A composite material (CM), containing boron-tungsten fibres and aluminium-alloy matrix is investigated. A method of grinding has been used for processing of CM Al-W-B. The grinding has been carried out in several stages in order to obtain a powder with pre-determined particle size. A morphology of Al-W-B CM particles is described. Particle size depends on the degree of comminution, and is defined within the range of 1–350 μm. The CM powder contains milled aluminium-alloy matrix and finely dispersed boron and tungsten. The chemical composition of the investigated material has been established. Results of the study of morphology and particle dimensions of the Al-W-B CM powder, and crushing mechanism are shown. A dependence of energy spent on the degree of milling is shown. Possible applications of the Al-W-B composite powder as a ligature in metallurgy, and for a composite ceramics are noted.