The kinematic viscosity of a liquid aluminum matrix composite (Al-7% Si + Al2O3) obtained by the method of purging a prehydrogenated melt with oxygen was studied using the method of torsional vibrations in comparison with the initial alloy. The photometric methodrevealed the proportion of oxide particles in the aluminum matrix. The absence of branching of polytherm melt composite material, which is associated with its inherent microheterogeneity. The possibility of predicting the viscosity of a composite material from known dependencies is shown, taking into account the fragmentation shape of the particles of the dispersed phase. The obtained data can be used to calculate the gating systems.