Dissolution-precipitation mechanism of laser igniting self-propagating high-temperature synthesis of Al/TiC composite

The microstructure evolution during laser ignition self-propagating high-temperature synthesis of Al/TiC composite from Ti, Al, and C powder mixtures was investigated to study the mechanism of the combustion synthesis of the composite by combustion front self-extinguished method. The X Ray Diffraction (XRD) patterns of different combustion zones are seen in addition to fine TiC particulates while Al3Ti phase is found in the reaction zone. The Ti and C particles immersed into the Al liquid leads to an increase in area of contaction between the Al liquid and Ti. The increase of the system temperature leads to an increase in Ti and C content in the Al melt. Scanning Electron Microscopic (SEM) images indicate that long needle-shaped Al 3Ti are formed in which small grains start to precipitate out in the Al-C-Ti liquid solution.