Pub Date : 2022-01-01DOI: 10.3934/matersci.2022018
I. Al-Omari, Muna Al-Mamari, D. Sellmyer
Different compounds of rare-earth orthochromites Gd1–xYxCrO3 (where x is 0.0–0.9) powder nanoparticles, were synthesized by the auto-combustion method followed by annealing at 700 ℃. All the compounds showed single-phase and crystallized into a distorted orthorhombic structure with the space group (Pbnm). The average particle size for all the samples were in the range 53–110 nm. The detailed and systematic magnetic measurements and analysis showed that all the samples up to x = 0.9 have large magnetization and large values of the change in the magnetic entropy. The magnitude of the change in the magnetic entropy (at 4.5 K and for all the values of the change in the applied magnetic field between 1 and 9 T) is found to increase with increasing x reaching a maximum value at x = 0.3 then it decreases as we increase the yttrium concentration. The nanoparticle compounds with low yttrium concentrations showed a giant change in the magnetic entropy and a giant relative cooling power. Based on the slopes of Arrott plots curves the order parameter of the magnetic transition has been estimated and found to be second order. The giant change in the magnetic entropy and the relative cooling power were tuned in the rages (-45.6 to -8.7 J/kg·K at a change in the applied magnetic field of 9 T; and 136–746 J/kg), around the helium liquefaction temperature. The magnitude of the change in the magnetic entropy is significantly larger for large range of temperatures, up to the nitrogen liquefaction temperature. The giant change in the magnetic entropy and the giant relative cooling power at low temperatures (in the range about 4 to 20 K.) make these samples candidate materials for the low temperature magnetic refrigerant applications, based on the magnetocaloric effect.
{"title":"Tuning the giant Magnetocaloric Effect and refrigerant capacity in Gd1–xYxCrO3 (0.0 ≤ x ≤ 0.9) perovskites nanoparticles","authors":"I. Al-Omari, Muna Al-Mamari, D. Sellmyer","doi":"10.3934/matersci.2022018","DOIUrl":"https://doi.org/10.3934/matersci.2022018","url":null,"abstract":"Different compounds of rare-earth orthochromites Gd1–xYxCrO3 (where x is 0.0–0.9) powder nanoparticles, were synthesized by the auto-combustion method followed by annealing at 700 ℃. All the compounds showed single-phase and crystallized into a distorted orthorhombic structure with the space group (Pbnm). The average particle size for all the samples were in the range 53–110 nm. The detailed and systematic magnetic measurements and analysis showed that all the samples up to x = 0.9 have large magnetization and large values of the change in the magnetic entropy. The magnitude of the change in the magnetic entropy (at 4.5 K and for all the values of the change in the applied magnetic field between 1 and 9 T) is found to increase with increasing x reaching a maximum value at x = 0.3 then it decreases as we increase the yttrium concentration. The nanoparticle compounds with low yttrium concentrations showed a giant change in the magnetic entropy and a giant relative cooling power. Based on the slopes of Arrott plots curves the order parameter of the magnetic transition has been estimated and found to be second order. The giant change in the magnetic entropy and the relative cooling power were tuned in the rages (-45.6 to -8.7 J/kg·K at a change in the applied magnetic field of 9 T; and 136–746 J/kg), around the helium liquefaction temperature. The magnitude of the change in the magnetic entropy is significantly larger for large range of temperatures, up to the nitrogen liquefaction temperature. The giant change in the magnetic entropy and the giant relative cooling power at low temperatures (in the range about 4 to 20 K.) make these samples candidate materials for the low temperature magnetic refrigerant applications, based on the magnetocaloric effect.","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":"70088065","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.2022021
Miguel-Angel Rojas-Yañez, C. Rodríguez-González, S. Martel-Estrada, L. Valencia-Gómez, C. Vargas-Requena, J. Hernández-Paz, M. Chavarría-Gaytán, I. Olivas-Armendáriz
Nowadays, the treatment for bone damage remains a significant challenge. As a result, the development of bioactive three-dimensional scaffolds for bone regeneration has become a key area of study within tissue engineering. This research is focused on the evaluation of the properties of Chitosan (Ch)/Polycaprolactone (PCL) scaffolds with the Mytilus californiensis protein by Thermally Induced Phase Separation (TIPS). This study used the extrapalleal fluid protein from Mytilus californiensis because it increases biological processes that support bone regeneration. Two methodologies were used for the scaffolds functionalization: (I) an immersion process in a solution with the protein and (II) the protein direct addition during the scaffold synthesis. The scaffolds were analyzed by Fourier Transformed Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), and Mechanical Compression test to determine the composition, morphology, and mechanical properties of each material. In vitro analysis of biodegradation, bioactivity, and biocompatibility were also performed. The scaffolds with the protein added directly presented superior properties in the tests of bioactivity and cellular proliferation, making these composites attractive for the area of bone regeneration.
{"title":"Composite scaffolds of chitosan/polycaprolactone functionalized with protein of Mytilus californiensis for bone tissue regeneration","authors":"Miguel-Angel Rojas-Yañez, C. Rodríguez-González, S. Martel-Estrada, L. Valencia-Gómez, C. Vargas-Requena, J. Hernández-Paz, M. Chavarría-Gaytán, I. Olivas-Armendáriz","doi":"10.3934/matersci.2022021","DOIUrl":"https://doi.org/10.3934/matersci.2022021","url":null,"abstract":"Nowadays, the treatment for bone damage remains a significant challenge. As a result, the development of bioactive three-dimensional scaffolds for bone regeneration has become a key area of study within tissue engineering. This research is focused on the evaluation of the properties of Chitosan (Ch)/Polycaprolactone (PCL) scaffolds with the Mytilus californiensis protein by Thermally Induced Phase Separation (TIPS). This study used the extrapalleal fluid protein from Mytilus californiensis because it increases biological processes that support bone regeneration. Two methodologies were used for the scaffolds functionalization: (I) an immersion process in a solution with the protein and (II) the protein direct addition during the scaffold synthesis. The scaffolds were analyzed by Fourier Transformed Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), and Mechanical Compression test to determine the composition, morphology, and mechanical properties of each material. In vitro analysis of biodegradation, bioactivity, and biocompatibility were also performed. The scaffolds with the protein added directly presented superior properties in the tests of bioactivity and cellular proliferation, making these composites attractive for the area of bone regeneration.","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":"70088169","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.2022030
Pawan Kumar, B. Verma
Aluminium is considered a green metal due to its environmental responsive characteristics. The 7475-T7351 aluminum alloy is extensively used in automotive and aerospace applications due to its light weight and high strength. In the present work, the effects of the corrosive environment on the high cycle fatigue (HCF) behaviors of the 7475-T7351 aluminum alloy was investigated. The aqueous solution of sodium chloride was used for solution treatment. The HCF test was performed on pre-cracked specimens using a servo-hydraulic universal testing machine, Instron 8800. The fractured specimens were characterized using a scanning electron microscope. It was observed that the crack propagation occurred through anodic dissolution at high stress and a significant crack tip blunting and crack extension occurred. However, no appreciable change in crack growth was noticed over the lower frequency range of 0.1 to 0.9 Hz. The slower growth rate envisages oxide debris formation between the cracked faces. When the alloy was treated under corrosive environments, the HCF tests depicted that the fatigue life reduces up to two orders of magnitude. The corrosion pits induced the crack initiation in stage-I at lower alternating stress; however, the fatigue crack growth rate (FCGR) was increased in the corrosive environment. The transition from stage-I to stage-II occurred at a lower stress intensity range (∆K) level; it was due to the combined effects of corrosion, hydrogen embrittlement, active path dissolution, and stress concentration. The corrosion fatigue test at low frequency also depicted a slower FCGR as compared to its moderate frequency counterpart and showed an irregular crack growth behavior.
{"title":"Propagation of corrosion induced fatigue crack in aluminum alloy","authors":"Pawan Kumar, B. Verma","doi":"10.3934/matersci.2022030","DOIUrl":"https://doi.org/10.3934/matersci.2022030","url":null,"abstract":"Aluminium is considered a green metal due to its environmental responsive characteristics. The 7475-T7351 aluminum alloy is extensively used in automotive and aerospace applications due to its light weight and high strength. In the present work, the effects of the corrosive environment on the high cycle fatigue (HCF) behaviors of the 7475-T7351 aluminum alloy was investigated. The aqueous solution of sodium chloride was used for solution treatment. The HCF test was performed on pre-cracked specimens using a servo-hydraulic universal testing machine, Instron 8800. The fractured specimens were characterized using a scanning electron microscope. It was observed that the crack propagation occurred through anodic dissolution at high stress and a significant crack tip blunting and crack extension occurred. However, no appreciable change in crack growth was noticed over the lower frequency range of 0.1 to 0.9 Hz. The slower growth rate envisages oxide debris formation between the cracked faces. When the alloy was treated under corrosive environments, the HCF tests depicted that the fatigue life reduces up to two orders of magnitude. The corrosion pits induced the crack initiation in stage-I at lower alternating stress; however, the fatigue crack growth rate (FCGR) was increased in the corrosive environment. The transition from stage-I to stage-II occurred at a lower stress intensity range (∆K) level; it was due to the combined effects of corrosion, hydrogen embrittlement, active path dissolution, and stress concentration. The corrosion fatigue test at low frequency also depicted a slower FCGR as compared to its moderate frequency counterpart and showed an irregular crack growth behavior.","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":"70088849","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.2022040
Y. P. Reddy, K. L. Narayana, M. K. Mallik, C. Paul, C. Singh
The gradual and uniform variation in the composition of the material, generally two, is called functionally graded materials (FGM). These FGM are used in practical applications to advantage both material properties. Several methods are used to fabricate the FGM components. The current article is research on the direct energy dispersive technique of 3D Printing employed for depositing the SS316L and Co-Cr-Mo alloy FGM samples. L9 orthogonal array of Taguchi method is used. Process parameters like laser power, powder feed rate and scan speed have been used for deposition. Their structural properties are analysed using scanning electron microscopy, X-ray diffraction, element dispersive technique, and Fourier transform impedance spectroscopy. The results reveal that defect-free samples were deposited, and all the samples have Body Centered Cubic structure except one. Good elemental bonding was observed between SS316L and Co-Cr-Mo alloy.
{"title":"Experimental evaluation of additively deposited functionally graded material samples-microscopic and spectroscopic analysis of SS-316L/Co-Cr-Mo alloy","authors":"Y. P. Reddy, K. L. Narayana, M. K. Mallik, C. Paul, C. Singh","doi":"10.3934/matersci.2022040","DOIUrl":"https://doi.org/10.3934/matersci.2022040","url":null,"abstract":"The gradual and uniform variation in the composition of the material, generally two, is called functionally graded materials (FGM). These FGM are used in practical applications to advantage both material properties. Several methods are used to fabricate the FGM components. The current article is research on the direct energy dispersive technique of 3D Printing employed for depositing the SS316L and Co-Cr-Mo alloy FGM samples. L9 orthogonal array of Taguchi method is used. Process parameters like laser power, powder feed rate and scan speed have been used for deposition. Their structural properties are analysed using scanning electron microscopy, X-ray diffraction, element dispersive technique, and Fourier transform impedance spectroscopy. The results reveal that defect-free samples were deposited, and all the samples have Body Centered Cubic structure except one. Good elemental bonding was observed between SS316L and Co-Cr-Mo alloy.","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":"70089239","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.2022052
M. Ozdemir, S. Oterkus, E. Oterkus, I. Amin, A. El-Aassar, H. Shawky
In this work, we address the mechanical response of the flat sheet polymeric water treatment membranes under the assumed operational loading conditions. Firstly, we perform quasi-static analyses of the membranes under normal pressure loads, which is the condition that resembles the actual loading for flat sheet membranes in the submerged membrane bioreactors. Then, the long-term deformation of the membranes is studied under the assumed filtration durations for the same loading conditions by utilizing the viscoelastic material models. The quasi-static and viscoelastic membrane simulations are performed by a commercial finite element code ANSYS. Finally, the mechanical fatigue life predictions are carried out based on the stress distributions from the quasi-static analyses and the long-term effects from the viscoelastic analyses.
{"title":"Mechanical analyses of flat sheet water treatment membranes","authors":"M. Ozdemir, S. Oterkus, E. Oterkus, I. Amin, A. El-Aassar, H. Shawky","doi":"10.3934/matersci.2022052","DOIUrl":"https://doi.org/10.3934/matersci.2022052","url":null,"abstract":"In this work, we address the mechanical response of the flat sheet polymeric water treatment membranes under the assumed operational loading conditions. Firstly, we perform quasi-static analyses of the membranes under normal pressure loads, which is the condition that resembles the actual loading for flat sheet membranes in the submerged membrane bioreactors. Then, the long-term deformation of the membranes is studied under the assumed filtration durations for the same loading conditions by utilizing the viscoelastic material models. The quasi-static and viscoelastic membrane simulations are performed by a commercial finite element code ANSYS. Finally, the mechanical fatigue life predictions are carried out based on the stress distributions from the quasi-static analyses and the long-term effects from the viscoelastic analyses.","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":"70089247","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.2022048
John (Ioannis) D. Kechagias
This Special Issue of AIMS Materials Science was devoted to the topic "Materials for Additive Manufacturing". It attracted significant attention from scholars and practitioners from ten different countries (Spain, Greece, France, Portugal, Italy, Finland, Ethiopia, Canada, Vietnam, and Iraq) and published five manuscripts of a total of ten submissions between April 2021 and March 2022. In addition, new materials, methodologies, and analysis approaches are presented in materials for additive manufacturing.
{"title":"Materials for Additive Manufacturing","authors":"John (Ioannis) D. Kechagias","doi":"10.3934/matersci.2022048","DOIUrl":"https://doi.org/10.3934/matersci.2022048","url":null,"abstract":"This Special Issue of AIMS Materials Science was devoted to the topic \"Materials for Additive Manufacturing\". It attracted significant attention from scholars and practitioners from ten different countries (Spain, Greece, France, Portugal, Italy, Finland, Ethiopia, Canada, Vietnam, and Iraq) and published five manuscripts of a total of ten submissions between April 2021 and March 2022. In addition, new materials, methodologies, and analysis approaches are presented in materials for additive manufacturing.","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":"70089117","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.2023001
Helbert Guillaume, Dieng Lamine, Chirani Shabnam Arbab, Pilvin Philippe
Thanks to high dissipation properties, embedding NiTi Shape Memory Alloys in passive damping devices is effective to mitigate vibrations in building and cable structures. These devices can inconceivably be tested directly on full-scale experimental structures or on structures in service. To predict their effectiveness and optimize the set-up parameters, numerical tools are more and more developed. Most of them consist of Finite Element models representing the structure equipped with the damping device, embedding parts associated with a superelastic behavior. Generally, the implemented behavior laws do not include all the phenomena at the origin of strain energy dissipation, but stress-induced martensitic transformation only. This article presents a thermomechanical behavior law including the following phenomena: (i) intermediate R-phase transformation, (ii) thermal effects and (iii) strain localization. This law was implemented in a commercial Finite Element code to study the dynamic response of a bridge cable equipped with a NiTi wire-based damping device. The numerical results were compared to full-scale experimental ones, by considering the above-mentioned phenomena taken coupled or isolated: it has been shown that it is necessary to take all of these phenomena into account in order to successfully predict the damping capacity of the device.
{"title":"Influence of the thermomechanical behavior of NiTi wires embedded in a damper on its damping capacity: Application to a bridge cable","authors":"Helbert Guillaume, Dieng Lamine, Chirani Shabnam Arbab, Pilvin Philippe","doi":"10.3934/matersci.2023001","DOIUrl":"https://doi.org/10.3934/matersci.2023001","url":null,"abstract":"Thanks to high dissipation properties, embedding NiTi Shape Memory Alloys in passive damping devices is effective to mitigate vibrations in building and cable structures. These devices can inconceivably be tested directly on full-scale experimental structures or on structures in service. To predict their effectiveness and optimize the set-up parameters, numerical tools are more and more developed. Most of them consist of Finite Element models representing the structure equipped with the damping device, embedding parts associated with a superelastic behavior. Generally, the implemented behavior laws do not include all the phenomena at the origin of strain energy dissipation, but stress-induced martensitic transformation only. This article presents a thermomechanical behavior law including the following phenomena: (i) intermediate R-phase transformation, (ii) thermal effects and (iii) strain localization. This law was implemented in a commercial Finite Element code to study the dynamic response of a bridge cable equipped with a NiTi wire-based damping device. The numerical results were compared to full-scale experimental ones, by considering the above-mentioned phenomena taken coupled or isolated: it has been shown that it is necessary to take all of these phenomena into account in order to successfully predict the damping capacity of the device.","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":"70089390","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.2022044
A. Santoso, Novita Agustin, S. Sumari, Siti Marfuah, R. Retnosari, I. B. Rachman, A. Wijaya, Muhammad Roy Asrori
Biodiesel products show corrosive properties. Biodiesel contains components of saturated and unsaturated esters which tend to be unstable, sensitive to light, temperature, and metal ions. Thus, the study aims to synthesize biodiesel from various vegetable oils (palm oil, sunflower seed oil, and candlenut oil), and to analyze its corrosiveness to ferrous nails and characterization of biodiesel. The research stages were: synthesis of methyl ester and its characterization, and corrosion test. The results showed that the methyl ester characteristics of the samples meet requirements with SNI7182 : 2015. In GC-MS results, the largest components of methyl esters from candlenut oil and sunflower seed oil were 35.04% methyl oleate and 46.79% methyl oleate respectively, while in palm oil, the largest components were 41.60% methyl oleate and 41.16%. methyl palmitate. Corrosion test showed that the corrosion rate of ferrous nail in biodiesel at room temperature was lower than 70 ℃. Based on GC-MS and SEM results, biodiesel contained high unsaturated fatty acids and had a corrosion rate, i.e., at room temperature, the methyl ester of palm oil, candlenut oil, and sunflower seed oil were 0.006 mpy, 0.011 mpy, and 0.011 mpy respectively, while at 70 ℃, they were 0.011 mpy, 0.016 mpy, and 0.017 mpy, respectively. The results corresponded to SEM results at high temperature and significantly high content of unsaturated fatty acids. It was indicated by the formation of pits.
{"title":"Synthesis of methyl esters from palm oil, candlenut oil, and sunflower seed oil and their corrosion phenomena on iron nail","authors":"A. Santoso, Novita Agustin, S. Sumari, Siti Marfuah, R. Retnosari, I. B. Rachman, A. Wijaya, Muhammad Roy Asrori","doi":"10.3934/matersci.2022044","DOIUrl":"https://doi.org/10.3934/matersci.2022044","url":null,"abstract":"Biodiesel products show corrosive properties. Biodiesel contains components of saturated and unsaturated esters which tend to be unstable, sensitive to light, temperature, and metal ions. Thus, the study aims to synthesize biodiesel from various vegetable oils (palm oil, sunflower seed oil, and candlenut oil), and to analyze its corrosiveness to ferrous nails and characterization of biodiesel. The research stages were: synthesis of methyl ester and its characterization, and corrosion test. The results showed that the methyl ester characteristics of the samples meet requirements with SNI7182 : 2015. In GC-MS results, the largest components of methyl esters from candlenut oil and sunflower seed oil were 35.04% methyl oleate and 46.79% methyl oleate respectively, while in palm oil, the largest components were 41.60% methyl oleate and 41.16%. methyl palmitate. Corrosion test showed that the corrosion rate of ferrous nail in biodiesel at room temperature was lower than 70 ℃. Based on GC-MS and SEM results, biodiesel contained high unsaturated fatty acids and had a corrosion rate, i.e., at room temperature, the methyl ester of palm oil, candlenut oil, and sunflower seed oil were 0.006 mpy, 0.011 mpy, and 0.011 mpy respectively, while at 70 ℃, they were 0.011 mpy, 0.016 mpy, and 0.017 mpy, respectively. The results corresponded to SEM results at high temperature and significantly high content of unsaturated fatty acids. It was indicated by the formation of pits.","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":"70089462","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.2022045
N.F.B.W. Anuar, M. S. Salleh, M. Z. Omar, Saifudin Hafiz Yahaya
This study investigated the microstructure, hardness, tensile and tribological behaviour of a cooling slope Al–Si–Mg alloy following ECAP and T6 heat treatment. The optical and scanning electron microscopes were applied to investigate the microstructure of the as-cast material and heat-treated ECAPed Al–Si–Mg alloy. The dry sliding wear test was tested with three different loads of 10 N, 50 N, and 100 N with constant sliding speed and sliding distance at 1.0 m/s and 9000 m, respectively, using the pin-on-disc tribometer. The hardness and tensile properties were evaluated through microhardness, UTS, and YS measurement for the as-cast Al–Si–Mg alloy, both heat-treated with and without ECAPed alloys. Moreover, wear rate and COF in the Al–Si–Mg alloy with different loads were analysed and linked with microstructural and strength behaviour after the ECAP process. Meanwhile, these analyses of results were correlated with the behaviour of the as-cast Al–Si–Mg aluminium alloy and heat-treated non-ECAPed alloy. Results demonstrated that a combination of ECAP processing and T6 heat treatment improves the mechanical behaviour, while the COF and wear rate are improved at a load of 100 N.
{"title":"Mechanical properties and dry sliding wear behaviour of Al–Si–Mg alloy by equal channel angular pressing","authors":"N.F.B.W. Anuar, M. S. Salleh, M. Z. Omar, Saifudin Hafiz Yahaya","doi":"10.3934/matersci.2022045","DOIUrl":"https://doi.org/10.3934/matersci.2022045","url":null,"abstract":"This study investigated the microstructure, hardness, tensile and tribological behaviour of a cooling slope Al–Si–Mg alloy following ECAP and T6 heat treatment. The optical and scanning electron microscopes were applied to investigate the microstructure of the as-cast material and heat-treated ECAPed Al–Si–Mg alloy. The dry sliding wear test was tested with three different loads of 10 N, 50 N, and 100 N with constant sliding speed and sliding distance at 1.0 m/s and 9000 m, respectively, using the pin-on-disc tribometer. The hardness and tensile properties were evaluated through microhardness, UTS, and YS measurement for the as-cast Al–Si–Mg alloy, both heat-treated with and without ECAPed alloys. Moreover, wear rate and COF in the Al–Si–Mg alloy with different loads were analysed and linked with microstructural and strength behaviour after the ECAP process. Meanwhile, these analyses of results were correlated with the behaviour of the as-cast Al–Si–Mg aluminium alloy and heat-treated non-ECAPed alloy. Results demonstrated that a combination of ECAP processing and T6 heat treatment improves the mechanical behaviour, while the COF and wear rate are improved at a load of 100 N.","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":"70089468","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.2023003
R. Cahyanti, S. Sumari, F. Fajaroh, Muhammad Roy Asrori, Yana Fajar Prakasa
Industrial wastewater contains non-biodegradable dyes that are highly toxic to humans and aquatic life. As solution from photocatalytic degradation, TiO2 is one of the effective photocatalysts for wastewater degradation, but it has low adsorption power. To overcome this deficiency, this study synthesized a new photocatalyst by Fe-TiO2/zeolite H-A. The photocatalyst was successfully synthesized by the impregnation method and was systematically characterized by XRD, XRF, SEM, FT-IR and UV-Vis DRS. XRD diffractogram at 2θ = 25.3° showed anatase phase of the photocatalyst. SEM results showed a rough and soft surface with a size of 491.49 nm. FT-IR analysis obtained the zeolite-A characteristic band, vibration of Ti-O-Ti groups and the vibration of the Fe-O group. The bandwidth of the band gap was 3.16 eV. The photocatalytic efficiency of methylene blue degradation reached 89.58% yield with optimum conditions: irradiation time of 50 min, pH 9 and concentration of methylene blue about 20 mg/L. Fe-TiO2/zeolite H-A as a new photocatalyst can be an alternative photocatalyst to purify methylene blue.
{"title":"Fe-TiO2/zeolite H-A photocatalyst for degradation of waste dye (methylene blue) under UV irradiation","authors":"R. Cahyanti, S. Sumari, F. Fajaroh, Muhammad Roy Asrori, Yana Fajar Prakasa","doi":"10.3934/matersci.2023003","DOIUrl":"https://doi.org/10.3934/matersci.2023003","url":null,"abstract":"Industrial wastewater contains non-biodegradable dyes that are highly toxic to humans and aquatic life. As solution from photocatalytic degradation, TiO2 is one of the effective photocatalysts for wastewater degradation, but it has low adsorption power. To overcome this deficiency, this study synthesized a new photocatalyst by Fe-TiO2/zeolite H-A. The photocatalyst was successfully synthesized by the impregnation method and was systematically characterized by XRD, XRF, SEM, FT-IR and UV-Vis DRS. XRD diffractogram at 2θ = 25.3° showed anatase phase of the photocatalyst. SEM results showed a rough and soft surface with a size of 491.49 nm. FT-IR analysis obtained the zeolite-A characteristic band, vibration of Ti-O-Ti groups and the vibration of the Fe-O group. The bandwidth of the band gap was 3.16 eV. The photocatalytic efficiency of methylene blue degradation reached 89.58% yield with optimum conditions: irradiation time of 50 min, pH 9 and concentration of methylene blue about 20 mg/L. Fe-TiO2/zeolite H-A as a new photocatalyst can be an alternative photocatalyst to purify methylene blue.","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":"70089488","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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