Papers by Keyword: SHS Method

Abstract: The optimal modes (temperature, time, pressure force) of spark plasma sintering (SPS) and hot pressing of boron carbide obtained by various methods are determined. The initial powders were obtained from soot and amorphous boron by the mechanochemical synthesis method, by the high-temperature synthesis (SHS) method and by the carbon reduction method. The structure and the properties of SPS sintered and hot-pressed boron carbide blanks were determined. The highest value of the relative density was achieved during SPS sintering of blanks from B₄C powders obtained by mechanosynthesis and SHS methods. It was found out the optimal conditions for sintering blanks from B₄C powder obtained by mechanosynthesis. The density value reaches 99.0 rel.% at 1500 °C/25 MPa and sintering time of 45 min. For powders obtained by the SHS method, the density of sintered blanks is 98.5 rel.%. at 1800 °C/30 MPa with sintering time of 45 min. The highest value of the relative density was achieved during the hot pressing of blanks from B₄C powders obtained by mechanosynthesis.

Abstract: The systematic studies of non-stoichiometric phases from Fe-Al system obtained by selfpropagating high-temperature synthesis (SHS) were the aim of the present work. Investigations were performed using 57Fe transmission Mössbauer spectroscopy. The presence of nonsteichiomertic FeAl, FeAl2 and Fe2Al5 phases was found. It is can be concluded that the studied powder material is in non-equilibrium state. As the result of milling process the contents of FeAl phase increase whereas of FeAl2 and Fe2Al5 ones decrease. The determined crystal structure parameters and the hyperfine interaction parameters are presented and discussed.