Study On Design And Fabrication Of Boron/Tungsten-Al Uminum Nuclear Radiation Shielding Composite

With the development of the nuclear industry,nuclear medicine,and space nuclear power,higher requirements have been placed on radiation shielding materials.In order to protect human life and health and protect the surrounding environmental equipment from radiation pollution,there is an urgent need for improvements in shielding materials.This paper takes B/WAl composite as the research goal,simulates the shielding performance of the composite from a theoretical perspective,and simulates the mechanical properties of the matrix alloy to provide theoretical support for the preparation and application of the B/WAl composite.The combination of mechanical alloying experiments and various microstructure analysis results reveals the microstructure and evolution of tungsten/aluminum powder during mechanical alloying.It is the acquisition of high-performance tungsten-aluminum alloy powder and B/WAl composite.Based on Monte Carlo numerical simulation calculations,a boron/tungsten aluminum composite that can shield ?-ray radiation and block thermal neutrons was designed,and it was confirmed that the amount of B added was greater than 3vol.% and the amount of tungsten added was greater than 33 vol.%.The B particle size of 1?m has basically reached the theoretical maximum thermal neutron shielding rate of the material under this composition,which provides a basis for the preparation of high-performance and practical boron/tungsten aluminum nuclear radiation shielding material.Based on first-principles calculations and CASTEP tool software,the tungsten aluminum alloy solid solution is calculated as an ordered solid solution.The difference between the ordered atomic structure and the atomic radius causes the crystal structure to gradually change from pure tungsten body-centered cubic to bodycentered tetragonal And,the tungsten-aluminum solid solution alloy exhibits anisotropy,and the difference between the ideal tensile strength calculated by stretching along the a-axis and the c-axis is more than 1GPa.Based on the adjustment of the crystal structure of the series of tungsten-aluminum solid solution and the optimization design of comprehensive mechanical properties,the W_68.75Al_31.25 and W_43.75Al_56.25 alloys with better toughness and the W₅₀Al₅₀ alloy with higher strength were selected.It provides an alternative matrix alloy with excellent properties for B/WAl composite.Based on the mechanical alloying test and various micro-analysis test results,the effects of ball milling speed and the addition of process control agents on the tungsten aluminum alloying process were clarified,and the powder extraction rate was balanced with the time required for mechanical alloying to optimize the process conditions for the preparation of tungsten aluminum alloy The amount of stearic acid added is 1wt.%,the ball milling speed is 600r/min,and the ball milling time is 70 h.During the ball milling process,the grain size of the BCC phase is reduced to 41.6 nm,and the microscopic strain is increased to 0.28%,which provides favorable conditions for rapid alloying.From the thermodynamic point of view,the reaction products of AlB₂,AlB₁₂,W₂B₅ and the like may appear in the W-Al-B system.