Activation of self-sustaining high-temperature reactions by mechanical processing of Ti–C powder mixtures

Ti–C powder mixtures of various chemical compositions were ball-milled at different collision energies. Within a relatively broad compositional range, the mechanical processing activates self-sustaining high-temperature reactions resulting in the formation of non-stoichiometric TiC phases. The number of collisions necessary to ignite the reaction varies with the chemical composition and the collision energy. It is shown that the experimental findings can be rationalized by assuming that a certain volume fraction of Ti must be suitably activated.