Volumetric cubic and cylindrical samples from MQP-S Nd-Fe-B-type material were 3D-printed using the LPBF technique. Two different scanning strategies were used: the convenient single laser exposure scanning strategy and the newly proposed double scanning strategy aimed at improving the melting process and increasing the density of the synthesized material. Samples with a relative density value higher than 95% were obtained using the new scanning strategy by reducing void volume and cracks. This was achieved by decreasing internal stresses and reducing the tendency to form and propagate cracks. The double scanning strategy of half laser power followed by full power exposure provides higher magnetic properties (both coercive force and remanence). The coercive force increases with energy input decrease, while remanence has inverse dependence.

This work presents experimental investigation of the thermoelectric and structural characteristics of new double half Heusler alloys Hf_2-xTi_xFeNiSb₂ (x= 0, 0.15, 0.25 and 0.4). The studied samples were synthesized using different techniques of melt spinning, arc melting and spark plasma sintering. Crystal structure of the studied compounds was examined via x-ray diffraction (XRD). A face centered cubic structure was found to be the dominant crystallization phase. Homogeneity and relatively high density were obtained in the fabricated samples. Thermoelectric properties of the samples were studied over a temperature range from 300 to 800 K. Thermal conductivity was found to be significantly decreased with the Titanium (Ti) doping due to enhanced the phonon scattering. The highest value of the thermoelectric figure of merit was obtained for Hf_1.75Ti_0.25FeNiSb₂ to be 0.28±0.014 at 800 K.

Skutterudites are one of the most efficient materials for use in thermoelectric applications. From an industrial point of view, along with the high efficiency of thermoelectric materials, it becomes actual to develop a rapid, scalable, and energy-efficient fabrication technique. In this regard, mechanochemical synthesis has gained significant attention as a promising approach. In this work, we demonstrate the applicability and the potential of mechanochemical synthesis for the preparation of p-type skutterudites using Yb0.75Ce0.25Fe3.5Co0.5Sb12 composition as an example. In fact, the time spent on a full cycle of synthesis of bulk samples is less than 10 h, and the highest figure of merit value was 0.62, which is comparable to the values for similar compositions from previously works, where the time for synthesis is tens of times longer.

The diffusion processes regularity in the reaction crucibles of the iron-tin system during their electrothermal treatment was studied by the numerical simulation methods. The effect of current density and temperature on the processes of heat and mass transfer in the reaction zone has been studied. Numerical simulation was performed by the finite element method. The developed model includes mechanical, thermal, electrical and chemical processes during the electrothermal treatment of the iron-tin system in the reaction crucible, taking into account the distribution of components under various processing conditions of the reaction crucible. A comparative analysis of the calculated data on the diffusion of tin into iron under conditions of long-term exposure to high temperatures without the application of an electric voltage and when the reaction zone is heated by passing a high-density electric current is performed. A picture of the distribution of mass fractions of components depending on the type of impact is obtained. The penetration depth of the interacting components was determined and the intensity of the mass transfer processes was assessed. The regularities of heat and mass transfer in the system of iron and tin with a change of the process initial parameters are established. The model was verified by comparing the simulation results with the data of full-scale experiments on control samples. The research results can be used to predict the conditions for obtaining new functional materials.