The Influence of Activation Preprocessing of the B4C and SiC Powder Mixture with Al on the Phase Composition, Structure, and Properties of Hot-Pressed Composites

The paper examines how the conditions of activation preprocessing (dry and wet grinding) of B4C-Al and SiC-Al powder mixtures in a planetary-ball mill influence the formation of phases in the mixtures and the phase composition, structure, and mechanical properties of the associated hot-pressed materials. It is shown that dry grinding, unlike the conventional powder charge preparation method, induces the mechanochemical synthesis of new phases in the B4C-Al powder mixture along with its mechanical activation. The formation of new phases in the SiC-Al powder mixture does not depend on the conditions of activation preprocessing. Secondary phases form in the hot pressing of the B4C-Al and SiC-Al powder mixtures. The structure and micromechanical characteristics of the materials indicate that dry grinding of the B4C-Al and SiC-Al powder mixtures has a greater activation effect on the hot pressing process, structural uniformity, phase composition, and mechanical properties compared to the conventional powder charge preparation method.