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In this study, the phase formation of aluminum oxide nanopowder during thermal heating of chemically precipitated aluminum hydroxide was discussed. Nanopowders of aluminum oxide and hydroxide were characterized by X-ray diffraction and thermogravimetric analysis, electron microscopy, energy dispersive X-ray spectroscopy analysis. XRD analysis detected a complex phase composition consisting of different modifications of aluminum hydroxide. It was shown that the precipitated aluminum hydroxide has a flake morphology with an average particle diameter of 5.5 nm. The differential thermal analysis showed that as-deposited aluminum hydroxide undergoes a multiple stage phase transformation. The deconvolution of the experimental differential curve by the Gaussian function and comparison of the temperature intervals of mass change with the literature data revealed that the precipitated aluminum hydroxide powder consists of bayerite α-Al(OH)3 and aluminum oxyhydroxide AlOH. It was found that bayerite is transformed to boehmite in the temperature range of 100 – 400 °C. After that γ-Аl2O3 is formed during the thermal decomposition of boehmite in the temperature range of 400 – 530 °C. The second hydroxide phase formed during the chemically precipitated method has a single stage phase transformation from AlO(OH) to γ-Аl2O3 in the temperature range of 260 – 500 °C. The nanopowder of γ-Аl2O3 formed at the temperature of higher than 600 °C has an equiaxed particle shape and an average size of 7 nm.

The possibility of using carbon nanofibers (CNF) in the production of aluminum matrix composite materials (AMC) by selective laser melting (SLM) has been experimentally shown. The powder composition based on the AlSi10Mg alloy with the addition of 0.5% (wt.) CNF was prepared by mechanical activation. The optimal parameters of the SLM process were determined to ensure the density of the synthesized AMC samples over 99%. The retention of CNFs in the AMC structure and the formation of Al4C3 inclusions, which have a higher strength and hardness as compared with the initial aluminum alloy AlSi10Mg, lead to strengthening of the synthesized material, the microhardness of which is 149 ± 8 HV, that is 20% higher than the hardness of the AlSi10Mg alloy.