Effect of extinction beam-plasma discharge while the injection thermoelectrons during transportation of the electron beam in the forevacuum pressure range

The article presents the results of experiments aimed at studying the effect of low-energy thermoelectrons on the parameters of the beam plasma and plasma of the beam-plasma discharge generated during the transportation of a powerful electron beam in the pressure range of the medium vacuum. It is shown that the injection of a sufficiently small current of low-energy thermoelectrons is capable of violating the conditions for the combustion of the beam-plasma discharge and reducing the power loss of the electron beam for SPR generation. In this case, the plasma concentration decreases by almost an order of magnitude (to 1015 m–3) and the temperature of plasma electrons decreases by almost three (to 0.3 eV).

Evaluation of magnetic properties of thin magneto-dielectric films deposited from beam plasma in medium vacuum

By electron-beam evaporation of a solid state dielectrics (alumina ceramics) and a magnetic material (steel-3) in fore-vacuum, thin films of several μm, possessing both dielectric and magnetic properties, were deposited on a substrate. The work shows that the microstrip resonator method can be used to assess the presence of magnetic properties in films.

Microstructure and Hardness of Spark Plasma Sintered Inconel 625-NbC Composites for High-Temperature Applications

The study focuses on obtaining Inconel 625-NbC composites for high-temperature applications, e.g., jet engines, waste-to-energy combusting systems or gas engine turbines, and characterizing them in terms of their microstructure and hardness improvement. Synthesis was performed utilizing Spark Plasma Sintering (SPS) at 1150 °C under the load of 45 MPa in medium vacuum (under 10−3 MPa) for a total time of 60 min. Four sets of samples with different Inconel 625 to NbC weight ratios were prepared (5, 10, 20, and 30 wt.%), followed by a reference sample containing no ceramic reinforcement. Obtained materials were hot-rolled at 1150 °C with a 10% reduction step and later cut and polished to perform characterization utilizing scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) module and microhardness testing device equipped with Vickers indenter. Hardness was improved proportionally to NbC addition achieving an increase of up to 20% of reference values. Additional heat treatment was conducted on the hot-rolled samples at 1200 °C in an argon atmosphere to further observe the interaction between reinforcement and alloy. Their microstructure revealed the coarsening of precipitates within the metal matrix and partial reinforcement dissolution, which proved to be crucial to obtaining the highest quality composites with homogenous hardness improvement.