Microstructure and Properties of Aluminum Based Shielding Materials with High Tungsten Concentration by Hot Deformation Densification Technology

As a novel kind of combined shielding materials, tungsten-boron-aluminum composite has shown a good prospect in the field of nuclear radiation protection. However, the densification of the composites with high tungsten concentration is still a key bottleneck in developing high-performance tungsten-boron-aluminum materials. Through a hot deformation densification process combining frame constraint forging and rolling, tungsten-boron-aluminum composite sheets were prepared. The microstructures and properties of the materials after forging and rolling were studied, and the influence of rolling deformation on the density of the materials was analyzed. The combined shielding performance of the sheets was obtained. The results show that the edge of the composite is combined tightly with the aluminum frame and the density of the materials is greatly increased after the constrained forging process, which would benefit the subsequent rolling of the materials. For the hot rolling of the forging blanks, a rolling process with multiple passes and large deformation would effectively solve the cracking problems of the composites with high content reinforcements, resulting in successful preparation of high density tungsten-boron-aluminum materials. The as-prepared materials exhibit both high mechanical properties and comprehensive shielding performance. The tensile strength of the composite could reach 290 MPa at room temperature. The thermal neutron shielding rate could reach above 98%(10 mm thickness) and the linear attenuation coefficients are 0.52 cm^-1 and 0.91 cm^-1 respectively for γ-rays from 60Co and 137Cs sources.