251As is known, industrial scale fabrication of fused titanium carbide is carried out in two stages: (a) fur nace synthesis of powders and (b) subsequent hot pressing into compact material. In this communica tion we suggest to apply the method of electrothermal explosion (ETE) [1, 2] under pressure to fabrication of fused TiC in a single stage process by using the exper imental setup described in [3].In our experiments we used commercial powders of Ti (PTM brand, mean particle size 40 μm) and carbon black (P804T brand, 1.0 μm) to prepare equiatomic cylindrical green compacts 20 mm in diameter, 17 mm long, and 10 g in weight. The samples were ignited upon electric warm up at varied heating rate W under applied pressure P. Figure 1 shows the temperature profiles of SHS reactions as initiated at different heating rates W and applied pressure P. For our purpose, the best condi tions were those corresponding to thermal explosion 1: W = 150 deg/s (j = 1.4 × 10 6 A/m 2 ), T ≈ 3500 K, and P = 96 MPa. The overall reaction time is several sec onds, while the industrial process for fabrication of pseudo fused TiC takes several hours. Figure 2 gives the overall view of fused TiC synthe sized at P = 96 MPa (d = 20 mm, h = 11 mm) and the SEM image of its polished surface. Volume contrac tion was about 30%. The microstructure of the synthe sized carbide-rounded grains with fritted edges-is similar to that of green compact. Upon combustion, the mean grain size diminished from starting 40 µm to 20-21 µm. The synthesized material showed the fol lowing characteristics: ρ = 4.90 g/cm 3 (99.4 of theo retical), HV = 31.5 GPa (standard value 29 GPa), bound carbon 20.31% (standard 19.8%). The diffrac tion pattern (Fig. 3) did not show signals from unre acted titanium and carbon.
The paper is devoted to the definition of the minimum electron beam power that is required to obtain stable layer formations during the additive electron beam wire deposition. Correlation between the minimum energy that is needed for stable deposition and the deposition speed has been established. Additionally, the influence of the electron beam oscillation type on geometrical parameters of single layers have been investigated.
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