuum using 1 mm thick magnesium sheets and 0.25 mm thick copper foils. The final microstructure consisted of alternating layers of a hypoeutectic alloy containing crystals of CuMg2 and eutectic mixture of CuMg2 and solid solution of copper in magnesium and unreacted magnesium. The mechanical properties and fracture behavior of the fabricated composites were examined under different loading directions through compression, three-point bending and impact tests. The results indicated that the composites exhibited anisotropic features. The specimens compressed in the parallel direction failed by cracking along the layers of intermetallics and buckling of magnesium layers. The specimens compressed in the perpendicular direction failed by transverse cracking in the intermetallic layers and fallowing catastrophic cracking inclined about 45° to the interface of both intermetallic and magnesium layers. The flexural strength of the composites was higher in perpendicular than in parallel direction. When the load parallel to the layers was applied, the failure occurred by cleavage mode showing limited plastic deformation. When the load perpendicular to the layers was applied, the failure occurred by transverse cracking of the intermetallic layers and gradual cracking of the Mg layers. The Charpy-tested samples showed the same fracture behavior as the bend-tested specimens, which indicated that the same mechanisms operated at both high impact rate and low bending-test rate.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088994","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 : 2022-01-01DOI: 10.3934/matersci.2022038
A. Kamat, B. Lubelli, E. Schlangen
Porous building materials are often subjected to damage due to salt crystallization. In recent years, the addition of crystallization inhibitors in lime-based mortar, has shown promising results in improving durability of this material against salt decay. Lime-based mortars have low mechanical properties and slow setting. They are often replaced with hydraulic binders to overcome these limitations. However, the effect of crystallization inhibitors in mortars with hydraulic binders is still unknown. Incorporation of crystallization inhibitors in hydraulic mortars would widen the application field of this new technology. In this research, the possibility to develop hydraulic mortars with mixed-in sodium ferrocyanide, an inhibitor of sodium chloride crystallization, is explored. As an essential first step, the influence of this inhibitor addition on the properties of hydraulic mortars is investigated. Two common types of hydraulic binders, natural hydraulic lime (NHL) and ordinary Portland cement (CEM I), were studied; the inhibitor was added in different amounts (0%, 0.1% and 1% by binder weight) during mortar (and binder paste) preparation. Relevant mortar and binder paste properties, in fresh (hydration, workability, setting time) and hardened (mechanical strength, elastic modulus, pore size distribution, water absorption) state, were assessed using several complementary methods and techniques. The results indicate that the addition of ferrocyanide does not alter the studied properties of both NHL and CEMI-based mortar and binder pastes. These results are promising for the further development of hydraulic mortars with an improved durability with respect to salt decay.
{"title":"Effect of a mixed-in crystallization inhibitor on the properties of hydraulic mortars","authors":"A. Kamat, B. Lubelli, E. Schlangen","doi":"10.3934/matersci.2022038","DOIUrl":"https://doi.org/10.3934/matersci.2022038","url":null,"abstract":"Porous building materials are often subjected to damage due to salt crystallization. In recent years, the addition of crystallization inhibitors in lime-based mortar, has shown promising results in improving durability of this material against salt decay. Lime-based mortars have low mechanical properties and slow setting. They are often replaced with hydraulic binders to overcome these limitations. However, the effect of crystallization inhibitors in mortars with hydraulic binders is still unknown. Incorporation of crystallization inhibitors in hydraulic mortars would widen the application field of this new technology. In this research, the possibility to develop hydraulic mortars with mixed-in sodium ferrocyanide, an inhibitor of sodium chloride crystallization, is explored. As an essential first step, the influence of this inhibitor addition on the properties of hydraulic mortars is investigated. Two common types of hydraulic binders, natural hydraulic lime (NHL) and ordinary Portland cement (CEM I), were studied; the inhibitor was added in different amounts (0%, 0.1% and 1% by binder weight) during mortar (and binder paste) preparation. Relevant mortar and binder paste properties, in fresh (hydration, workability, setting time) and hardened (mechanical strength, elastic modulus, pore size distribution, water absorption) state, were assessed using several complementary methods and techniques. The results indicate that the addition of ferrocyanide does not alter the studied properties of both NHL and CEMI-based mortar and binder pastes. These results are promising for the further development of hydraulic mortars with an improved durability with respect to salt decay.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70089111","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 : 2022-01-01DOI: 10.3934/matersci.2022017
Katrin Gossen, Marius Dotter, Bennet Brockhagen, J. L. Storck, A. Ehrmann
Long-term stability belongs to the main problems of dye-sensitized solar cells (DSSCs), impeding their practical application. Especially the usually fluid electrolyte tends to evaporation, thus drying the cells if they are not perfectly sealed. While gelling the electrolyte with different polymers often reduces the efficiency, using a glycerol-based electrolyte was already shown to result in similar or even improved efficiency. At the same time, drying of the cells was significantly reduced. Here we report on improving glycerol-based electrolytes further by varying the iodine-triiodide ratio and the overall concentration in the electrolyte. Long-term tests with unsealed glass-based DSSCs were performed over more than 1 year, showing that most of the cells increased efficiency during this time, opposite to cells with a commercial solvent-based iodine-triiodide electrolyte which completely dried after 2–3 months.
{"title":"Long-term investigation of unsealed DSSCs with glycerol-based electrolytes of different compositions","authors":"Katrin Gossen, Marius Dotter, Bennet Brockhagen, J. L. Storck, A. Ehrmann","doi":"10.3934/matersci.2022017","DOIUrl":"https://doi.org/10.3934/matersci.2022017","url":null,"abstract":"Long-term stability belongs to the main problems of dye-sensitized solar cells (DSSCs), impeding their practical application. Especially the usually fluid electrolyte tends to evaporation, thus drying the cells if they are not perfectly sealed. While gelling the electrolyte with different polymers often reduces the efficiency, using a glycerol-based electrolyte was already shown to result in similar or even improved efficiency. At the same time, drying of the cells was significantly reduced. Here we report on improving glycerol-based electrolytes further by varying the iodine-triiodide ratio and the overall concentration in the electrolyte. Long-term tests with unsealed glass-based DSSCs were performed over more than 1 year, showing that most of the cells increased efficiency during this time, opposite to cells with a commercial solvent-based iodine-triiodide electrolyte which completely dried after 2–3 months.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088012","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 : 2022-01-01DOI: 10.3934/matersci.2022020
M. Hawryluk, J. Marzec, Tatiana Karczewska, Łukasz Dudkiewicz
The article discusses the selected mechanical and plastic properties of modelling materials based on plasticine and filia wax utilized in the physical modelling. Application of the physical modelling with the utilize of soft model materials as well as plasticine and waxes with different inoculants, is a frequently used method applied as an alternative or verification of FE modelling of volumetric plastic working processes. First, in the ring test, the friction coefficients for the base model materials for various lubricants were determined. Then, in the compression test, the flow curves for model materials modified with various modifying substances (kaolin, lanolin, paraffin, chalk, etc.) were determined. The last step of the research studies was to verify the correctness of determining the flow curves using the inverse method. Based on the research carried out, a database was developed for soft model materials, covering the entire spectrum of flow curves and selected mechanical (friction coefficient, true and critical stress) and plastic properties (plastic deformation), which allows the selection of an appropriate mixture of model material to the real metallic material. Based on the obtained results, it can be concluded that both in the case of plasticine and filia wax, both of these materials together with modifiers very well simulate the behavior of warm and hot deformed metallic materials (with softening), much worse for materials with a clear hardening, characterizing cold work. In the case of filia wax, more stable properties were observed compared to plasticine-based materials.
{"title":"Determination of the characteristics and mechanical properties for soft materials based on plasticine and filia wax with inoculants","authors":"M. Hawryluk, J. Marzec, Tatiana Karczewska, Łukasz Dudkiewicz","doi":"10.3934/matersci.2022020","DOIUrl":"https://doi.org/10.3934/matersci.2022020","url":null,"abstract":"The article discusses the selected mechanical and plastic properties of modelling materials based on plasticine and filia wax utilized in the physical modelling. Application of the physical modelling with the utilize of soft model materials as well as plasticine and waxes with different inoculants, is a frequently used method applied as an alternative or verification of FE modelling of volumetric plastic working processes. First, in the ring test, the friction coefficients for the base model materials for various lubricants were determined. Then, in the compression test, the flow curves for model materials modified with various modifying substances (kaolin, lanolin, paraffin, chalk, etc.) were determined. The last step of the research studies was to verify the correctness of determining the flow curves using the inverse method. Based on the research carried out, a database was developed for soft model materials, covering the entire spectrum of flow curves and selected mechanical (friction coefficient, true and critical stress) and plastic properties (plastic deformation), which allows the selection of an appropriate mixture of model material to the real metallic material. Based on the obtained results, it can be concluded that both in the case of plasticine and filia wax, both of these materials together with modifiers very well simulate the behavior of warm and hot deformed metallic materials (with softening), much worse for materials with a clear hardening, characterizing cold work. In the case of filia wax, more stable properties were observed compared to plasticine-based materials.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088152","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 : 2022-01-01DOI: 10.3934/matersci.2022013
C. Srikanth, G. Madhu, Shrey Kashyap
Epoxy composites were prepared by doping nano Zirconia Toughened Alumina (ZTA) which were synthesized by solution combustion method into epoxy resin and hardener. Initially ZTA nanopowder was characterized to check its purity, morphology and to confirm its metal-oxide bonding using XRD, SEM and FTIR respectively. The thermal properties such as TGA and DTG were also analysed. The polymer composites were obtained by uniformly dispersing ZTA nanopowder into epoxy using an ultrasonicator. Polymer composites of various concentrations viz, 0.5, 1, 1.5, 2 and 2.5 wt% were synthesized, all concentrations were prepared on weight basis. All the polymer composites were tested for compression properties, flexural properties and tensile properties. Best results for all the mechanical properties were obtained for epoxy with 1.5 wt% ZTA composites. Electrical properties such as breakdown voltage and breakdown strength were analysed and outstanding results were observed for epoxy with 2.5 wt% ZTA composite.
{"title":"Enhanced structural, thermal, mechanical and electrical properties of nano ZTA/epoxy composites","authors":"C. Srikanth, G. Madhu, Shrey Kashyap","doi":"10.3934/matersci.2022013","DOIUrl":"https://doi.org/10.3934/matersci.2022013","url":null,"abstract":"Epoxy composites were prepared by doping nano Zirconia Toughened Alumina (ZTA) which were synthesized by solution combustion method into epoxy resin and hardener. Initially ZTA nanopowder was characterized to check its purity, morphology and to confirm its metal-oxide bonding using XRD, SEM and FTIR respectively. The thermal properties such as TGA and DTG were also analysed. The polymer composites were obtained by uniformly dispersing ZTA nanopowder into epoxy using an ultrasonicator. Polymer composites of various concentrations viz, 0.5, 1, 1.5, 2 and 2.5 wt% were synthesized, all concentrations were prepared on weight basis. All the polymer composites were tested for compression properties, flexural properties and tensile properties. Best results for all the mechanical properties were obtained for epoxy with 1.5 wt% ZTA composites. Electrical properties such as breakdown voltage and breakdown strength were analysed and outstanding results were observed for epoxy with 2.5 wt% ZTA composite.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088311","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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