Seungjin Nam, Sang Jun Kim, K. Yoon, M. Kim, M. Quevedo-López, J. Hwang, E. Park, Hyun-joo Choi
Property-targeted alloys were designed by exploring the phase stability and mechanical behaviors of a series of AlCoCrFeNi-based multicomponent alloy films fabricated via grain boundary diffusion-assisted solid-state alloying from their multilayer films. For phase identification and hardness evaluation for the multicomponent alloy films, compositional-dependent property contour maps were constructed, and their deformation behaviors were investigated. The results indicate that the alloys revealed a solid solution phase with an FCC structure, whereas Sigma phase was also formed in alloys with a high concentration of Cr. Moreover, the concentration ratio of Co To Ni was dominant to improve solid-solution strengthening, as expected by atomic-level complexity related to the electronegativity difference, and to activate metastable deformation behaviors by reducing the stacking fault energy. Based on the screening results of the compositional-dependent behaviors in the films, consequently, we developed novel metastable CoCrFeNi-based high-entropy alloys with the outstanding tensile properties of 234 MPa in yield strength, 720 MPa in ultimate tensile strength, and 80 % in fracture strain through compositional tailoring the concentration ratio of Co to Ni. This approach shows prospects of property customization of multicomponent alloys
采用晶界扩散辅助固态合金化法制备了一系列alcocrfeni基多组分合金薄膜，研究了其相稳定性和力学行为，设计了性能目标合金。为了对多组分合金薄膜进行物相识别和硬度评定，构建了成分相关的性能等高线图，并对其变形行为进行了研究。结果表明，合金呈现FCC结构的固溶相，而高浓度Cr合金还形成Sigma相。此外，Co To Ni的浓度比对提高固溶强化起主导作用，正如与电负性差相关的原子级复杂性所期望的那样，并通过降低层错能激活亚稳变形行为。基于对薄膜成分依赖行为的筛选结果，通过调整Co与Ni的浓度比，我们开发出了新型亚稳态cocrfeni基高熵合金，该合金具有优异的抗拉性能，屈服强度为234 MPa，极限抗拉强度为720 MPa，断裂应变为80%。该方法显示了多组分合金性能定制的前景
{"title":"Property-Targeted Design of High-Entropy Alloys Based on Tailoring Through Solid-State Alloying from Multilayer Thin Films","authors":"Seungjin Nam, Sang Jun Kim, K. Yoon, M. Kim, M. Quevedo-López, J. Hwang, E. Park, Hyun-joo Choi","doi":"10.2139/ssrn.3757766","DOIUrl":"https://doi.org/10.2139/ssrn.3757766","url":null,"abstract":"Property-targeted alloys were designed by exploring the phase stability and mechanical behaviors of a series of AlCoCrFeNi-based multicomponent alloy films fabricated via grain boundary diffusion-assisted solid-state alloying from their multilayer films. For phase identification and hardness evaluation for the multicomponent alloy films, compositional-dependent property contour maps were constructed, and their deformation behaviors were investigated. The results indicate that the alloys revealed a solid solution phase with an FCC structure, whereas Sigma phase was also formed in alloys with a high concentration of Cr. Moreover, the concentration ratio of Co To Ni was dominant to improve solid-solution strengthening, as expected by atomic-level complexity related to the electronegativity difference, and to activate metastable deformation behaviors by reducing the stacking fault energy. Based on the screening results of the compositional-dependent behaviors in the films, consequently, we developed novel metastable CoCrFeNi-based high-entropy alloys with the outstanding tensile properties of 234 MPa in yield strength, 720 MPa in ultimate tensile strength, and 80 % in fracture strain through compositional tailoring the concentration ratio of Co to Ni. This approach shows prospects of property customization of multicomponent alloys","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87080804","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 : 2020-12-30DOI: 10.15587/2706-5448.2020.218410
Y. Kovalenko, A. Klymenko, V. Tokarchuk, V. Sviderskyi
The object of research is organic additives of methyl hydroxyethyl cellulose of medium and high viscosity, namely, their nature of the effect on the physical and mechanical durability under the destructive influence of various sulfate-ionic media. The need to study the nature of the effect of this additive on resistance to an aggressive environment is also associated mainly with the expansion of the types of building mixtures to create competitive products without losing product quality and to improve the mechanical and rheological properties. In the course of the study, cellulose ethers of medium (17000–23000 mPa∙s) and high (20,000–30,000 mP s) viscosity were used. Additives were added to the cement in the amount of 0.25, 0.5 and 0.75 wt. %. It was found that the introduction of cellulose ether into cement leads to an increase in the normal density of the dough and an extension of the setting time of solutions, in turn, affects the process of strength gain of the latter, in comparison with control samples without additives. With the introduction of the additive, the rate of water separation of the mixtures also significantly decreases, indicating the water-retention capacity of the additive. For the concentration of additives in the amount of 0.25 wt. %. This decrease is 2 times less than for control samples. For a concentration of 0.5–0.75 wt. % Water loss is reduced by 3 times compared to samples without additive. Significant changes also occur during the early strength gain of the samples with an increase in the additive concentration. The destructive effect of an aggressive sulfate medium was determined by the change in compressive strength. With prolonged exposure to an aggressive environment on control and test samples, it is noted that the introduction of this additive of organic origin negatively affects the strength characteristics of cement mixtures with cellulose ethers with an increase in the additive content. The above results indicate the advisability of using cellulose ethers of medium viscosity in dry building mixtures as such, which will provide the necessary storage time for the fluidity of the solution and sufficient strength of the final material.
{"title":"Effect of Sulfate Ion Environment on Physical and Mechanical Durability of Cement Products Modified by Cellulose Ethers","authors":"Y. Kovalenko, A. Klymenko, V. Tokarchuk, V. Sviderskyi","doi":"10.15587/2706-5448.2020.218410","DOIUrl":"https://doi.org/10.15587/2706-5448.2020.218410","url":null,"abstract":"The object of research is organic additives of methyl hydroxyethyl cellulose of medium and high viscosity, namely, their nature of the effect on the physical and mechanical durability under the destructive influence of various sulfate-ionic media. The need to study the nature of the effect of this additive on resistance to an aggressive environment is also associated mainly with the expansion of the types of building mixtures to create competitive products without losing product quality and to improve the mechanical and rheological properties. In the course of the study, cellulose ethers of medium (17000–23000 mPa∙s) and high (20,000–30,000 mP s) viscosity were used. Additives were added to the cement in the amount of 0.25, 0.5 and 0.75 wt. %. It was found that the introduction of cellulose ether into cement leads to an increase in the normal density of the dough and an extension of the setting time of solutions, in turn, affects the process of strength gain of the latter, in comparison with control samples without additives. With the introduction of the additive, the rate of water separation of the mixtures also significantly decreases, indicating the water-retention capacity of the additive. For the concentration of additives in the amount of 0.25 wt. %. This decrease is 2 times less than for control samples. For a concentration of 0.5–0.75 wt. % Water loss is reduced by 3 times compared to samples without additive. Significant changes also occur during the early strength gain of the samples with an increase in the additive concentration. The destructive effect of an aggressive sulfate medium was determined by the change in compressive strength. With prolonged exposure to an aggressive environment on control and test samples, it is noted that the introduction of this additive of organic origin negatively affects the strength characteristics of cement mixtures with cellulose ethers with an increase in the additive content. The above results indicate the advisability of using cellulose ethers of medium viscosity in dry building mixtures as such, which will provide the necessary storage time for the fluidity of the solution and sufficient strength of the final material.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75444337","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}
We determined that a severe martensitic transformation during electrochemical polishing (EP) in 16Cr-5Ni metastable austenitic stainless steel was caused solely by EP. The specimen was treated by EP, then sealed in a quartz tube to protect the surface, then annealed at 1150 °C to form a single austenite phase, and again subjected to EP. As the duration of the second EP increased, the fraction of martensite increased to 72.2% when the duration is 160s at 20V of voltage. However, Ferritescope measurements showed that the martensite fraction of the whole specimen was < 1%; comparison of these results suggests that the martensite transformation by EP was limited to the surface. Calculation of the temperature-dependent difference in Gibbs free energy between α’ martensite and austenite confirmed that the energy applied to the specimen during EP is sufficient to cause martensitic transformation at room temperature.
{"title":"Martensitic Transformation Induced by Electro-Chemical Polishing in Metastable Austenitic Stainless Steel","authors":"Hojun Gwon, D. H. Kim, D. Chae, Sung-Joon Kim","doi":"10.2139/ssrn.3729653","DOIUrl":"https://doi.org/10.2139/ssrn.3729653","url":null,"abstract":"We determined that a severe martensitic transformation during electrochemical polishing (EP) in 16Cr-5Ni metastable austenitic stainless steel was caused solely by EP. The specimen was treated by EP, then sealed in a quartz tube to protect the surface, then annealed at 1150 °C to form a single austenite phase, and again subjected to EP. As the duration of the second EP increased, the fraction of martensite increased to 72.2% when the duration is 160s at 20V of voltage. However, Ferritescope measurements showed that the martensite fraction of the whole specimen was < 1%; comparison of these results suggests that the martensite transformation by EP was limited to the surface. Calculation of the temperature-dependent difference in Gibbs free energy between α’ martensite and austenite confirmed that the energy applied to the specimen during EP is sufficient to cause martensitic transformation at room temperature.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73809094","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: 10.21303/2461-4262.2020.001516
S. Sudirja, A. Hapid, Amin Amin, S. Kaleg, A. C. Budiman
Stress analysis of welded steel-to-steel, bolted steel-to-steel, and bolted composite-steel chassis in an electric low floor medium bus structure is presented in this paper. The analysis was carried out on the condition that is when the bus is full of load in idle/static. This condition reflects the situation of the vehicle in full load with passengers and components, which is important to be analyzed to anticipate the unwanted structural failure of the chassis. Finite Element Method (Harmonic response simulation) is used to investigate the structural behavior of both welded and bolted methods. Several parameters such as 2 Hertz for the maximum frequency, 5000 kg for the total vehicle weight, and the uniform distribution of load are used for this study to simulate the simplified, real application in the real world. The first comparison is between the welded and bolted steel-to-steel chassis which results in the bolted method has a lower stress value by the difference of 4.3 MPa in the joint section than the welded joint. This means that the bolted joint is more recommended than welded for the use as an electric low floor medium bus and has the potential to be optimized further. In terms of reducing the weight of the chassis structure, then lightweight material (carbon fiber composite) is used to replace the full steel chassis to be a composite-steel chassis. The use of this hybrid material depicts the stress value of 61.5 MPa in the joint area, this value is still far below the limit of carbon fiber that is 3200 MPa makes this bolted composite-steel is considerably safe in full load condition as an electric low floor medium bus structure. Using this hybrid bolted composite-steel chassis structure also reduces the total chassis weight by about 22.7 % compared to the full steel chassis structure, thus one could expect to extend the mileage of electric vehicles by more than 20 %
{"title":"Stress Analysis Simulations of Welded and Bolted Joints Method for Full Steel and Composite-Steel Chassis Structure of Electric Low Floor Medium Bus","authors":"S. Sudirja, A. Hapid, Amin Amin, S. Kaleg, A. C. Budiman","doi":"10.21303/2461-4262.2020.001516","DOIUrl":"https://doi.org/10.21303/2461-4262.2020.001516","url":null,"abstract":"Stress analysis of welded steel-to-steel, bolted steel-to-steel, and bolted composite-steel chassis in an electric low floor medium bus structure is presented in this paper. The analysis was carried out on the condition that is when the bus is full of load in idle/static. This condition reflects the situation of the vehicle in full load with passengers and components, which is important to be analyzed to anticipate the unwanted structural failure of the chassis. Finite Element Method (Harmonic response simulation) is used to investigate the structural behavior of both welded and bolted methods. Several parameters such as 2 Hertz for the maximum frequency, 5000 kg for the total vehicle weight, and the uniform distribution of load are used for this study to simulate the simplified, real application in the real world. The first comparison is between the welded and bolted steel-to-steel chassis which results in the bolted method has a lower stress value by the difference of 4.3 MPa in the joint section than the welded joint. This means that the bolted joint is more recommended than welded for the use as an electric low floor medium bus and has the potential to be optimized further. In terms of reducing the weight of the chassis structure, then lightweight material (carbon fiber composite) is used to replace the full steel chassis to be a composite-steel chassis. The use of this hybrid material depicts the stress value of 61.5 MPa in the joint area, this value is still far below the limit of carbon fiber that is 3200 MPa makes this bolted composite-steel is considerably safe in full load condition as an electric low floor medium bus structure. Using this hybrid bolted composite-steel chassis structure also reduces the total chassis weight by about 22.7 % compared to the full steel chassis structure, thus one could expect to extend the mileage of electric vehicles by more than 20 %","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83434215","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}
Resource allocation and proficient practice of spectral frequencies to the cognitive consumers is remaining as a major apprehension in cognitive radio networks. Dynamic resource allocation can resolve the numerous research trials in CRAHNs with respect to spectrum access, allocation, and sharing. In the view of aforementioned research issue, dynamic resource allocation using non-pre-emptive scheduling is proposed by a combination of spectrum assignment and prioritization scheduling of secondary users in a cognitive wireless environment. This research work is proposing an algorithm for multiple input multiple output dynamic spectrum allocation using non-pre-emptive scheduling (MIMO-DSANPS) in CRAHNs is proposed. The simulation is performed on heterogeneous wireless environment and comparing our proposed algorithm with existing Dynamic Resource Allocation (DRA-CRN) algorithm and comparing the quality of service parameters, throughput, interference with sub-channels, packet drop and delay evaluation. As per the simulation study, the existing algorithm is improved with our proposed MIMO-DSANPS by 17% efficient in accessing the spectrum.
{"title":"MIMODSA:Non-Pre-emptive Scheduling in Cognitive Radio Ad-Hoc Networks (CRAHNs)","authors":"M. Shaikh, Dr. Sivasankari G G, Dr. Venugopal K R","doi":"10.2139/ssrn.3736547","DOIUrl":"https://doi.org/10.2139/ssrn.3736547","url":null,"abstract":"Resource allocation and proficient practice of spectral frequencies to the cognitive consumers is remaining as a major apprehension in cognitive radio networks. Dynamic resource allocation can resolve the numerous research trials in CRAHNs with respect to spectrum access, allocation, and sharing. In the view of aforementioned research issue, dynamic resource allocation using non-pre-emptive scheduling is proposed by a combination of spectrum assignment and prioritization scheduling of secondary users in a cognitive wireless environment. This research work is proposing an algorithm for multiple input multiple output dynamic spectrum allocation using non-pre-emptive scheduling (MIMO-DSANPS) in CRAHNs is proposed. The simulation is performed on heterogeneous wireless environment and comparing our proposed algorithm with existing Dynamic Resource Allocation (DRA-CRN) algorithm and comparing the quality of service parameters, throughput, interference with sub-channels, packet drop and delay evaluation. As per the simulation study, the existing algorithm is improved with our proposed MIMO-DSANPS by 17% efficient in accessing the spectrum.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87546664","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}
Y. Dhamecha, S. Gadekara, S. Deshmukh, Y. Haribhakta
With ever-growing utilization of online and offline videos and increasing video content, Video Summarization serves as the best aid for video browsing. It involves domain explicit semantic comprehension of a video and understanding of user expectations. Generally, video summarization systems include extracting video features, analyzing the visual variations and selecting video frames. Over the years, various methodologies have been developed for the same. Different supervised and unsupervised algorithms have been established and these models have been trained on various factors or various rewards. The challenges these methods face stand as a motivation for the approach this paper discusses. Like in many cases, summary frames may be repeated if some scene or concept appears more than once. This paper presents a novel approach based on clustering of video frames based on their feature vectors. The clustering takes into consideration the semantic factor of video frames. Each concept cluster gives a representative frame which then forms the summary set, here concept cluster refers to the independent entity present in a video which can be easily distinguished by another concept or entity. This entity can be a scene of a mountain or different persons. It also aims to increase system performance by removing the redundancy. The system is developed using a CNN for feature extraction and a clustering algorithm that takes into consideration the similarity factor between these vectors. The model is evaluated on the measures Precision and Recall and tested on the VSUMM dataset. The results outperform some of the established methodologies and serve the summarization purpose.
{"title":"Video Summarization Using Feature Vector Clustering","authors":"Y. Dhamecha, S. Gadekara, S. Deshmukh, Y. Haribhakta","doi":"10.2139/ssrn.3734732","DOIUrl":"https://doi.org/10.2139/ssrn.3734732","url":null,"abstract":"With ever-growing utilization of online and offline videos and increasing video content, Video Summarization serves as the best aid for video browsing. It involves domain explicit semantic comprehension of a video and understanding of user expectations. Generally, video summarization systems include extracting video features, analyzing the visual variations and selecting video frames. Over the years, various methodologies have been developed for the same. Different supervised and unsupervised algorithms have been established and these models have been trained on various factors or various rewards. The challenges these methods face stand as a motivation for the approach this paper discusses. Like in many cases, summary frames may be repeated if some scene or concept appears more than once. This paper presents a novel approach based on clustering of video frames based on their feature vectors. The clustering takes into consideration the semantic factor of video frames. Each concept cluster gives a representative frame which then forms the summary set, here concept cluster refers to the independent entity present in a video which can be easily distinguished by another concept or entity. This entity can be a scene of a mountain or different persons. It also aims to increase system performance by removing the redundancy. The system is developed using a CNN for feature extraction and a clustering algorithm that takes into consideration the similarity factor between these vectors. The model is evaluated on the measures Precision and Recall and tested on the VSUMM dataset. The results outperform some of the established methodologies and serve the summarization purpose.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84895894","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}
B. Denkena, M. Dittrich, M. Lindauer, J. Mainka, Lukas Stürenburg
Manufacturing of tool molds represents a single part production characterized by varying designs and various different process steps. The associated milling processes require a precise and complex process planning, which subsequently has to be optimized by running-in tests and adaptions to meet the quality specifications. Moreover, high costs of the raw material and the milling tools require a particularly careful and therefore time-consuming choice of process parameters, mainly based on human experience. Often, subsequent rework becomes necessary. This results in additional efforts during the process. For that purpose, machine learning can be used to find correlations between the process parameters in the process planning and the resulting shape error prior to the first cut. Hereby, the choice of the machine learning algorithm and its hyperparameters largely defines the prediction quality. As a disadvantage, finding the optimum of these hyperparameters to model a process with machine learning can be a tedious, timeconsuming and error-prone procedure that also highly relies on the experience of the respective user. Automated machine learning (AutoML) offers a method to automatically search for a well-performing set of hyperparameters for a specific machine learning application. This study shows the performance improvements achieved by AutoML to predict shape errors that can occur during milling. For this purpose, a series of experimental investigations was conducted to collect representative data in a varying pocket milling process of cold working steel 1.2842. The design of experiment is supposed to ensure a variety of process parameters. As a novel addition, the machine learning model is incorporating the time-variant behavior such as tool wear. Additionally, the study is making a more realistic approach as it is considering error influences from CAD until the machined part in contrast to other studies. We show that we can achieve substantial improvements in terms of prediction RMSE by using the AutoML tool autosklearn; depending on the data between a factor of five and three orders of magnitude compared to plain default settings. This study demonstrates the high potential of using automated machine learning regarding the reduction of efforts in process planning due to improved prediction of shape errors and the ease of using state-of-the-art machine learning.
{"title":"Using AutoML to Optimize Shape Error Prediction in Milling Processes","authors":"B. Denkena, M. Dittrich, M. Lindauer, J. Mainka, Lukas Stürenburg","doi":"10.2139/ssrn.3724234","DOIUrl":"https://doi.org/10.2139/ssrn.3724234","url":null,"abstract":"Manufacturing of tool molds represents a single part production characterized by varying designs and various different process steps. The associated milling processes require a precise and complex process planning, which subsequently has to be optimized by running-in tests and adaptions to meet the quality specifications. Moreover, high costs of the raw material and the milling tools require a particularly careful and therefore time-consuming choice of process parameters, mainly based on human experience. Often, subsequent rework becomes necessary. This results in additional efforts during the process. For that purpose, machine learning can be used to find correlations between the process parameters in the process planning and the resulting shape error prior to the first cut. Hereby, the choice of the machine learning algorithm and its hyperparameters largely defines the prediction quality. As a disadvantage, finding the optimum of these hyperparameters to model a process with machine learning can be a tedious, timeconsuming and error-prone procedure that also highly relies on the experience of the respective user. Automated machine learning (AutoML) offers a method to automatically search for a well-performing set of hyperparameters for a specific machine learning application. This study shows the performance improvements achieved by AutoML to predict shape errors that can occur during milling. For this purpose, a series of experimental investigations was conducted to collect representative data in a varying pocket milling process of cold working steel 1.2842. The design of experiment is supposed to ensure a variety of process parameters. As a novel addition, the machine learning model is incorporating the time-variant behavior such as tool wear. Additionally, the study is making a more realistic approach as it is considering error influences from CAD until the machined part in contrast to other studies. We show that we can achieve substantial improvements in terms of prediction RMSE by using the AutoML tool autosklearn; depending on the data between a factor of five and three orders of magnitude compared to plain default settings. This study demonstrates the high potential of using automated machine learning regarding the reduction of efforts in process planning due to improved prediction of shape errors and the ease of using state-of-the-art machine learning.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87672882","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}
J. Hidalgo, M. Vittorietti, H. Farahani, F. Vercruysse, R. Petrov, J. Sietsma
Understanding the local strain enhancement and lattice distortion resulting from different microstructure features in metal alloys is crucial in many engineering processes. The development of heterogeneous strain not only plays an important role in the work hardening of the material but also in other processes such as recrystallization and damage inheritance and fracture. Isolating the contribution of precipitates to the development of heterogeneous strain can be challenging due to the presence of grain boundaries or other microstructure features that might cause ambiguous interpretation. In this work a statistical analysis of local strains measured by electron back scatter diffraction and crystal plasticity based simulations are combined to determine the effect of M23C6 carbides on the deformation of an annealed AISI 420 steel. Results suggest that carbides provide a more effective hardening at low plastic strain by a predominant long-range interaction mechanism than that of a pure ferritic microstructure. Carbides not only influence local strain directly by elastic incompatibilities with the ferritic matrix, but also the spatial interactions between ferrite grains. Carbides placed at the grain boundaries enhanced the development of strain near ferrite grain boundaries. However the positive effect of carbides and grain boundaries to develop high local strains is mitigated at regions with high density of carbides and ferrite grain boundaries.
{"title":"Influence of M 23C 6 Carbides on the Heterogeneous Strain Development in Annealed 420 Stainless Steel","authors":"J. Hidalgo, M. Vittorietti, H. Farahani, F. Vercruysse, R. Petrov, J. Sietsma","doi":"10.2139/ssrn.3558254","DOIUrl":"https://doi.org/10.2139/ssrn.3558254","url":null,"abstract":"Understanding the local strain enhancement and lattice distortion resulting from different microstructure features in metal alloys is crucial in many engineering processes. The development of heterogeneous strain not only plays an important role in the work hardening of the material but also in other processes such as recrystallization and damage inheritance and fracture. Isolating the contribution of precipitates to the development of heterogeneous strain can be challenging due to the presence of grain boundaries or other microstructure features that might cause ambiguous interpretation. In this work a statistical analysis of local strains measured by electron back scatter diffraction and crystal plasticity based simulations are combined to determine the effect of M23C6 carbides on the deformation of an annealed AISI 420 steel. Results suggest that carbides provide a more effective hardening at low plastic strain by a predominant long-range interaction mechanism than that of a pure ferritic microstructure. Carbides not only influence local strain directly by elastic incompatibilities with the ferritic matrix, but also the spatial interactions between ferrite grains. Carbides placed at the grain boundaries enhanced the development of strain near ferrite grain boundaries. However the positive effect of carbides and grain boundaries to develop high local strains is mitigated at regions with high density of carbides and ferrite grain boundaries.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75246695","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: 10.15587/1729-4061.2020.215129
G. Kochetov, O. Kovalchuk, D. Samchenko
A study of the products of ferritization processing of galvanic waste: sludge and spent process solutions is carried out. As a result of experiments on dynamic leaching of heavy metal ions, the immobilization properties of the sludge, obtained at different process parameters of ferritization are determined. It is shown that the level of immobilization of heavy metals in ferrite sludge after leaching is 99.96 wt % and in the sludge of traditional wastewater neutralization <97.83 wt %. The studies determine the possibility of reliable utilization of ferritized galvanic waste – introduction into the charge to produce alkaline cements. It is found that the main crystalline phases in the structure of alkaline cements with ferrite sludge are calcite, quartz and heavy metal ferrites. In addition, jelly-like formations are found, which are further capable of crystallization. Such formations reliably bind heavy metals in the chemical structure of cement. It is found that when using up to 10 wt % of ferrite sludge in the total weight of cement, the compressive strength of artificial stone reaches 40 MPa, which meets the requirements of the current standard. The chemical stability of the alkali cement matrix using ferrite sludge is confirmed by the study of leaching of heavy metals for one day in neutral, alkaline and acidic media. It is shown that the degree of immobilization of heavy metal ions in cement with a ferrite sludge content of 30 wt % is >99.98 %. In addition, the concentrations of heavy metal ions during leaching meet the national and international standards for their MPC in drinking water and soil. This approach will allow solving the problem of utilization of hazardous galvanic waste and production of general construction materials.
{"title":"Development of Technology of Utilization of Products of Ferritization Processing of Galvanic Waste in the Composition of Alkaline Cements","authors":"G. Kochetov, O. Kovalchuk, D. Samchenko","doi":"10.15587/1729-4061.2020.215129","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.215129","url":null,"abstract":"A study of the products of ferritization processing of galvanic waste: sludge and spent process solutions is carried out. As a result of experiments on dynamic leaching of heavy metal ions, the immobilization properties of the sludge, obtained at different process parameters of ferritization are determined. It is shown that the level of immobilization of heavy metals in ferrite sludge after leaching is 99.96 wt % and in the sludge of traditional wastewater neutralization <97.83 wt %. The studies determine the possibility of reliable utilization of ferritized galvanic waste – introduction into the charge to produce alkaline cements. It is found that the main crystalline phases in the structure of alkaline cements with ferrite sludge are calcite, quartz and heavy metal ferrites. In addition, jelly-like formations are found, which are further capable of crystallization. Such formations reliably bind heavy metals in the chemical structure of cement. It is found that when using up to 10 wt % of ferrite sludge in the total weight of cement, the compressive strength of artificial stone reaches 40 MPa, which meets the requirements of the current standard. The chemical stability of the alkali cement matrix using ferrite sludge is confirmed by the study of leaching of heavy metals for one day in neutral, alkaline and acidic media. It is shown that the degree of immobilization of heavy metal ions in cement with a ferrite sludge content of 30 wt % is >99.98 %. In addition, the concentrations of heavy metal ions during leaching meet the national and international standards for their MPC in drinking water and soil. This approach will allow solving the problem of utilization of hazardous galvanic waste and production of general construction materials.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84595756","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 : 2020-10-30DOI: 10.15587/2706-5448.2020.214172
V. Aulin, O. Derkach, D. Makarenko, A. Hrynkiv, D. Krutous, E. Muranov
The object of research is the process of monitoring the limiting wear of polymer-composite bushings of the bear-ing unit of the parallelogram mechanism of seeding machines. This process is clearly manifested in determining the good condition of the moving joints of machines operating in severe operating conditions. The studies performed are based on the principle of breaking the active link. The diagnostics is based on this principle, which makes it possible to assert with sufficient accuracy about the failure of the control link of the mates of parts. The main hypothesis of the study is that by developing a diagnostic system based on the control of composite bushings, it is possible to determine the boundaries of the normal functioning of the sowing sections as a whole. The solution of this issue without intervention in the design of the sowing section itself is impossible. Since the material of the sleeve is a polymer composite, which has sufficient resistance not to pass an electric current, conditions are created for the implementation of the proposed diagnostic system. In this work, a regression model is built to control and identify changes in the lateral backlash from the operating time of the seeding complex. By analyzing the data obtained, it is possible to establish the relationship between the diagnostic parameter, namely, the fixation of the rupture of the active link passing near the working surface of the composite sleeve. The main limitations in the development of this diagnostic system are the boundaries of the control gaps in the mates, as well as the presence of dielectric materials for the control parts. In the case of a significant occurrence of an active rupture link or an incorrect selection of its required diameter, then this diagnostic method may work inappropriately and the diagnostic system becomes ineffective. The work reflects the timeliness and rationality of the developed diagnostic system. On the basis of such a diagnostic system, it is possible to create an automated diagnostic complex for monitoring the state of the parallelogram mechanisms of the seeding complex as a whole.
{"title":"Development of a System for Diagnosing Bearing Assemblies With Polymer Parts During Operation","authors":"V. Aulin, O. Derkach, D. Makarenko, A. Hrynkiv, D. Krutous, E. Muranov","doi":"10.15587/2706-5448.2020.214172","DOIUrl":"https://doi.org/10.15587/2706-5448.2020.214172","url":null,"abstract":"The object of research is the process of monitoring the limiting wear of polymer-composite bushings of the bear-ing unit of the parallelogram mechanism of seeding machines. This process is clearly manifested in determining the good condition of the moving joints of machines operating in severe operating conditions. The studies performed are based on the principle of breaking the active link. The diagnostics is based on this principle, which makes it possible to assert with sufficient accuracy about the failure of the control link of the mates of parts. The main hypothesis of the study is that by developing a diagnostic system based on the control of composite bushings, it is possible to determine the boundaries of the normal functioning of the sowing sections as a whole. The solution of this issue without intervention in the design of the sowing section itself is impossible. Since the material of the sleeve is a polymer composite, which has sufficient resistance not to pass an electric current, conditions are created for the implementation of the proposed diagnostic system. In this work, a regression model is built to control and identify changes in the lateral backlash from the operating time of the seeding complex. By analyzing the data obtained, it is possible to establish the relationship between the diagnostic parameter, namely, the fixation of the rupture of the active link passing near the working surface of the composite sleeve. The main limitations in the development of this diagnostic system are the boundaries of the control gaps in the mates, as well as the presence of dielectric materials for the control parts. In the case of a significant occurrence of an active rupture link or an incorrect selection of its required diameter, then this diagnostic method may work inappropriately and the diagnostic system becomes ineffective. The work reflects the timeliness and rationality of the developed diagnostic system. On the basis of such a diagnostic system, it is possible to create an automated diagnostic complex for monitoring the state of the parallelogram mechanisms of the seeding complex as a whole.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86741982","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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