| As a safety barrier to ensure the safety of the environment and human life and property,boron carbide composites are one of the research hotspots in the nuclear field.Traditional metal,concrete and ceramic composite materials have high density and high mass,which are difficult to meet the application requirements for light weight and miniaturization,and the accumulation of shielding by-products can easily lead to material failure.High boron-containing polymer composites have low density and corrosion resistance,but insufficient mechanical strength.Adding fibers can enhance the mechanical strength of the material by changing the fracture mechanism of the material,and at the same time improve the thermal conductivity of the material,so as to meet the use of the material in different fields.The multi-layered shielding material utilizes interlayer reflection and refraction to accelerate the attenuation of radiation energy and has a better shielding effect.In this paper,aiming at the problem of poor mechanical strength of polymer shielding materials,fiber reinforced boron carbide epoxy resin matrix composites are prepared,and fiber reinforced boron carbide foam ceramic materials are prepared to solve the problem that boron carbide ceramics are easy to break and fail.The epoxy resin filled boron carbide foam ceramic material was prepared by compounding it,and its mechanical strength,thermal conductivity and specific surface area were studied.The main contents are as follows:(1)Using epoxy resin,boron carbide powder,silicon carbide nanofiber,carbon fiber,carbon nanotube and metal powder as the main raw materials to prepare composite materials with different compositions and ratios.The test results show that the mechanical strength of the material increases first and then decreases with the increase of fiber content.The thermal conductivity of the material first decreased and then increased with the increase of carbon nanotube and silicon carbide nanofiber content,but showed a decreasing trend with the increase of carbon fiber content.The carbon nanotubes in the three fibers have better comprehensive reinforcement effect on the material.(2)Using boron carbide powder,silicon carbide nanofiber,carbon fiber,carbon nanotube,and metal powder as main raw materials to prepare foamed ceramic materials with different compositions and ratios.The characterization results show that the microstructure and mechanical properties of the material are significantly anisotropic.Among the three fibers,silicon carbide nanofibers have a better effect on the thermal conductivity and mechanical strength of the material,and the compressive strength in the parallel and vertical directions can reach 5.47 MPa and 1.65 MPa,respectively,and the thermal conductivity can be increased to 0.29 W/m*K with the increase of the content.(3)Compound epoxy resin and foam ceramic material to prepare epoxy resin filled foam ceramic material.The compressive strength in the parallel and vertical directions can reach85.25 MPa and 67.16 MPa,respectively,and the thermal conductivity can reach 0.855W/m*K.The test results show that the epoxy resin composite further enhances the comprehensive properties of the material,while retaining the various properties of the foamed ceramic material. |
