31 research outputs found
Generation of Electron Beam Plasma inside the Dielectric Tube
The results of experimental study of electron beam plasma inside the dielectric tube are presented. Beam plasma was generated by the fore-vacuum plasma electron source at (2-10) Pa in dc mode. It is shown, that the dependence of the plasma potential on gas pressure inside the tube is completely different in comparison with similar dependence without a tube. Monotonic dependence of the insulated beam col-lector potential in the tube on beam energy has two stages: slow and fast growth
Sintering of oxide and carbide ceramics by electron beam at forevacuum pressure
Novel approaches for electron beam sintering of zirconia and silicon carbide ceramics have been investigated: application of forevacuum pressure plasma-cathode to compensate the charge induced by the electron beam on the green compact surface, and previous dry powder compaction under powerful ultrasound assistance. Dense YSZ ceramics with submicron and micron grains have been consolidated by electron beam sintering after powder compaction using ultrasound
Sintering of oxide and carbide ceramics by electron beam at forevacuum pressure
Novel approaches for electron beam sintering of zirconia and silicon carbide ceramics have been investigated: application of forevacuum pressure plasma-cathode to compensate the charge induced by the electron beam on the green compact surface, and previous dry powder compaction under powerful ultrasound assistance. Dense YSZ ceramics with submicron and micron grains have been consolidated by electron beam sintering after powder compaction using ultrasound
Electron beam nitriding of titanium in medium vacuum
We describe a novel method for electron-beam nitriding of metal (titanium) under medium (fore-vacuum)
pressures (2–8 Pa) of nitrogen. Titanium sample was heated by a dc electron beam generated by a fore-vacuum
plasma-cathode electron source with current up to 100 mA and energy up to 8 kV; this beam also generated
beam-produced plasma with active nitrogen atoms, ions and other reactive species near the sample. SEM chemical composition analysis of the nitride layer have shown the presence of approximately 25 wt% of N, wt. 68%
of Ti and only wt. 6% of O atoms within the processed layer. The X-ray diffraction spectrum of the nitride sample
showed that the modified layer has a crystalline structure predominantly orientated along the crystallographic
directions (111), (200), (220), characteristic of δ-TiN with a face-centered lattice. Besides the δ-TiN phase, there
are present in the nitrided layer a γ phase of Ti2N (tetragonal nitride) with predominant orientation (200). These
results show the advantage of using forevacuum sources for electron beam and plasma nitriding of metals