Microstructure and mechanical properties of B_p/Al neutron shielding composites

In this paper, a new type of neutron shielding material, boron particles reinforced Al composites (B_p/Al), was prepared by vacuum hot pressing method. Effect of volume fraction of boron particles and heat treatment on the microstructure and mechanical properties of the composites was studied. The results show that boron particles distribute uniformly in the composites and possess a good interface bonding with the matrix. Meanwhile, some boron particles react with Al matrix to form product AlB₂ in the interfacial area. The bending strength of the composites first increases and then decreases as the volume fraction of boron particles increasing, and it also increases significantly after T6 treatment. The highest bending strength, 398 MPa, is obtained as the boron content is 30 vol%. Superabundant boron particles result in more micro-pores and micro-cracks through particle agglomeration and interfacial reaction. Therefore, the B_p/Al composites show brittle fracture when bearing excess external load.