Synthesis and characterization of AlMgB14 hot pressed under different environments

AlMgB14 hot pressed under different environments from the elemental powders was investigated. The microstructure of the products was analyzed by scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX) and X-ray diffractometer (XRD). The density, hardness and fracture toughness of AlMgB14 were also examined. The results show that single phase of MgAl2O4 is formed in hot pressed Al-Mg-B system in air. The addition of carbon powder cannot reduce the formation of MgAl2O4. Additional Al (10 wt.%) and Mg (10 wt.%) can effectively compensate for their loss in the formation of MgAl2O4 and enhance the production of AlMgB14 under agron atmosphere. The AlMgB14 with 10 vol.% spinel MgAl2O4 owns a hardness of 28.42 GPa and a fracture toughness of 2.92 MPa•m1/2.