Nanocomposites and nanomaterials

Structural disordering of graphite additives and specification of carbide formation temperature in hypo-eutectic Al-Cu/C powder composites
Ya.I. Matvienko1, A.D. Rud1, O.M. Fesenko2, A.D. Yaremkevich2, V.V. Trachevskii3
1 G. V. Kurdyumov Institute for Metal Physics of the NAS of Ukraine, Vernadsky blvd., 36, Kyiv-03142, Ukraine.
E-mail: yana_matv@ukr.net
2 Institute of Physics of the NAS of Ukraine, Nauki Ave., 46, Kyiv-03028, Ukraine.
3 Technical Center of the NAS of Ukraine, Pokrovskaya str., 13, Kyiv-04070, Ukraine.

Positive effect of 5 wt.% of graphite additives on the microstructure, mechanical properties and reactivity of Al-Cu powder composites obtained by high-energy milling and solid-state sintering have been comprehensively examined in our previous works [1,2]. These methods were also shown to be easy and cheap ways to produce Al-Cu/C powder composites.
This work is the continuation of our previous researches and includes the study of structural disordering of graphite after mechanical mixing of Al, Cu and graphite elemental powders and milling from 1 to 8 hours of the powder mixture with hypo-eutectic Al-16 wt. % Cu/ 5 wt. % C (Al81Cu7C12 at. %) composition, specification of carbide formation temperature below 510ºC.
Tree stages of order-disorder transition of graphite additives were identified: graphite - graphite nanoplatels (GNPs) (after mixing), crystalline-amorphous carbon (a-C) phase transition (after milling), and Al4C3 formation (only after heat treatment at 500ºC for 2 hours). Structural and spectral analysis of the samples after heat treatment at 400°C for 2 hours didn’t reveal any characteristic carbide peaks. The average in-plane crystallite sizes (La) was also estimated.

1.	Matvienko Ya. et al. Effect of graphite additives on microstructure and mechanical properties of Al-Cu composites prepared by mechanical alloying and sintering // Mater. Chem. Phys.-2020.-254.-P. 123437.
2.	Ya. I. Matvienko et al. Structure and Mechanical Properties of Al–Cu/C Composites Produced by Mechanical Alloying and Solid-State Sintering // Metallofiz. Noveishie Tekhnol.-2019.-41, N 8.-P. 1035-1054.