Research And Performance Analysis Of Alumina Ceramic Slurry

3D printing technology is also known as additive manufacturing technology,the whole parts of the molding process does not involve any traditional machine tools,fixture,mold and tool cutting equipment,solve the problem of traditional ceramic molding need mold,fast and refined to produce the traditional molding difficult to process,complex structure of the parts model,widely used in various modern fields.This dissertation adopts 3D direct ink writing process,based on water-based alumina slurry,the composition and proportion of the slurry were optimized by combining orthogonal experiments with artificial neural networks,the alumina ceramic slurry with excellent performance is prepared.Build the direct writing system printing device system of water-based alumina slurry,and carry out the performance research of the direct writing system of slurry,sintering of ceramic billet and ceramic parts.The alumina grade distribution size and the type of dispersant were determined by univariate method,through orthogonal experiments and simulated predictions of artificial neural networks,mainly study the effects of solid content,dispersant,plasticity,binder and the lubricant on the viscosity and shrinkage of alumina slurry.The results show that the particle size ofα-Al₂O₃is 0.3μm and 0.5μm,ceramic powder has the best performance at 62.5wt.%and 37.5wt.%,respectively.When choose the DS-165A as the dispersant and the dosage is 3.86wt.%,the slurry has the best stability.In the remaining additives,the plasticizer uses polyethylene glycol,the amount is 4wt.%,the lubricant is propylene alcohol,the amount is 2wt.%,the binder is carrageenan,and the amount is 0.4wt.%.The above parameters can prepare the alumina ceramic slurry with solid phase content of 75.74wt.%.In this dissertation,the water-based alumina slurry direct writing type printing device system is built for the extrusion molding of direct writing type slurry.The air compressor and the three-dimensional coordinate motion system of the melting deposition device with the displacement plunger extrusion device are determined.Different caliber of printing needle can be chose,the minimum printed silk diameter can reach 0.3mm,and the solid phase content can reach up to 80wt.%.The result show that when the air pressure is controlled at 6-10 MPa,the needle movement speed is15-35mm/min,the extrusion height of the needle from the platform is 0.8-1.2mm,the platform temperature is about 65℃,the printing forming effect is the best and the surface filling rate is the highest.Sinter the ceramic green body,the optimal sintering curve is obtained according to the surface forming quality of the parts under different heating rate and thermal insulation time.After sintering,the surface of the workpiece has a high degree of surface smoothness,the shrinkage rate is small,the surface is complete,without cracking and warping deformation.The sintered samples are tested for packing rate,density and bending strength,which showed that the average filling rate was 92%,with an average density of 3.979g/cm³and bending strength up to 425MPa.Through continuous experimental debugging and optimization,formed an optimization process from slurry blending,simulation to verification,the process of assembling and debugging the best experimental parameters of the equipment,the rapid molding process of direct ink writing of ceramic materials,and the final process of the sintering and performance.