Modeling And Forming Of Metal-resin Heterogeneous Parts By 3D Printing

Metal-resin composites have the dual characteristics of metal and resin,and have a wide range of applications.Traditional molding methods of dissimilar metal components,such as welding and injection molding,have some limitations,such as long processing cycle and difficult manufacturing.With the technical advantages of high molding accuracy,fast personalized manufacturing and complex structure processing of light-cured 3D printing,it is expected to realize the integrated molding of heterogeneous components of metal-resin by compounding resin with metal inserts through 3D printing.Therefore,this paper studies the molding of heterogeneous metal-resin components based on photo-curing3D printing.Focusing on the problems of laser shielding,insert positioning,supporting structure,resin coating,and molding accuracy in this molding process,this paper has carried out the following research:In the aspect of model processing,the problem of laser shielding is solved by classifying the model,the problem that the insert can’t be embedded is solved by adding blank support,and the problem of model positioning is solved by designing positioning structure and aligning the center point with Cartesian coordinates.Taking the composite of prosthetic socket and metal three-claw insert as an example,we can finally print the metal-resin integrated product,which verifies the effectiveness of the related treatment scheme.Aiming at the rheological property and rheological behavior of resin in UV-curable 3D printing,based on the leveling equation,the hydrodynamic analysis was carried out to explore the influence of resin viscosity,liquid level thickness,leveling distance and other parameters on leveling time.The experimental data show that the leveling time is shortened by nearly 93%when the resin is raised from 18℃to 26℃.The layer thickness increases from 0.05 mm to 0.2 mm,and the leveling time is shortened by nearly 64%.When the part area is reduced from 2500mm~2 to 400 mm~2,the leveling time is shortened by nearly 70%.The results show that reducing resin viscosity,surface tension,interfacial tension between resin and the surface of cured layer,and increasing the surface tension of cured layer are all beneficial to reducing the leveling time of resin.Increasing the layer thickness,increasing the temperature,reducing the resin flow distance and prolonging the leveling time are all conducive to the full leveling of the resin level.In order to improve the molding accuracy of the product in the Z-axis direction,the UV-curing 3D printing equipment was used to explore the resin under the condition of free leveling,and the geometric parameters(height,wall thickness,shape,area)of the target model and printing process parameters(leveling time,slice thickness,descending speed of the platform,printing temperature)were used as variables to print the products with and without inserts,and the accuracy of these parameters on the molding size of the product in the Z-axis direction was obtained through experimental inquiry.The results show that increasing the height,reducing the wall thickness,reducing the printing area,setting the shape of triangle and punching holes;Or increasing the layer thickness,increasing the descending speed of the printing platform,increasing the printing temperature and prolonging the leveling time are all conducive to reducing the relative error of the dimension of the workpiece in the Z-axis direction.Based on the orthogonal experimental design method,the experiment was carried out with process parameters such as leveling time,slice thickness,descending speed of the platform and printing temperature as variables,and the forming dimension of the workpiece in Z axis direction was measured.The range of experimental data was analyzed,and the best combination of process parameters was obtained.The results show that the factors influencing the dimensional accuracy of the workpiece in Z-axis direction are slice thickness,leveling time,printing temperature,and descending speed of printing platform in descending order.The optimum parameter optimization results are as follows:slice thickness of 0.2 mm,descending speed of platform of 4mm/s,leveling time of 45 s and printing temperature of 27℃.At this time,the dimensional accuracy of workpiece in Z axis direction is improved by about 12%.Comprehensive verification experiments show that the dimensional accuracy of prosthetic socket in Z-axis direction is obviously improved.The research on the molding of metal-resin heterogeneous components based on photo-curing 3D printing has laid a foundation for the rapid,personalized and intelligent manufacturing of complex devices in biomedical,robotics and other fields.