International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The melt spinning and ball-milling techniques were applied to fabricate powder Al-Si-Ni alloy. The obtained Al-Si-Ni powder was compacted in pellet and solid-state sintered at 530 °C at a pressure of ~200 MPa. The phase composition, structure, coefficient of linear thermal expansion and hardness sintered samples were determined. The coefficient of linear thermal expansion of samples formed after sintering is in the range from 14.7×10-6 K-1 to 17.5×10-6 K-1. It is typical for steel. The synthesized powder composite, contains intermetallic Al3Ni phase, crystalline aluminum, and silicon. The hardness of sintering samples is 113 HV.

The reactive ball milling technique was applied to fabricate the Mg-based composite with graphite additives. The sorption/desorption kinetics of the composites were investigated under isothermal conditions. The best hydrogen sorption/desorption kinetics was attained for the magnesium-carbon composite synthesized using the low surface area graphite powder as an active additive. This sample is characterised by the best kinetics performance compared to other composites. It releases 4.2 wt.% of hydrogen at 270 ºC within ~18 min and uptakes 4.6 wt/.% of hydrogen for ~130 min at 200 ºC.

The changes in the structure of the crystalline graphite are studied during high-energy ball milling (BM) treatment. It was found by XRD analysis the milling time increasing up to 3.5 h leads to the formation of an amorphous phase in the milling process. After 10 h of ball milling treatment, complete amorphization of graphite takes place. It has been shown by high-resolution electron microscopy the individual particles have complex morphology which depends on the BM time. After 1 h of BM carbon materials characterized by an onion-like structure: the individual particles have a spheroidal shape with a size of ~ 10 nm. However, unlike the previous ones after 10 h of ball milling carbon nanomaterials are characterized by a disordered structure, which is typical for amorphous carbon.