Liners in wet ball mill for mineral processing industry must bear abrasive wear and corrosive wear, and consequently,the service life of the liner made from traditional materials,such as Hadfield steel and alloyed ste...Liners in wet ball mill for mineral processing industry must bear abrasive wear and corrosive wear, and consequently,the service life of the liner made from traditional materials,such as Hadfield steel and alloyed steels,is typically less than ten months.Bimetal liner,made from high Cr white cast iron and carbon steel,has been successfully developed by using liquid-liquid composite lost foam casting process.The microstructure and interface of the composite were analyzed using optical microscope,SEM,EDX and XRD.Micrographs indicate that the boundary of bimetal combination regions is staggered like dogtooth,two liquid metals are not mixed,and the interface presents excellent metallurgical bonding state.After heat treatment,the composite liner specimens have shown excellent properties,including hardness>61 HRC,fracture toughnessα k >16.5 J·cm-2 and bending strength >1,600 MPa.Wear comparison was made between the bimetal composite liner and alloyed steel liner in an industrial hematite ball mill of WISCO,and the results of eight-month test in wet grinding environment have proved that the service life of the bimetal composite liner is three times as long as that of the alloyed steel liner.展开更多
In spray atomization and codeposition, a molten stream of metal is disintegrated into a fine dispersion of droplets by high velocity gas jets. The resulting semi-solidified droplets are directed towards a substrate wh...In spray atomization and codeposition, a molten stream of metal is disintegrated into a fine dispersion of droplets by high velocity gas jets. The resulting semi-solidified droplets are directed towards a substrate where they impact and collect as rapidly solidified splats. Relatively high rates of solidification are achieved as a result of the thinness of the splats and the rapid heat extraction during flight and upon impacting with the substrate. The processing method uses codeposition of the metallic semi-solidified droplets (metallic matrix) with the injected reinforcement ceramic particles. In the present paper, the microstructures, mechanical properties, interfacial properties, thermal stability and aging behaviour of spray atomized and codeposited Al-Li-X MMC’s (injected X=SiC, Al2O3) are reported and correlated to the processing conditions.展开更多
Process regression models,such as Gaussian process regression model(GPR),have been widely applied to analyze kinds of functional data.This paper introduces a composite of two T-process(CT),where the first one captures...Process regression models,such as Gaussian process regression model(GPR),have been widely applied to analyze kinds of functional data.This paper introduces a composite of two T-process(CT),where the first one captures the smooth global trend and the second one models local details.TheCThas an advantage in the local variability compared to general T-process.Furthermore,a composite T-process regression(CTP)model is developed,based on the composite T-process.It inherits many nice properties as GPR,while it is more robust against outliers than GPR.Numerical studies including simulation and real data application show that CTP performs well in prediction.展开更多
Effect of distribution of iron concentrates between pelletized and matrix feed on the preparation of blast furnace burdens from two different kinds of fine iron concentrates (magnetite and hematite) by composite agglo...Effect of distribution of iron concentrates between pelletized and matrix feed on the preparation of blast furnace burdens from two different kinds of fine iron concentrates (magnetite and hematite) by composite agglomeration process (CAP) was explored. It was found that when the mass ratio of iron concentrate A (magnetite) to iron concentrate B (hematite) in the mixed feed was constant, the proportion of iron concentrate A in the pelletized and matrix feed significantly affected the quality of CAP products. Particularly, as the proportion of iron concentrate A in the pelletized feed increased from 0 to 100%, the yield decreased from 82.11% to 79.19% and the tumbler index decreased from 71.33% to 68.27%. The mineralization characterization results indicated that when 100% iron concentrate A was used as the pelletized feed, the crystallization styles of the outer layer and the inner layer of the pellet were different, and a lot of pores exist around hematite and magnetite phases in the pelletized part, with the weak connection of pelletized and matrix part, resulting in poor strength of agglomeration product.展开更多
Lithium ion batteries have achieved extensive applications in portable electronics and recently in electronic vehicles since its commercialization in 1990s.The vast applications of lithium ion batteries are not only d...Lithium ion batteries have achieved extensive applications in portable electronics and recently in electronic vehicles since its commercialization in 1990s.The vast applications of lithium ion batteries are not only derived from the innovation in electrochemistry based on emerging energy materials and chemical engineering science,but also the technological advances in the powder technologies for electrode processing and cell fabrication.Revealing the effects of powder technology on electrode microstructure evolution during electrode processing is with critical value to realize the superior electrochemical performance.This review presents the progress in understanding the basic principles of the materials processing technologies for electrodes in lithium ion batteries.The impacts of slurry mixing and coating,electrode drying,and calendering on the electrode characteristics and electrochemical performance are comprehensively analyzed.Conclusion and outlook are drawn to shed fresh lights on the further development of efficient lithium ion batteries by advancing powder technologies and related advanced energy materials.展开更多
Metal‐organic frameworks(MOFs)have shown numerous potentials as promising materials to address real‐world problems.However,their practical utilization in commercial products was largely limited by the lack of downst...Metal‐organic frameworks(MOFs)have shown numerous potentials as promising materials to address real‐world problems.However,their practical utilization in commercial products was largely limited by the lack of downstream processing methodologies to transform MOF powders into functional products.In this study,a commercially viable solution for the general synthesis of MOF‐fabric composites was introduced.On account of coordination bonding between poly(acrylic acid)and MOF substrates,MOF powders securely adhered onto the surface of fabric materials via a drip cast method to give MOF‐fabric composites easily.This strategy can be applied to different MOF types,as well as a wide variety of fabric materials.The prepared materials showed excellent bacterial killing efficacy attributed to the embedded HKUST‐1 MOF.In light of the recent coronavirus disease 2019 pandemic,this methodology could enable the large‐scale fabrication of essential MOF‐based personal protective wearables(e.g.,clothing and masks)for use by healthcare professionals.展开更多
基金supported by the National Natural Science Foundation of China under grant No.50805109the Fundamental Research Funds for the Central Universities under grant No.2011-1a-023
文摘Liners in wet ball mill for mineral processing industry must bear abrasive wear and corrosive wear, and consequently,the service life of the liner made from traditional materials,such as Hadfield steel and alloyed steels,is typically less than ten months.Bimetal liner,made from high Cr white cast iron and carbon steel,has been successfully developed by using liquid-liquid composite lost foam casting process.The microstructure and interface of the composite were analyzed using optical microscope,SEM,EDX and XRD.Micrographs indicate that the boundary of bimetal combination regions is staggered like dogtooth,two liquid metals are not mixed,and the interface presents excellent metallurgical bonding state.After heat treatment,the composite liner specimens have shown excellent properties,including hardness>61 HRC,fracture toughnessα k >16.5 J·cm-2 and bending strength >1,600 MPa.Wear comparison was made between the bimetal composite liner and alloyed steel liner in an industrial hematite ball mill of WISCO,and the results of eight-month test in wet grinding environment have proved that the service life of the bimetal composite liner is three times as long as that of the alloyed steel liner.
文摘In spray atomization and codeposition, a molten stream of metal is disintegrated into a fine dispersion of droplets by high velocity gas jets. The resulting semi-solidified droplets are directed towards a substrate where they impact and collect as rapidly solidified splats. Relatively high rates of solidification are achieved as a result of the thinness of the splats and the rapid heat extraction during flight and upon impacting with the substrate. The processing method uses codeposition of the metallic semi-solidified droplets (metallic matrix) with the injected reinforcement ceramic particles. In the present paper, the microstructures, mechanical properties, interfacial properties, thermal stability and aging behaviour of spray atomized and codeposited Al-Li-X MMC’s (injected X=SiC, Al2O3) are reported and correlated to the processing conditions.
基金supported by National Natural Science Foundation of China(Grant No.11971457)Anhui Provincial Natural Science Foundation(Grant No.1908085MA06).
文摘Process regression models,such as Gaussian process regression model(GPR),have been widely applied to analyze kinds of functional data.This paper introduces a composite of two T-process(CT),where the first one captures the smooth global trend and the second one models local details.TheCThas an advantage in the local variability compared to general T-process.Furthermore,a composite T-process regression(CTP)model is developed,based on the composite T-process.It inherits many nice properties as GPR,while it is more robust against outliers than GPR.Numerical studies including simulation and real data application show that CTP performs well in prediction.
基金supported by the National Natural Science Foundation of China under Grant U1960114,51774337,and U1660206the Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University under Grant CSUZC201905the Fundamental Research Funds for the Central Universities of Central South University under Grant 2018zzts220.
文摘Effect of distribution of iron concentrates between pelletized and matrix feed on the preparation of blast furnace burdens from two different kinds of fine iron concentrates (magnetite and hematite) by composite agglomeration process (CAP) was explored. It was found that when the mass ratio of iron concentrate A (magnetite) to iron concentrate B (hematite) in the mixed feed was constant, the proportion of iron concentrate A in the pelletized and matrix feed significantly affected the quality of CAP products. Particularly, as the proportion of iron concentrate A in the pelletized feed increased from 0 to 100%, the yield decreased from 82.11% to 79.19% and the tumbler index decreased from 71.33% to 68.27%. The mineralization characterization results indicated that when 100% iron concentrate A was used as the pelletized feed, the crystallization styles of the outer layer and the inner layer of the pellet were different, and a lot of pores exist around hematite and magnetite phases in the pelletized part, with the weak connection of pelletized and matrix part, resulting in poor strength of agglomeration product.
基金This work was supported by National Natural Science Foundation of China(Grant Nos.21805161,21808121,and 21825501)National Key Research and Development Program(Grant No.2016YFA0202500)+1 种基金China Post-Doctoral Science Foundation(Grant Nos.2020M670155 and 2020T130054)the Tsinghua University Initiative Scientific Research Program.
文摘Lithium ion batteries have achieved extensive applications in portable electronics and recently in electronic vehicles since its commercialization in 1990s.The vast applications of lithium ion batteries are not only derived from the innovation in electrochemistry based on emerging energy materials and chemical engineering science,but also the technological advances in the powder technologies for electrode processing and cell fabrication.Revealing the effects of powder technology on electrode microstructure evolution during electrode processing is with critical value to realize the superior electrochemical performance.This review presents the progress in understanding the basic principles of the materials processing technologies for electrodes in lithium ion batteries.The impacts of slurry mixing and coating,electrode drying,and calendering on the electrode characteristics and electrochemical performance are comprehensively analyzed.Conclusion and outlook are drawn to shed fresh lights on the further development of efficient lithium ion batteries by advancing powder technologies and related advanced energy materials.
基金supported by the Singapore National Research Foundation Investigatorship(NRF‐NRFI2018‐03)the Ministry of Education Singapore under the Academic Research Funds(RT12/19 and MOE‐MOET2EP10120‐0003)the Singapore Agency for Science,Technology,and Research(A*STAR)AME IRG grant(A1883c0005).
文摘Metal‐organic frameworks(MOFs)have shown numerous potentials as promising materials to address real‐world problems.However,their practical utilization in commercial products was largely limited by the lack of downstream processing methodologies to transform MOF powders into functional products.In this study,a commercially viable solution for the general synthesis of MOF‐fabric composites was introduced.On account of coordination bonding between poly(acrylic acid)and MOF substrates,MOF powders securely adhered onto the surface of fabric materials via a drip cast method to give MOF‐fabric composites easily.This strategy can be applied to different MOF types,as well as a wide variety of fabric materials.The prepared materials showed excellent bacterial killing efficacy attributed to the embedded HKUST‐1 MOF.In light of the recent coronavirus disease 2019 pandemic,this methodology could enable the large‐scale fabrication of essential MOF‐based personal protective wearables(e.g.,clothing and masks)for use by healthcare professionals.
基金supported by the Basic Science Center Project of the National Natural Science Foundation of China(51788104)the National Key R&D Program of China(2018YFB0703603)。
