K. Mungale, T. Lamichhane, Haobo Wang, B. Sales, M. Paranthaman, U. Vaidya
Abstract Anisotropic bonded Nd2Fe14B (NdFeB) magnets in a polycarbonate (PC) binder matrix are fabricated using a compression molding process. The weight fractions (w.f.) of NdFeB in PC on the batch mixer are 20, 50, 75, 85 and 95% compared to the twin screw extruder with 20, 50 and 75% respectively. The density of the 95% batch mixed magnets fabricated was 5.34 g/cm3 and the magnetic properties are, intrinsic coercivity Hci = 942.99 kA/m, remanence Br = 0.86 T, and energy product (BH)max = 120.96 kJ/m3. The measured tensile properties are in the range of 27-59 MPa, comparable to that of polyamide (PA), polyphenylene sulfide (PPS) bonded magnets and demonstrating potential for bonded magnet applications. Scanning electron microscopy showed that the onset of failure occurs in the magnetic particle- matrix interface. This study demonstrates that compression additive molding technique can be used to fabricate high performance NdFeB polycarbonate composite magnets with improved mechanical properties.
{"title":"Compression Molding of Anisotropic Ndfeb Bonded Magnets in a Polycarbonate Matrix","authors":"K. Mungale, T. Lamichhane, Haobo Wang, B. Sales, M. Paranthaman, U. Vaidya","doi":"10.2139/ssrn.3844700","DOIUrl":"https://doi.org/10.2139/ssrn.3844700","url":null,"abstract":"Abstract Anisotropic bonded Nd2Fe14B (NdFeB) magnets in a polycarbonate (PC) binder matrix are fabricated using a compression molding process. The weight fractions (w.f.) of NdFeB in PC on the batch mixer are 20, 50, 75, 85 and 95% compared to the twin screw extruder with 20, 50 and 75% respectively. The density of the 95% batch mixed magnets fabricated was 5.34 g/cm3 and the magnetic properties are, intrinsic coercivity Hci = 942.99 kA/m, remanence Br = 0.86 T, and energy product (BH)max = 120.96 kJ/m3. The measured tensile properties are in the range of 27-59 MPa, comparable to that of polyamide (PA), polyphenylene sulfide (PPS) bonded magnets and demonstrating potential for bonded magnet applications. Scanning electron microscopy showed that the onset of failure occurs in the magnetic particle- matrix interface. This study demonstrates that compression additive molding technique can be used to fabricate high performance NdFeB polycarbonate composite magnets with improved mechanical properties.","PeriodicalId":412391,"journal":{"name":"ChemRN: Materials Processing (Topic)","volume":"891 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132054207","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}
Metal additive manufacturing is promising for designing advanced metallic parts of complex geometries. The challenge lies in process control on melt flow dynamics, alloy mixing and vapour mass loss, which is significantly vital for the final quality. A high-fidelity thermal-solutal-fluid modelling approach including accurate tracking of surface shape, thermo-capillary dynamics and vaporisation has been developed. Multi-species formulations are also included for multi-metals simulation. Using this method, the physical link between metal vapour mass loss and melt flow process for 21 transition metals and 3 binary alloys is investigated. The mass loss rate is governed by a fluid dynamic parameter of Reynolds number with a simple proportional correlation linked with thermal-fluid behaviour of the melt pool, and convective mixing further complicates the behaviour in in-situ binary alloying. The digital materials approach is effective in understanding complex interdependent thermal-fluid flow dynamics and can advance process-based materials design.
{"title":"Digital Materials Design by Thermal-Fluid Science for Multi-Metals Additive Manufacturing","authors":"J. Shinjo, C. Panwisawas","doi":"10.2139/ssrn.3770985","DOIUrl":"https://doi.org/10.2139/ssrn.3770985","url":null,"abstract":"Metal additive manufacturing is promising for designing advanced metallic parts of complex geometries. The challenge lies in process control on melt flow dynamics, alloy mixing and vapour mass loss, which is significantly vital for the final quality. A high-fidelity thermal-solutal-fluid modelling approach including accurate tracking of surface shape, thermo-capillary dynamics and vaporisation has been developed. Multi-species formulations are also included for multi-metals simulation. Using this method, the physical link between metal vapour mass loss and melt flow process for 21 transition metals and 3 binary alloys is investigated. The mass loss rate is governed by a fluid dynamic parameter of Reynolds number with a simple proportional correlation linked with thermal-fluid behaviour of the melt pool, and convective mixing further complicates the behaviour in in-situ binary alloying. The digital materials approach is effective in understanding complex interdependent thermal-fluid flow dynamics and can advance process-based materials design.","PeriodicalId":412391,"journal":{"name":"ChemRN: Materials Processing (Topic)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133958109","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 work is an investigation towards making the spot welding joint reliable by improving the quality of a welded joint for a commercially available low carbon steel of BIS 513:2008 standard. The focus is to analyze the microstructure of spot welded low carbon steel using tungsten carbide powder. Tensile shear strength was employed to check the failure of such joints. The verification was done through the experimentation using optimized combination of levels for parameters. Tensile tests were performed using instron type UTM machines to give accurate results. Finally, an attempt was made to outline modes of failure for different sets of experiment and preventing them to strength the welded joint making them reliable. The investigation proved the nature of failure in relation with the microstructure of welded component during the loaded condition.
{"title":"Microstructure Analysis of Resistance Spot Welding of Commercial Low Carbon Steel using WC Micro-Powder","authors":"Nirmalendu Hota, Triloki Nath Mishra","doi":"10.2139/ssrn.3767399","DOIUrl":"https://doi.org/10.2139/ssrn.3767399","url":null,"abstract":"The present work is an investigation towards making the spot welding joint reliable by improving the quality of a welded joint for a commercially available low carbon steel of BIS 513:2008 standard. The focus is to analyze the microstructure of spot welded low carbon steel using tungsten carbide powder. Tensile shear strength was employed to check the failure of such joints. The verification was done through the experimentation using optimized combination of levels for parameters. Tensile tests were performed using instron type UTM machines to give accurate results. Finally, an attempt was made to outline modes of failure for different sets of experiment and preventing them to strength the welded joint making them reliable. The investigation proved the nature of failure in relation with the microstructure of welded component during the loaded condition.","PeriodicalId":412391,"journal":{"name":"ChemRN: Materials Processing (Topic)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117352968","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 : 2020-11-30DOI: 10.21303/2585-6847.2020.001479
K. Deineka, Yuriy Naumenko
The influence of the structure of a two-fraction polygranular feed of the chamber on the value of the drum rotation speed at auto-excitation of self-excited oscillations with a maximum swing is considered. Such a pulsating mode of movement of the charge is used in the self-oscillating process of grinding in a tumbling mill. The coarse fraction simulated the grinding bodies was steel bullets with a relative size ψdb=0.026. The fine fraction, simulated the particles of the crushed material, was a cement clinker with a relative particle size ψdm=0.00013. Variable factors of experimental studies were: the degree of filling the chamber in the state of rest κbr=0.25; 0.29; 0.33 and the degree of filling the gaps between the particles of the coarse fraction with particles of the fine fraction κmbgr=0.0625; 0.375; 0.6875; 1. The method of visual analysis of transient processes of self-oscillating modes of feed behavior in the cross section of the rotating drum chamber is applied. Measurements of the speed limits of the drum rotation were carried out with auto-excitation of self-oscillations of the filling. The magnitude of the self-oscillation swing was estimated by the increase in the difference between the maximum and minimum values of the filling dilatancy for one period of pulsations. An increase in the upper limit of the speed range ψω2 with a decrease in κbr and κmbgr was established. The growth rate of ψω2 increases at low values of κbr and κmbgr. Some increase in the lower limit of the ψω1 range with a decrease in κbr and κmbgr was revealed. An increase in the range of speeds of rotation was recorded at the maximum range of self-oscillations ψω1–ψω2 with a decrease in the connected interaction of the intra-mill filling. This coherent interaction is due to an increase in κbr and κmbgr. The value of the ψω1–ψω2 range varies from 1.01–1.03 at κbr=0.33 and κmbg=1 to 1.22–1.66 at κbr=0.25 and κmbgr=0.0625. The range gets its maximum value with fine and superfine grinding
{"title":"Establishing the Rotation Speed Variation Range Limits for Auto-Excitation of Self-Oscillating Grinding in a Tumbling Mill","authors":"K. Deineka, Yuriy Naumenko","doi":"10.21303/2585-6847.2020.001479","DOIUrl":"https://doi.org/10.21303/2585-6847.2020.001479","url":null,"abstract":"The influence of the structure of a two-fraction polygranular feed of the chamber on the value of the drum rotation speed at auto-excitation of self-excited oscillations with a maximum swing is considered. Such a pulsating mode of movement of the charge is used in the self-oscillating process of grinding in a tumbling mill. The coarse fraction simulated the grinding bodies was steel bullets with a relative size ψdb=0.026. The fine fraction, simulated the particles of the crushed material, was a cement clinker with a relative particle size ψdm=0.00013. Variable factors of experimental studies were: the degree of filling the chamber in the state of rest κbr=0.25; 0.29; 0.33 and the degree of filling the gaps between the particles of the coarse fraction with particles of the fine fraction κmbgr=0.0625; 0.375; 0.6875; 1. The method of visual analysis of transient processes of self-oscillating modes of feed behavior in the cross section of the rotating drum chamber is applied. Measurements of the speed limits of the drum rotation were carried out with auto-excitation of self-oscillations of the filling. The magnitude of the self-oscillation swing was estimated by the increase in the difference between the maximum and minimum values of the filling dilatancy for one period of pulsations. An increase in the upper limit of the speed range ψω2 with a decrease in κbr and κmbgr was established. The growth rate of ψω2 increases at low values of κbr and κmbgr. Some increase in the lower limit of the ψω1 range with a decrease in κbr and κmbgr was revealed. An increase in the range of speeds of rotation was recorded at the maximum range of self-oscillations ψω1–ψω2 with a decrease in the connected interaction of the intra-mill filling. This coherent interaction is due to an increase in κbr and κmbgr. The value of the ψω1–ψω2 range varies from 1.01–1.03 at κbr=0.33 and κmbg=1 to 1.22–1.66 at κbr=0.25 and κmbgr=0.0625. The range gets its maximum value with fine and superfine grinding","PeriodicalId":412391,"journal":{"name":"ChemRN: Materials Processing (Topic)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117159948","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 : 2020-10-31DOI: 10.15587/1729-4061.2020.215160
O. Kovaliova, O. Pivovarov, V. Kalyna, Yuriy Tchoursinov, Ekaterina Kunitsia, A. Chernukha, Dmytro Polkovnychenko, N. Grigorenko, Tetiana Kurska, O. Yermakova
This study has established patterns in the plasmochemical activation of technological solutions in the process of malt production. Of importance is the application of innovative technologies to purify water and technological solutions used at malt enterprises that consume large quantities of water resources. A promising technology is the plasmochemical treatment of water and technological solutions in order to purify them and, partially or completely, destroy pathogenic microflora. Due to the use of plasmochemical activation, it has become possible not only to improve the malting process but also to reduce the consumption of water resources for technological purposes by 2‒3 times. This is achieved by improving the technological malting process and by the possibility of reuse of wastewater after its filtering and plasmochemical treatment. The experimental laboratory tests have proven the effectiveness of using plasmochemical activation of technological solutions in order to improve the qualitative indicators of wastewater and the possibility of reuse of such solutions after their plasmochemical activation. Applying the proposed method for treating technological solutions decreased the level of contamination of wastewater from malt production. Sewage contamination after activation decreased. Thus, pollution indicators decreased as follows: per dry residue – by 65‒95 %; the content of suspended substances – by 33‒66 %; residue after roasting – by 58‒79 %; total nitrogen – by 58‒80 %; P2O5 (phosphorus) – by 75‒88 %; K2O (potassium) – by 75‒ 92 %; CaO (calcium) – by 81‒92 %; Na2O – by 67–83 %; Cl- – not detected; oxidation – by 78‒95 %; BOC5 (biochemical oxygen consumption) ‒ by 92‒97 %; pH became alkaline. In plasmochemical treatment, there is a disinfection of wastewater, namely, during an activation mode of 60 min the phytopathogenic microflora (Aspergillus, Alternaria, Penicillium, Fusarium, Mucor) were destroyed. This indicates the effectiveness of the purification and decontamination of technological solutions. Its application is the key to the environmental safety of malt production when all its stages meet the requirements of "green" technologies.
{"title":"Implementation of the Plasmochemical Activation of Technological Solutions in the Process of Ecologization of Malt Production","authors":"O. Kovaliova, O. Pivovarov, V. Kalyna, Yuriy Tchoursinov, Ekaterina Kunitsia, A. Chernukha, Dmytro Polkovnychenko, N. Grigorenko, Tetiana Kurska, O. Yermakova","doi":"10.15587/1729-4061.2020.215160","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.215160","url":null,"abstract":"This study has established patterns in the plasmochemical activation of technological solutions in the process of malt production. Of importance is the application of innovative technologies to purify water and technological solutions used at malt enterprises that consume large quantities of water resources. A promising technology is the plasmochemical treatment of water and technological solutions in order to purify them and, partially or completely, destroy pathogenic microflora. Due to the use of plasmochemical activation, it has become possible not only to improve the malting process but also to reduce the consumption of water resources for technological purposes by 2‒3 times. This is achieved by improving the technological malting process and by the possibility of reuse of wastewater after its filtering and plasmochemical treatment. The experimental laboratory tests have proven the effectiveness of using plasmochemical activation of technological solutions in order to improve the qualitative indicators of wastewater and the possibility of reuse of such solutions after their plasmochemical activation. Applying the proposed method for treating technological solutions decreased the level of contamination of wastewater from malt production. Sewage contamination after activation decreased. Thus, pollution indicators decreased as follows: per dry residue – by 65‒95 %; the content of suspended substances – by 33‒66 %; residue after roasting – by 58‒79 %; total nitrogen – by 58‒80 %; P2O5 (phosphorus) – by 75‒88 %; K2O (potassium) – by 75‒ 92 %; CaO (calcium) – by 81‒92 %; Na2O – by 67–83 %; Cl- – not detected; oxidation – by 78‒95 %; BOC5 (biochemical oxygen consumption) ‒ by 92‒97 %; pH became alkaline. In plasmochemical treatment, there is a disinfection of wastewater, namely, during an activation mode of 60 min the phytopathogenic microflora (Aspergillus, Alternaria, Penicillium, Fusarium, Mucor) were destroyed. This indicates the effectiveness of the purification and decontamination of technological solutions. Its application is the key to the environmental safety of malt production when all its stages meet the requirements of \"green\" technologies.","PeriodicalId":412391,"journal":{"name":"ChemRN: Materials Processing (Topic)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127784988","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}
Qian Liu, Hongkun Wu, M. J. Paul, P. He, Zhongxiao Peng, B. Gludovatz, J. Kruzic, Chun H. Wang, Xiaopeng Li
Abstract In this study, a machine-learning approach based on Gaussian process regression was developed to identify the optimized processing window for laser powder bed fusion (LPBF). Using this method, we found a new and much larger optimized LPBF processing window than was known before for manufacturing fully dense AlSi10Mg samples (i.e., relative density ≥ 99%). The newly determined optimized processing parameters (e.g., laser power and scan speed) made it possible to achieve previously unattainable combinations of high strength and ductility. The results showed that although the AlSi10Mg specimens exhibited similar Al-Si eutectic microstructures (e.g., cell structures in fine and coarse grains), they displayed large difference in their mechanical properties including hardness (118 - 137 HV 10), ultimate tensile strength (297 - 389 MPa), elongation to failure (6.3 - 10.3%), and fracture toughness (9.9 - 12.7 kJ/m2). The underlying reason was attributed to the subtle microstructural differences that were further revealed using two newly defined morphology indices (i.e., dimensional-scale index Id and shape index Is) based on several key microstructural features obtained from scanning electron microscopy images. It was found that in addition to grain structure, the sub-grain cell size and cell boundary morphology of the LPBF fabricated AlSi10Mg also strongly affected the mechanical properties of the material. The method established in this study can be readily applied to the LPBF process optimization and mechanical properties manipulation of other widely used metals and alloys or newly designed materials.
{"title":"Machine-Learning Assisted Laser Powder Bed Fusion Process Optimization for AlSi10mg: New Microstructure Description Indices and Fracture Mechanisms","authors":"Qian Liu, Hongkun Wu, M. J. Paul, P. He, Zhongxiao Peng, B. Gludovatz, J. Kruzic, Chun H. Wang, Xiaopeng Li","doi":"10.2139/ssrn.3681162","DOIUrl":"https://doi.org/10.2139/ssrn.3681162","url":null,"abstract":"Abstract In this study, a machine-learning approach based on Gaussian process regression was developed to identify the optimized processing window for laser powder bed fusion (LPBF). Using this method, we found a new and much larger optimized LPBF processing window than was known before for manufacturing fully dense AlSi10Mg samples (i.e., relative density ≥ 99%). The newly determined optimized processing parameters (e.g., laser power and scan speed) made it possible to achieve previously unattainable combinations of high strength and ductility. The results showed that although the AlSi10Mg specimens exhibited similar Al-Si eutectic microstructures (e.g., cell structures in fine and coarse grains), they displayed large difference in their mechanical properties including hardness (118 - 137 HV 10), ultimate tensile strength (297 - 389 MPa), elongation to failure (6.3 - 10.3%), and fracture toughness (9.9 - 12.7 kJ/m2). The underlying reason was attributed to the subtle microstructural differences that were further revealed using two newly defined morphology indices (i.e., dimensional-scale index Id and shape index Is) based on several key microstructural features obtained from scanning electron microscopy images. It was found that in addition to grain structure, the sub-grain cell size and cell boundary morphology of the LPBF fabricated AlSi10Mg also strongly affected the mechanical properties of the material. The method established in this study can be readily applied to the LPBF process optimization and mechanical properties manipulation of other widely used metals and alloys or newly designed materials.","PeriodicalId":412391,"journal":{"name":"ChemRN: Materials Processing (Topic)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132370399","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 : 2020-08-12DOI: 10.20998/2074-272x.2020.4.02
M. Ben Slimene
Purpose: This paper presents a d-q model of six-phase induction machine supplied by a two identical voltage source inverters suitable for analysis the dynamic steady under balanced operating condition. In the analytical model, the effects of common mutual leakage inductance between the dual stator have been included. The model has been developed in general reference frame taking into account of 0°, 30° and 60° displacements between two stator winding sets. The main purpose of this work is to conduct a quantitative study to show the advantage of supplying the six-phase induction machine by a multilevel inverter. The voltage and current total harmonic distortion and the torque ripple rate are the main targets. This paper is organized into four sections. After the introduction, the second section includes development of mathematical models concerning the six-phase induction machine. The third presents the effect of displacements of 0°, 30 ° and 60 ° between two stator-winding sets, and a comparison of three cases. After that, we present a comparative study between two, three, five and seven inverter levels when feeding the six-phase induction machine. For this purpose, simulations were carried out to obtain phase currents and torque ripple rates in steady state.
{"title":"Performance Analysis of Six-Phase Induction Machine-Multilevel Inverter with Arbitrary Displacement","authors":"M. Ben Slimene","doi":"10.20998/2074-272x.2020.4.02","DOIUrl":"https://doi.org/10.20998/2074-272x.2020.4.02","url":null,"abstract":"Purpose: This paper presents a d-q model of six-phase induction machine supplied by a two identical voltage source inverters suitable for analysis the dynamic steady under balanced operating condition. In the analytical model, the effects of common mutual leakage inductance between the dual stator have been included. The model has been developed in general reference frame taking into account of 0°, 30° and 60° displacements between two stator winding sets. The main purpose of this work is to conduct a quantitative study to show the advantage of supplying the six-phase induction machine by a multilevel inverter. The voltage and current total harmonic distortion and the torque ripple rate are the main targets. This paper is organized into four sections. After the introduction, the second section includes development of mathematical models concerning the six-phase induction machine. The third presents the effect of displacements of 0°, 30 ° and 60 ° between two stator-winding sets, and a comparison of three cases. After that, we present a comparative study between two, three, five and seven inverter levels when feeding the six-phase induction machine. For this purpose, simulations were carried out to obtain phase currents and torque ripple rates in steady state. <br>","PeriodicalId":412391,"journal":{"name":"ChemRN: Materials Processing (Topic)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129023379","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 this paper we focus on physical & chemical aspects of AlF3∙3H2O crystals dehydration process. A new highly efficient single-stage method for drying and calcination of AlF3∙3H2O crystals is presented for the first time. In this method a countercurrent drum dryer-calciner of original design is used. The method ensures high quality product (more than 97 % of AlF3 with high flowability) and low heat loss due to combining both drying and calcination processes in one dryer-calciner. Economic factors of this method are assessed and compared with existent methods.
{"title":"Improvements in Technology of AlF3 from FSA","authors":"E. Torochkov, Constantin Gorbovskiy","doi":"10.2139/ssrn.3638919","DOIUrl":"https://doi.org/10.2139/ssrn.3638919","url":null,"abstract":"In this paper we focus on physical & chemical aspects of AlF3∙3H2O crystals dehydration process. A new highly efficient single-stage method for drying and calcination of AlF3∙3H2O crystals is presented for the first time. In this method a countercurrent drum dryer-calciner of original design is used. The method ensures high quality product (more than 97 % of AlF3 with high flowability) and low heat loss due to combining both drying and calcination processes in one dryer-calciner. Economic factors of this method are assessed and compared with existent methods.","PeriodicalId":412391,"journal":{"name":"ChemRN: Materials Processing (Topic)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131526540","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 : 2020-06-19DOI: 10.15587/1729-4061.2020.203685
R. Strelchuk, S. Trokhymchuk, M. Sofronova, T. Osipova
The electro-erosive wheel dressing exerts a significant impact on the machining accuracy of an article and the efficiency of the profile grinding process. To effectively control machining accuracy, the most important is the error due to the wear of a diamond wheel. The wheel should be dressed when wear approaches to the border but does not go beyond the tolerance field. This would reduce the number of defects at machining and bring down the utilization of diamonds. In addition, this reduces the dressing time and, therefore, improves the efficiency of profile diamond grinding. The paper reports the methodology and results of an experimental study into the wear of profiled diamond wheels. The specific utilization of diamonds was examined on the grinding wheels of the direct profile. The amount of a wheel linear wear was measured by a contactless method applying a special device based on the use of eddy current sensors. This was followed by determining the integrated amount of the worn volume of a diamond layer; after that, the weight of the used diamonds was measured. The mass of the sanded material was determined by weighing it before and after machining. A mathematical method of planning and analysis of experiments was used to establish the functional dependence of the specific utilization of diamonds on the technological machining modes and the diamond layer parameters. The result of regression analysis is the derived functional dependence of diamond specific utilization on the following factors: the concentration of diamonds in a wheel, the grit of the tool, the grinding wheel velocity, the depth of grinding, and the speed of an article. To determine the patterns of wear of the shaped diamond wheel, we received an imprint of its profile on a control plate made from a solid alloy and measured the coordinates of the points of the working part of the profile relative to the non-utilized areas. Determining the difference of coordinates before and after the experiment has helped find the amount of radial wear of the grinding wheel at the appropriate profile point
{"title":"Revealing Patterns in the Wear of Profile Diamond Wheels","authors":"R. Strelchuk, S. Trokhymchuk, M. Sofronova, T. Osipova","doi":"10.15587/1729-4061.2020.203685","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.203685","url":null,"abstract":"The electro-erosive wheel dressing exerts a significant impact on the machining accuracy of an article and the efficiency of the profile grinding process. To effectively control machining accuracy, the most important is the error due to the wear of a diamond wheel. The wheel should be dressed when wear approaches to the border but does not go beyond the tolerance field. This would reduce the number of defects at machining and bring down the utilization of diamonds. In addition, this reduces the dressing time and, therefore, improves the efficiency of profile diamond grinding. The paper reports the methodology and results of an experimental study into the wear of profiled diamond wheels. The specific utilization of diamonds was examined on the grinding wheels of the direct profile. The amount of a wheel linear wear was measured by a contactless method applying a special device based on the use of eddy current sensors. This was followed by determining the integrated amount of the worn volume of a diamond layer; after that, the weight of the used diamonds was measured. The mass of the sanded material was determined by weighing it before and after machining. A mathematical method of planning and analysis of experiments was used to establish the functional dependence of the specific utilization of diamonds on the technological machining modes and the diamond layer parameters. The result of regression analysis is the derived functional dependence of diamond specific utilization on the following factors: the concentration of diamonds in a wheel, the grit of the tool, the grinding wheel velocity, the depth of grinding, and the speed of an article. To determine the patterns of wear of the shaped diamond wheel, we received an imprint of its profile on a control plate made from a solid alloy and measured the coordinates of the points of the working part of the profile relative to the non-utilized areas. Determining the difference of coordinates before and after the experiment has helped find the amount of radial wear of the grinding wheel at the appropriate profile point","PeriodicalId":412391,"journal":{"name":"ChemRN: Materials Processing (Topic)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125983117","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 : 2020-04-30DOI: 10.15587/1729-4061.2020.200573
O. Zhuchenko, M. Khibeba
Among the most energy-intensive industries is the production of carbon articles, therefore, the improvement of its efficiency is a relevant scientific and technical task. One of the ways to resolve the set task is to create a modern production management system.
This paper considers the creation of a control system for one of the essential technological processes in carbon articles production – the process of their formation. Underlying the control system is the optimality criterion based on the specific cost of products taking into consideration their quality indicators. The control method used is Model Predictive Control (MPC). The results of studying the dependence of an optimality criterion on the setting parameters of an MPC-controller have made it possible to determine the optimum values for the prediction and control horizons, which could ensure the minimization of the products’ specific cost. The structure of the proposed control system, developed in the Simulink programming environment, makes it possible to investigate a given control system through computer simulations.
The efficiency of the proposed system to control the process of carbon product molding was examined by comparing the quality of control by a given system and by the system that uses the classic PID control law. To this end, a three-circuit control system based on the PID-controllers was synthesized in the Simulink programming environment. Each controller was set, using a Powell method, for a minimum value of the integrated criterion. The results of the comparative study have demonstrated that at each operation cycle the optimality criterion value in the control system employing an MPC-controller was 8.8 % less than that in the system with PID-controllers at the same indicators of product quality. That testifies to the improvement in the technical and economic indicators of the formation process. This fact is of particular importance when taking into consideration the circularity of the technological process of carbon product formation.
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