M. Dioktyanto, D. Aryanto, A. Noviyanto, A. H. Yuwono, N. Rochman
Dense monolithic silicon carbide (SiC) was successfully sintered by hot-pressing at 1750 ?C for 1 h under an applied pressure of 20 MPa with the addition of a nitrate-based additive. A relative density of more than 98% were obtained with the addition of MgO-Y2O3 and Al2O3-Y2O3 in nitrate form, while in the oxide form they were 85.0 and 96.0%, respectively. Indeed, MgO-Y2O3 showed poor densification due to the eutectic temperature of 2110?C, however, the addition of nitrate form of MgO-Y2O3 enhanced the densification greatly. The sintering mechanism in the nitrate-based additive is liquid phase sintering, which is identified by the presence of an oxide phase, i.e., Y2O3 in the SiC with the addition of Al2O3-Y2O3 in nitrate form. Moreover, the addition of nitrate form suppressed the grain growth of SiC, which was believed to be due to the adequate rearrangement stage during sintering.
{"title":"Enhancing the density of silicon carbide with the addition of nitrate-based additives","authors":"M. Dioktyanto, D. Aryanto, A. Noviyanto, A. H. Yuwono, N. Rochman","doi":"10.2298/jmmb220215020d","DOIUrl":"https://doi.org/10.2298/jmmb220215020d","url":null,"abstract":"Dense monolithic silicon carbide (SiC) was successfully sintered by hot-pressing at 1750 ?C for 1 h under an applied pressure of 20 MPa with the addition of a nitrate-based additive. A relative density of more than 98% were obtained with the addition of MgO-Y2O3 and Al2O3-Y2O3 in nitrate form, while in the oxide form they were 85.0 and 96.0%, respectively. Indeed, MgO-Y2O3 showed poor densification due to the eutectic temperature of 2110?C, however, the addition of nitrate form of MgO-Y2O3 enhanced the densification greatly. The sintering mechanism in the nitrate-based additive is liquid phase sintering, which is identified by the presence of an oxide phase, i.e., Y2O3 in the SiC with the addition of Al2O3-Y2O3 in nitrate form. Moreover, the addition of nitrate form suppressed the grain growth of SiC, which was believed to be due to the adequate rearrangement stage during sintering.","PeriodicalId":51090,"journal":{"name":"Journal of Mining and Metallurgy Section B-Metallurgy","volume":"24 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80902858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The phase equilibria of Bi-Te-RE (Yb, Nd, Sm, Er, Tb) at 673K were established through equilibrated alloys, the isothermal sections of Bi-Te-RE (Yb, Nd, Sm, Er, Tb) at 673K were established according to the result of Scanning Electron Microscopy (SEM), Electron probe micro-analysis (EPMA) and Powder X-ray diffractometry (XRD). In the Bi-Te-Yb system at 673 K, the existence of 4 three-phase equilibria (YbTe+Bi2Te3+Te, YbTe+Bi2Te3+?, YbTe+Bi+?, YbTe+Yb5Bi3+Yb4Bi3) has been established, while 3 three-phase regions (NdTe2+?+Bi2Te3, NdTe2+?+Bi, Nd2Te3+Bi+BiTeNd) in Bi-Te-Nd system, 3 three-phase regions (SmTe3+Te+Bi2Te3, SmTe1.8+ Bi2Te3+?, SmTe1.8+?+Bi) in Bi-Te-Nd system, 3 three-phase regions (TbTe3+Te+Bi2Te3, Tb4Te7+Bi2Te3+?, TbTe+Bi+?) in Bi-Te-Nd system, and 4 three-phase regions (ErTe3+Te+Bi2Te3, ErTe3+Bi2Te3+Er2Te3, Bi2Te3+Er2Te3+?, Er2Te3+?+ErTe, ?+ErTe+Bi) in Bi-Te-Nd system have also been identified respectively. Among the Bi-Te-RE (Nd, Sm, Er, Tb, Yb) systems, the solubilities of RE in Bi2Te3 are 0.19 at % Nd, 0.22 at % Sm, 0.28 at % Tb, 0.35 at %Er, and 0.37 at % Yb. In general, the maximum solubility of elements in Bi2Te3 phase alloy become more and more larger with the increase in RE atomic number. A ternary compound BiTeNd in the Bi-Te-Nd ternary system was confirmed in this work.
通过平衡合金建立了Bi-Te-RE (Yb, Nd, Sm, Er, Tb)在673K处的相平衡，通过扫描电镜(SEM)、电子探针显微分析(EPMA)和粉末x射线衍射(XRD)建立了Bi-Te-RE (Yb, Nd, Sm, Er, Tb)在673K处的等温截面。在673 K的Bi-Te-Yb体系中，存在YbTe+Bi2Te3+Te、YbTe+Bi2Te3+?, YbTe + Bi + ?， YbTe+Yb5Bi3+Yb4Bi3)，而三个三相区(NdTe2+?+ Bi2Te3, NdTe2 + ?+Bi, Nd2Te3+Bi+BiTeNd)， 3个三相区(SmTe3+Te+Bi2Te3, SmTe1.8+ Bi2Te3+?， SmTe1.8+?+Bi)在Bi-Te- nd体系中，3个三相区(TbTe3+Te+Bi2Te3, Tb4Te7+Bi2Te3+?在Bi-Te- nd体系中，有4个三相区(ErTe3+Te+Bi2Te3、ErTe3+Bi2Te3+Er2Te3、Bi2Te3+Er2Te3+?Er2Te3 + ?在Bi- te - nd体系中分别鉴定出了+ErTe、?+ErTe+Bi。在Bi-Te-RE (Nd, Sm, Er, Tb, Yb)体系中，RE在Bi2Te3中的溶解度分别为% Nd = 0.19， % Sm = 0.22， % Tb = 0.28， %Er = 0.35， % Yb = 0.37。总的来说，元素在Bi2Te3相合金中的最大溶解度随着RE原子序数的增加而越来越大。本文证实了Bi-Te-Nd三元体系中存在一种三元化合物BiTeNd。
{"title":"Phase equilibria of Bi-Te-RE (Yb,Nd,Sm,Er,Tb) ternary systems at 673K","authors":"L.-G. Zhang, Q. Song, M. Tan, Y. Jiang, L.-B. Liu","doi":"10.2298/jmmb211118007z","DOIUrl":"https://doi.org/10.2298/jmmb211118007z","url":null,"abstract":"The phase equilibria of Bi-Te-RE (Yb, Nd, Sm, Er, Tb) at 673K were established through equilibrated alloys, the isothermal sections of Bi-Te-RE (Yb, Nd, Sm, Er, Tb) at 673K were established according to the result of Scanning Electron Microscopy (SEM), Electron probe micro-analysis (EPMA) and Powder X-ray diffractometry (XRD). In the Bi-Te-Yb system at 673 K, the existence of 4 three-phase equilibria (YbTe+Bi2Te3+Te, YbTe+Bi2Te3+?, YbTe+Bi+?, YbTe+Yb5Bi3+Yb4Bi3) has been established, while 3 three-phase regions (NdTe2+?+Bi2Te3, NdTe2+?+Bi, Nd2Te3+Bi+BiTeNd) in Bi-Te-Nd system, 3 three-phase regions (SmTe3+Te+Bi2Te3, SmTe1.8+ Bi2Te3+?, SmTe1.8+?+Bi) in Bi-Te-Nd system, 3 three-phase regions (TbTe3+Te+Bi2Te3, Tb4Te7+Bi2Te3+?, TbTe+Bi+?) in Bi-Te-Nd system, and 4 three-phase regions (ErTe3+Te+Bi2Te3, ErTe3+Bi2Te3+Er2Te3, Bi2Te3+Er2Te3+?, Er2Te3+?+ErTe, ?+ErTe+Bi) in Bi-Te-Nd system have also been identified respectively. Among the Bi-Te-RE (Nd, Sm, Er, Tb, Yb) systems, the solubilities of RE in Bi2Te3 are 0.19 at % Nd, 0.22 at % Sm, 0.28 at % Tb, 0.35 at %Er, and 0.37 at % Yb. In general, the maximum solubility of elements in Bi2Te3 phase alloy become more and more larger with the increase in RE atomic number. A ternary compound BiTeNd in the Bi-Te-Nd ternary system was confirmed in this work.","PeriodicalId":51090,"journal":{"name":"Journal of Mining and Metallurgy Section B-Metallurgy","volume":"336 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75931574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Changfa Du, S.-P. Huang, Qianhui Min, Y. Liu, Shiyu Wen
In this work, the interdiffusion coefficient and atomic mobility for fcc Ag-Cu-Mg phase at 1073 K have been investigated by combining diffusion couple experiments and calculations. Based on the experimental composition profiles, the diffusion coefficients at intersection points in diffusion paths were calculated by means of Matano-Kirkaldy method. Using the thermodynamic descriptions available in literature, the atomic mobilities for fcc Ag-Cu-Mg phase were automatically optimized by numerical inverse method incorporated in the CALTPP (CALculation of ThermoPhysical Properties) program. Moreover, the obtained atomic mobilities were verified to be reliable through good agreements between the model-simulated composition profiles and the measured ones. In addition, three-dimensional surfaces for the interdiffusion coefficient, activation energy, and frequency factor were presented. The presently obtained atomic mobilities can be incorporated into the diffusion database for Ag-based alloys, which can contribute to microstructure simulation and materials design.
{"title":"Interdiffusion coefficient and atomic mobility for fcc Ag-Cu-Mg phase at 1073 K","authors":"Changfa Du, S.-P. Huang, Qianhui Min, Y. Liu, Shiyu Wen","doi":"10.2298/jmmb220926029d","DOIUrl":"https://doi.org/10.2298/jmmb220926029d","url":null,"abstract":"In this work, the interdiffusion coefficient and atomic mobility for fcc Ag-Cu-Mg phase at 1073 K have been investigated by combining diffusion couple experiments and calculations. Based on the experimental composition profiles, the diffusion coefficients at intersection points in diffusion paths were calculated by means of Matano-Kirkaldy method. Using the thermodynamic descriptions available in literature, the atomic mobilities for fcc Ag-Cu-Mg phase were automatically optimized by numerical inverse method incorporated in the CALTPP (CALculation of ThermoPhysical Properties) program. Moreover, the obtained atomic mobilities were verified to be reliable through good agreements between the model-simulated composition profiles and the measured ones. In addition, three-dimensional surfaces for the interdiffusion coefficient, activation energy, and frequency factor were presented. The presently obtained atomic mobilities can be incorporated into the diffusion database for Ag-based alloys, which can contribute to microstructure simulation and materials design.","PeriodicalId":51090,"journal":{"name":"Journal of Mining and Metallurgy Section B-Metallurgy","volume":"3 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88100121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The desulfurization in metallurgical process is electrochemical reaction in nature. Desulfurization using the electrochemical method was proposed with the CaO-MgO-Al2O3 molten slag covering molten steel. Effect of an applied external DC voltage, varied from 0 to 8V, was discussed. The results indicated that sulfur in molten steel can be removed effectively with applied external voltage. According to the mechanism analyses of the desulfurization under the applied external voltage, kinetics formulae were developed, and the model calculated results accord well with the experimental values. The transfer coefficient of sulfur in molten slag under electromigration conditions is approximately 2.09?10-5 m?s-1?V-1. The desulfurization of molten steel with molten slag can be promoted by increasing the applied voltage, reducing the partial pressure of atmospheric oxygen, strengthening the stirring intensity of the reaction system, and optimizing the composition and properties of the slag.
{"title":"Desulfurization of molten steel with molten slag using the electrochemical method","authors":"X-Q Wu, J.-F. Xu, Py Gu, J.-Y. Zhang","doi":"10.2298/jmmb211014012w","DOIUrl":"https://doi.org/10.2298/jmmb211014012w","url":null,"abstract":"The desulfurization in metallurgical process is electrochemical reaction in nature. Desulfurization using the electrochemical method was proposed with the CaO-MgO-Al2O3 molten slag covering molten steel. Effect of an applied external DC voltage, varied from 0 to 8V, was discussed. The results indicated that sulfur in molten steel can be removed effectively with applied external voltage. According to the mechanism analyses of the desulfurization under the applied external voltage, kinetics formulae were developed, and the model calculated results accord well with the experimental values. The transfer coefficient of sulfur in molten slag under electromigration conditions is approximately 2.09?10-5 m?s-1?V-1. The desulfurization of molten steel with molten slag can be promoted by increasing the applied voltage, reducing the partial pressure of atmospheric oxygen, strengthening the stirring intensity of the reaction system, and optimizing the composition and properties of the slag.","PeriodicalId":51090,"journal":{"name":"Journal of Mining and Metallurgy Section B-Metallurgy","volume":"379 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77893960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y.T. Ma, P. Yang, Bo Lu, Yicheng Dou, Jianke Tian, W.-B. Guo, Z. Zhang, Yingying Shen
A great deal of nickel slag containing a lot of Fe in the form of FeO is produced in the process of nickel smelting. The effect of FeO content on the melting characteristics and structure of nickel slag is studied via thermodynamic calculation and experiments, with the nickel slag of water quenching furnace as raw material, which is simplified to CaO-SiO2-FeO-MgO slag system. The results are shown as follows: with the increasing of FeO content, the precipitated primary phase changes from melilite to olivine. The liquidus temperature, softening temperature, hemispheric temperature, flow temperature, viscosity and critical viscosity temperature of slag system tends to decrease gradually, but the solid phase temperature tends to decrease first and then increase. The centre of [SiO4]4- tetrahedron symmetric stretching vibration band in the slag system moves to the low wave number region. The mole fraction of O0 in the slag decreases continuously, the mole fraction of O- and O2- increases. The complex silicon-oxygen tetrahedron structure gradually disintegrates and the structural unit tends to be simple.
{"title":"Effect of FeO content on melting characteristics and structure of nickel slag","authors":"Y.T. Ma, P. Yang, Bo Lu, Yicheng Dou, Jianke Tian, W.-B. Guo, Z. Zhang, Yingying Shen","doi":"10.2298/jmmb220317024m","DOIUrl":"https://doi.org/10.2298/jmmb220317024m","url":null,"abstract":"A great deal of nickel slag containing a lot of Fe in the form of FeO is produced in the process of nickel smelting. The effect of FeO content on the melting characteristics and structure of nickel slag is studied via thermodynamic calculation and experiments, with the nickel slag of water quenching furnace as raw material, which is simplified to CaO-SiO2-FeO-MgO slag system. The results are shown as follows: with the increasing of FeO content, the precipitated primary phase changes from melilite to olivine. The liquidus temperature, softening temperature, hemispheric temperature, flow temperature, viscosity and critical viscosity temperature of slag system tends to decrease gradually, but the solid phase temperature tends to decrease first and then increase. The centre of [SiO4]4- tetrahedron symmetric stretching vibration band in the slag system moves to the low wave number region. The mole fraction of O0 in the slag decreases continuously, the mole fraction of O- and O2- increases. The complex silicon-oxygen tetrahedron structure gradually disintegrates and the structural unit tends to be simple.","PeriodicalId":51090,"journal":{"name":"Journal of Mining and Metallurgy Section B-Metallurgy","volume":"46 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81106727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Yang, K. Nie, K. Deng, J. Han, Tao Xiao, X.Z. Han
In this work, a new Mg-2Zn-0.8Sr-0.2Ca alloy with low content of alloying elements was subjected to extrusion at relatively low-temperatures (240 and 200?C) and slow-speed (1.0 mm/s and 0.1 mm/s). The average size and volume fraction of recrystallized grains in the extruded Mg-2Zn-0.8Sr-0.2Ca alloy gradually decreased with the reduction in extrusion rate or extrusion temperature. Some broken second phases including Ca2Mg6Zn3 and Mg17Sr2 appeared in the extruded Mg-2Zn-0.8Sr-0.2Ca alloy along with some precipitated nano-sized MgZn2 phases. The volume fraction of MgZn2 phases gradually in the alloy increased as extrusion rate or temperature decreased. High performance with yield strength of 393.1 MPa, ultimate tensile strength of 418.4 MPa and the elongation of 5.7% was obtained in the Mg-2Zn- 0.8Sr-0.2Ca alloy extruded at 200?C & 0.1 mm/s. The main strengthening mechanisms could be attributed to grain-boundary strengthening, dislocation strengthening, precipitation strengthening, which were related to the change in grain size, second phases and basal texture intensity for the extruded Mg-2Zn-0.8Sr-0.2Ca alloy.
{"title":"Microstructures and tensile properties of Mg-2Zn-0.8Sr-0.2Ca alloy extruded at relatively slow speed and low temperature","authors":"A. Yang, K. Nie, K. Deng, J. Han, Tao Xiao, X.Z. Han","doi":"10.2298/jmmb210325004y","DOIUrl":"https://doi.org/10.2298/jmmb210325004y","url":null,"abstract":"In this work, a new Mg-2Zn-0.8Sr-0.2Ca alloy with low content of alloying elements was subjected to extrusion at relatively low-temperatures (240 and 200?C) and slow-speed (1.0 mm/s and 0.1 mm/s). The average size and volume fraction of recrystallized grains in the extruded Mg-2Zn-0.8Sr-0.2Ca alloy gradually decreased with the reduction in extrusion rate or extrusion temperature. Some broken second phases including Ca2Mg6Zn3 and Mg17Sr2 appeared in the extruded Mg-2Zn-0.8Sr-0.2Ca alloy along with some precipitated nano-sized MgZn2 phases. The volume fraction of MgZn2 phases gradually in the alloy increased as extrusion rate or temperature decreased. High performance with yield strength of 393.1 MPa, ultimate tensile strength of 418.4 MPa and the elongation of 5.7% was obtained in the Mg-2Zn- 0.8Sr-0.2Ca alloy extruded at 200?C & 0.1 mm/s. The main strengthening mechanisms could be attributed to grain-boundary strengthening, dislocation strengthening, precipitation strengthening, which were related to the change in grain size, second phases and basal texture intensity for the extruded Mg-2Zn-0.8Sr-0.2Ca alloy.","PeriodicalId":51090,"journal":{"name":"Journal of Mining and Metallurgy Section B-Metallurgy","volume":"12 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85897619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Li, C. Wang, Z. Wang, Peixu Yang, F. Xue, Feng Liu, S.-J. Zhang
The variable thermophysical properties was introduced in the coupling model of heat transfer and reduction reaction in the Pidgeon process to improve the accuracy of numerical calculation. The distribution of temperature and magnesium reduction extent in the briquette layer, and overall magnesium reduction extent in the retort was investigated. The model results show a better agreement with those of industrial production. The characteristic of ?Layer Shift? in the briquette layer during reduction process was clearly presented. It was shown that the reduction reaction occurs only a thin interface. The slag layer producing in the reduction with lower thermal conductivity of 0.4 W?m-1?K-1 greatly impedes the reaction to move forward inside layers, resulting into the slow magnesium production rate in the Pidgeon process. The improved model can provide a more accurate quantitative prediction in magnesium reduction in the Pidgeon process, which is of significance in innovation of key equipment and development of new magnesium production techniques.
{"title":"Improvement of modeling on the Ppidgeon process for magnesium production by introducing the variable thermophysical properties","authors":"R. Li, C. Wang, Z. Wang, Peixu Yang, F. Xue, Feng Liu, S.-J. Zhang","doi":"10.2298/jmmb220111026l","DOIUrl":"https://doi.org/10.2298/jmmb220111026l","url":null,"abstract":"The variable thermophysical properties was introduced in the coupling model of heat transfer and reduction reaction in the Pidgeon process to improve the accuracy of numerical calculation. The distribution of temperature and magnesium reduction extent in the briquette layer, and overall magnesium reduction extent in the retort was investigated. The model results show a better agreement with those of industrial production. The characteristic of ?Layer Shift? in the briquette layer during reduction process was clearly presented. It was shown that the reduction reaction occurs only a thin interface. The slag layer producing in the reduction with lower thermal conductivity of 0.4 W?m-1?K-1 greatly impedes the reaction to move forward inside layers, resulting into the slow magnesium production rate in the Pidgeon process. The improved model can provide a more accurate quantitative prediction in magnesium reduction in the Pidgeon process, which is of significance in innovation of key equipment and development of new magnesium production techniques.","PeriodicalId":51090,"journal":{"name":"Journal of Mining and Metallurgy Section B-Metallurgy","volume":"5 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87765777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B.X. Wang, W. Yuan, Z. Wang, J. Li, Hong-zhou Ma, Y. Song
Molten salt electrolysis was applied for the boronizing of nickel with Na2B4O7?10H2O-Na2CO3 as the electrolyte and characterizations and the growth kinetics of borided layer is reported. The experiment was carried out in silicon carbide crucible at 1193 K, 1223 K and 1243 K for 1 h, 2 h, 3 h and 4 h. The morphology and phases formed on the surface of pure nickel were analyzed by means of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis (XRD). The surface hardness and corrosion resistance of the boronized sample were tested by micro hardness tester and electrochemical workstation respectively. The borided layer was composed of nickel borides and its thickness ranged from 71 to 184 ?m. After 1 h boronizing, the hardness of the silicon rich borides is 966 HK, which is a little lower than that of the nickel borides (992-1008 HK); the surface hardness reached 1755 HK after 4 h electrolysis. Electrochemical impedance spectroscopy analysis showed that the corrosion resistance of boronized sample is better than that of pure nickel. Borided layer growth kinetics was studied by analyzing the relationship between thickness of the borided layer and time by mathematical method. Then the diffusion coefficient constant of boron atom in nickel at 1193 K, 1223 K and 1243 K was calculated accordingly and an equation was obtained to estimate the thickness of the borided layer.
{"title":"Characterizations and growth kinetics of the borided layer formed on pure nickel by molten salt electrolysis","authors":"B.X. Wang, W. Yuan, Z. Wang, J. Li, Hong-zhou Ma, Y. Song","doi":"10.2298/jmmb211101003w","DOIUrl":"https://doi.org/10.2298/jmmb211101003w","url":null,"abstract":"Molten salt electrolysis was applied for the boronizing of nickel with Na2B4O7?10H2O-Na2CO3 as the electrolyte and characterizations and the growth kinetics of borided layer is reported. The experiment was carried out in silicon carbide crucible at 1193 K, 1223 K and 1243 K for 1 h, 2 h, 3 h and 4 h. The morphology and phases formed on the surface of pure nickel were analyzed by means of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis (XRD). The surface hardness and corrosion resistance of the boronized sample were tested by micro hardness tester and electrochemical workstation respectively. The borided layer was composed of nickel borides and its thickness ranged from 71 to 184 ?m. After 1 h boronizing, the hardness of the silicon rich borides is 966 HK, which is a little lower than that of the nickel borides (992-1008 HK); the surface hardness reached 1755 HK after 4 h electrolysis. Electrochemical impedance spectroscopy analysis showed that the corrosion resistance of boronized sample is better than that of pure nickel. Borided layer growth kinetics was studied by analyzing the relationship between thickness of the borided layer and time by mathematical method. Then the diffusion coefficient constant of boron atom in nickel at 1193 K, 1223 K and 1243 K was calculated accordingly and an equation was obtained to estimate the thickness of the borided layer.","PeriodicalId":51090,"journal":{"name":"Journal of Mining and Metallurgy Section B-Metallurgy","volume":"29 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86739589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Smelting reduction of spent lithium-ion batteries (LIBs) results in metallic alloys containing Co, Ni, Cu, Fe and Mn. Dissolution of the valuable metals present in the metallic alloys is necessary to recover them. In this work, the mixture of Fe2(SO4)3 and FeSO4, single Fe2(SO4) and FeCl3 solutions were employed as leaching agents and the effects of parameters like ferric salt concentration, reaction temperature and time, and pulp density on the leaching of the metals were studied. The difference in the leaching percentage of the metals by the nature of the ferric solutions was insignificant. In these leaching systems, ferric and hydrogen ions act as oxidizing agents and sulfate/bisulfate and chloride anions as ligands. Optimum conditions for the complete leaching of metals by single ferric solutions were 0.35 mol/L Fe2(SO4)3 or 0.7 mol/L FeCl3 with 12.5 g/L pulp density for 60 min at 22oC. Addition of H2O2 to the leaching solution for the oxidation of Fe(II) to Fe(III) enhanced the selective extraction of iron over Co(II), Ni(II), Cu(II), Mn(II) and Si(IV) by D2EHPA. Stripping of iron from the loaded D2EHPA with aqua regia resulted in a pure iron solution. Compared to HCl and H2SO4 solutions, use of single ferric solution showed some advantages like fast reaction kinetics at 22oC and the reduction in dosage of acids and oxidizing agents.
{"title":"Use of ferric salt solutions as leaching agents of Co, Ni, Cu, Fe, and Mn from metallic alloys of spent lithium-ion batteries and separation of iron from the leaching solution","authors":"T. T. Tran, M.S. Lee","doi":"10.2298/jmmb220311023t","DOIUrl":"https://doi.org/10.2298/jmmb220311023t","url":null,"abstract":"Smelting reduction of spent lithium-ion batteries (LIBs) results in metallic alloys containing Co, Ni, Cu, Fe and Mn. Dissolution of the valuable metals present in the metallic alloys is necessary to recover them. In this work, the mixture of Fe2(SO4)3 and FeSO4, single Fe2(SO4) and FeCl3 solutions were employed as leaching agents and the effects of parameters like ferric salt concentration, reaction temperature and time, and pulp density on the leaching of the metals were studied. The difference in the leaching percentage of the metals by the nature of the ferric solutions was insignificant. In these leaching systems, ferric and hydrogen ions act as oxidizing agents and sulfate/bisulfate and chloride anions as ligands. Optimum conditions for the complete leaching of metals by single ferric solutions were 0.35 mol/L Fe2(SO4)3 or 0.7 mol/L FeCl3 with 12.5 g/L pulp density for 60 min at 22oC. Addition of H2O2 to the leaching solution for the oxidation of Fe(II) to Fe(III) enhanced the selective extraction of iron over Co(II), Ni(II), Cu(II), Mn(II) and Si(IV) by D2EHPA. Stripping of iron from the loaded D2EHPA with aqua regia resulted in a pure iron solution. Compared to HCl and H2SO4 solutions, use of single ferric solution showed some advantages like fast reaction kinetics at 22oC and the reduction in dosage of acids and oxidizing agents.","PeriodicalId":51090,"journal":{"name":"Journal of Mining and Metallurgy Section B-Metallurgy","volume":"14 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74929210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, functionally graded AZ91/WC nanocomposites were produced by a novel multi-stage reduction of chamber diameter method. The WC nanoparticles were packed in chambers having graduated diameters and friction stir processing was applied using tool with four-sided fluted probe. The functionally graded nanocomposites were obtained using different tool rotational speeds (830, 960 and 1160 rpm) with a constant traverse speed and plunge depth of 40 mm/min and 0.1 mm, respectively. The characteristics of the functionally graded samples and AZ91 Mg alloy were evaluated utilizing optical and scanning electron microscopes, and energy dispersive spectroscopy as well as other tests such as hardness, pin on disc wear and potentiodynamic polarization tests. The results showed that ?-Mg refining and graded distribution of WC nanoparticles were enhanced with augmenting tool rotational speed. The hardness increased slightly with augmenting tool rotational speed. The results also revealed that the wear rate was decreased and corrosion resistance was improved by adding WC nanoparticles. Abrasive wear mode was the main mode of material removal during dry sliding while cracks and pits were the main features of corroded surface.
{"title":"Functionally graded AZ91/WC nanocomposite fabricated via friction stir processing using a novel way","authors":"A. Subhi, M. Abdulkareem, H. Hussein","doi":"10.2298/jmmb220322018s","DOIUrl":"https://doi.org/10.2298/jmmb220322018s","url":null,"abstract":"In this work, functionally graded AZ91/WC nanocomposites were produced by a novel multi-stage reduction of chamber diameter method. The WC nanoparticles were packed in chambers having graduated diameters and friction stir processing was applied using tool with four-sided fluted probe. The functionally graded nanocomposites were obtained using different tool rotational speeds (830, 960 and 1160 rpm) with a constant traverse speed and plunge depth of 40 mm/min and 0.1 mm, respectively. The characteristics of the functionally graded samples and AZ91 Mg alloy were evaluated utilizing optical and scanning electron microscopes, and energy dispersive spectroscopy as well as other tests such as hardness, pin on disc wear and potentiodynamic polarization tests. The results showed that ?-Mg refining and graded distribution of WC nanoparticles were enhanced with augmenting tool rotational speed. The hardness increased slightly with augmenting tool rotational speed. The results also revealed that the wear rate was decreased and corrosion resistance was improved by adding WC nanoparticles. Abrasive wear mode was the main mode of material removal during dry sliding while cracks and pits were the main features of corroded surface.","PeriodicalId":51090,"journal":{"name":"Journal of Mining and Metallurgy Section B-Metallurgy","volume":"88 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73778727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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