Study on microstructures and properties of high boron aluminum alloy prepared by powder metallurgy combined with hot rolling

High boron aluminum alloys for neutron shielding (Al-7%B and Al-12%B alloys by mass) were fabricated by powder metallurgy combined with hot rolling. The microstructures and properties of high boron aluminum alloys were investigated in different process conditions. In the results, the volume fraction of AlB₂ particles in Al-7%B alloy compacts sintered by spark plasma sintering after ball milling for 5 min is higher than that of Al-12%B alloy, and the distribution of AlB₂ particles shows more uniformly in Al-7%B alloy compacts. The hot rolling after spark plasma sintering is beneficial to increase the relative densities of compacts and decrease the agglomerations of boron powder in samples. The tensile and yield strengths of Al-7%B alloy quenched at 450℃ for 2 h reach 145.7 MPa and 99.4 MPa, respectively. According to the theoretical calculations, the areal densities of the hot rolled aluminum boron alloys reach the level of Boral^TM.