Effects of Ti powder size and ignition method onproducts of SHS reaction in Cu-Ti-C system

Abstract

The influences of titanium particle size and ignition mode on the products of SHS reactions in the Cu-Ti-C system have been investigated. Ignition by thermal explosion mode results in Cu-TiC composites with higher levels of porosity and coarser TiC particles than ignition by combustion mode, owing to higher reaction temperatures facilitated by preheating of the reactants. The use of coarse titanium results in incomplete reaction and lower reaction temperatures, irrespective of the ignition method, as a result of increased carbon rich and carbon depleted reacting regions brought about by less homogeneous mixing of the reactants. The lower reaction temperatures result in finer TiC particles and reduced porosity. Incomplete reactions result in higher levels of titanium dissolved in copper and TiC particles of lower stoichiometry. This improves wetting between the two phases and results in a more even distribution of the carbides in the Cu matrix.