A. Trostianchyn, Z. Duriagina, I. Izonin, R. Tkachenko, V. Kulyk, O. Pavliuk
The use of machine learning tools in modern materials science can significantly reduce the duration and cost of developing new materials and improving the properties of existing ones. This is especially true in studying expensive and strategic importance materials like alloys of rare earth metals, which are used to manufacture high-energy permanent magnets. At the same time, single machine learning algorithms do not always provide the accuracy required to solve a particular applied task. Therefore, the current paper aimed to develop an ensemble model for predicting the magnetic properties of Sm-Co system alloys with high accuracy. Based on literature data, we have collected the dataset of the relationship between phase composition, sample state, crystallographic orientation, microstructure, and magnetic properties. We have compared different machine learning algorithms. A stacking ensemble model was designed based on high-precision machine learning algorithms: Neural Networks, AdaBoost, Gradient Boosting, and Random Forest algorithm. The proposed ensemble scheme showed a significant increase in the accuracy for predicting the magnetic properties of Sm-Co alloys on the example of coercivity.
{"title":"Sm-Co ALLOYS COERCIVITY PREDICTION USING STACKING HETEROGENEOUS ENSEMBLE MODEL","authors":"A. Trostianchyn, Z. Duriagina, I. Izonin, R. Tkachenko, V. Kulyk, O. Pavliuk","doi":"10.36547/ams.27.4.1173","DOIUrl":"https://doi.org/10.36547/ams.27.4.1173","url":null,"abstract":"The use of machine learning tools in modern materials science can significantly reduce the duration and cost of developing new materials and improving the properties of existing ones. This is especially true in studying expensive and strategic importance materials like alloys of rare earth metals, which are used to manufacture high-energy permanent magnets. At the same time, single machine learning algorithms do not always provide the accuracy required to solve a particular applied task. Therefore, the current paper aimed to develop an ensemble model for predicting the magnetic properties of Sm-Co system alloys with high accuracy. Based on literature data, we have collected the dataset of the relationship between phase composition, sample state, crystallographic orientation, microstructure, and magnetic properties. We have compared different machine learning algorithms. A stacking ensemble model was designed based on high-precision machine learning algorithms: Neural Networks, AdaBoost, Gradient Boosting, and Random Forest algorithm. The proposed ensemble scheme showed a significant increase in the accuracy for predicting the magnetic properties of Sm-Co alloys on the example of coercivity.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48669291","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}
Magnesium is a promising lightweight metal required in many industries such as automobile, aerospace, electronics, etc. It is also a biodegradable material, which eliminates the secondary removal procedure of the implant. Furthermore, its mechanical properties are similar to the mechanical properties of human bone. In this research, eggshells were used as an environmentally friendly composite reinforcement material in the Mg-2.5Zn-1Mn matrix. Composites were prepared using the powder metallurgy route. The effect of eggshells on the morphology, mechanical, and corrosion behaviour of Mg-2.5Zn-1Mn alloy was investigated. The results revealed an enhancement in grain refining ability and mechanical properties of Mg-2.5Zn-1Mn with eggshell additives. The corrosion behaviour improved at a higher percentage of eggshells (10%).
{"title":"The effect of eggshell as a reinforcement on the mechanical and Corrosion properties of Mg-Zn-Mn matrix composite","authors":"Hasan A. Fattah, M. Gouda, S. Salman, A. Elsayed","doi":"10.36547/ams.27.4.1088","DOIUrl":"https://doi.org/10.36547/ams.27.4.1088","url":null,"abstract":"Magnesium is a promising lightweight metal required in many industries such as automobile, aerospace, electronics, etc. It is also a biodegradable material, which eliminates the secondary removal procedure of the implant. Furthermore, its mechanical properties are similar to the mechanical properties of human bone. In this research, eggshells were used as an environmentally friendly composite reinforcement material in the Mg-2.5Zn-1Mn matrix. Composites were prepared using the powder metallurgy route. The effect of eggshells on the morphology, mechanical, and corrosion behaviour of Mg-2.5Zn-1Mn alloy was investigated. The results revealed an enhancement in grain refining ability and mechanical properties of Mg-2.5Zn-1Mn with eggshell additives. The corrosion behaviour improved at a higher percentage of eggshells (10%).","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43742411","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. Koveria, L. Kieush, M. Boyko, Maksym Yaholnyk, Natalia Poliakova
Steel production is the most dynamic industry and one of the key sectors for the development of the global economy. The growing production of iron ore increases the need for its beneficiation and granulating for subsequent use in the production of iron and steel. As a result, the number of CO2 emissions and harmful substances increases, which negatively affects both society and the environment. It is important to study the use of biomass for the production of iron ore pellets. Lignocellulosic biomass is a renewable and sustainable source of heat and energy that can mitigate climate change. The efficiency of using sunflower husks on the combined machine “straight grate - rotary kiln - annular cooler” to partially replace natural gas in the production of iron ore pellets has been studied. The influences of alternative fuel use on technological indicators of the process and quality of iron ore pellets have been analyzed. It was found that the combustion of sunflower husks generates enough heat to obtain iron ore pellets with good strength. The main indicators of the quality of iron ore pellets remain at the same level as the iron ore pellet quality when using natural gas.
{"title":"PRODUCTION OF IRON ORE PELLETS BY UTILIZATION OF SUNFLOWER HUSKS","authors":"A. Koveria, L. Kieush, M. Boyko, Maksym Yaholnyk, Natalia Poliakova","doi":"10.36547/ams.27.4.1052","DOIUrl":"https://doi.org/10.36547/ams.27.4.1052","url":null,"abstract":"Steel production is the most dynamic industry and one of the key sectors for the development of the global economy. The growing production of iron ore increases the need for its beneficiation and granulating for subsequent use in the production of iron and steel. As a result, the number of CO2 emissions and harmful substances increases, which negatively affects both society and the environment. It is important to study the use of biomass for the production of iron ore pellets. Lignocellulosic biomass is a renewable and sustainable source of heat and energy that can mitigate climate change. The efficiency of using sunflower husks on the combined machine “straight grate - rotary kiln - annular cooler” to partially replace natural gas in the production of iron ore pellets has been studied. The influences of alternative fuel use on technological indicators of the process and quality of iron ore pellets have been analyzed. It was found that the combustion of sunflower husks generates enough heat to obtain iron ore pellets with good strength. The main indicators of the quality of iron ore pellets remain at the same level as the iron ore pellet quality when using natural gas.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46740530","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 bimetallic joining elements were designed for lap joints of thin metallic (Fe-Fe, Fe-Al) as well as metallic – nonmetallic (Fe-PMMA, Al-PMMA) sheets by Resistance Element Welding (REW). The Cu tubes with an outer diameter of 4 mm, wall thickness of 0.5 mm, and a length of 11 mm filled with a solder Sn60Pb40 were used for the bimetallic joining elements producing. The required shape of joining elements is obtained by cold forming. Simulation by ANSYS software was chosen for the optimization of the forming process and geometry of functional parts of the forming tool allowing to use only one extrusion forming operation. The simulation results are stresses, strains, and modification of cross-section geometry of elements for the three proposed forming modes. The geometry of functional parts of the forming tool was compared with the results of cross-section macroanalysis of joining elements.
{"title":"FORMING PROCESS SIMULATION OF BIMETALLIC BILLET BY EXTRUSION FOR REW METHOD","authors":"A. Schrek, A. Brusilová, P. Sejč, B. Vanko","doi":"10.36547/ams.27.4.1254","DOIUrl":"https://doi.org/10.36547/ams.27.4.1254","url":null,"abstract":"The bimetallic joining elements were designed for lap joints of thin metallic (Fe-Fe, Fe-Al) as well as metallic – nonmetallic (Fe-PMMA, Al-PMMA) sheets by Resistance Element Welding (REW). The Cu tubes with an outer diameter of 4 mm, wall thickness of 0.5 mm, and a length of 11 mm filled with a solder Sn60Pb40 were used for the bimetallic joining elements producing. The required shape of joining elements is obtained by cold forming. Simulation by ANSYS software was chosen for the optimization of the forming process and geometry of functional parts of the forming tool allowing to use only one extrusion forming operation. The simulation results are stresses, strains, and modification of cross-section geometry of elements for the three proposed forming modes. The geometry of functional parts of the forming tool was compared with the results of cross-section macroanalysis of joining elements.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43040773","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 study, the effect of different pre-surface finishing method on the aluminium anodization was investigated for AA 6063 alloy. Within the scope of pre-surface finishing method which is acidic solution concentrations and process time were determined. Acidic solution was determined by using hydrofluoric acid (HF) and nitric acid (HNO3). Also Gresoff LIM-5 LV chemical was used with different concentrations and process time for degreasing process. The etching effect of acidic solution on aluminium samples was investigated. The optimal etching behaviour was obtained with 1.0% concentration of HF and 3.2% concentration of HNO3 at 10 minutes process time. Also optimal surface properties were observed with 1.0% concentration of Gresoff LIM-5 LV at 12 minutes process time. Then anodic oxidation was performed by using 180 g / L sulfuric acid (H2SO4) and 18 volt (V). Surface morphology of the final aluminium profiles were examined with SEM analysis, Roughness, Gloss and Thickness tests.
研究了不同表面预处理方法对AA 6063铝合金阳极氧化性能的影响。在预表面处理方法的范围内，确定了酸性溶液的浓度和处理时间。酸性溶液用氢氟酸(HF)和硝酸(HNO3)测定。并采用Gresoff LIM-5 LV化学剂，在不同浓度和工艺时间下进行脱脂处理。研究了酸性溶液对铝样品的腐蚀作用。当HF浓度为1.0%，HNO3浓度为3.2%，工艺时间为10 min时，刻蚀效果最佳。当Gresoff LIM-5 LV浓度为1.0%时，处理时间为12分钟，表面性能最佳。然后用180 g / L硫酸(H2SO4)和18伏(V)进行阳极氧化。通过SEM分析、粗糙度、光泽和厚度测试来检测最终铝型材的表面形貌。
{"title":"The Effect of Different Pre-Surface Finishing Method on the Aluminium Anodization of the 6XXX Series Alloy","authors":"Merve Özcan, Bilge Tunca, Ipek Biltaş, T. Tuken","doi":"10.36547/ams.27.4.1109","DOIUrl":"https://doi.org/10.36547/ams.27.4.1109","url":null,"abstract":"In this study, the effect of different pre-surface finishing method on the aluminium anodization was investigated for AA 6063 alloy. Within the scope of pre-surface finishing method which is acidic solution concentrations and process time were determined. Acidic solution was determined by using hydrofluoric acid (HF) and nitric acid (HNO3). Also Gresoff LIM-5 LV chemical was used with different concentrations and process time for degreasing process. The etching effect of acidic solution on aluminium samples was investigated. The optimal etching behaviour was obtained with 1.0% concentration of HF and 3.2% concentration of HNO3 at 10 minutes process time. Also optimal surface properties were observed with 1.0% concentration of Gresoff LIM-5 LV at 12 minutes process time. Then anodic oxidation was performed by using 180 g / L sulfuric acid (H2SO4) and 18 volt (V). Surface morphology of the final aluminium profiles were examined with SEM analysis, Roughness, Gloss and Thickness tests.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42021831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aims to investigate the thermal conditions of the molds, changes in microstructure and hardness of casting products using sand mold and permanent mold. The use of sand mold and permanent mold results in different cooling rates. Thermal analysis was performed using a thermocouple to obtain a temperature versus time curve. Metallographic observations were carried out using a Scanning Electron Microscope equipped with Energy-Dispersive X-ray Spectroscopy. The Vickers hardness test was carried out in three areas with different thicknesses. The results showed a constant temperature at 691 oC where the eutectoid phase reaction occurred. Testing with sand mold showed that cast iron with flake graphite was finer and spreader than graphite in cast iron produced by permanent mold. Meanwhile, gray cast iron from a casting process with a permanent mold has a higher hardness than gray cast iron from a casting process using a sand mold.
{"title":"EFFECT OF COOLING RATE ON MICROSTRUCTURE AND HARDNESS IN GRAY CAST IRON CASTING PROCESS","authors":"A. Yulianto, R. Soenoko, W. Suprapto, A. Sonief","doi":"10.36547/ams.27.3.996","DOIUrl":"https://doi.org/10.36547/ams.27.3.996","url":null,"abstract":"This study aims to investigate the thermal conditions of the molds, changes in microstructure and hardness of casting products using sand mold and permanent mold. The use of sand mold and permanent mold results in different cooling rates. Thermal analysis was performed using a thermocouple to obtain a temperature versus time curve. Metallographic observations were carried out using a Scanning Electron Microscope equipped with Energy-Dispersive X-ray Spectroscopy. The Vickers hardness test was carried out in three areas with different thicknesses. The results showed a constant temperature at 691 oC where the eutectoid phase reaction occurred. Testing with sand mold showed that cast iron with flake graphite was finer and spreader than graphite in cast iron produced by permanent mold. Meanwhile, gray cast iron from a casting process with a permanent mold has a higher hardness than gray cast iron from a casting process using a sand mold.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49588973","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 copper based alloys Al-bronze and α-brass containing each of 10wt% aluminum and zinc were prepared by casting. Afterwards, the specimens were cold-rolled with various percentages of deformation and the cold-rolled samples were aged subsequently at the varied time for four hours and temperatures ranging up to 500°C. Samples underwent characterizations by microhardness testing, electrical resistivity, optical properties, differential scanning calorimetry as well as microstructure analysis using an optical microscope. The results showed that the hardening of Cu-based alloys was taken place due to solid-solution hardening. Al addition accelerated the hardness through ageing due to the formation of various intermetallic copper aluminites into the aged alloy which was hard and brittle in nature. The resistivity decreased marginally through heat treatment due to the stage of stress relieving, recovery, precipitation coarsening as well as recrystallization and increased for arranging different intermetallics into the alloys. The microstructural study revealed that the cold rolled alloys content the different phases of elongated grain at the rolling direction. Meanwhile higher ageing temperatures at 500°C for one hour led to recrystallization and grain growth especially in pure copper and Cu-10Zn alloys.
{"title":"IMPACT OF COLD PLASTIC DEFORMATION AND THERMAL POST-TREATMENT ON THE PHYSICAL PROPERTIES OF COPPER BASED ALLOYS Al-BRONZE AND α-BRASS","authors":"Samiul Kaiser, M. S. Kaiser","doi":"10.36547/ams.27.3.951","DOIUrl":"https://doi.org/10.36547/ams.27.3.951","url":null,"abstract":"The copper based alloys Al-bronze and α-brass containing each of 10wt% aluminum and zinc were prepared by casting. Afterwards, the specimens were cold-rolled with various percentages of deformation and the cold-rolled samples were aged subsequently at the varied time for four hours and temperatures ranging up to 500°C. Samples underwent characterizations by microhardness testing, electrical resistivity, optical properties, differential scanning calorimetry as well as microstructure analysis using an optical microscope. The results showed that the hardening of Cu-based alloys was taken place due to solid-solution hardening. Al addition accelerated the hardness through ageing due to the formation of various intermetallic copper aluminites into the aged alloy which was hard and brittle in nature. The resistivity decreased marginally through heat treatment due to the stage of stress relieving, recovery, precipitation coarsening as well as recrystallization and increased for arranging different intermetallics into the alloys. The microstructural study revealed that the cold rolled alloys content the different phases of elongated grain at the rolling direction. Meanwhile higher ageing temperatures at 500°C for one hour led to recrystallization and grain growth especially in pure copper and Cu-10Zn alloys.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41764192","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}
P. Mulidrán, E. Spišák, M. Tomáš, J. Majerníková, Ján Varga
In this work, the influence of material models used in the FEM simulation on the springback prediction is investigated. The interest of this paper is to extend the knowledge base regarding springback predictions in numerical simulation. The springback effect of a V-shaped sheet metal part made of TRIP steel, with a thickness of 0.75 mm was investigated. The bending angle was set to 90°. In the numerical simulation, Hill48 and Barlat yield criteria were used in combination with Ludwik's and Swift's hardening models. Achieved data from the numerical simulations were compared and evaluated with experimental test results. The experimental results showed the relation between springback and calibration force. The effect of specimen cut direction on the springback was smaller in comparison with the calibration force. The numerical results of the springback were not identical with the experimentally achieved springback values in most cases. Particularly, when a calibration force of 1 800 N was used in the simulation. The simulation results showed a good correlation between experimental and numerical results, when Hill48 and Barlat yield criteria were used in combination with Ludwik hardening law and calibration force F with the value 900 N was applied.
{"title":"THE EFFECT OF MATERIAL MODELS IN THE FEM SIMULATION ON THE SPRINGBACK PREDICTION OF THE TRIP STEEL","authors":"P. Mulidrán, E. Spišák, M. Tomáš, J. Majerníková, Ján Varga","doi":"10.36547/ams.27.3.899","DOIUrl":"https://doi.org/10.36547/ams.27.3.899","url":null,"abstract":"In this work, the influence of material models used in the FEM simulation on the springback prediction is investigated. The interest of this paper is to extend the knowledge base regarding springback predictions in numerical simulation. The springback effect of a V-shaped sheet metal part made of TRIP steel, with a thickness of 0.75 mm was investigated. The bending angle was set to 90°. In the numerical simulation, Hill48 and Barlat yield criteria were used in combination with Ludwik's and Swift's hardening models. Achieved data from the numerical simulations were compared and evaluated with experimental test results. The experimental results showed the relation between springback and calibration force. The effect of specimen cut direction on the springback was smaller in comparison with the calibration force. The numerical results of the springback were not identical with the experimentally achieved springback values in most cases. Particularly, when a calibration force of 1 800 N was used in the simulation. The simulation results showed a good correlation between experimental and numerical results, when Hill48 and Barlat yield criteria were used in combination with Ludwik hardening law and calibration force F with the value 900 N was applied.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42038721","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 phenomenon of electrochemical phase formation in metals and alloys via a supercooled liquid state stage was discussed. Assuming the electrodeposited metal to be a product of formation and ultrarapid solidification of supercooled metallic liquid, a possibility of metastable phase formation during electrodeposition of polymorphous metals was suggested. It was anticipated that the polymorphic transition of the metal’s metastable form to the stable one occurs by shear, as does the martensitic transformation. To enable revealing an orientation relationship between grains of the two phases, a method for X-ray texture analysis of metals was developed using a combination of direct pole figures. It was established that the phase formation during electrodeposition of polymorphous metals produces metastable modifications typical of entities that crystallized from a liquid state at extremely high rates. In regards polymorphic transitions in metal electrodeposition, certain orientation relationships were observed between grains of the stable and the metastable phase, which is typical of phase transformations proceeding at extremely high rates. The results obtained provided additional arguments in favor of the phenomenon under discussion.
{"title":"ELECTROCHEMICAL POLYMORPHIC PHASE FORMATION IN METALS","authors":"O. Girin","doi":"10.36547/ams.27.3.1011","DOIUrl":"https://doi.org/10.36547/ams.27.3.1011","url":null,"abstract":"The phenomenon of electrochemical phase formation in metals and alloys via a supercooled liquid state stage was discussed. Assuming the electrodeposited metal to be a product of formation and ultrarapid solidification of supercooled metallic liquid, a possibility of metastable phase formation during electrodeposition of polymorphous metals was suggested. It was anticipated that the polymorphic transition of the metal’s metastable form to the stable one occurs by shear, as does the martensitic transformation. To enable revealing an orientation relationship between grains of the two phases, a method for X-ray texture analysis of metals was developed using a combination of direct pole figures. It was established that the phase formation during electrodeposition of polymorphous metals produces metastable modifications typical of entities that crystallized from a liquid state at extremely high rates. In regards polymorphic transitions in metal electrodeposition, certain orientation relationships were observed between grains of the stable and the metastable phase, which is typical of phase transformations proceeding at extremely high rates. The results obtained provided additional arguments in favor of the phenomenon under discussion.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43786241","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 current work explores the strain hardening and stretches formability behaviour of the developed Triple Phase (TP) steel. Double quenched TP steel strips posse three distinguished stages of strain hardening on tensile forming. 1st stage represents the highest n-value reflecting resistance to homogeneous deformation, where steel can be safely stretched. 2nd and 3rd stage reveals lower n-values, where localized thinning exist. On Erichsen testing, the relationship between punch forming force and punch stroke exhibits two forming regions. The 1st region is delineated by a straight line showing an ultra-high strain-hardening rate, which represents a reversible elastic stretch forming. The 2nd forming region continues to a higher Erichsen punch stroke than that of the 1st region and presents the permanent plastic stretch forming behaviour. It is found that bainite and martensite clusters created, by double quenching, in TP-steel exaggerated the elastic stretch forming limit 10 times higher than the as-hot rolled condition. 7 min. holding time of strips in the salt bath is considered the most effective for the creation of a useful volume fraction of the bainite phase. However, 21 min. holding time in salt bath grows martensite laths through the bainite aggregates, affecting negatively on stretch formability.
{"title":"Strain Hardening and Stretch Formability Behavior of Triple Phase (TP) Steel Strips","authors":"Maha ElMeligy, T. El-Bitar","doi":"10.36547/ams.27.3.1048","DOIUrl":"https://doi.org/10.36547/ams.27.3.1048","url":null,"abstract":"The current work explores the strain hardening and stretches formability behaviour of the developed Triple Phase (TP) steel. Double quenched TP steel strips posse three distinguished stages of strain hardening on tensile forming. 1st stage represents the highest n-value reflecting resistance to homogeneous deformation, where steel can be safely stretched. 2nd and 3rd stage reveals lower n-values, where localized thinning exist. On Erichsen testing, the relationship between punch forming force and punch stroke exhibits two forming regions. The 1st region is delineated by a straight line showing an ultra-high strain-hardening rate, which represents a reversible elastic stretch forming. The 2nd forming region continues to a higher Erichsen punch stroke than that of the 1st region and presents the permanent plastic stretch forming behaviour. It is found that bainite and martensite clusters created, by double quenching, in TP-steel exaggerated the elastic stretch forming limit 10 times higher than the as-hot rolled condition. 7 min. holding time of strips in the salt bath is considered the most effective for the creation of a useful volume fraction of the bainite phase. However, 21 min. holding time in salt bath grows martensite laths through the bainite aggregates, affecting negatively on stretch formability.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47275704","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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