Nanocomposites and nanomaterials
Formation of metastable structures in powder and multilayered
 Cu-Al nanocomposites

Matvienko Ya.I.1, Polishchuk S.S.1, Rud A.D. 1, 
Ustinov A.I.2, Demchenkov S.A.2
1 G. V. Kurdyumov Institute for Metal Physics of the NAS of Ukraine
academician Vernadsky blvd, 36, Kyiv-03142, Ukraine 
E-mail: yanamatv18@gmail.com
2 E.O. Paton Electric Welding Institute of the NAS of Ukraine
Kazymyr Malevych st., 11, Kyiv-03150, Ukraine

Due to a high level of mechanical properties, excellent electrical and thermal conductivity and good corrosion resistance, Cu–Al alloys are of particular interest for marine and automotive applications. Moreover, powder materials of the system are promising for the use in additive technologies [1], while multilayered Cu-Al  foils may be used as  adding materials for diffusion welding [2].
It has been shown that non-equilibrium processing methods, such as mechanical alloying (MA) and electron-beam vapor deposition (EB PVD) enable production of highly refined structure, expansion of the solubility region in the solid state, as well the formation of new crystalline and non-crystalline metastable phases. 
The present work studies the formation of metastable phases in Cu-Al materials with high densities of interphasial area during mechanical alloying of elemental Cu and Al powders, as well as reactive diffusion in multilayered foils. It was found that both MA process and EB PVD multilayered foils heating leads to the formation CuAl2 phase and Cu9Al4 phases. 

1.	Ya.I. Matvienko, A.D. Rud, S.S. Polishchuk, V.V. Trachevsky, Yu.A. Zagorodny, T.M.Mikа, O.V. Marunyak, Effect of graphite on structure of eutectic Al-Cu powder mixtures during ball milling // матеріали міжнародної конференції “Матеріали для роботи в ектремальних умовах - 8“.-2018.-P. 40-44. 
2.	А. I. Ustinov, Ya. I. Matvienko, S. S. Polishchuk, A. E. Shishkin, Investigation of phase transformations and plastic deformation at continuous heating of Al/Cu multilayer foils // Paton Welding Journal.-2009.- 10.-P. 23-2