A mechanical work piece created industrially frequently contains more than one machining process. Furthermore, it is a common activity of programmers, who make this selection every time a milling and drilling operation is conducted. Tool wear and borehole quality are two essential challenges for high precision drilling procedures, with Al 356 alloy being employed in experimental planning. Drilling specifications will be assessed in this work to get optimal parameters in minimizing the influence of drilling damage on alloy using a swarm-based optimization model. The drilling parameters are optimized using the Bacterial Foraging Optimization (BFO) method, which includes three control factors: depth, feed rate, and spindle speed. Each parameter is designed in three levels, with multiple performance characteristics such as thrust force, surface roughness, and delamination factor. This investigation was carried out in order to obtain the proper optimization. The feed rate, next to the spindle speed, was discovered to be the essential element inducing lamination in drilling, with this phenomenon occurring in each diameter of the drill bit. The results reveal that the feed rate and drill type are the most important parameters influencing the drilling process, and that employing this strategy can successfully improve drilling process outcomes.
{"title":"Numerical Study of Drilling Parameters with Al 356 Alloy Using Bacterial Foraging Optimization","authors":"Pandian Pitchipoo, Muthiah Athi, Manikandan Annamalai, Jeyakumar Kadarkarai, Rajakarunakaran Sivaprakasam","doi":"10.4028/p-6hukkb","DOIUrl":"https://doi.org/10.4028/p-6hukkb","url":null,"abstract":"A mechanical work piece created industrially frequently contains more than one machining process. Furthermore, it is a common activity of programmers, who make this selection every time a milling and drilling operation is conducted. Tool wear and borehole quality are two essential challenges for high precision drilling procedures, with Al 356 alloy being employed in experimental planning. Drilling specifications will be assessed in this work to get optimal parameters in minimizing the influence of drilling damage on alloy using a swarm-based optimization model. The drilling parameters are optimized using the Bacterial Foraging Optimization (BFO) method, which includes three control factors: depth, feed rate, and spindle speed. Each parameter is designed in three levels, with multiple performance characteristics such as thrust force, surface roughness, and delamination factor. This investigation was carried out in order to obtain the proper optimization. The feed rate, next to the spindle speed, was discovered to be the essential element inducing lamination in drilling, with this phenomenon occurring in each diameter of the drill bit. The results reveal that the feed rate and drill type are the most important parameters influencing the drilling process, and that employing this strategy can successfully improve drilling process outcomes.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140979251","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}
Djilali Bouha, L. Gaidi, Abdellah Kaou, B. Moulai Ali, El Bahri Ould Chikh, H. Meddah, Athmane Khalifa Bouha
In Algeria, polyethylene (PE) pipes are commonly installed for the distribution of potable water and natural gas in urban and rural areas. They are used for economic reasons, in addition to perfect maintenance, compared to metal pipes. The experiences of these tube installations have shown technical advantages in operational safety aspects and structures lifespan with very interesting mechanical properties. The connection between the polyethylene pipes is done through couplings, which are considered expensive during their replacement due to frequent use, especially in the agricultural field. The main objective of the present experiment is to elicit the main parameters of friction stir welding on polyethylene pipes (butt welding) using a milling machine, especially the rotational speed of the clamped pipe sections called the rotational welding speed, which replaced the welding speed, with the highlighting of the clamping device to form a butt joint. In the present work, the process using the conventional tool is presented with the design and provision of a pipe assembly device intended for this research in order to weld these pipes together during the FSW process. The rotary device used in this experiment is mounted on a milling machine and rotates the tube sections attached to the rotating arms of the support. The spindle can rotate freely 360 ̊ with the tool's rotating speed of 1100 rpm. Two sections of high-density polyethylene pipes with an outer diameter of 125 mm, which are intended for natural gas distribution, were successfully welded to achieve the conventional friction stir welding (C-FSW) reliability of polyethylene pipes. This study makes it possible to highlight the parameters and the method, on which it is recommended to improve welded joints, in the context of research that will always be ongoing.
{"title":"Experimental Study of the Possibility of Butt Friction Stir Welding on Polyethylene Pipes","authors":"Djilali Bouha, L. Gaidi, Abdellah Kaou, B. Moulai Ali, El Bahri Ould Chikh, H. Meddah, Athmane Khalifa Bouha","doi":"10.4028/p-flck3c","DOIUrl":"https://doi.org/10.4028/p-flck3c","url":null,"abstract":"In Algeria, polyethylene (PE) pipes are commonly installed for the distribution of potable water and natural gas in urban and rural areas. They are used for economic reasons, in addition to perfect maintenance, compared to metal pipes. The experiences of these tube installations have shown technical advantages in operational safety aspects and structures lifespan with very interesting mechanical properties. The connection between the polyethylene pipes is done through couplings, which are considered expensive during their replacement due to frequent use, especially in the agricultural field. The main objective of the present experiment is to elicit the main parameters of friction stir welding on polyethylene pipes (butt welding) using a milling machine, especially the rotational speed of the clamped pipe sections called the rotational welding speed, which replaced the welding speed, with the highlighting of the clamping device to form a butt joint. In the present work, the process using the conventional tool is presented with the design and provision of a pipe assembly device intended for this research in order to weld these pipes together during the FSW process. The rotary device used in this experiment is mounted on a milling machine and rotates the tube sections attached to the rotating arms of the support. The spindle can rotate freely 360 ̊ with the tool's rotating speed of 1100 rpm. Two sections of high-density polyethylene pipes with an outer diameter of 125 mm, which are intended for natural gas distribution, were successfully welded to achieve the conventional friction stir welding (C-FSW) reliability of polyethylene pipes. This study makes it possible to highlight the parameters and the method, on which it is recommended to improve welded joints, in the context of research that will always be ongoing.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"28 51","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140980084","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. Cuamatzi-Meléndez, M. Salazar-Martínez, Fernando Juárez-López
Measurements over fractured surfaces of samples obtained from impact Charpy tests and four-point double-notch bend tests, carried out at-60°C and-196°C were performed in the present work. This in order to quantify cleavage facets misorientation for the resistance of cleavage fracture propagation. The material used for the analyses was a ferritic Grade A ship plate steel. The grains misorientation angle was quantified by measuring the orientation of single cleavage facets with respect to its neighbors, of a number of cleavage facets, and the misorientation angle was measured. The misorientation angle of cleavage facets was analyze in four groups: all facets, small-small, small-large and large-large facets in order to identify how this classification can affect the misorientation angle of cleavage facets. The results showed that high misorientation angles between neighboring grains, can act as barriers for cleavage propagation, and offer more resistance for brittle fracture propagation or may arrest potential microcracks of critical size in the ductile-brittle transition of ferritic steels. Therefore, the analysis revealed arrest of microcracks when the fracture path found high misoriented grains in the lower shelf of a Grade A ship plate steel. The effect of the misorientation of the ferrite grains in terms of the cleavage facets misorientation on fracture propagation was also discussed in the present work. Keywords: Cleavage fracture, Misorientation angle, Charpy tests, Four-point double-notch bend tests, Cleavage facets.
本研究对在 60°C 和 196°C 下进行的冲击夏比试验和四点双缺口弯曲试验中获得的样品断裂表面进行了测量。这是为了量化劈裂面错位对劈裂断口扩展阻力的影响。用于分析的材料是铁素体 A 级船板钢。通过测量单个劈裂面相对于其相邻劈裂面的取向来量化晶粒的错位角，并测量多个劈裂面的错位角。将裂隙面的错误取向角分为四组进行分析：所有裂隙面、小-小裂隙面、小-大裂隙面和大-大裂隙面，以确定这种分类如何影响裂隙面的错误取向角。结果表明，相邻晶粒间的高错取向角可作为劈裂扩展的障碍，并为脆性断裂扩展提供更多阻力，或在铁素体钢的韧性-脆性转变过程中阻止潜在的临界尺寸微裂纹。因此，分析表明，当断裂路径在 A 级船板钢的下层发现高取向错位晶粒时，微裂纹会被阻止。本研究还讨论了铁素体晶粒的取向错位对断裂扩展的影响。关键词劈裂断裂、偏斜角、夏比试验、四点双缺口弯曲试验、劈裂面。
{"title":"Misorientation Angle Study on Cleavage Fracture Propagation Surfaces of a Grade a Ship Steel, through Charpy and Four-Point Double-Notch Bend Tests","authors":"R. Cuamatzi-Meléndez, M. Salazar-Martínez, Fernando Juárez-López","doi":"10.4028/p-nqg5sc","DOIUrl":"https://doi.org/10.4028/p-nqg5sc","url":null,"abstract":"Measurements over fractured surfaces of samples obtained from impact Charpy tests and four-point double-notch bend tests, carried out at-60°C and-196°C were performed in the present work. This in order to quantify cleavage facets misorientation for the resistance of cleavage fracture propagation. The material used for the analyses was a ferritic Grade A ship plate steel. The grains misorientation angle was quantified by measuring the orientation of single cleavage facets with respect to its neighbors, of a number of cleavage facets, and the misorientation angle was measured. The misorientation angle of cleavage facets was analyze in four groups: all facets, small-small, small-large and large-large facets in order to identify how this classification can affect the misorientation angle of cleavage facets. The results showed that high misorientation angles between neighboring grains, can act as barriers for cleavage propagation, and offer more resistance for brittle fracture propagation or may arrest potential microcracks of critical size in the ductile-brittle transition of ferritic steels. Therefore, the analysis revealed arrest of microcracks when the fracture path found high misoriented grains in the lower shelf of a Grade A ship plate steel. The effect of the misorientation of the ferrite grains in terms of the cleavage facets misorientation on fracture propagation was also discussed in the present work. Keywords: Cleavage fracture, Misorientation angle, Charpy tests, Four-point double-notch bend tests, Cleavage facets.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"33 35","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140980232","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}
The monooxidation of methane into methanol was carried out on biomimetic heterogeneous catalyst – iron pentafluorotetraphenylporphyrin on Al2O3 (ImtOH), at atmospheric pressure and temperatures of 200-350°C, which resulted in liquid one-carbon compounds CH3OH (19.2%), CH2O (1.55%), CH3OCH3 (8.2%) with high selectivity and are widely used in the chemical industry. In order to establish the routes of these products formation and the mechanism for the methane conversion into them, the investigation of the methanol conversion reaction was carried out, as an intermediate compound of the methane oxidation, under identical conditions on the same catalyst.The result was only dimethyl ether with 100% selectivity. This proved that in this reaction system, methanol obtained from the methane monooxidation is converted only into dimethyl ether, and formaldehyde, in parallel with methanol, is formed from methane. The mechanisms of the elementary stages of the formation of methanol, formaldehyde and dimethyl ether on the surface of the bioimitator through the formation of an active complex (ImtOOH) are presented, in which the unity of the mechanisms of redox and acid-base catalysis traced within the framework of the principle of the bond redistribution chain (BRC), similar to enzymatic reactions.
{"title":"Study of the Methanol Conversion into Dimethyl Ether Obtained in the Process of Biomimetic Methane Monooxidation by Hydrogen Peroxide","authors":"G. Nahmatova, Latifa Gasanova, Tofig Nagiev","doi":"10.4028/p-35bwu0","DOIUrl":"https://doi.org/10.4028/p-35bwu0","url":null,"abstract":"The monooxidation of methane into methanol was carried out on biomimetic heterogeneous catalyst – iron pentafluorotetraphenylporphyrin on Al2O3 (ImtOH), at atmospheric pressure and temperatures of 200-350°C, which resulted in liquid one-carbon compounds CH3OH (19.2%), CH2O (1.55%), CH3OCH3 (8.2%) with high selectivity and are widely used in the chemical industry. In order to establish the routes of these products formation and the mechanism for the methane conversion into them, the investigation of the methanol conversion reaction was carried out, as an intermediate compound of the methane oxidation, under identical conditions on the same catalyst.The result was only dimethyl ether with 100% selectivity. This proved that in this reaction system, methanol obtained from the methane monooxidation is converted only into dimethyl ether, and formaldehyde, in parallel with methanol, is formed from methane. The mechanisms of the elementary stages of the formation of methanol, formaldehyde and dimethyl ether on the surface of the bioimitator through the formation of an active complex (ImtOOH) are presented, in which the unity of the mechanisms of redox and acid-base catalysis traced within the framework of the principle of the bond redistribution chain (BRC), similar to enzymatic reactions.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"14 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140979283","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}
Gabriel V. Buzato, Pedro H. P. Olivio, Adriano L. Souza
The study of water treatment technologies has been growing due to mounting concerns regarding dye contamination. Adsorption-based technologies that use porous materials have been proven useful in water decontamination. However, porous silica xerogels have not been extensively explored as adsorbents for the methyl orange (MO) dye. In this study, the MO-adsorptive behavior of silica xerogels was investigated. Two silica xerogels were synthesized using tetraethyl orthosilicate, and one was modified with cetyltrimethylammonium bromide (CTAB). The adsorptive capacities of the unmodified silica xerogel (SiO2-UN) and the CTAB-modified silica xerogel (SiO2-CTAB) were compared. Results showed a better fit to the Langmuir isotherm model, with maximum adsorbed amounts of 1.52 mg g-1 and 25.5 mg g-1 for SiO2-UN and SiO2-CTAB, respectively. The higher value for SiO2-CTAB is mainly attributed to the electrostatic interactions between MO and the ammonium groups present in the modified xerogel. A study of the porosities of both xerogels, using N2 adsorption and desorption isotherms, indicated the samples were mesoporous. These findings suggest that SiO2-CTAB exhibits favorable MO adsorption and could be employed in future wastewater treatment processes.
由于人们越来越关注染料污染问题，对水处理技术的研究也日益增多。使用多孔材料的吸附技术已被证明可用于水净化。然而，多孔二氧化硅 xerogels 作为甲基橙（MO）染料的吸附剂还没有得到广泛的研究。本研究调查了二氧化硅 xerogels 对 MO 的吸附行为。使用正硅酸四乙酯合成了两种二氧化硅异构凝胶，其中一种用十六烷基三甲基溴化铵（CTAB）进行了改性。比较了未改性二氧化硅异凝胶（SiO2-UN）和 CTAB 改性二氧化硅异凝胶（SiO2-CTAB）的吸附容量。结果表明，SiO2-UN 和 SiO2-CTAB 与 Langmuir 等温线模型的拟合度较高，最大吸附量分别为 1.52 mg g-1 和 25.5 mg g-1。SiO2-CTAB 的吸附值较高，主要是因为 MO 与改性异凝胶中的铵基团之间存在静电相互作用。利用 N2 吸附和解吸等温线对两种异构凝胶的孔隙率进行的研究表明，样品都是介孔的。这些研究结果表明，SiO2-CTAB 具有良好的 MO 吸附性能，可用于未来的废水处理工艺中。
{"title":"Silica Xerogel Modified with Cetyltrimethylammonium Bromide as an Effective Adsorbent for Methyl Orange Dye","authors":"Gabriel V. Buzato, Pedro H. P. Olivio, Adriano L. Souza","doi":"10.4028/p-od9juf","DOIUrl":"https://doi.org/10.4028/p-od9juf","url":null,"abstract":"The study of water treatment technologies has been growing due to mounting concerns regarding dye contamination. Adsorption-based technologies that use porous materials have been proven useful in water decontamination. However, porous silica xerogels have not been extensively explored as adsorbents for the methyl orange (MO) dye. In this study, the MO-adsorptive behavior of silica xerogels was investigated. Two silica xerogels were synthesized using tetraethyl orthosilicate, and one was modified with cetyltrimethylammonium bromide (CTAB). The adsorptive capacities of the unmodified silica xerogel (SiO2-UN) and the CTAB-modified silica xerogel (SiO2-CTAB) were compared. Results showed a better fit to the Langmuir isotherm model, with maximum adsorbed amounts of 1.52 mg g-1 and 25.5 mg g-1 for SiO2-UN and SiO2-CTAB, respectively. The higher value for SiO2-CTAB is mainly attributed to the electrostatic interactions between MO and the ammonium groups present in the modified xerogel. A study of the porosities of both xerogels, using N2 adsorption and desorption isotherms, indicated the samples were mesoporous. These findings suggest that SiO2-CTAB exhibits favorable MO adsorption and could be employed in future wastewater treatment processes.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"33 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140979224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. A. G. Pido, Norodin A. Rangaig, A. A. Z. Munio, Meriam A. Gabule, Rayno Vic B. Janayon, Angel Lou Liwagon, Mitchelle D. Janayon, Johndell C. Canata, Caironesa P. Dulpina
Chemical inertness of pristine carbon nanotubes (CNTs) poses challenges on their biocompatibility. In this paper, surface modification of pristine (5, 5) single-walled carbon nanotube (SWCNT) was explored through substitutional Boron (B) and Nitrogen (N) doping forming a C38NB isomer. The electronic topology and binding mechanism of acetic acid adsorption on the isomer was then examined in the context of first-principles Density Functional Theory (DFT). Accordingly, high abundance of localized electrons between the substitutional doping sites indicates chemical binding of the substitutional atoms with the SWCNT. These are further supported by the calculated bond angles. When the acid was adsorbed on the C38NB isomer, spontaneous charge redistributions were observed which are attributed to the oxidation caused by the O atoms and the charge acceptance of the C atoms. Topological analyses revealed that the net charge transfers for all considered configurations were towards the acid. In addition, the Lowest Unoccupied Molecular Orbital (LUMO) and Highest Occupied Molecular Orbital (HOMO) revealed the nonuniform distribution of electronic charges near the Fermi level. Finally, calculations of the electron localization function (ELF) showed that there was no orbital hybridization between the acid and the isomer. Further, the absence of localized electrons between their interaction points implied a physical binding mechanism. The results of the study could be used for future opto-electronic experiments and electrochemical biosensing applications of CNTs.
原始碳纳米管（CNTs）的化学惰性对其生物相容性提出了挑战。本文通过掺杂硼（B）和氮（N）形成的 C38NB 异构体，探索了原始（5，5）单壁碳纳米管（SWCNT）的表面改性。然后在第一原理密度泛函理论（DFT）的背景下，研究了该异构体上醋酸吸附的电子拓扑结构和结合机制。结果表明，取代掺杂位点之间的高丰度局域电子表明取代原子与 SWCNT 发生了化学结合。计算得出的键角进一步证明了这一点。当酸吸附在 C38NB 异构体上时，观察到自发的电荷再分布，这归因于 O 原子的氧化作用和 C 原子的电荷接受作用。拓扑分析表明，所有考虑到的构型的净电荷转移都是向酸转移的。此外，最低未占分子轨道（LUMO）和最高已占分子轨道（HOMO）显示了费米水平附近电子电荷的不均匀分布。最后，对电子局域函数（ELF）的计算表明，酸和异构体之间不存在轨道杂化。此外，它们的相互作用点之间没有局部电子，这意味着存在一种物理结合机制。研究结果可用于未来的光电实验和碳纳米管的电化学生物传感应用。
{"title":"Exploring the Electronic Topology and Binding Mechanism of Acetic Acid Adsorption on Nitrogen and Boron Co-Doped (5, 5) SWCNT","authors":"A. A. G. Pido, Norodin A. Rangaig, A. A. Z. Munio, Meriam A. Gabule, Rayno Vic B. Janayon, Angel Lou Liwagon, Mitchelle D. Janayon, Johndell C. Canata, Caironesa P. Dulpina","doi":"10.4028/p-pqmgi7","DOIUrl":"https://doi.org/10.4028/p-pqmgi7","url":null,"abstract":"Chemical inertness of pristine carbon nanotubes (CNTs) poses challenges on their biocompatibility. In this paper, surface modification of pristine (5, 5) single-walled carbon nanotube (SWCNT) was explored through substitutional Boron (B) and Nitrogen (N) doping forming a C38NB isomer. The electronic topology and binding mechanism of acetic acid adsorption on the isomer was then examined in the context of first-principles Density Functional Theory (DFT). Accordingly, high abundance of localized electrons between the substitutional doping sites indicates chemical binding of the substitutional atoms with the SWCNT. These are further supported by the calculated bond angles. When the acid was adsorbed on the C38NB isomer, spontaneous charge redistributions were observed which are attributed to the oxidation caused by the O atoms and the charge acceptance of the C atoms. Topological analyses revealed that the net charge transfers for all considered configurations were towards the acid. In addition, the Lowest Unoccupied Molecular Orbital (LUMO) and Highest Occupied Molecular Orbital (HOMO) revealed the nonuniform distribution of electronic charges near the Fermi level. Finally, calculations of the electron localization function (ELF) showed that there was no orbital hybridization between the acid and the isomer. Further, the absence of localized electrons between their interaction points implied a physical binding mechanism. The results of the study could be used for future opto-electronic experiments and electrochemical biosensing applications of CNTs.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"75 20","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140979029","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}
In the present study the notched fatigue behavior of two multi-phase medium entropy alloys (MEAs) AlCrFe2Ni2 and AlCrFe2Ni2Mo0.1 was characterized by three-point-bending (3-PB), along with a super-duplex steel 1.4517 as a reference material. An analytical approach for characterizing the fatigue notch factor (kf), based on grain size analysis in combination with finite element modelling (FEM) was used, relating the theory of critical distances (TCD) to the grain size of the material. To validate the approach, for the reference steel, the fatigue notch factor was also determined experimentally by comparing the fatigue behavior of notched and smooth specimens, resulting in an experimentally determined fatigue notch factor (kf) ~ 1.07. The numerically and analytically estimated notch effects increase with decreasing average grain size and vary between ~ 1.07 for the coarse-grained reference material – in very good agreement with the experimental results – and ~ 1.35 for the much more fine-grained AlCrFe2Ni2Mo0.1 medium entropy alloy. Note that these values are significantly lower than the stress concentration factor (kt) ~ 1.58, associated with the notch geometry. Fatigue endurance limits were measured at a fatigue stress ratio R ~ 0.1 (unidirectional stress), but were converted to fatigue amplitudes at R = -1 (σa, R-1, fully reversed stress), to be able to make due comparisons with available literature data, by using the elliptical relationship. The resulting fatigue endurance limit amplitudes for specimens surviving at least 2E+06 cycles for a minimum of three tested samples and including notch effects are σa, R-1 ~ 508 MPa for the AlCrFe2Ni2 alloy, σa, R-1 ~ 540 MPa for the AlCrFe2Ni2Mo0.1 alloy modification and σa, R-1 ~ 400 MPa for the reference super-duplex steel, putting the analyzed MEAs into a very competitive position compared to Cobalt containing multi-phase high or medium entropy alloys as well as commercially available steels.
{"title":"Fatigue Behavior of Medium Entropy Alloys AlCrFe2Ni2 and AlCrFe2Ni2Mo0.1 - A Comparison with Super Duplex Steel 1.4517","authors":"Susanne Hemes, Sergej Gein, Niloofar Navaeilavasani, Ulrike Hecht","doi":"10.4028/p-w0f1ck","DOIUrl":"https://doi.org/10.4028/p-w0f1ck","url":null,"abstract":"In the present study the notched fatigue behavior of two multi-phase medium entropy alloys (MEAs) AlCrFe2Ni2 and AlCrFe2Ni2Mo0.1 was characterized by three-point-bending (3-PB), along with a super-duplex steel 1.4517 as a reference material. An analytical approach for characterizing the fatigue notch factor (kf), based on grain size analysis in combination with finite element modelling (FEM) was used, relating the theory of critical distances (TCD) to the grain size of the material. To validate the approach, for the reference steel, the fatigue notch factor was also determined experimentally by comparing the fatigue behavior of notched and smooth specimens, resulting in an experimentally determined fatigue notch factor (kf) ~ 1.07. The numerically and analytically estimated notch effects increase with decreasing average grain size and vary between ~ 1.07 for the coarse-grained reference material – in very good agreement with the experimental results – and ~ 1.35 for the much more fine-grained AlCrFe2Ni2Mo0.1 medium entropy alloy. Note that these values are significantly lower than the stress concentration factor (kt) ~ 1.58, associated with the notch geometry. Fatigue endurance limits were measured at a fatigue stress ratio R ~ 0.1 (unidirectional stress), but were converted to fatigue amplitudes at R = -1 (σa, R-1, fully reversed stress), to be able to make due comparisons with available literature data, by using the elliptical relationship. The resulting fatigue endurance limit amplitudes for specimens surviving at least 2E+06 cycles for a minimum of three tested samples and including notch effects are σa, R-1 ~ 508 MPa for the AlCrFe2Ni2 alloy, σa, R-1 ~ 540 MPa for the AlCrFe2Ni2Mo0.1 alloy modification and σa, R-1 ~ 400 MPa for the reference super-duplex steel, putting the analyzed MEAs into a very competitive position compared to Cobalt containing multi-phase high or medium entropy alloys as well as commercially available steels.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"68 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140979068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. A. Z. Munio, A. A. G. Pido, Rayno Vic B. Janayon, L. C. C. Ambolode II
This study provides accounts of the bonding character, electronic structure, and optical properties of the cellulose–polyaniline hybrid complex using principles of quantum mechanics. The calculations revealed cellulose and polyaniline binding energy per unit ranged from -0.52 eV to -0.68 eV. The electron localization function of the complex revealed that there was no value at the interface but deformed basins, indicating a physisorption type of interaction. The highest occupied molecular orbitals and lowest molecular orbitals are mainly dominated by the polyaniline, with minor hybridization of the orbitals of the cellulose in all configurations. These results indicate that the bonding between cellulose and polyaniline is characterized as an unshared electron interaction. Generally, the density of states of the cellulose and polyaniline complex can be considered a superposition of the states of isolated subsystems—the bandgap of the complex ranges from 2.30 eV to 2.87 eV. The lowest bandgap is observed when the prototype polyaniline is placed near the cellulose hydroxy and hydroxymethyl group. Further, the optical absorption spectra are calculated using time-dependent density functional theory. The results indicate that the prominent peak of the prototype polyaniline at 3.59 eV (345.36 nm) is suppressed at the complex. Meanwhile, in the higher energy region, the optical absorption spectra can be considered a superposition of the absorption spectra of the isolated constituents. The results presented here provide new information on the cellulose–polyaniline complex's bonding mechanism and give the resulting electronic–optical properties. The results will be helpful in the development of innovative biomaterials, fibers, and multifunctional composites based on cellulose and polyaniline.
{"title":"A Quantum Chemical Study on the Bonding Mechanism, Electronic Structure, and Optical Properties of Cellulose and Polyaniline Nanohybrid","authors":"A. A. Z. Munio, A. A. G. Pido, Rayno Vic B. Janayon, L. C. C. Ambolode II","doi":"10.4028/p-fa4iq3","DOIUrl":"https://doi.org/10.4028/p-fa4iq3","url":null,"abstract":"This study provides accounts of the bonding character, electronic structure, and optical properties of the cellulose–polyaniline hybrid complex using principles of quantum mechanics. The calculations revealed cellulose and polyaniline binding energy per unit ranged from -0.52 eV to -0.68 eV. The electron localization function of the complex revealed that there was no value at the interface but deformed basins, indicating a physisorption type of interaction. The highest occupied molecular orbitals and lowest molecular orbitals are mainly dominated by the polyaniline, with minor hybridization of the orbitals of the cellulose in all configurations. These results indicate that the bonding between cellulose and polyaniline is characterized as an unshared electron interaction. Generally, the density of states of the cellulose and polyaniline complex can be considered a superposition of the states of isolated subsystems—the bandgap of the complex ranges from 2.30 eV to 2.87 eV. The lowest bandgap is observed when the prototype polyaniline is placed near the cellulose hydroxy and hydroxymethyl group. Further, the optical absorption spectra are calculated using time-dependent density functional theory. The results indicate that the prominent peak of the prototype polyaniline at 3.59 eV (345.36 nm) is suppressed at the complex. Meanwhile, in the higher energy region, the optical absorption spectra can be considered a superposition of the absorption spectra of the isolated constituents. The results presented here provide new information on the cellulose–polyaniline complex's bonding mechanism and give the resulting electronic–optical properties. The results will be helpful in the development of innovative biomaterials, fibers, and multifunctional composites based on cellulose and polyaniline.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":"24 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140981654","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}
In high strength aluminium alloy material turning operation, high material removal and good surface are desirable output characteristics. In this investigation, experiments were conducted according to design of experiments concept with a combination of turning input parameters such as cutting speed, feed rate and depth of cut and also studied the effect of process parameters on multi outputs for machining of Al2024 aluminium alloy. Grey relation analysis was applied to know the robust process parameters. The contribution each parameter was realized with analysis of variance statistical method. The cutting speed is the most influencing parameter with contribution of 62.3% followed by depth of cut with 26.4%, and feed rate with 9.9%.
{"title":"Multi Objective Optimization of Turning Operation Parameters for Aluminium Alloy Using Grey Relational Analysis Method","authors":"Bhanodaya Kiran Babu Nadikudi","doi":"10.4028/p-p5szm8","DOIUrl":"https://doi.org/10.4028/p-p5szm8","url":null,"abstract":"In high strength aluminium alloy material turning operation, high material removal and good surface are desirable output characteristics. In this investigation, experiments were conducted according to design of experiments concept with a combination of turning input parameters such as cutting speed, feed rate and depth of cut and also studied the effect of process parameters on multi outputs for machining of Al2024 aluminium alloy. Grey relation analysis was applied to know the robust process parameters. The contribution each parameter was realized with analysis of variance statistical method. The cutting speed is the most influencing parameter with contribution of 62.3% followed by depth of cut with 26.4%, and feed rate with 9.9%.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":" 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140686726","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}
The present investigation focuses on the implementation of the multi-axial forging process, recognized as a severe plastic deformation (SPD) technique, with the aim of elevating the mechanical features of the widely employed Al 6061 alloy. Specifically utilized in the automotive and aviation industries, this alloy's behavior was meticulously examined through a series of quasi-static and dynamic tests. To achieve this objective, the multi-directional forging (MDF) process was implemented for up to three cycles, involving a total of nine passes, at a raised temperature of 200 °C. Subsequently, the severely deformed material underwent utilizing high strain rate loading for the Split Hopkinson Pressure Bar (SHPB) test system. After MDF, the grain size is refined down to below 11 microns with a starting grain size of 13 microns. This is reflected as increased hardness and yield strength in the quasi-static regime. For SHPB characterization, increased dynamic strength is also observed. However, although the yield strength showed about 60% increase with decent ductility, the maximum dynamic strength increased about 10% after SPD with a relatively brittle behavior.
多轴锻造工艺被认为是一种严重塑性变形（SPD）技术，本研究的重点是多轴锻造工艺的实施，目的是提高广泛使用的铝 6061 合金的机械性能。这种合金专门用于汽车和航空工业，我们通过一系列准静态和动态试验对其性能进行了细致的研究。为实现这一目标，在 200 °C 的升温条件下采用了多向锻造（MDF）工艺，最多可进行三次循环，共九次。随后，严重变形的材料在分体式霍普金森压力棒（SHPB）测试系统中进行高应变率加载。在中密度纤维板之后，晶粒细化到 11 微米以下，而起始晶粒大小为 13 微米。这反映在准静态条件下硬度和屈服强度的提高上。就 SHPB 特性而言，动态强度也有所提高。不过，虽然屈服强度增加了约 60%，延展性也不错，但 SPD 后的最大动态强度却增加了约 10%，行为相对较脆。
{"title":"Comparison of Static and Dynamic Mechanical Response of Aluminum 6061 Subjected to Multi-Directional Forging","authors":"Burak Bahat, G. G. Yapici","doi":"10.4028/p-1ijzjx","DOIUrl":"https://doi.org/10.4028/p-1ijzjx","url":null,"abstract":"The present investigation focuses on the implementation of the multi-axial forging process, recognized as a severe plastic deformation (SPD) technique, with the aim of elevating the mechanical features of the widely employed Al 6061 alloy. Specifically utilized in the automotive and aviation industries, this alloy's behavior was meticulously examined through a series of quasi-static and dynamic tests. To achieve this objective, the multi-directional forging (MDF) process was implemented for up to three cycles, involving a total of nine passes, at a raised temperature of 200 °C. Subsequently, the severely deformed material underwent utilizing high strain rate loading for the Split Hopkinson Pressure Bar (SHPB) test system. After MDF, the grain size is refined down to below 11 microns with a starting grain size of 13 microns. This is reflected as increased hardness and yield strength in the quasi-static regime. For SHPB characterization, increased dynamic strength is also observed. However, although the yield strength showed about 60% increase with decent ductility, the maximum dynamic strength increased about 10% after SPD with a relatively brittle behavior.","PeriodicalId":18262,"journal":{"name":"Materials Science Forum","volume":" 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140689187","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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