Features of compaction by means of the extrusion of powders of Al-40Sn alloy are investigated. Compaction is carried out in a temperature range of 25–230°C at a reduction coefficient of 4.5 (ɛ = 1.5). An investigation into the structure along the length of a sample, including the butt end, has shown that the main part of its change occurs at the steps of formation of a billet and upon the placement of the latter within an operating channel of a press mold for extrusion. Under pressure operation in this period of time, a new composite material is formed which consists of aluminum particles dispersed into an unbroken soft tin matrix. As such material is forced through the die, tin strata act as an interparticle lubricant, making the mutual displacement of aluminum particles, which do not deform much as a result, easier. As a consequence, oxide films on aluminum particles remain and prevent the establishment of strong interfaces. The extruded material contains cracks along interfaces and shows low plasticity.