Development And Experimental Research Of Dual Head Slurry Extrusion Freezing 3D Printing Device

Compared with the traditional preparation of ceramics,additive manufacturing has the advantages of complex structure forming,sho rt forming cycle and wide use of materials,and is widely used in functional ceramics,medicine,bio-ceramics and other fields.Compared with other additive manufacturing processes,extrusion freezing 3D printing technology has the advantages of low equipm ent cost,low environmental pollution,and rapid prototyping of medium and small ceramic parts,but when forming ceramic parts with complex structures,it will cause damage to parts collapse and surface quality damage due to the lack of support materials o r when the main material and support materials use the same material,so based on the principle of the process and the forming of complex structural parts,The development and construction of double extrusion head forming equipment and freezing equipment,and the optimization of the process parameters of the main material and support material,and finally discussed the formability of complex structural parts,the specific results are as follows:(1)Developed and constructed double extrusion head forming eq uipment,the equipment mainly includes motion system,extrusion system and control system;The structural type of the equipment is XYZ type,in order to reduce the influence of the reciprocating motion of the forming platform on the accuracy of the forming parts,the movement of the extrusion head is in the X direction,and the forming platform is moving along the Y-Z axis;Using screw plunger type as the slurry extrusion system,the structure is easy to achieve,low cost,easy to clean the extrusion head a nd other advantages,the two extrusion heads are placed parallel along the X axis,the center distance along the X axis direction is 78 mm,and the center distance along the Y axis direction is 0mm to ensure the accurate positioning of the extrusion head in the forming process;The quick-freezer is selected as the freezing equipment of the forming equipment,and the temperature range can be adjusted from-45 °C to 3 °C,and the display window is designed for the freezing equipment to facilitate the observati on of the preparation process of the parts,and the forming equipment and the freezing equipment are assembled,thus forming an extrusion freezing 3D printing process device(2)Using Chitu FV3.14 as the control motherboard of the equipment,the forming of double extrusion heads is realized by modifying the main parameters of the equipment,such as the number of extrusion heads of the equipment,the maximum forming size,the direction of rotation of the stepper motor of each axis,the movement configuration of the extrusion head/platform of X,Y,and Z axis,the distance traveled by the number of pulses,the maximum moving speed of each axis,the center distance between the two extrusion heads,and other parameters;Repetier-Host slicing software is selected as the data processing software of the equipment to debug the printing parameters of the equipment,such as the layering height,printing speed,the number of skirt layers and distance,needle parameters,retraction distance,filling method and density,and support angle and other parameters to obtain the reference range of the printing parameters.(3)Using bauxite slurry as the main material and hydrogel material as the supporting material,the single-factor method was used to study the effects of print ing speed,delamination height,extrusion rate and freezing temperature on the printing and forming effect of parts by single extrusion head,and the results showed that when the extrusion speed was 8mm/s,the delamination height was 80% of the inner diame ter of the extrusion head,the extrusion rate was 1,and the freezing temperature was-40 °C,the size deviation of the prepared parts was the smallest and the printing and forming effect was the best.On the basis of the best process of single extrusion h ead,the formability of complex structural parts was studied,and suspended "L" shaped parts were prepared by using double extrusion head forming equipment.The results show that the double extrusion head forming equipment designed in this paper is feasibl e to prepare complex structural parts.