Nanocomposites and nanomaterials

Nano-scale non-metallic microstructure modifiers in materials for aluminum welding and 3D printing
Korzhyk V.M., Shcheretskyi V.O., Demianov O.I., Grynyuk A.A., Voitenko O.M., Strohonov D.V.
E.O. Paton Electric Welding Institute the NAS of Ukraine, 1 Kazymyr Malevych St., Kyiv 03150 Ukraine.

The study is dedicated to discover the effect of non-metallic microstructure modifiers (TiC, WC, TiB2 etc.) for modifying microstructure and mechanical properties of aluminum welds and metallic objects obtained via layer-by-layer welding of aluminum alloys.
Through theoretical (thermodynamic calculations [1]) and experimental studies (microstructure, thermal analyses etc.) were stated regimes (atmosphere, time-temperature range) for consolidation of nano-scale particles with aluminum alloys during welding process, established regimes allows for nano-scale carbides retain their ability to modify alloys` microstructure during welding and 3D printing. 
There was stated promising number of the aluminum alloys systems: 5183, 4047, 4043, 1100, 5356 and 707 as matrix alloys for improvement of characteristics of its welding joints by non-metallic inoculation modifying of microstructure with nano-scale particles. 
4th series (Al-Si) aluminum alloys with Si content more than 5 weight % are promising materials to be improved with highly dispersed nano-scale tungsten carbide (WC), cause, silicon in an amount of more than 5 percent completely blocks formation of the aluminum carbide in the thermodynamic system and phase equilibrium shifts towards formation of the tungsten silicide and silicon carbide, both of these compounds are highly stable in aluminum melts.
Especial particular interest has the obtained data for Al10SiMg alloy, currently actively used for 3D printing, including the usage for welding and hybrid technologies. Structure modification of Al10SiMg alloy and its discrete strengthening by nano-scale high-modulus particles is promising in usage for welding of composites based on aluminum alloys and creating 3D prototyping by welding processes.

1. 	V.M. Korzhik, V.O. Shcheretskii, A.A. Chaika, Yi Jianglong Calculated evauation of application of nano-sized particles in modifying the cast structure of weld metal // Avtomaticheskaya Svarka (Automatic Welding).-2020.-2.- P. 18-23, DOI: 10.5604/01.3001.0012.8383