L. Hahn, Paul Penzel, Danny Friese, Marina Stümpel, Harald Michler, B. Beckmann, M. Curbach, C. Cherif
Textile reinforcements have outstanding load-bearing capabilities due to the excellent tensile properties of high performance multifilament yarns (e.g. carbon fibers). However, in order to take full advantage of their high potential, it is necessary to ensure that the filaments run in a straight line. In order to guarantee this straight filament course, the highly efficient multiaxial warp knitting process is used for the production of 2D non-crimp fabrics (NCF) as textile preforms. In various industrial applications, most structures have complex 3D geometries. Therefore, the 2D textile needs to be shaped for reinforcement, which often results in a rearrangement of the filament orientation. Consequently, the 3D shaping process has to be taken into account during the textile production or in the shaping process itself in order to guarantee the highest mechanical properties. Using the example of lattice girders for concrete reinforcement, a new approach for the fabrication of 3D textile lattice girders in a continous shaping process is presented. The results of the production tests of the developed technology approach show no apparent filament damage and exact roving orientation with no inadvertent deflection, compression or bulging, indicating a precise and gentle shaping process. The developed technology contributes to the future reduction of the production costs of 3D textile reinforcements.
{"title":"New Approaches to 3D Non-Crimp Fabric Manufacturing","authors":"L. Hahn, Paul Penzel, Danny Friese, Marina Stümpel, Harald Michler, B. Beckmann, M. Curbach, C. Cherif","doi":"10.4028/p-0jh5hc","DOIUrl":"https://doi.org/10.4028/p-0jh5hc","url":null,"abstract":"Textile reinforcements have outstanding load-bearing capabilities due to the excellent tensile properties of high performance multifilament yarns (e.g. carbon fibers). However, in order to take full advantage of their high potential, it is necessary to ensure that the filaments run in a straight line. In order to guarantee this straight filament course, the highly efficient multiaxial warp knitting process is used for the production of 2D non-crimp fabrics (NCF) as textile preforms. In various industrial applications, most structures have complex 3D geometries. Therefore, the 2D textile needs to be shaped for reinforcement, which often results in a rearrangement of the filament orientation. Consequently, the 3D shaping process has to be taken into account during the textile production or in the shaping process itself in order to guarantee the highest mechanical properties. Using the example of lattice girders for concrete reinforcement, a new approach for the fabrication of 3D textile lattice girders in a continous shaping process is presented. The results of the production tests of the developed technology approach show no apparent filament damage and exact roving orientation with no inadvertent deflection, compression or bulging, indicating a precise and gentle shaping process. The developed technology contributes to the future reduction of the production costs of 3D textile reinforcements.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"7 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140229714","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}
This study was performed to investigate comfort properties and antimicrobial activity of cotton and nylon knits treated with microcapsules containing sea buckthorn fruit oil reported as having antimicrobial efficacy depending on concentration of microcapsules and treatment types. Chitosan-arabic gum microcapsules containing sea buckthorn fruit oil were prepared and they were treated on cotton and nylon/PU knit respectively by an experimental design of 2 different treatment types (bath immersion method and screen printing method) Χ 5 different concentration levels of microcapsules (20, 30, 40, 50, and 60% on the weight of fabric). As comfort properties, stiffness, water-vapor permeability, and air permeability were measured objectively. Antimicrobial activity was evaluated by calculating the percentage reduction of the bacterium. As results, stiffness values of the treated knits were slightly higher than those of untreated ones, which was thought not to affect touch in wear. The values of water-vapor permeability and air permeability of both cotton and nylon after the treatment were not significantly decreased. These results means that microcapsules loaded on the knits might not worsen their wear comfort. As for antimicrobial activity, more than 90% of bacterial reduction rates against S. Aureus were shown in cotton jersey by screen printing even after repeated laundry while those was found in nylon/PU tricot by bath immersion. From these results, it was concluded that chitosan-arabic gum microcapsule containing sea buckthorn fruit oil could be utilized for textiles to provide antimicrobial activity.
{"title":"Comfort Properties and Antimicrobial Activity of Cotton and Nylon/PU Knits Treated with Microcapsules Containing Sea Buckthorn Oil","authors":"Badmaanyambuu Sarmandakh, E. Yi","doi":"10.4028/p-nsfrj7","DOIUrl":"https://doi.org/10.4028/p-nsfrj7","url":null,"abstract":"This study was performed to investigate comfort properties and antimicrobial activity of cotton and nylon knits treated with microcapsules containing sea buckthorn fruit oil reported as having antimicrobial efficacy depending on concentration of microcapsules and treatment types. Chitosan-arabic gum microcapsules containing sea buckthorn fruit oil were prepared and they were treated on cotton and nylon/PU knit respectively by an experimental design of 2 different treatment types (bath immersion method and screen printing method) Χ 5 different concentration levels of microcapsules (20, 30, 40, 50, and 60% on the weight of fabric). As comfort properties, stiffness, water-vapor permeability, and air permeability were measured objectively. Antimicrobial activity was evaluated by calculating the percentage reduction of the bacterium. As results, stiffness values of the treated knits were slightly higher than those of untreated ones, which was thought not to affect touch in wear. The values of water-vapor permeability and air permeability of both cotton and nylon after the treatment were not significantly decreased. These results means that microcapsules loaded on the knits might not worsen their wear comfort. As for antimicrobial activity, more than 90% of bacterial reduction rates against S. Aureus were shown in cotton jersey by screen printing even after repeated laundry while those was found in nylon/PU tricot by bath immersion. From these results, it was concluded that chitosan-arabic gum microcapsule containing sea buckthorn fruit oil could be utilized for textiles to provide antimicrobial activity.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"44 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140229139","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}
Mmb Hasan, A. Abdkader, Tobias Georg Lang, T. Gereke, C. Cherif
The development of different hybrid yarn structures from recycled carbon fibre (rCF) (rCF content approx. 50% by weight) and thermoplastic fibres for thermoplastic composites has been reported earlier. However, manufacturing of yarns with high rCF content (>90%) required for thermoset composites is still not realizable due to high shortening (≥ 70%) in fibre length of rCF, which occurs during different processing steps of spinning. The reason lies in low shear strength, smooth fibre surface, small diameter and high brittleness of rCF. In addition to this, lack of crimp in rCF leads to drafting error during drawing and spinning process. Therefore, there is a high demand on rCF yarns for thermoset composites, as around 70% of composites are produced based on thermoset matrix. In this paper, yarns consisting of staple rCF with high rCF content (>90 weight%) are developed on DREF-friction spinning and wrap spinning technologies. For the production of yarns, slivers with different rCF content are produced using carding and drawing machine. The effect of different spinning parameters suction air pressure for DREF friction spun yarns and yarn twist for wrap spun yarns is investigated and their effect on tensile properties of yarn is analysed. The results show that the tensile properties of yarns can be adjusted to a wide range varying the yarn structure and spinning parameters.
{"title":"Tensile Properties of Different Yarn Structures Based on Recycled Carbon Fibre for Sustainable Thermoset Composites","authors":"Mmb Hasan, A. Abdkader, Tobias Georg Lang, T. Gereke, C. Cherif","doi":"10.4028/p-xrj5ka","DOIUrl":"https://doi.org/10.4028/p-xrj5ka","url":null,"abstract":"The development of different hybrid yarn structures from recycled carbon fibre (rCF) (rCF content approx. 50% by weight) and thermoplastic fibres for thermoplastic composites has been reported earlier. However, manufacturing of yarns with high rCF content (>90%) required for thermoset composites is still not realizable due to high shortening (≥ 70%) in fibre length of rCF, which occurs during different processing steps of spinning. The reason lies in low shear strength, smooth fibre surface, small diameter and high brittleness of rCF. In addition to this, lack of crimp in rCF leads to drafting error during drawing and spinning process. Therefore, there is a high demand on rCF yarns for thermoset composites, as around 70% of composites are produced based on thermoset matrix. In this paper, yarns consisting of staple rCF with high rCF content (>90 weight%) are developed on DREF-friction spinning and wrap spinning technologies. For the production of yarns, slivers with different rCF content are produced using carding and drawing machine. The effect of different spinning parameters suction air pressure for DREF friction spun yarns and yarn twist for wrap spun yarns is investigated and their effect on tensile properties of yarn is analysed. The results show that the tensile properties of yarns can be adjusted to a wide range varying the yarn structure and spinning parameters.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"58 17","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140231031","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. M. Kabeb, Azman Hassan, Farah Hanani Zulkifli, Farasuraya Che Zakaria, Atif Ur Rahman
A layered clay/epoxy coating was fabricated to investigate the effects of montmorillonite (MMT) and halloysite nanotube (HNT) loading at 0.5, 1.5, and 2.5 parts per hundred resin (phr) on the corrosion resistance and thermal stability of coated mild steel plates. The corrosion study was carried out by Electrochemical Impedance Spectroscopy (EIS) and Tafel polarization. The |Z|0.1Hz value, Rct, and Rp of the layered/clay epoxy coatings containing 1.5 phr of HNT and MMT exhibited the best anticorrosion performance compared to other clay content levels. The |Z|0.1Hz value for the epoxy coating filled with 1.5 phr of MMT (M1.5) is 2.132 × 109 Ω·cm², while it is slightly higher for H1.5 coatings, i.e., 2.629 × 109 Ω·cm². Water absorption trends were consistent with EIS and Tafel polarization studies. The presence of highly compatible nanocontainers clay reduced the total free volume and promoted cross-linking, enhancing anticorrosion performance. Thermal Gravimetry Analysis (TGA) showed that a 1.5 phr loading of MMT in layered/clay epoxy coating demonstrated better thermal stability than a coating embedded with HNT. This improvement can be attributed to the barrier effect of MMT, which retards the diffusion of oxygen molecules into the coating.
{"title":"Corrosion Resistance and Thermal Stability Enhancement of Green Layered Clay/Epoxy Coating","authors":"S. M. Kabeb, Azman Hassan, Farah Hanani Zulkifli, Farasuraya Che Zakaria, Atif Ur Rahman","doi":"10.4028/p-efeh4q","DOIUrl":"https://doi.org/10.4028/p-efeh4q","url":null,"abstract":"A layered clay/epoxy coating was fabricated to investigate the effects of montmorillonite (MMT) and halloysite nanotube (HNT) loading at 0.5, 1.5, and 2.5 parts per hundred resin (phr) on the corrosion resistance and thermal stability of coated mild steel plates. The corrosion study was carried out by Electrochemical Impedance Spectroscopy (EIS) and Tafel polarization. The |Z|0.1Hz value, Rct, and Rp of the layered/clay epoxy coatings containing 1.5 phr of HNT and MMT exhibited the best anticorrosion performance compared to other clay content levels. The |Z|0.1Hz value for the epoxy coating filled with 1.5 phr of MMT (M1.5) is 2.132 × 109 Ω·cm², while it is slightly higher for H1.5 coatings, i.e., 2.629 × 109 Ω·cm². Water absorption trends were consistent with EIS and Tafel polarization studies. The presence of highly compatible nanocontainers clay reduced the total free volume and promoted cross-linking, enhancing anticorrosion performance. Thermal Gravimetry Analysis (TGA) showed that a 1.5 phr loading of MMT in layered/clay epoxy coating demonstrated better thermal stability than a coating embedded with HNT. This improvement can be attributed to the barrier effect of MMT, which retards the diffusion of oxygen molecules into the coating.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"128 37","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140079036","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}
U. Anamu, E. Olorundaisi, O. Ayodele, B. Babalola, P.I. Odetola, A. Ogunmefun, K. Ukoba, T.-C. Jen, P. Olubambi
In this study, the influence of operating parameters on the relative density and microhardness property of a septenary equiatomic Ti-Al-Cr-Nb-Ni-Cu-Co high entropy alloy developed via spark plasma sintering (SPS) process was investigated at constant heating rate (100 °C/min), dwell time (5 min), pressure (50 MPa). Using response surface methodology (RSM) on the sintering temperature (ST) and milling time (MT) as the process variable parameters, a predictive model was established. The design of experiment approach was employed to minimize numbers of runs of experiment, which invariably eliminates trial by error associated with traditional experimental methods. MT and ST were taken as the variables towards the development of the design model. The optimum operating parameters were predicted using the user-defined design (UDD) under RSM and the result was validated through experiments. Observation from the results shows that MT and ST play a significant role in achieving high densification, which translates to high hardness. At 900 °C ST and MT of 10 hours, the highest hardness value of 580.1 HV, densification of 99.98%, and percentage porosity of 0.02% were recorded.
本研究在恒定的加热速率（100 °C/min）、停留时间（5 分钟）和压力（50 兆帕）条件下，研究了操作参数对通过火花等离子烧结（SPS）工艺开发的隔元等原子钛-铝-铬-铌-镍-铜-钴高熵合金的相对密度和显微硬度特性的影响。采用响应面方法（RSM）对烧结温度（ST）和铣削时间（MT）作为工艺变量参数建立了预测模型。采用了实验设计方法，以尽量减少实验次数，从而避免了传统实验方法中的误差试验。在设计模型的开发过程中，将 MT 和 ST 作为变量。使用 RSM 下的用户自定义设计（UDD）预测了最佳运行参数，并通过实验对结果进行了验证。观察结果表明，MT 和 ST 在实现高致密化方面起着重要作用，而高致密化则意味着高硬度。在 ST 值为 900 °C 和 MT 值为 10 小时的条件下，记录到的最高硬度值为 580.1 HV，致密化率为 99.98%，孔隙率为 0.02%。
{"title":"Process Optimization of Spark Plasma Sintered Parameters for Ti-Al-Cr-Nb-Ni-Cu-Co High Entropy Alloy by Response Surface Methodology","authors":"U. Anamu, E. Olorundaisi, O. Ayodele, B. Babalola, P.I. Odetola, A. Ogunmefun, K. Ukoba, T.-C. Jen, P. Olubambi","doi":"10.4028/p-0bsg8t","DOIUrl":"https://doi.org/10.4028/p-0bsg8t","url":null,"abstract":"In this study, the influence of operating parameters on the relative density and microhardness property of a septenary equiatomic Ti-Al-Cr-Nb-Ni-Cu-Co high entropy alloy developed via spark plasma sintering (SPS) process was investigated at constant heating rate (100 °C/min), dwell time (5 min), pressure (50 MPa). Using response surface methodology (RSM) on the sintering temperature (ST) and milling time (MT) as the process variable parameters, a predictive model was established. The design of experiment approach was employed to minimize numbers of runs of experiment, which invariably eliminates trial by error associated with traditional experimental methods. MT and ST were taken as the variables towards the development of the design model. The optimum operating parameters were predicted using the user-defined design (UDD) under RSM and the result was validated through experiments. Observation from the results shows that MT and ST play a significant role in achieving high densification, which translates to high hardness. At 900 °C ST and MT of 10 hours, the highest hardness value of 580.1 HV, densification of 99.98%, and percentage porosity of 0.02% were recorded.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140263932","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}
Copper alloys have high thermal conductivity, relatively high mechanical strength, and toughness over a wide range of temperature; hence they are highly sorted for complex structural applications that required extreme heat flux under load. Creep of materials is classically associated with time-dependent plasticity under a constant stress/load at an elevated temperature, often greater than the absolute melting temperature. This research is aimed to study the evaluation of stress and creep rate in copper, identifying the mechanisms at which copper can easily be exposed to stress and creep deformations in structures. A 12 mm diameter copper rod with the composition of 52.05 % CuO and 30.26 % SnO2 was procured locally. Samples from the procured rod were heat treated to 650°C for 30 minutes and cooled in the still air as well as inside the furnace. Creep test was carried out at 760uC with a constant load corresponding to an initial stress (between 1.5 MPa and 350 MPa) and stress relation was carried out on a 98 kN capacity stress relaxation frame (from 350 MPa to 300 MPa). Rockwell hardness test and metallographic analysis (at 200 mm) were also conducted on the heat treated and unheated control samples. It was established that heat treatment reduced the hardness property of stress relaxed copper, accelerated the stress relaxation process up to 60 %, speed up both primary creep rate and the tertiary creep rate as well altered the linear creep pattern and behaviour.
{"title":"Investigation into Stress Relaxation and Creep Rate of C47200 Copper Alloy","authors":"S. Akande, Tuoyo Ikomi, T. Azeez, O. Ikumapayi","doi":"10.4028/p-yyjr2w","DOIUrl":"https://doi.org/10.4028/p-yyjr2w","url":null,"abstract":"Copper alloys have high thermal conductivity, relatively high mechanical strength, and toughness over a wide range of temperature; hence they are highly sorted for complex structural applications that required extreme heat flux under load. Creep of materials is classically associated with time-dependent plasticity under a constant stress/load at an elevated temperature, often greater than the absolute melting temperature. This research is aimed to study the evaluation of stress and creep rate in copper, identifying the mechanisms at which copper can easily be exposed to stress and creep deformations in structures. A 12 mm diameter copper rod with the composition of 52.05 % CuO and 30.26 % SnO2 was procured locally. Samples from the procured rod were heat treated to 650°C for 30 minutes and cooled in the still air as well as inside the furnace. Creep test was carried out at 760uC with a constant load corresponding to an initial stress (between 1.5 MPa and 350 MPa) and stress relation was carried out on a 98 kN capacity stress relaxation frame (from 350 MPa to 300 MPa). Rockwell hardness test and metallographic analysis (at 200 mm) were also conducted on the heat treated and unheated control samples. It was established that heat treatment reduced the hardness property of stress relaxed copper, accelerated the stress relaxation process up to 60 %, speed up both primary creep rate and the tertiary creep rate as well altered the linear creep pattern and behaviour.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"51 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140264858","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}
R. Barboza, Harish Daruari, Antonieta Rocha, Miguel A. Carvalho, Paulo Mendonça
Currently, the Azores face a significant problem due to the existence of a large quantity of marine debris derived from fishing activities and gear. This issue represents a threat to the social and environmental aspects of the region. The lack of adequate disposal of this waste produced by the fishing industries is leading to a disruption of the ecosystem. A broad study within the scope of the Azores Ecoblue project in partnership with the Regional Government of the Azores aims to quantify/parameterize and qualify waste from fishing gear. Focused on analyzing the possibility and opportunity of creating a source of revenue for the Region from these raw materials used by the stakeholders identified by a research project called Azores Ecoblue. This survey is being carried out with the aim of identifying adversities related to materials, resulting in the proposal of solutions, involving the recycling and transformation of the polymer, Polyethylene, typically used in mooring cables on fishing vessels. It is essential to raise awareness of the need to reconsider the collection of waste with sustainable potential and relevance in the social and economic context of the region. Polymer identification and characterization was performed in an attempt to address the problem at the source. In addition to identifying the material, this research focuses on characterizing its thermal properties. The development of a construction system composed of reused cables, to be included in a demonstrative prototype, was developed and is presented in this article, emphasizing the importance of implementing sustainable solutions to address the issue of marine litter on the Azorean coast and promote the circular economy.
{"title":"Identification of Waste Potential from Maritime Activity - Incorporating Polyethylene Cables into Building Construction","authors":"R. Barboza, Harish Daruari, Antonieta Rocha, Miguel A. Carvalho, Paulo Mendonça","doi":"10.4028/p-h5jgdw","DOIUrl":"https://doi.org/10.4028/p-h5jgdw","url":null,"abstract":"Currently, the Azores face a significant problem due to the existence of a large quantity of marine debris derived from fishing activities and gear. This issue represents a threat to the social and environmental aspects of the region. The lack of adequate disposal of this waste produced by the fishing industries is leading to a disruption of the ecosystem. A broad study within the scope of the Azores Ecoblue project in partnership with the Regional Government of the Azores aims to quantify/parameterize and qualify waste from fishing gear. Focused on analyzing the possibility and opportunity of creating a source of revenue for the Region from these raw materials used by the stakeholders identified by a research project called Azores Ecoblue. This survey is being carried out with the aim of identifying adversities related to materials, resulting in the proposal of solutions, involving the recycling and transformation of the polymer, Polyethylene, typically used in mooring cables on fishing vessels. It is essential to raise awareness of the need to reconsider the collection of waste with sustainable potential and relevance in the social and economic context of the region. Polymer identification and characterization was performed in an attempt to address the problem at the source. In addition to identifying the material, this research focuses on characterizing its thermal properties. The development of a construction system composed of reused cables, to be included in a demonstrative prototype, was developed and is presented in this article, emphasizing the importance of implementing sustainable solutions to address the issue of marine litter on the Azorean coast and promote the circular economy.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"108 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140079400","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}
Hayate Sakaguchi, Takuma Kishimoto, Takayuki Hama, K. Tashima, Shinsuke Suzuki
The objective of this study was to clarify whether the surface roughness suppression orientation actually suppresses surface roughness by using the crystal plasticity finite element method (CPFEM), which is based on the relationship between the surface roughness suppression orientation and deformation in the inner surface direction that we have clarified in the past. In order to simplify the calculation and reduce the computational cost, a model was created by embedding cylinders in a rectangular body, which was then divided into 1/4 for the analysis. A dislocation density increase model that takes work hardening into account was applied to the model, and values obtained from tensile tests were used for material constants. The model was divided into 2130 elements. The simulation results show that the surface roughness suppression orientation is actually more difficult to deform than its surroundings.
{"title":"Investigation of the Behavior of Surface Roughness Suppression Orientation on the Inner Surface of Metal Microtubes Using Crystal Plasticity Finite Element Method","authors":"Hayate Sakaguchi, Takuma Kishimoto, Takayuki Hama, K. Tashima, Shinsuke Suzuki","doi":"10.4028/p-loh9kf","DOIUrl":"https://doi.org/10.4028/p-loh9kf","url":null,"abstract":"The objective of this study was to clarify whether the surface roughness suppression orientation actually suppresses surface roughness by using the crystal plasticity finite element method (CPFEM), which is based on the relationship between the surface roughness suppression orientation and deformation in the inner surface direction that we have clarified in the past. In order to simplify the calculation and reduce the computational cost, a model was created by embedding cylinders in a rectangular body, which was then divided into 1/4 for the analysis. A dislocation density increase model that takes work hardening into account was applied to the model, and values obtained from tensile tests were used for material constants. The model was divided into 2130 elements. The simulation results show that the surface roughness suppression orientation is actually more difficult to deform than its surroundings.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"63 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140264666","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}
Lakshmi Vara Prasad Meesaraganda, E. Mazumder, L. R. Reddy
The service life of structural members is significantly impacted by the durability of the concrete and that they are made of. The embedded reinforcing steel in durable concrete is protected from corrosion, and the possibility of concrete spalling in the concrete as a result of chemical attack is reduced. This study investigates the effectiveness of geopolymer concretes prepared using fly ash or a mixture of fly ash and slag (SLG). The performance of OPC concrete is likewise evaluated for comparing the durability of geopolymer concretes. This is done in order to compare the two types of concrete. All of the prepared specimens were submerged in theee types of distinct solutions up to 9 months. Four different types of solutions are (i) sodium chloride with 5% concentration, (ii) sodium sulphate 5% concentration, (iii) combination of magnesium sulphate with sodium sulphate with 5% concentration both, and sulphuric acid 3% concentration. The variation in properties were evaluated throughout the duration of the exposure period. According to the findings, it has been demonstrated that Na2SO4 (sodium sulphate) has the most significant effect on the geopolymer concretes, whereas sulphuric acid has the greatest potential to break down OPC concrete. With the effect of sulfuric acid, the strength reduction was 26.57% for OPC concrete and where as for flyash & SLG concretes it is 10.87% & 7.26% respectively. According to the findings, the durability performance of geopolymer concrete is, in general, better to that of cement concrete.
{"title":"Durability Studies of Conventional Cement Concrete and Geopolymer Concrete","authors":"Lakshmi Vara Prasad Meesaraganda, E. Mazumder, L. R. Reddy","doi":"10.4028/p-o39dkm","DOIUrl":"https://doi.org/10.4028/p-o39dkm","url":null,"abstract":"The service life of structural members is significantly impacted by the durability of the concrete and that they are made of. The embedded reinforcing steel in durable concrete is protected from corrosion, and the possibility of concrete spalling in the concrete as a result of chemical attack is reduced. This study investigates the effectiveness of geopolymer concretes prepared using fly ash or a mixture of fly ash and slag (SLG). The performance of OPC concrete is likewise evaluated for comparing the durability of geopolymer concretes. This is done in order to compare the two types of concrete. All of the prepared specimens were submerged in theee types of distinct solutions up to 9 months. Four different types of solutions are (i) sodium chloride with 5% concentration, (ii) sodium sulphate 5% concentration, (iii) combination of magnesium sulphate with sodium sulphate with 5% concentration both, and sulphuric acid 3% concentration. The variation in properties were evaluated throughout the duration of the exposure period. According to the findings, it has been demonstrated that Na2SO4 (sodium sulphate) has the most significant effect on the geopolymer concretes, whereas sulphuric acid has the greatest potential to break down OPC concrete. With the effect of sulfuric acid, the strength reduction was 26.57% for OPC concrete and where as for flyash & SLG concretes it is 10.87% & 7.26% respectively. According to the findings, the durability performance of geopolymer concrete is, in general, better to that of cement concrete.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"131 36","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140078740","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}
Organic soil presents significant challenges for construction due to its unsuitability as a soil type, often necessitating stabilization using conventional agents like cement. The Silica Fume (SF)-Red Mud (RM) binder mix emerges as a promising alternative stabilizer due to its low carbon footprint coupled with its superior strength-enhancing properties. In this study,we explore the feasibility of employing SF-RM based geopolymer to stabilize organic soil. To activate the collected samples, a solution of sodium hydroxide (NaOH) with molarity (M) of 6, 9, and 12 were utilized, as well as binder (SF + RM) proportions of 10%, 20%, 30%, and 40% relative to dried organic soil and alkali-to-binder (A/B) proportions of 0.5, 0.7, and 0.9, respectively. The experimental results reveal that a variety of factors, including NaOH molarity, A/B proportions, pH, and curing duration, have an effect on the unconfined compressive strength (UCS) of treated organic soil. The best combination was obtained with a binder concentration of 30%, a NaOH molarity of 9M, and an A/B proportion of 0.7. After 28 days of curing, the UCS of the treated organic soil (1714 kPa) was found to be 168 times that of the untreated organic soil (10.2kPa). Further, the production of compounds such as aluminium silicate, sodium aluminosilicate, and potassium aluminosilicate, which have been found by X-ray diffraction (XRD) research, can be ascribed to the increase in strength. Furthermore, when subjected to analysis through Field Emission Scanning Electron Microscopy (FESEM), it becomes evident that these items play a pivotal role in filling the voids within the soil-binder composite. As a consequence, they facilitate the creation of a more smoother, compact and denser structure.
{"title":"Silica Fume-Red Mud Based Geopolymer Stabilized Organic Soil","authors":"Rezaul Islam Choudhury, Monowar Hussain","doi":"10.4028/p-vdler9","DOIUrl":"https://doi.org/10.4028/p-vdler9","url":null,"abstract":"Organic soil presents significant challenges for construction due to its unsuitability as a soil type, often necessitating stabilization using conventional agents like cement. The Silica Fume (SF)-Red Mud (RM) binder mix emerges as a promising alternative stabilizer due to its low carbon footprint coupled with its superior strength-enhancing properties. In this study,we explore the feasibility of employing SF-RM based geopolymer to stabilize organic soil. To activate the collected samples, a solution of sodium hydroxide (NaOH) with molarity (M) of 6, 9, and 12 were utilized, as well as binder (SF + RM) proportions of 10%, 20%, 30%, and 40% relative to dried organic soil and alkali-to-binder (A/B) proportions of 0.5, 0.7, and 0.9, respectively. The experimental results reveal that a variety of factors, including NaOH molarity, A/B proportions, pH, and curing duration, have an effect on the unconfined compressive strength (UCS) of treated organic soil. The best combination was obtained with a binder concentration of 30%, a NaOH molarity of 9M, and an A/B proportion of 0.7. After 28 days of curing, the UCS of the treated organic soil (1714 kPa) was found to be 168 times that of the untreated organic soil (10.2kPa). Further, the production of compounds such as aluminium silicate, sodium aluminosilicate, and potassium aluminosilicate, which have been found by X-ray diffraction (XRD) research, can be ascribed to the increase in strength. Furthermore, when subjected to analysis through Field Emission Scanning Electron Microscopy (FESEM), it becomes evident that these items play a pivotal role in filling the voids within the soil-binder composite. As a consequence, they facilitate the creation of a more smoother, compact and denser structure.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"114 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140079161","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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