Porous metals fabricated via three-dimensional(3D)printing have attracted extensive attention in many fields owing to their open pores and customization potential.However,dense internal structures produced by the powd...Porous metals fabricated via three-dimensional(3D)printing have attracted extensive attention in many fields owing to their open pores and customization potential.However,dense internal structures produced by the powder bed fusion technique fails to meet the feature of porous materials in scenarios that demand large specific surface areas.Herein,we propose a strategy for 3D printing of titanium scaffolds featuring multiscale porous internal structures via powder modification and digital light processing(DLP).After modification,the titanium powders were composited with acrylic resin and maintained spherical shapes.Compared with the raw powder slurries,the modified powder slurries exhibited higher stability and preferable curing characteristics,and the depth sensitivity of the modified powder slurries with 45 vol%solid loading increased by approximately 72%.Green scaffolds were subsequently printed from the slurries with a solid loading reaching 45 vol%via DLP 3D printing.The scaffolds had macropores(pore diameters of approximately 1 mm)and internal open micropores(pore diameters of approximately 5.7-13.0μm)after sintering.Additionally,these small-featured(approximately 320μm)scaffolds retained sufficient compressive strength((70.01±3.53)MPa)even with high porosity(approximately 73.95%).This work can facilitate the fabrication of multiscale porous metal scaffolds with high solid loading slurries,offering potential for applications requiring high specific surface area ratios.展开更多
A simple method for the magnetic modification of various types of powdered agglomerate forming dia- magnetic materials was developed. Magnetic iron oxide particles were prepared from ferrous sulfate by microwave assis...A simple method for the magnetic modification of various types of powdered agglomerate forming dia- magnetic materials was developed. Magnetic iron oxide particles were prepared from ferrous sulfate by microwave assisted synthesis. A suspension of the magnetic particles in water soluble organic solvent （methanol, ethanol, propanol, isopropyl alcohol, or acetone） was mixed with the material to be modified and then completely dried at elevated temperature. The magnetically modified materials were found to be stable in water suspension at least for 2 months.展开更多
The inherent properties of powder are the core factors influencing rheological characteristics.Fluctuations in rheological properties can lead to instability issues in powder during mixing,storage,and transportation.T...The inherent properties of powder are the core factors influencing rheological characteristics.Fluctuations in rheological properties can lead to instability issues in powder during mixing,storage,and transportation.This review focuses on factors influencing rheology in dry powder systems and their specific trends.It presents the trends of six significant powder properties that affect rheology:particle size,particle size distribution,shape,charge,moisture content,specific surface area,and surface roughness.While explaining the influencing mechanisms,it also summarizes modification methods and detection techniques for monitoring rheological behavior.It provides a good explanation of the relationship between rheological properties and powder properties,aiming to offer solutions to problems encountered during the mixing,storage,and transportation of powders through a summary of powder science modification methods.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52405326,52105588 and 52075421)the Key Research and Development Program of Shaanxi(Nos.2024GX-YBXM-222 and 2023-YBSF-276)。
文摘Porous metals fabricated via three-dimensional(3D)printing have attracted extensive attention in many fields owing to their open pores and customization potential.However,dense internal structures produced by the powder bed fusion technique fails to meet the feature of porous materials in scenarios that demand large specific surface areas.Herein,we propose a strategy for 3D printing of titanium scaffolds featuring multiscale porous internal structures via powder modification and digital light processing(DLP).After modification,the titanium powders were composited with acrylic resin and maintained spherical shapes.Compared with the raw powder slurries,the modified powder slurries exhibited higher stability and preferable curing characteristics,and the depth sensitivity of the modified powder slurries with 45 vol%solid loading increased by approximately 72%.Green scaffolds were subsequently printed from the slurries with a solid loading reaching 45 vol%via DLP 3D printing.The scaffolds had macropores(pore diameters of approximately 1 mm)and internal open micropores(pore diameters of approximately 5.7-13.0μm)after sintering.Additionally,these small-featured(approximately 320μm)scaffolds retained sufficient compressive strength((70.01±3.53)MPa)even with high porosity(approximately 73.95%).This work can facilitate the fabrication of multiscale porous metal scaffolds with high solid loading slurries,offering potential for applications requiring high specific surface area ratios.
文摘A simple method for the magnetic modification of various types of powdered agglomerate forming dia- magnetic materials was developed. Magnetic iron oxide particles were prepared from ferrous sulfate by microwave assisted synthesis. A suspension of the magnetic particles in water soluble organic solvent （methanol, ethanol, propanol, isopropyl alcohol, or acetone） was mixed with the material to be modified and then completely dried at elevated temperature. The magnetically modified materials were found to be stable in water suspension at least for 2 months.
基金supported by the General Project of National Natural Science Foundation of China(grant No.82274095)Key Research and Development Project of Shaanxi Province(grant No.2022ZDLSF05-13)+2 种基金Shaanxi Provincial Key Industry Innovation Chain Project(grant No.2022ZDLSF05-09)Shaanxi Provincial Administration of Traditional Chinese Medicine Research Project(grant No.2021-ZZ-ZY005)Shaanxi Provincial Department of Education Youth Innovation Team Project(grant No.22JP005).
文摘The inherent properties of powder are the core factors influencing rheological characteristics.Fluctuations in rheological properties can lead to instability issues in powder during mixing,storage,and transportation.This review focuses on factors influencing rheology in dry powder systems and their specific trends.It presents the trends of six significant powder properties that affect rheology:particle size,particle size distribution,shape,charge,moisture content,specific surface area,and surface roughness.While explaining the influencing mechanisms,it also summarizes modification methods and detection techniques for monitoring rheological behavior.It provides a good explanation of the relationship between rheological properties and powder properties,aiming to offer solutions to problems encountered during the mixing,storage,and transportation of powders through a summary of powder science modification methods.
