Influence of Impurity Gases on Combustion of Ti + 2B Mixture

A comparative analysis of forced SHS compaction of single- and double-layer pressed Ti + 2B mixtures was carried out. High-velocity impurity gases were found to be able to initiate SHS reaction in the green mixture. It was shown that the use of double-layer combustion scheme permits to reduce the burning time of pellet in half due to the propagation of red-hot impurity gases between its layers. Their propagation velocity was found to be determined by total pellet mass: the larger the pellet mass, the higher the propagation velocity of impurity gases through artificially organized channels (gaps between the layers). Short burning time reduces the delay interval for the onset of consolidation of SHS products and facilitates the consolidation of synthesis products (hot pressing) at higher temperature and lower temperature gradient over the burned pellet.