Study On Formability Of ZrO₂ Thin Wall Parts Prepared By Freeze-form Extrusion Fabrication Process

Ceramic parts are widely used due to their superior properties such as high strength,high wear resistance,and high resistance to oxidation.Traditional ceramic parts have complicated production processes,long production cycles and difficulty in customizing.In recent years,ceramic 3D printing technology has developed rapidly.Freeze-form Extrusion Fabrication process using water-based ceramic paste as a kind of ceramic 3D printing technology,because of the process equipment is low-cost,simple structure and easy to operate,low-pollution,can be formed the advantages of high density and complex ceramic parts,the forming process has attracted the attention of more and more researchers.Due to the difficulty of forming complex ceramic parts,it is necessary to further study the thin-walled ceramic parts with high precision.Therefore,in this paper,the water-based ZrO₂ was used to extrude the thin-walled ceramics under the Freeze-form Extrusion Fabrication process to provide the data reference for forming high-precision thin-wall ceramics.Extruding the thin-walled ZrO₂ ceramic parts in a frozen environment,by changing the freezing extrusion temperature,thin-walled extruded wire constitutes layers and the slope of thin-walled parts,the diameter of the extrusion head and the height of the extruded layer to study their influence on the formability of thin-walled ceramic parts.Freezing extrusion temperature is not as low as possible,the lower the temperature,the worse the extruded thin-walled part and the greater the deformation.The more the number of thin-walled extruded filaments,the higher the precision of the formed part and the greater the range of slope that can be formed.However,the more the number of extruded filaments is formed,the longer its time and lower production efficiency.The smaller the diameter of the extruded thin-walled part with the same wall thickness,the better the formability and the higher the precision of the formed part,but the smaller the diameter,the longer the extrusion forming time and lower forming efficiency.The smaller the extruded layer thickness,the smaller the deformation of the molded part,but the smaller the layer height,the better.When the extrusion layer height reaches a certain value,the formability is reduced.When the temperature is-10?,the forming accuracy is the highest and the deviation of the formed part varies little with the thin-walled slope.When the number of thin-walled extruded wires is not less than 3 layers,the thin-walled parts have goodformability and the accurately-formable thin-walled inclined angle is-30° to 20°.Forming the thin-walled part with a wall thickness of 2.4 mm,the best formability when the extrusion head diameter is 0.8 mm.There is a linear relationship between the extrusion layer height y and the extrusion head extrusion diameter x,extrusion layer height y=3/4x.