In-situ synthesis of Al3BC/Al composites from amorphous boron and graphene nanoplates by solid reaction

Abstract

In the present work, highly reactive amorphous B and small-size graphene nanoplates (GNPs) were used as raw materials, and in-situ synthesis of Al3BC/Al composites by solid reaction was explored. During the solid reaction process, relative contents of AlB2 and Al3BC were increased linearly with the reaction temperature (from 578 to 645 °C) and reaction time (1–12 h). However, for the composites reacted at 660 °C, the Al3BC content was slightly increased while the content of AlB2 was decreased gradually with increase in reaction time. Regardless of the reaction temperature and time, no Al4C3 phase was observed in the present work. It is suggested that the Al matrix and amorphous B were initially reacted to form AlB2, which was further reacted with C element to form Al3BC. Although, Al4C3 has been widely reported in literature, AlB2 could also be used as reactant to form Al3BC. It has been found that the bending strength of the composites has been increased 30% (from 353 to 462 MPa) since the reinforcement was evolved from amorphous B and GNPs to Al3BC and small content of AlB2.