Ceramic vat photopolymerization(VPP)enables the fabrication of complex components with excellent properties and high precision.However,compared with metals and polymers,the industrial application of ceramic VPPs remai...Ceramic vat photopolymerization(VPP)enables the fabrication of complex components with excellent properties and high precision.However,compared with metals and polymers,the industrial application of ceramic VPPs remains relatively limited.This can be attributed to the challenges associated with ceramic feedstock printability,the complexity of the printing process,insufficient performance evaluation,and service verification.To overcome these limitations,the design of a viscoelastic paste and corresponding VPP strategies offer a promising solution.This paper presents a review of the research on the state of viscoelastic ceramic paste-based VPP.The main tech-nical aspects,including the paste design,support strategies,green-body cleaning,and subsequent post-treatment,are discussed.Furthermore,representative applications of VPP for various types of advanced ceramics are sur-veyed.This review also highlights the technical challenges involved and provides suggestions for addressing these issues.Finally,future directions for promoting the additive manufacturing of advanced ceramic components with enhanced efficiency and reliability are discussed.展开更多
Additive manufacturing(AM)is gaining traction in the manufacturing industry for the fabrication of components with complex geometries using a variety of materials.Selective laser melting(SLM)is a common AM technique t...Additive manufacturing(AM)is gaining traction in the manufacturing industry for the fabrication of components with complex geometries using a variety of materials.Selective laser melting(SLM)is a common AM technique that is based on powder-bed fusion(PBF)to process metals;however,it is currently focused only on the fabrication of macroscale and mesoscale components.This paper reviews the state of the art of the SLM of metallic materials at the microscale level.In comparison with the direct writing techniques that are commonly used for micro AM,micro SLM is attractive due to a number of factors,including a faster cycle time,process simplicity,and material versatility.A comprehensive evaluation of various research works and commercial systems for the fabrication of microscale parts using SLM and selective laser sintering(SLS)is conducted.In addition to identifying existing issues with SLM at the microscale,which include powder recoating,laser optics,and powder particle size,this paper details potential future directions.A detailed review of existing recoating methods in powder-bed techniques is conducted,along with a description of emerging efforts to implement dry powder dispensing methods in the AM domain.A number of secondary finishing techniques for AM components are reviewed,with a focus on implementation for microscale features and integration with micro SLM systems.展开更多
Highly stable and permeable silicone emulsions were prepared by encapsulating N-octyl triethoaysilane microdroplets into micelles of NH_(2)-PDMS/SiO_(2).The conversion of siloxane to sub-1μm emulsions,on one hand,end...Highly stable and permeable silicone emulsions were prepared by encapsulating N-octyl triethoaysilane microdroplets into micelles of NH_(2)-PDMS/SiO_(2).The conversion of siloxane to sub-1μm emulsions,on one hand,endows the concrete with a highly hydrophobic internal surface.While,its outside surface maintains relatively high surface energy,which is beneficial for the post-coating of other polymers.As a result,the coated concreted can simultaneously acquire water repellency and low permeability.The utilization of water-dispersed silicone emulsions,on the other hand,is beneficial for the environmental protection.Thus,this work offered a green procedure for the comprehensive protection of concrete.展开更多
基金supported by Suzhou Key Industrial Technology In-novation Projects of China(Grant Nos.SYG202040,SGC2021063)Open Fund Project of 3D Printing Equipment and Manufacturing Key Laboratory in Jiangsu Province of China(Grant.No.3DL202103).
文摘Ceramic vat photopolymerization(VPP)enables the fabrication of complex components with excellent properties and high precision.However,compared with metals and polymers,the industrial application of ceramic VPPs remains relatively limited.This can be attributed to the challenges associated with ceramic feedstock printability,the complexity of the printing process,insufficient performance evaluation,and service verification.To overcome these limitations,the design of a viscoelastic paste and corresponding VPP strategies offer a promising solution.This paper presents a review of the research on the state of viscoelastic ceramic paste-based VPP.The main tech-nical aspects,including the paste design,support strategies,green-body cleaning,and subsequent post-treatment,are discussed.Furthermore,representative applications of VPP for various types of advanced ceramics are sur-veyed.This review also highlights the technical challenges involved and provides suggestions for addressing these issues.Finally,future directions for promoting the additive manufacturing of advanced ceramic components with enhanced efficiency and reliability are discussed.
基金financial support from the Science and Engineering Research Council,Agency for Science,Technology and Research(A*STAR),Singapore(142 68 00088)
文摘Additive manufacturing(AM)is gaining traction in the manufacturing industry for the fabrication of components with complex geometries using a variety of materials.Selective laser melting(SLM)is a common AM technique that is based on powder-bed fusion(PBF)to process metals;however,it is currently focused only on the fabrication of macroscale and mesoscale components.This paper reviews the state of the art of the SLM of metallic materials at the microscale level.In comparison with the direct writing techniques that are commonly used for micro AM,micro SLM is attractive due to a number of factors,including a faster cycle time,process simplicity,and material versatility.A comprehensive evaluation of various research works and commercial systems for the fabrication of microscale parts using SLM and selective laser sintering(SLS)is conducted.In addition to identifying existing issues with SLM at the microscale,which include powder recoating,laser optics,and powder particle size,this paper details potential future directions.A detailed review of existing recoating methods in powder-bed techniques is conducted,along with a description of emerging efforts to implement dry powder dispensing methods in the AM domain.A number of secondary finishing techniques for AM components are reviewed,with a focus on implementation for microscale features and integration with micro SLM systems.
基金Funded by Fundamental Research Funds for the Central Universities(No.2019MS062)City University of Hong Kong(No.SRG7004918)
文摘Highly stable and permeable silicone emulsions were prepared by encapsulating N-octyl triethoaysilane microdroplets into micelles of NH_(2)-PDMS/SiO_(2).The conversion of siloxane to sub-1μm emulsions,on one hand,endows the concrete with a highly hydrophobic internal surface.While,its outside surface maintains relatively high surface energy,which is beneficial for the post-coating of other polymers.As a result,the coated concreted can simultaneously acquire water repellency and low permeability.The utilization of water-dispersed silicone emulsions,on the other hand,is beneficial for the environmental protection.Thus,this work offered a green procedure for the comprehensive protection of concrete.
