Abstract: The aluminum-based boron carbide composites (Al-B₄C) were fabricated by hot isostatic pressing. The density, tensile strength, microstructures, and fracture morphology of the Al-B₄C composites were investigated. The results show that, the plate size of Al-31% B₄C composites by mass is 3 mm×200 mm×5000 mm; the relative density of Al-31% B₄C composites is greater than 99.69%, the tensile strength is greater than 300 MPa, and the elongation is greater than 3%; the B₄C particles are evenly embedded in the Al matrix, and the B₄C particles are tightly bound to the Al matrix; the physical properties of aluminum-based boron carbide composite plates meet the requirement of the neutron-absorbing materials used in engineering. The physical properties of Al-B₄C composites with different B₄C contents by mass (10%, 15%, 20%, 25%, 30%, 31%, 35%, and 40%)are compared. When the content of B₄C is 10%~40% by mass, with the increase of B₄C content in the matrix, the density and relative density of Al-B₄C composites gradually decrease; when the B₄C content by mass ranges from 10% to 35%, with the increase of B₄C content in the matrix, the tensile strength of Al-B₄C composites gradually increases, and the elongation gradually decreases.