Combustion synthesis of TiC/Ti-Al based composites

In order to make up for the brittleness of Ti-Al intermetallics, TiC/Ti-Al based composites were prepared by SHS/PHIP. The theoretical analysis indicates that the adiabatic temperature increases with increased carbon contents, and the composites can be synthesized when the carbon contents are in excess of or equal to 2%. Scanning electron microscope and X-ray diffraction were used to analyze the products. Results show that ternary phases Ti₃AlC and Ti₂AlC exist in the synthesized products besides binary Ti₃Al and TiAl substrate and strengthening phase TiC. The shape of the strengthening phase changes from granular to claviform and flaky with increased Al contents. The hardness and compression strength of the composites increase with increased carbon contents, whereas the relative density increases initially and decreases subsequently with increased carbon contents. The actual and relative densities reach its maximum when the carbon content is 4%.