In the present study, 98.6–99.5% dense in situ reinforced Ti6Al4V/TiB composites were manufactured with a newly developed approach based on hydrogen-assisted blended elemental powder metallurgy (BEPM). The approach includes the activation milling of titanium powder produced with hydrogenation-dehydrogenation (HDH-Ti powder) with finer TiB₂ additives, following blending with TiH₂ and master alloy (MA) powders, and final press-and-sinter operations. Scanning electron microscope (SEM) observations prove the formation of microstructures with improved density and homogeneous distribution of TiB reinforcements in a sintered Ti6Al4V matrix. Hardness and compressive tests validated the high mechanical characteristics of produced composites. The effect of preliminary milling time over 2–6 h and the ratio of hydrogenated and non-hydrogenated titanium powders used (TiH₂ vs. HDH Ti) on microstructure and mechanical properties were studied to further optimize the processing parameters. Test results indicate the above approach can be regarded as a promising route for the cost-effective manufacturing of Ti6Al4V/TiB composite with reduced porosity, tailored microstructure uniformity, acceptable impurity level and, hence, mechanical characteristics sufficient for practice applications.

The phase relations in the Nd2O3-Fe2O3 system at 1300 and 1400 ?C were studied in the whole concentration range by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The isothermal cross-sections of the Nd2O3-Fe2O3 phase diagram at 1300 and 1400 ?C are characterized by the presence of three singlephase (A-Nd2O3, NdFeO3, Fe2O3) and two two-phase (A-Nd2O3 + NdFeO3, NdFeO3 + Fe2O3) regions. The composition corresponding to the perovskite phase is 51mol% Nd2O3 - 49mol% Fe2O3. In the next step, the investigation was focused on this composition. Nanocrystalline NdFeO3 powders with perovskite structure were obtained by the Pechini method and heterogeneous precipitation from nitrate solutions. The influence of the production method on the microstructure, morphology and magnetic properties of the NdFeO3 nanopowders was studied. According to XRD, SEM and TEM, the synthesized perovskite NdFeO3 is single-phase with a particle size of 60-90 nm. The morphology of powder particles primarily depends on the synthesis method. The powder showed ferromagnetic behaviour and had saturation magnetization 0.8 and 0.81 emu/g.

The investigation results on peculiarities of phase and structure formation as well as sintering kinetic of compacted TiH2 - TiВ2 powder blends. It was shown, the most intensive shrinkage upon heating took place within temperature range of TiH2 dehydrogenation (400 ÷ 650 0С). Heating of powder blend up to sintering temperature (1350 0С) resulted in formation of acicular TiB particles in titanium matrix, the amount of particles is increased with increase in exposure to 20 min. The longer duration of isothermal exposure did not lead to increase in amount and size growing of TiB particles. X-ray analysis of sintered TiН2+TiВ2 powder blend demonstrated the presence of titanium matrix phase, orthorhombic TiВ phase, and traces of Ti-B compounds of different concentrations (Ті3В4 and Ті2В5). The dilatometric investigations proved that addition of boride compounds and increase in boride content in powder blend led to decrease in shrinkage upon sintering as compared to shrinkage of single TiH2 powder compacts.