화학공학소재연구정보센터
Combustion and Flame, Vol.160, No.11, 2631-2637, 2013
Low-temperature combustion waves in low-energy K2TaF7-Si-additive systems
This work presents the use of a thermocouple technique for measuring temperature profiles in a condensed K2TaF7-Si system blended with a small amount of Teflon [(C2F4)(n)] or potassium chlorate (KClO3). A base experiment is described in detail to demonstrate the ability of the system to react under a low-rate self-sustaining mode at ambient temperature. The ignition temperatures, temperature-time profiles, combustion parameters, and final products are presented with respect to the additive concentration. The combustion processes begin at 340 and 450 degrees C for the KClO3 and (C2F4)(n)-containing mixtures, respectively. The maximum temperatures of both KClO3 and (C2F4)(n)-containing mixtures range from 470 to 960 degrees C and the combustion self-propagates along the sample at a speed of 0.01-0.08 cm/s. The solid combustion products produced under the optimized conditions include fine powders of tantalum, tantalum carbide, and tantalum suicides. The chemical mechanism of the combustion process and reaction parameters responsible for low-speed wave propagation are presented and discussed. (c) 2013 The Combustion Institute. Published by Elsevier Inc. All rights reserved.