Synthesis and mechanical properties of AlMgB14–Al composite

Abstract

In this work, light-weight, high toughness and high strength AlMgB14–Al composites were prepared by hot pressing sintering. The wettability of aluminum on AlMgB14 was improved by increasing sintering temperature and prolonging sintering time. Density of composites can be improved to 97–99% of theoretical densities at the sintering temperature of 1500 °C. Aluminum plays an active role in the growth of AlMgB14 grains. The barrier action of high-toughness second phase can also reduce the stress intensity factor at the crack tip and increase the fracture toughness of composites. As the amount of aluminum increased, the fracture toughness increased while the bending strength decreased. The hardness with AlMgB14–5Al was 22.4 ± 0.5 GPa, and the fracture toughness with AlMgB14–30Al was about 10.7 ± 0.4 MPa m1/2.