Abstract:
The processes of combustion and phase separation in thermite SHS systems in the synthesis of cast composite materials based on the silicides of molybdenum, tungsten, niobium, and titanium in a wide range of ratios between them have been studied. Thermodynamic calculations for the hot MoO$_3$/2Al/2Si and WO$_3$/2Al/2Si systems have shown that the pressure has a the strong effect on the combustion temperature and yield of gaseous products, and for the cold 3Nb$_2$O$_5$/10Al/12Si and 3TiO$_2$/4Al/6Si systems, this effect has not been found. The effect of the ratio of the initial reagents and the activating high-temperature additive (CaO$_2$+ Al) on the combustion and phase-separation parameters have been studied experimentally.
Keywords:combustion, thermite mixture, gas pressure, temperature and rate of combustion, melting, phase separation, cast silicides.