The results of reinforcing the aluminum alloy Al–12%Si with nanopowder ligatures containing particles of the (SiC + Si3N4) composition produced by azide self-propagating high-temperature synthesis are reported. The effect of introducing Al–12%Si ligatures containing 2.5–7.5 wt % of the reinforcing phase into the aluminum melt was examined. The nanopowder ligatures were Cu–(SiC + Si3N4) compacts fabricated by mechanical activation of PMS-1 copper powder with particle sizes of 20–100 μm and SHS-Az (SiC + Si3N4) nanopowder with a particle size of approximately 100 nm in a Pulverisette-5 planetary mill for 5 min at a grinding ball rotation speed of 300 rpm, followed by compaction of the resulting mixtures in a cylindrical die using a PSU-50 hydraulic press at pressures of 80–320 MPa. The resulting nanopowder ligatures had a diameter of 18 ± 0.5 mm, a height of up to 3 mm, a mass of up to 2.5 g, and a relative density of up to 90%. Reinforcement of the Al–12%Si alloy was carried out in a GRAFICARBO furnace using a ceramic crucible with a capacity of up to 0.2 kg. The melt temperature ranged from 850 to 1000°C. The microstructures of the reinforced cast samples are presented. It was found that the maximum incorporation of the strengthening phase (SiC + Si3N4) is achieved when it is introduced into the Al–12%Si alloy in the form of a Cu + 5 wt % (SiC + Si3N4) nanopowder ligature.
A. A. Kuzina (Mon,) studied this question.