Abstract Fabrication of Ti 5 Si 3 and V 5 Si 3 was conducted by self-propagating high-temperature synthesis (SHS) from the elemental powder compacts of their stoichiometries. Combustion wave kinetics… Click to show full abstract
Abstract Fabrication of Ti 5 Si 3 and V 5 Si 3 was conducted by self-propagating high-temperature synthesis (SHS) from the elemental powder compacts of their stoichiometries. Combustion wave kinetics was experimentally studied by measuring the combustion front velocity and temperature, and numerically investigated to determine the Arrhenius factor of the rate function ( K 0 ) and to evaluate the effective thermal conductivity ( k eff ). Experimental results showed that the 5Ti + 3Si reaction is more exothermic than the 5V + 3Si reaction. With the increase of sample density from 50% to 60% TMD, the flame-front velocity increased from 28 to 50 mm/s for the formation of Ti 5 Si 3 and from 6.9 to 8.5 mm/s for V 5 Si 3 . Based upon numerical simulation and experimental validation, K 0 = 3 × 10 9 s −1 and 5 × 10 7 s −1 were deduced for combustion synthesis of Ti 5 Si 3 and V 5 Si 3 , respectively. The ratio of k eff / k bulk increasing from 0.02 to 0.05 was employed in the numerical calculations to simulate the effect of sample compaction density on combustion wave kinetics. Moreover, the measured and calculated combustion front temperatures were comparable, which confirmed the reaction exothermicity of the numerical model.
               
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