The Research On Fused Deposition Modeling Of Ceramics

Fused Deposition Modeling has been paid more and more attention because of its low cost,wide applicability and great development potential.This technology possesses a cost performance which makes it one of the most rapid development addictive manufacturing processes.However,the low ceramics content of the feedstock used in the fused deposition molding often leads to low sintering strength.In view of the problem existing in the fused deposition modeling of ceramic,this work designed an extrusion nozzle based on the small variable cross-section screw.High density prototypes are obtained by extruding feedstock with high ceramic content and high viscosity through a high shear strength screw.In addition,in order to improve the precision and strength of the components,it is necessary to make a systematic study on the forming process.Based on the above ideas,the main research work is as follows.First of all,an extrusion nozzle based on small variable cross-section screw is designed.The main parameters of the screw were determined through calculation,and finally,the design of small variable cross-section screw was completed.The forming speed and extrusion pressure can be enhanced effectively,thus feedstock with high ceramics content and high viscosity is able to be extruded to manufacture more compact prototypes.Secondly,several experiments have been conducted to test the continuity and uniformity of the extrusion nozzle.The experimental results show that filaments can be extruded continuously,uniformly and stably through the nozzle,based on which the diameters of the extruded filaments at different temperatures through different diameter nozzles have been measured to optimize the forming process parameters.Finally,the research of 3D solid forming process of FDM has been conducted.One dimensional forming,two-dimensional forming experiments were carried out to determine the parameters of FDM forming process(nozzle temperature,layer height,scanning speed etc.).In the end,the ceramic prototypes were produced under the optimized forming parameters.