Al–Al2O3 powder composites obtained by hydrothermal oxidation method: Powders and sintered samples characterization

The aluminum powder composites based on Al–Al2O3 were obtained by the advanced in–situ partial hydrothermal oxidation method. The opportunity to obtain the controlled amount of alumina on the particle’s surfaces was studied. The water vapor temperature fixed at 90 °C and 120 °C gave the possibility to obtain two composites with the amount of Al2O3 at 9.90 wt % (OAP–1) and 18.75 wt % (OAP–2). Their median diameters were 41–42 μm with normal particle size distribution. The comparison with atomized 7068 alloy (AP–7068) powder showed their better particle sphericity. The OAP–1 sintered sample has the highest hardness of 471 MPa that provided by the highest density of 97.1% and the finest grain structure. [Display omitted] •Hydrothermal oxidation method was used to produce aluminum-alumina composites.•A detailed description of the hydrothermal oxidation method for the production of Al–Al2O3 composites was proposed.•The particles after oxidation and the surface of the sintered objects were examined in detail.•Hardness (HV) of Al–Al2O3 composites and standart 7068 aluminum alloy was compared.