Pub Date : 2024-06-13DOI: 10.55713/jmmm.v34i3.1861
Reettiporn Thongpron, P. Ninpetch, P. Chalermkarnnon, P. Kowitwarangkul
The Selective Laser Melting (SLM) process is a promising additive manufacturing technology for producing complex metal parts. However, this process has certain limitations, including lack of fusion and defects, which can hinder its industrial applications. These challenges can be addressed by determining the appropriate overlap percentage parameters. This study used numerical simulation to explore the effect of overlap percentage on multi-track melting in the SLM process for Ti-6Al-4V. The simulation results categorize the multi-track melting morphologies into two distinct groups. The first group, (0% to 40% overlap), displays consistent surface roughness with an average Ra value of 7 µm. In contrast, the second group (50% to 60% overlap), shows non-uniform shapes. Specifically, the three central tracks in this group present an Ra value of approximately 4 µm. However, when all five tracks of this group are taken into account, the average Ra rises to 14 µm. These differences in surface roughness can be attributed to factors like energy density and the Marangoni effect. Both melt pool depth and shrinkage depth in the overlap area are significant as they might contribute to the risk of the lack of fusion defects. The insights from this research hold potential in shaping scanning pattern strategy design.
选择性激光熔融（SLM）工艺是一种很有前途的增材制造技术，可用于生产复杂的金属零件。然而，这种工艺也有一定的局限性，包括缺乏熔合和缺陷，这可能会阻碍其工业应用。这些挑战可以通过确定适当的重叠百分比参数来解决。本研究利用数值模拟探讨了重叠百分比对 Ti-6Al-4V SLM 工艺中多轨熔化的影响。模拟结果将多轨熔化形态分为两组。第一组（0% 至 40% 重叠）显示出一致的表面粗糙度，平均 Ra 值为 7 µm。相比之下，第二组（50% 至 60% 重叠）显示出不均匀的形状。具体来说，这一组中的三条中心轨迹的 Ra 值约为 4 µm。然而，如果将该组的所有五条轨道都考虑在内，平均 Ra 值将上升到 14 µm。表面粗糙度的这些差异可归因于能量密度和马兰戈尼效应等因素。重叠区域的熔池深度和收缩深度都很重要，因为它们可能会导致缺乏熔合缺陷的风险。这项研究的启示可能会影响扫描模式的设计。
{"title":"Effect of hatch spacing in selective laser melting process of Ti-6Al-4V alloy on finished surface roughness: A computational study","authors":"Reettiporn Thongpron, P. Ninpetch, P. Chalermkarnnon, P. Kowitwarangkul","doi":"10.55713/jmmm.v34i3.1861","DOIUrl":"https://doi.org/10.55713/jmmm.v34i3.1861","url":null,"abstract":"The Selective Laser Melting (SLM) process is a promising additive manufacturing technology for producing complex metal parts. However, this process has certain limitations, including lack of fusion and defects, which can hinder its industrial applications. These challenges can be addressed by determining the appropriate overlap percentage parameters. This study used numerical simulation to explore the effect of overlap percentage on multi-track melting in the SLM process for Ti-6Al-4V. The simulation results categorize the multi-track melting morphologies into two distinct groups. The first group, (0% to 40% overlap), displays consistent surface roughness with an average Ra value of 7 µm. In contrast, the second group (50% to 60% overlap), shows non-uniform shapes. Specifically, the three central tracks in this group present an Ra value of approximately 4 µm. However, when all five tracks of this group are taken into account, the average Ra rises to 14 µm. These differences in surface roughness can be attributed to factors like energy density and the Marangoni effect. Both melt pool depth and shrinkage depth in the overlap area are significant as they might contribute to the risk of the lack of fusion defects. The insights from this research hold potential in shaping scanning pattern strategy design.","PeriodicalId":502897,"journal":{"name":"Journal of Metals, Materials and Minerals","volume":"11 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141349027","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 : 2024-06-13DOI: 10.55713/jmmm.v34i3.2010
Sorawit Duangsripat, P. Patanathabutr, N. Hongsriphan
Carbon-based nanofillers have been applied in various products, especially electrical and electronic products. It could be used to modify electrical conductivity of the integrated circuit (IC) polymeric packaging in order to prevent electrostatic discharge that would damage electronic integrity. This research reported the influence of ammonia plasma functionalization and its concentration on electrical, mechanical and thermal properties of Acrylonitrile-Butadiene-Styrene (ABS) reinforced with a mixture of CNTs and GNPs. Nanocomposites were successfully compounded using a twin-screw extruder, which firstly the masterbatch was prepared and then mixed with neat polymer into various concentrations (2 wt%, 4 wt%, 6 wt%, and 8 wt%). It was found that ammonia plasma functionalization increased the dispersion of nanofillers in the ABS matrix. When using a hybrid nanofillers in the weight ratio of CNTs:GNPs 60:40, it was found that the percolation threshold could be reached with a nanofiller concentration of 4 wt%. The surface electrical resistivity of the NH3-functionalzed hybrid nanocomposites was reduced more than those adding the non-functionalized hybrid nanofillers. At this suitable weight ratio, tensile modulus of the CNT-NH3:GNP-NH3 60:40 of 2 wt%, 4 wt%, 6 wt%, and 8 wt% could enhance the tensile modulus of ABS to be 35.98%, 38.29%, 43.54%, and 45.48% higher than that of neat ABS, respectively. Interestingly, the nanocomposites still had the ultimate tensile strength presented at yield with higher values. In addition, the NH3-plasma functionalized nanofillers enhanced thermal conductivity of the ABS matrix much better than the non-functionalized ones, which these nanofillers could provide heat transfer by heat dissipation thoroughly in the polymer matrix.
{"title":"Properties of Acrylonitrile-Butadiene-Styrene nanocomposites adding ammonia plasma treated carbon nanotubes/graphene nanoplatelets for electronic discharge application","authors":"Sorawit Duangsripat, P. Patanathabutr, N. Hongsriphan","doi":"10.55713/jmmm.v34i3.2010","DOIUrl":"https://doi.org/10.55713/jmmm.v34i3.2010","url":null,"abstract":"Carbon-based nanofillers have been applied in various products, especially electrical and electronic products. It could be used to modify electrical conductivity of the integrated circuit (IC) polymeric packaging in order to prevent electrostatic discharge that would damage electronic integrity. This research reported the influence of ammonia plasma functionalization and its concentration on electrical, mechanical and thermal properties of Acrylonitrile-Butadiene-Styrene (ABS) reinforced with a mixture of CNTs and GNPs. Nanocomposites were successfully compounded using a twin-screw extruder, which firstly the masterbatch was prepared and then mixed with neat polymer into various concentrations (2 wt%, 4 wt%, 6 wt%, and 8 wt%). It was found that ammonia plasma functionalization increased the dispersion of nanofillers in the ABS matrix. When using a hybrid nanofillers in the weight ratio of CNTs:GNPs 60:40, it was found that the percolation threshold could be reached with a nanofiller concentration of 4 wt%. The surface electrical resistivity of the NH3-functionalzed hybrid nanocomposites was reduced more than those adding the non-functionalized hybrid nanofillers. At this suitable weight ratio, tensile modulus of the CNT-NH3:GNP-NH3 60:40 of 2 wt%, 4 wt%, 6 wt%, and 8 wt% could enhance the tensile modulus of ABS to be 35.98%, 38.29%, 43.54%, and 45.48% higher than that of neat ABS, respectively. Interestingly, the nanocomposites still had the ultimate tensile strength presented at yield with higher values. In addition, the NH3-plasma functionalized nanofillers enhanced thermal conductivity of the ABS matrix much better than the non-functionalized ones, which these nanofillers could provide heat transfer by heat dissipation thoroughly in the polymer matrix.","PeriodicalId":502897,"journal":{"name":"Journal of Metals, Materials and Minerals","volume":"29 25","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141346196","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 : 2024-06-13DOI: 10.55713/jmmm.v34i3.1902
Nathawat Poopakdee, Warut Thammawichai
This work investigated the effects of the crystallinity index (CI) of cellulose on the flexural properties of hybrid-cellulose epoxy composites. The CI was varied by combining cellulose microfibrils (CMF) and microcrystalline cellulose (MCC), extracted from coir and eucalyptus, respectively, in various mixing ratios. From the XRD analysis, it was shown that the CI values and the CMF/MCC content follow a parabolic-fitting pattern, reaching a maximum value of 82.06% for the CMF/MCC of 30/70. The composites with cellulose of different CI values were fabricated and the flexural properties were measured. The results showed that the flexural strength increased as the CI increased, reaching a maximum of 105.45 MPa for a CI value of 81.87%. However, the flexural modulus displayed a parabolic relationship with respect to the CI value, reaching a maximum of 3,015.53 MPa for a CI value of 81.45%. FTIR spectroscopy was used to study the correlation between the interfacial bonding via hydrogen bonding of hydroxyl groups in cellulose and epoxy, the CI value, and the flexural properties. It was suggested that the strength of the cellulose was an important factor for the flexural strength of the composite, whereas both cellulose strength and interfacial bonding were crucial for the enhancement of the flexural modulus.
这项研究探讨了纤维素的结晶度指数（CI）对混合纤维素环氧树脂复合材料挠曲性能的影响。通过将分别从椰子纤维和桉树纤维中提取的纤维素微纤维（CMF）和微晶纤维素（MCC）以不同的混合比例进行组合，改变了 CI。XRD 分析表明，CI 值和 CMF/MCC 含量呈抛物线拟合模式，当 CMF/MCC 为 30/70 时，CI 值达到最大值 82.06%。制作了含有不同 CI 值纤维素的复合材料，并对其弯曲性能进行了测量。结果表明，抗弯强度随着 CI 值的增加而增加，当 CI 值为 81.87% 时，抗弯强度达到最大值 105.45 兆帕。然而，弯曲模量与 CI 值呈抛物线关系，当 CI 值为 81.45% 时，弯曲模量达到最大值 3,015.53 兆帕。傅立叶变换红外光谱法用于研究纤维素和环氧树脂中羟基氢键的界面结合、CI 值和弯曲性能之间的相关性。结果表明，纤维素的强度是影响复合材料抗弯强度的重要因素，而纤维素强度和界面结合对于提高抗弯模量至关重要。
{"title":"The effects of the crystallinity index of cellulose on the flexural properties of hybrid-cellulose epoxy composites","authors":"Nathawat Poopakdee, Warut Thammawichai","doi":"10.55713/jmmm.v34i3.1902","DOIUrl":"https://doi.org/10.55713/jmmm.v34i3.1902","url":null,"abstract":"This work investigated the effects of the crystallinity index (CI) of cellulose on the flexural properties of hybrid-cellulose epoxy composites. The CI was varied by combining cellulose microfibrils (CMF) and microcrystalline cellulose (MCC), extracted from coir and eucalyptus, respectively, in various mixing ratios. From the XRD analysis, it was shown that the CI values and the CMF/MCC content follow a parabolic-fitting pattern, reaching a maximum value of 82.06% for the CMF/MCC of 30/70. The composites with cellulose of different CI values were fabricated and the flexural properties were measured. The results showed that the flexural strength increased as the CI increased, reaching a maximum of 105.45 MPa for a CI value of 81.87%. However, the flexural modulus displayed a parabolic relationship with respect to the CI value, reaching a maximum of 3,015.53 MPa for a CI value of 81.45%. FTIR spectroscopy was used to study the correlation between the interfacial bonding via hydrogen bonding of hydroxyl groups in cellulose and epoxy, the CI value, and the flexural properties. It was suggested that the strength of the cellulose was an important factor for the flexural strength of the composite, whereas both cellulose strength and interfacial bonding were crucial for the enhancement of the flexural modulus.","PeriodicalId":502897,"journal":{"name":"Journal of Metals, Materials and Minerals","volume":"85 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141347874","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 : 2024-06-13DOI: 10.55713/jmmm.v34i3.1916
P. Sancharoen, Sothyrak Rath, D. Tran, P. Klomjit, S. Tangtermsirikul
Infrastructure has been aged and deteriorated by various causes. Maintenance of its safety and serviceability are crucial and many countries have raised concerns about the existing infrastructure. Infrastructure in Thailand has been also aged. This paper shows results of studies relating to maintenance of infrastructure in Thailand. Inspection of the existing infrastructure in Bangkok was conducted by both visual and non-destructive testing (NDT) showing many deteriorations, and damages. Most of the deteriorations are caused by low concrete covering depth and water leakage. While in marine environment, chloride attack is the main cause. Evaluation criteria for NDT results are studied and modified to be suitable for concrete used in Thailand. To predict the service life of structure, studies have also been conducted to evaluate the corrosion rate of reinforcing steel in reinforced concrete structures in different deterioration mechanisms and environmental conditions. Together with inspection results, service life of structure can be predicted, and maintenance can be well planned. The results of this study could raise awareness of the important of infrastructure maintenance in Thailand.
{"title":"Maintenance of the deteriorated infrastructure in Thailand","authors":"P. Sancharoen, Sothyrak Rath, D. Tran, P. Klomjit, S. Tangtermsirikul","doi":"10.55713/jmmm.v34i3.1916","DOIUrl":"https://doi.org/10.55713/jmmm.v34i3.1916","url":null,"abstract":"Infrastructure has been aged and deteriorated by various causes. Maintenance of its safety and serviceability are crucial and many countries have raised concerns about the existing infrastructure. Infrastructure in Thailand has been also aged. This paper shows results of studies relating to maintenance of infrastructure in Thailand. Inspection of the existing infrastructure in Bangkok was conducted by both visual and non-destructive testing (NDT) showing many deteriorations, and damages. Most of the deteriorations are caused by low concrete covering depth and water leakage. While in marine environment, chloride attack is the main cause. Evaluation criteria for NDT results are studied and modified to be suitable for concrete used in Thailand. To predict the service life of structure, studies have also been conducted to evaluate the corrosion rate of reinforcing steel in reinforced concrete structures in different deterioration mechanisms and environmental conditions. Together with inspection results, service life of structure can be predicted, and maintenance can be well planned. The results of this study could raise awareness of the important of infrastructure maintenance in Thailand.","PeriodicalId":502897,"journal":{"name":"Journal of Metals, Materials and Minerals","volume":"42 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141348967","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}
Composites materials with more than two reinforcing materials are called hybrid composites. Tailoring the composites by hybridizing fillers, fibers and matrix will yield better properties compared to mono-composites. Hence, an effort has been made in the current research work to develop carbon fiber epoxy hybrid nanocomposites, comprising different weight percentage of Hydroxyapatite (HAP) to evaluate the potential effects on tribological properties using two body sliding wear method. Taguchi technique (L27 array) has been adopted to investigate the impact of parameters such as filler inclusion (0%, 1.5%, and 3%), load (30, 45, and 60 N), sliding velocity (1, 2, and 3 m·s‒1) and distance (1000, 2000, and 3000 m·s‒1) on wear loss of developed composite. It was observed that the combination of 1.5 wt% HAP composite showed the lowest Ks and the COF. The combination of 1.5 wt% HAP filler, 1 m·s‒1 sliding velocity, 45 N load and 3000 m sliding distance exhibited the lower Ks and COF of 0.44652 × 10‒14 (m3·Nm‒1) and 0.136 respectively. The significance of the parameters was assessed using analysis of variance, revealing that the filler's contribution significantly impacted wear resistance. Developed mathematical model using Regression analysis and the predicted values from K-Nearest Neighbors (KNN) have showed good agreement with experimental values. Micrograph images were captured to analyze the wear mechanisms evident on worn surfaces, revealing failure mechanisms such as extensive matrix damage, fiber exposure resulting from matrix removal, and fiber breakage.
{"title":"Adhesive wear characteristics of mono and hybrid CF/Ep composite with nano-HAP filler","authors":"Divya GURKAR SOMASHEKAR, Naveena BETTAHALLI ESWAREGOWDA, Suresha Bheemappa","doi":"10.55713/jmmm.v34i3.2040","DOIUrl":"https://doi.org/10.55713/jmmm.v34i3.2040","url":null,"abstract":"Composites materials with more than two reinforcing materials are called hybrid composites. Tailoring the composites by hybridizing fillers, fibers and matrix will yield better properties compared to mono-composites. Hence, an effort has been made in the current research work to develop carbon fiber epoxy hybrid nanocomposites, comprising different weight percentage of Hydroxyapatite (HAP) to evaluate the potential effects on tribological properties using two body sliding wear method. Taguchi technique (L27 array) has been adopted to investigate the impact of parameters such as filler inclusion (0%, 1.5%, and 3%), load (30, 45, and 60 N), sliding velocity (1, 2, and 3 m·s‒1) and distance (1000, 2000, and 3000 m·s‒1) on wear loss of developed composite. It was observed that the combination of 1.5 wt% HAP composite showed the lowest Ks and the COF. The combination of 1.5 wt% HAP filler, 1 m·s‒1 sliding velocity, 45 N load and 3000 m sliding distance exhibited the lower Ks and COF of 0.44652 × 10‒14 (m3·Nm‒1) and 0.136 respectively. The significance of the parameters was assessed using analysis of variance, revealing that the filler's contribution significantly impacted wear resistance. Developed mathematical model using Regression analysis and the predicted values from K-Nearest Neighbors (KNN) have showed good agreement with experimental values. Micrograph images were captured to analyze the wear mechanisms evident on worn surfaces, revealing failure mechanisms such as extensive matrix damage, fiber exposure resulting from matrix removal, and fiber breakage.","PeriodicalId":502897,"journal":{"name":"Journal of Metals, Materials and Minerals","volume":"15 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141347446","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 : 2024-03-25DOI: 10.55713/jmmm.v34i1.1828
Naritsara Toobpeng, S. Jiemsirilers
This study describes a simple microwave process for fabricating porous geopolymer-polymer based Shirasu soil. The porous geopolymer samples were synthesized using sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solution as alkaline solution in range of 0.5 M to 9 M. After mixing process, the geopolymer slurry was heated and stimulated geopolymerization reaction by different microwave powers at 200 W, 500 W and 700 W for 30 s, 60 s, 90 s and 120 s. The influence of NaOH concentration, microwave powers and heating times on the apparent bulk density, the water adsorption was focused. Results showed that the microwave powers and heating time affected the apparent bulk density, the water adsorption, and the densification of geopolymer matrix. Higher microwave power can promote higher water adsorption related to lower apparent bulk density. Moreover, the results revealed that the porosity and the nitrogen adsorption of geopolymers at 120 s of heating time increased with an increment of the NaOH from 1 M to 4 M. On the other hand, geopolymers activated by 200 W at 30 s could not be hardened. This work provides the feasibility of porous geopolymer synthesis based natural soil.
本研究介绍了一种制造基于多孔土工聚合物的 Shirasu 土壤的简单微波工艺。使用硅酸钠（Na2SiO3）和氢氧化钠（NaOH）溶液合成多孔土工聚合物样品，碱性溶液的浓度范围为 0.5 M 至 9 M。混合过程结束后，加热土工聚合物浆料，并在 200 W、500 W 和 700 W 的不同微波功率下进行 30 s、60 s、90 s 和 120 s 的土工聚合物反应。结果表明，微波功率和加热时间会影响土工聚合物基体的表观堆积密度、吸水性和致密性。微波功率越大，吸水率越高，表观体积密度越低。此外，研究结果表明，在加热时间为 120 秒时，土工聚合物的孔隙率和氮吸附量随着 NaOH 的浓度从 1 M 增至 4 M 而增加。这项工作为基于天然土壤合成多孔土工聚合物提供了可行性。
{"title":"Fast microwave synthesis of high-silica natural soil based porous geopolymer","authors":"Naritsara Toobpeng, S. Jiemsirilers","doi":"10.55713/jmmm.v34i1.1828","DOIUrl":"https://doi.org/10.55713/jmmm.v34i1.1828","url":null,"abstract":"This study describes a simple microwave process for fabricating porous geopolymer-polymer based Shirasu soil. The porous geopolymer samples were synthesized using sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solution as alkaline solution in range of 0.5 M to 9 M. After mixing process, the geopolymer slurry was heated and stimulated geopolymerization reaction by different microwave powers at 200 W, 500 W and 700 W for 30 s, 60 s, 90 s and 120 s. The influence of NaOH concentration, microwave powers and heating times on the apparent bulk density, the water adsorption was focused. Results showed that the microwave powers and heating time affected the apparent bulk density, the water adsorption, and the densification of geopolymer matrix. Higher microwave power can promote higher water adsorption related to lower apparent bulk density. Moreover, the results revealed that the porosity and the nitrogen adsorption of geopolymers at 120 s of heating time increased with an increment of the NaOH from 1 M to 4 M. On the other hand, geopolymers activated by 200 W at 30 s could not be hardened. This work provides the feasibility of porous geopolymer synthesis based natural soil.\u0000 ","PeriodicalId":502897,"journal":{"name":"Journal of Metals, Materials and Minerals","volume":" 1270","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140382424","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 : 2024-03-25DOI: 10.55713/jmmm.v34i1.1848
S. W. Suciyati, Junaidi Junaidi, R. Situmeang, Posman Manurung
This research aimed to synthesize nano-ZnO from chaya (Cnidoscolus aconitifolius) and mango leaves extract (Mangifera indica) as environmentally friendly photocatalysts. Nano-ZnO was synthesized using green synthesis, with leaves extracts as reducing agents and nanoparticle size stabilizers. The samples were prepared using two methods, namely nano-ZnO-1 and nano-ZnO-2. The results of Fourier transform infrared spectroscopy (FTIR) analysis showed the contribution of metabolite compounds in nano-ZnO synthesis. X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed the crystal size in nano range, with spherical nanorod morphology observed. Ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) determined the band gap energy of 2.97 eV and 3.17 eV. Furthermore, photocatalytic activity test showed that photocatalyst performance after 90 min was 68.86% (nano-ZnO-1) and 96.46% (nano-ZnO-2).
{"title":"Nano-ZnO prepared by using chaya and mango leaves extract for photocatalyst of methylene blue","authors":"S. W. Suciyati, Junaidi Junaidi, R. Situmeang, Posman Manurung","doi":"10.55713/jmmm.v34i1.1848","DOIUrl":"https://doi.org/10.55713/jmmm.v34i1.1848","url":null,"abstract":"This research aimed to synthesize nano-ZnO from chaya (Cnidoscolus aconitifolius) and mango leaves extract (Mangifera indica) as environmentally friendly photocatalysts. Nano-ZnO was synthesized using green synthesis, with leaves extracts as reducing agents and nanoparticle size stabilizers. The samples were prepared using two methods, namely nano-ZnO-1 and nano-ZnO-2. The results of Fourier transform infrared spectroscopy (FTIR) analysis showed the contribution of metabolite compounds in nano-ZnO synthesis. X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed the crystal size in nano range, with spherical nanorod morphology observed. Ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) determined the band gap energy of 2.97 eV and 3.17 eV. Furthermore, photocatalytic activity test showed that photocatalyst performance after 90 min was 68.86% (nano-ZnO-1) and 96.46% (nano-ZnO-2).","PeriodicalId":502897,"journal":{"name":"Journal of Metals, Materials and Minerals","volume":"9 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140381567","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 : 2024-03-25DOI: 10.55713/jmmm.v34i1.1926
Laxmidhar Sahoo, S. A. Behera, Rajesh Kumar Singh, Santosh Parida, P. Achary
A double-perovskite material Bi2FeMn0.94Ce0.06O6 (BFMCO) was synthesized by solid state reaction technique and characterized it by various techniques (structural, microstructural, dielectric, impedance and modulus properties). The material has an orthorhombic crystal structure with an average crystallite size of 52.4 nm, as revealed by X-ray diffraction data (XRD). The scanning electron microscope (SEM) image shows the presence of nano rod-shaped grains and well-defined grain boundaries in this material, with an average grain size of 21.8 µm. The Energy dispersive X-ray (EDX) analysis and color mapping confirm the purity and the composition of the material. The dielectric, impedance and modulus properties are investigated in the temperature range of 25℃ to 500℃ and frequency range of 1 kHz to 1 MHz. The material exhibits a high dielectric constant at low frequency region and a low dielectric loss, which make it a suitable candidate for better energy storage devices. The impedance study reveals the negative temperature coefficient of resistance (NTCR) behavior of the material. The modulus study indicates the non-Debye relaxation of the material. The semi-conducting nature of the material is verified by the semi-circular arcs observed in both Nyquist and Cole-Cole plots. Thermally activated conduction mechanism is confirmed from ac conductivity study.
{"title":"Microstructural and dielectric characteristics of the Ce-doped Bi(_{2})FeMnO(_{6})","authors":"Laxmidhar Sahoo, S. A. Behera, Rajesh Kumar Singh, Santosh Parida, P. Achary","doi":"10.55713/jmmm.v34i1.1926","DOIUrl":"https://doi.org/10.55713/jmmm.v34i1.1926","url":null,"abstract":"A double-perovskite material Bi2FeMn0.94Ce0.06O6 (BFMCO) was synthesized by solid state reaction technique and characterized it by various techniques (structural, microstructural, dielectric, impedance and modulus properties). The material has an orthorhombic crystal structure with an average crystallite size of 52.4 nm, as revealed by X-ray diffraction data (XRD). The scanning electron microscope (SEM) image shows the presence of nano rod-shaped grains and well-defined grain boundaries in this material, with an average grain size of 21.8 µm. The Energy dispersive X-ray (EDX) analysis and color mapping confirm the purity and the composition of the material. The dielectric, impedance and modulus properties are investigated in the temperature range of 25℃ to 500℃ and frequency range of 1 kHz to 1 MHz. The material exhibits a high dielectric constant at low frequency region and a low dielectric loss, which make it a suitable candidate for better energy storage devices. The impedance study reveals the negative temperature coefficient of resistance (NTCR) behavior of the material. The modulus study indicates the non-Debye relaxation of the material. The semi-conducting nature of the material is verified by the semi-circular arcs observed in both Nyquist and Cole-Cole plots. Thermally activated conduction mechanism is confirmed from ac conductivity study.\u0000 ","PeriodicalId":502897,"journal":{"name":"Journal of Metals, Materials and Minerals","volume":" 25","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140384529","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 : 2024-03-25DOI: 10.55713/jmmm.v34i1.1898
Mohammad Reza Hermawan, B. H. Setiamarga, Ilham Nur Hakim, Rizka Mulia Anggraeni
In this research, heat-treatment was used to determine changes in the microstructure and mechanical characteristics of austenitic manganese steel equivalent to ASTM A128-C. Carbide formed in as-cast conditions is transformed into dispersed hardened austenite to increase the toughness of the material because it can inhibit dislocation movement. Heat treatment is carried out in two heating stages. The first stage of heating was carried out at a temperature of 625°C with a holding time varying by 2.5, 3.5, and 4.5 h, and the second stage was carried out at a temperature of 1000°C with a constant holding time of 1.5 h. Microstructure observations were carried out to observe the structural morphology and carbide transformation in both the first and second stages of heating. Tensile and hardness tests were also carried out to determine the mechanical properties and their effect on two-stage heating. The research results show that the pearlite structure is formed in the first stage of heating with different lamella thicknesses. With the help of ImageJ software, the measured pearlite fraction was higher as the holding time increased in the first stage of heating. This affects the morphology of the carbide colonies formed in the second stage of heating. The higher the pearlite fraction, the more uniform the morphology of the carbide formed with round shapes that are more evenly distributed. These dispersed carbide colonies can increase the toughness of the material up to 17 times higher than the as-cast condition obtained through mechanical testing.
{"title":"Effect of two-stage heat treatment on the microstructure and mechanical properties of high chrome austenitic manganese steel","authors":"Mohammad Reza Hermawan, B. H. Setiamarga, Ilham Nur Hakim, Rizka Mulia Anggraeni","doi":"10.55713/jmmm.v34i1.1898","DOIUrl":"https://doi.org/10.55713/jmmm.v34i1.1898","url":null,"abstract":"In this research, heat-treatment was used to determine changes in the microstructure and mechanical characteristics of austenitic manganese steel equivalent to ASTM A128-C. Carbide formed in as-cast conditions is transformed into dispersed hardened austenite to increase the toughness of the material because it can inhibit dislocation movement. Heat treatment is carried out in two heating stages. The first stage of heating was carried out at a temperature of 625°C with a holding time varying by 2.5, 3.5, and 4.5 h, and the second stage was carried out at a temperature of 1000°C with a constant holding time of 1.5 h. Microstructure observations were carried out to observe the structural morphology and carbide transformation in both the first and second stages of heating. Tensile and hardness tests were also carried out to determine the mechanical properties and their effect on two-stage heating. The research results show that the pearlite structure is formed in the first stage of heating with different lamella thicknesses. With the help of ImageJ software, the measured pearlite fraction was higher as the holding time increased in the first stage of heating. This affects the morphology of the carbide colonies formed in the second stage of heating. The higher the pearlite fraction, the more uniform the morphology of the carbide formed with round shapes that are more evenly distributed. These dispersed carbide colonies can increase the toughness of the material up to 17 times higher than the as-cast condition obtained through mechanical testing.\u0000 ","PeriodicalId":502897,"journal":{"name":"Journal of Metals, Materials and Minerals","volume":"113 37","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140381323","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 : 2024-03-20DOI: 10.55713/jmmm.v34i1.1833
Fia Amalia, A. Nugraheni, Sholihun Sholihun
Based on density functional theory, calculations have been carried out to study the structural and electronic properties of the polymer Poly (3-hexylthiophene) (P3HT) interacting with monolayer graphene as an active layer. (P3HT)1-graphene and (P3HT)2-graphene are optimized on graphene using the generalized-gradient-approximation type of the exchange-correlation functional. Adsorption energy, band gap, and charge transfer are calculated. The calculated adsorption energy shows that all systems have negative adsorption energy, indicating that the reaction is exothermic. Compared to (P3HT)1-graphene, (P3HT)2-graphene has a lower band gap. As for the charge transfer calculation, a negative ΔN indicates that electron transfers from P3HT to graphene.
{"title":"First-principles study on structural and electronic properties of P3HT-graphene","authors":"Fia Amalia, A. Nugraheni, Sholihun Sholihun","doi":"10.55713/jmmm.v34i1.1833","DOIUrl":"https://doi.org/10.55713/jmmm.v34i1.1833","url":null,"abstract":"Based on density functional theory, calculations have been carried out to study the structural and electronic properties of the polymer Poly (3-hexylthiophene) (P3HT) interacting with monolayer graphene as an active layer. (P3HT)1-graphene and (P3HT)2-graphene are optimized on graphene using the generalized-gradient-approximation type of the exchange-correlation functional. Adsorption energy, band gap, and charge transfer are calculated. The calculated adsorption energy shows that all systems have negative adsorption energy, indicating that the reaction is exothermic. Compared to (P3HT)1-graphene, (P3HT)2-graphene has a lower band gap. As for the charge transfer calculation, a negative ΔN indicates that electron transfers from P3HT to graphene.","PeriodicalId":502897,"journal":{"name":"Journal of Metals, Materials and Minerals","volume":" 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140388246","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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