Electricity is an efficient form of energy,and the growing interest in electricity-assisted manufacturing is motivated by its inherent energy saving and reduced environmental impact.Beyond this,Electromagnetic Process...Electricity is an efficient form of energy,and the growing interest in electricity-assisted manufacturing is motivated by its inherent energy saving and reduced environmental impact.Beyond this,Electromagnetic Processing of Materials(EPM)allows the fabrication of materials with new compositions,metastable phases and nanograined microstructures that cannot be obtained using conventional heating processes using furnaces.This review covers EPM for the manufacture of ceramic and metal bulk components,with a specific focus on the effects of electric fields and electromagnetic radiations on processing in a wide spectrum of frequencies ranging from DC(f=0 Hz)to visible light(f=10^(14)–10^(15)Hz).The manuscript is divided into two parts.The first part provides a comprehensive overview of the interactions between matter and electric field/current,including heating phenomena(resistive Joule,induction,dielectric heating,electric arcs)and athermal effects(electromigration,electroplasticity,electrochemical reactions,ponderomotive force and others).The second part is focused on the technological application of the techniques,covering heat treatments,joining,sintering and forming.Seven distinct physical phenomena are involved in EPM:resistive Joule and induction heating,electrochemical reactions,electroplasticity,electric arcs and electromagnetic heating based on radio and microwave frequencies(mainly used for heating dielectric materials;i.e.,dielectric heating)or on the IR/visible light(IR heating and lasers).展开更多
We developed a novel consolidation technique,Cold Hydrostatic Sintering(CHS),which allows near full densification of silica.The technique is inspired by biosilicification and geological formation of siliceous rocks.Un...We developed a novel consolidation technique,Cold Hydrostatic Sintering(CHS),which allows near full densification of silica.The technique is inspired by biosilicification and geological formation of siliceous rocks.Unlike established cold sintering method which is based on uniaxial pressure,CHS employs an isostatic pressure to enable room temperature consolidation of bulks having a complex threedimensional shape.The resulting material is transparent(in line transmittance exceeding 70% in the visible range)and amorphous.After drying,the Vickers hardness was as high 1.4 GPa which half of materials consolidated at 1200℃ and it is the highest among all materials processed at room temperature.The CHS method,because of its simplicity,might be suitable for broad range of applications including 3D printing,mould forming and preparation of multi-layered devices.Because of the absence of the firing step,CHS could be directly integrated in the manufacturing of a wide range of hybrid(organic/inorganic)materials for functional and biological applications.展开更多
基金the Thousand Talents Program of China and Sichuan Province。
文摘Electricity is an efficient form of energy,and the growing interest in electricity-assisted manufacturing is motivated by its inherent energy saving and reduced environmental impact.Beyond this,Electromagnetic Processing of Materials(EPM)allows the fabrication of materials with new compositions,metastable phases and nanograined microstructures that cannot be obtained using conventional heating processes using furnaces.This review covers EPM for the manufacture of ceramic and metal bulk components,with a specific focus on the effects of electric fields and electromagnetic radiations on processing in a wide spectrum of frequencies ranging from DC(f=0 Hz)to visible light(f=10^(14)–10^(15)Hz).The manuscript is divided into two parts.The first part provides a comprehensive overview of the interactions between matter and electric field/current,including heating phenomena(resistive Joule,induction,dielectric heating,electric arcs)and athermal effects(electromigration,electroplasticity,electrochemical reactions,ponderomotive force and others).The second part is focused on the technological application of the techniques,covering heat treatments,joining,sintering and forming.Seven distinct physical phenomena are involved in EPM:resistive Joule and induction heating,electrochemical reactions,electroplasticity,electric arcs and electromagnetic heating based on radio and microwave frequencies(mainly used for heating dielectric materials;i.e.,dielectric heating)or on the IR/visible light(IR heating and lasers).
基金supported by Thousand Talents Program of China and Sichuan Provincethe Open Project of State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials(17kffk01)+1 种基金Outstanding Young Scientific and Technical Talents in Sichuan Province(2019JDJQ0009)the Natural Sciences Foundation of China(No.51741208).
文摘We developed a novel consolidation technique,Cold Hydrostatic Sintering(CHS),which allows near full densification of silica.The technique is inspired by biosilicification and geological formation of siliceous rocks.Unlike established cold sintering method which is based on uniaxial pressure,CHS employs an isostatic pressure to enable room temperature consolidation of bulks having a complex threedimensional shape.The resulting material is transparent(in line transmittance exceeding 70% in the visible range)and amorphous.After drying,the Vickers hardness was as high 1.4 GPa which half of materials consolidated at 1200℃ and it is the highest among all materials processed at room temperature.The CHS method,because of its simplicity,might be suitable for broad range of applications including 3D printing,mould forming and preparation of multi-layered devices.Because of the absence of the firing step,CHS could be directly integrated in the manufacturing of a wide range of hybrid(organic/inorganic)materials for functional and biological applications.
