The heats of ordering for mechanochemically synthesized nano-sized supersaturated solid solutions were demonstrated for Ni-In,
Ni-Sn, Ni-Al, Cu-Sn, Cu-Hg systems. It is shown that increasing concentration of doping element leads to decreasing of decomposition
temperature and to increasing of decomposition enthalpy. The concentration heterogeneity of doping elements in mechanochemically
synthesized supersaturated solid solutions was found. The reactivity of alloys Cu 20 mass % Sn for commercial powder and MA
powder was investigated.