In this paper, the effect of introducing the ultradispersed W powder, which had been preliminary activated and wetted with Cu powder in planetary ball mill, in the amount of 102 0.01-0.5 wt. % on the structure, the phase state and the mechanical properties of the АК12 alloy was investigated. It was established that the optimum additive is 0.1 wt. % W+Cu, as far as it results in the uniform eutectic distribution ([alpha]-Al+Si), smaller plates of the eutectic Si, change in shape of coarse plates and improvement of mechanical properties. Further treatment with the ultradispersed W powder allows for reducing the amount of the deposited powder from 30 % to 6 %.