Study On Design And Properties Of Tungsten-Boron Compound/Aluminum Shielding Composites

In recent years,the application of nuclear energy has become more and more extensive.Nuclear energy also produces nuclear radiation while creating value for human beings,thus causing damage to the surrounding environment and human health.Therefore,research on nuclear shielding materials is particularly necessary.In this paper,tungsten boron compounds are selected as functional particles,which can simultaneously shield neutrons and gamma rays with strong penetrating power.An aluminum alloy that is light in weight and can ensure mechanical property is selected as a matrix.Firstly,the MCNP software of Monte Carlo simulation method was used to design the tungsten-boron compound/aluminum shielding composites according to the shielding requirements of the material and the preparation feasibility.The composites were prepared by ball-milling and spark plasma sintering,and the preparation process was optimized.Different volume fractions of WB/6061Al composites were prepared according to the optimized process.The effects of WB particle volume fraction on the mechanical properties and shielding properties of the composites were systematically investigated.Regularity and analysis of related mechanisms;The microstructure of the composites was observed and analyzed by scanning electron microscopy and transmission electron microscopy.Different matrix composites with WB volume fraction of 30%were prepared,and the influence of matrix types on the mechanical properties of the composites was studied.The relationship between theγ-ray absorption coefficient of tungsten-boron compound/aluminum composite shielding material and the volume fraction of tungsten-boron compound was obtained by simulation,that is,the volume fraction of tungsten-boron compound and the absorption coefficient ofγ-ray line have linear law,and tungsten was further determined.The relationship between areal density and material shielding rate provides guidance for further application of the shielding material.According to the simulation results and material preparation feasibility,it is determined that WB is a functional particle with a volume fraction of 30%and uniform distribution.It is found that with the increase of ball milling time,the particle size of WB powder is getting smaller and smaller,the degree of flaking of Al matrix is increased,the inlay welding of WB and Al matrix is gradually increased,and the mixing of the two powders is more uniform.With the SPS holding time extended from 20min to30min,the density of WB/Al composites increased first and then remained unchanged.The optimized SPS process was incubated at 570°C for 25 min and the sintering pressure was 40MPa.The WB particles in the composite material are uniformly distributed and increase in volume fraction,and the WB particle size is reduced.The interface product WAl₁₂ exists in the composites,and the Si element in the 6061 Al matrix is largely segregated onto the WB particles.With the increase of WB volume fraction of WB/6061Al composite,the hardness and elastic modulus of WB/6061Al composites gradually increase,the elongation decreases gradually,the tensile strength increases first and then decreases,and the tensile strength is 287 MPa when the WB volume fraction is 20%.When the volume fraction of WB is 30%,the linear absorption coefficient of WB/Al composite for ⁶⁰Co is 0.32cm^-1,and the macroscopic reaction cross section for thermal neutron is 5.62cm^-1.