Metallurgical Processes at the Recycling of Aluminum Matrix Composites Via Direct Remelting

The features of metallurgical processes during the reprocessing of cast aluminum matrix composites of the Al–Si–B₄C system by direct remelting were studied, and the degree of degradation of boron carbide particles was assessed. It is shown that as a result of interaction with an aluminum melt, a partial degradation of the reinforcing particles of boron carbide occurs with the formation of a new Al₃BC phase in the form of an interfacial layer at the “matrix-particle” interfaces. During remelting of aluminum matrix composites, processes of redistribution of reinforcing particles are observed, accompanied by the destruction of agglomerates and improvement in the uniformity of distribution of particles in the bulk of the ingot. Multiple remelting leads to a fragmentation of the B₄C reinforcing particles due to cyclic thermal loads, as well as to an increase in the percentage of porosity in the cast structure of the composite.