Research On Three Dimensional Printing Process Of Aqueous Alumina Ceramic Slurry

Three dimensional printing technology can also be expressed as additive manufacturing.During molding process,the traditional machine tool,fixture,cutting tools are not needed,at the same time,we don't use the mould during molding,which can get rid of the limit of the mould's shape.Complex model can be manufactured quickly and precisely.We can seriously realize the "the freedom fabrication”.During experiments,the extruder of three dimensional printer is modified.we use aqueous alumina ceramic slurry as ink to realize printing ceramics.Aqueous alumina ceramic slurry use water as a medium,only contains a small amount of organic binder.During the preparation of the slurry,we focused research on the influence of pH,solid loading,plastic agent,binder,lubricant and dispersant on slurry's rheological property.Results show that the slurry is stable when the dispersant dosage was 0.4 wt%.At the same time,when the plastic agent dosage was 1.0 wt%,the dosage of the lubricant is 4.0 wt%,the amount of binder was 1.0 wt%,aqueous alumina ceramic slurry have good dispersancy.The original desktop three dimensional printer is modified to a printer which can print ceramic.We try the following several attempts:(1)spiral agitator extruder,(2)stationary plunger extruder,(3)replaceable plunger extruder.Finally we determines the printer which use the original X-Y-Z motor system as the foundation,make the linear stepper motor as the mode of movement and replaceable plunger extruder for extruding alumina slurry.Through the firmware upgrading and debugging,we formed a processing of rapid prototyping for the ceram ic.?When using copy paper as the base material,the minimum size of alumina filament diameter can reach 0.6 mm.With different solid loading of alumina slurry,when the movement speed within 15-30 mm/min,extrusion height at 0.8-1.2 mm,extrusion velocity in 20-35 steps/mm,curing temperature below 40?,filling rate can reach more than 90%,and effective height can be consistent with the model.The workpiece's minimum roughness value is 2.3339 ?m,which means the surface has high degree of smooth surface.The workpiece has less porosity,high density,the surface outline is clear,the artifact is flat and level.