Research On The Forming Of Ceramic Static Spiral Cutter Based On 3D Printed Mold

High quality,low cost,short cycle,and small batches have become the development trend of modern machinery manufacturing gradually.Traditional mechanical processing can no longer meet the personalized demands of the market entirely.As a new type of static mixer with complex shape and variable pitches,the static spiral cutter has excellent performances of preparing oxygen-enriched water,wet flue gas desulfurization and gas-liquid mass transfer enhanced.At present,a static spiral cutter developed in our lab is mainly manufactured by stainless steel pieces that are manufactured by wire cutting,resulting in corrosion,adhesion,long processing cycle and high cost.In this study,3D printed mold and gelcasting were employed to manufacture ceramic static spiral cutter with low-cost.Also,the effects of different parameters on quality of ceramic static spiral cutter were investigated,and changes of the surface material of cavity core were also analyzed by actual operation.Main research contents are as follows:?1?The clarity of steps,difficulty of demoulding and strength of ceramics manufactured by compacting and gelcasting were compared in detail.It shows that the green body produced by gelcasting is easier to be demoulded.The sintered bodies of Si C,ZrO2,and clay were also evaluated to explain that the clay part had clearer steps and higher strength at the same sintering temperature.Therefore,it is more reasonable to manufacture the cavity core of static spiral cutter by gelcasting,taking clay as solid phase.?2?According to the characteristics of gelcasting and structure of static spiral cutter,a mold with eight parting surfaces in the axial direction and four parting surfaces in the radial direction was designed,and the stereo lithography apparatus was used to print it out.After experiments,it demonstrates that the green body of static spiral cutter can be demoulded completely,and surface steps are not damaged.The combination of stereo lithography apparatus and gelcasting can fabricate complex-shaped ceramics.?3?Effects of process parameters on the slurry properties,gel-reaction rate,and characteristics of sintered bodies were investigated and characterized by Zeta potential,viscosity,SEM,XRD and other methods.The gel kinetics was studied,and the gel reaction and slurry dispersion mechanism were also summarized.Then,optimal parameters are obtained as following:the concentration of monomer is 15 wt%,the monomer-crosslinker ratio is 14,the pH is 12,the concentration of dispersant is 3.0 vol%,the concentration of solid phase is 55 wt%,the concentration of initiator is 4 vol%,and the sintering temperature is 1200?.A ceramic static spiral cutter cavity core with clear steps and high cylindricity was then successfully manufactured based on the above process parameters.?4?Changes in the microstructure,functional groups and phases of cavity core were analyzed to evaluate the erosion after it operated in the system of acid-base solution and ozone water for 168 hours by SEM,FTIR and XRD and other methods.It shows that the erosion of Ca?OH?₂ solution with a concentration of 15 wt%has a small effect on the surface of ceramic static spiral cutter cavity core,with slight spalling and small cracks only.The corrosion of H₂SO₄ solution with a concentration of 0.429 wt%has a greater impact on the cavity core surface,with large-scale spalling,because that H2SO4 reacts with hematite?Fe2O3?and mullite?3Al2O3·2SiO2?to generate sulfate.After it operated in the ozone water erosion system,there is no change on the microscopic surface.The strong oxidation of ozone water has almost no effect on the surface of ceramic static spiral cutter.In this paper,the process of forming static spiral cutters by gelcasting was proposed by use of the clay as solid phase.It solves the problem that the structure of static spiral cutters is so complicated that it is difficult to manufacture.Meanwhile,it will provide possibility for the popularization of static spiral cutters in the industry.