Key Technology And Mechanism Of Metal Paste Injection 3D Printing Fabricating Small Complex Three-dimensional Structure

Metal 3D printing technology has been widely used in high-end fields such as aviation and medical treatment at present.However,in the field of civil consumption,3D printing technology has the characteristics of saving material,forming complex structure and personalizing manufacturing.It also provides technical means for manufacturing innovative products with high added value.Under the background of jewelry industry in urgent need of 3D printing advanced manufacturing technology to improve the innovation ability and added value of products,and constantly meet the individual needs of consumers,laser and electron beam printing faces the defects of forming performance.High cost and limited printable material,metal paste injection 3D printing technology provides jewelry High cost-effective advanced manufacturing innovation ideas.In order to produce metal or alloy composition with more complex structure,excellent physical and chemical properties,it is necessary to discuss and optimize the key technology and process control mechanism of metal paste injection 3D printing.Taking copper paste as the research object and combining experimental research with theoretical analysis,the material preparation involved in injection 3D printing of metal paste for micro-metal three-dimensional structure is studied in this paper.The key scientific and technical problems in the process of forming property control and degreasing sintering process are discussed.The influence of printing parameters on three-dimensional structure forming,the kinetics of degreasing and the optimization of sintering process are mainly studied.In this study,the effects of paste viscosity,single layer height,retraction distance and extrusion amount on the forming properties were characterized by designing printing tests under different layer height,shrinkage value and extrusion volume parameters,and the influence of paste viscosity,single layer height,retraction distance and extrusion amount on the forming properties was characterized.The influencing factors and control mechanism of metal paste injection 3D printing were revealed.Then the mass transfer route of hot degreasing of copper paste was analyzed,the diffusion coefficient was introduced,the kinetic problem of copper paste degreasing was clarified,and the activation energy and preexponential factor corresponding to the degreasing chemical reaction were calculated.Finally,based on the analysis of forming control and the study of degreasing mechanism,the sintering experiments under different thermal parameters were designed.The properties of density,hardness,porosity and micro-morphology were characterized.The sintering process and forming property control law of copper paste samples were revealed.The influencing factors and control analysis of metal paste injection 3D printing,the mass transfer mechanism and dynamics of metal paste injection 3D printing samples,and the sintering process and forming properties of copper paste samples were studied.It lays a theoretical and technical foundation for the micro-complex 3D structure of metal paste injection 3D printing.