Research On Direct Writing 3D Printing Of SiO_2f/Phosphate Composite And Its Properties

3D printing technology has the advantages of full use of raw materials,simple molding process and rapid prototyping of complex structures.At present,3D printing fiber reinforced materials are a major research hotspot,especially short fiber materials.In addition to improving the mechanical properties of materials,It can also improve the performance of the material in terms of electromagnetic performance,thermal performance,etc.The related research on the preparation of short fiber composite materials using slurry direct-write 3D printing technology is also a hot spot in 3D printing.In this paper,quartz fiber,nano-SiO2 powder and phosphate are used as raw materials to prepare short-fiber composite materials using slurry direct writing 3D printing preparation technology.By adjusting the rheological properties of the slurry,based on the research background of 3D printing and printing wave-transmitting materials,using quartz fiber as the reinforcing phase,3D printing molding of quartz fiber reinforced SiO2/phosphate composite material was successfully achieved.In order to guide the experiment on fiber orientation,this paper conducted a finite element simulation of the slurry flow in the needle and the fiber orientation in the needle.The finite element simulation results show that 3D printing needle structure,slurry flow rate and slurry viscosity have a certain effect on the slurry flow.The finer the needle outlet,the more drastic the change in slurry flow rate,as well as the needle structure,fiber content and slurry The flow velocity has a significant effect on the fiber orientation distribution,but the slurry viscosity and fiber length have little effect on the fiber orientation distribution of the system.Studies have shown that increasing the content of the curing agent and nano-SO2 powder can increase the viscosity of the SiO2/phosphate slurry,and the addition of nano-SiO2 can make the slurry shear thinning behavior,turning the phosphate liquid into a non-Newtonian fluid.Temperature has a great influence on the structure of SiO2/phosphate.With the increase of temperature,the material undergoes dehydration condensation reaction to form phosphate.The phase composition after curing is mainly Al(H2PO4)3 and Al PO4.SiO2/phosphate is a low dielectric constant material with good wave-transmitting properties.Increasing the content of curing agent and nano-SiO2 can improve the mechanical properties and dielectric properties of the materials.The flexural strength of the SiO2 fiber reinforced Si O2/phosphate composite material produced by the short fiber fiber reinforced 3D printing technologydesigned in this subject is improved;and the dielectric properties of the material are significantly improved compared to the SiO2/phosphate without fiber.