In this work, reactions between titanium and aluminum powders were studied at temperatures lower than aluminum melting point. Different Ti/Al ratio as the precursor powders were prepared for combustion synthesis at 620 °C for different times. For this purpose titanium and aluminum powders by 1:3, 1:1 and 3:1 molar ratio were pressed to form cylindrical tablets with 1 mm diameter. Two samples of each ratio put into a controlled-atmosphere furnace for 10 minutes and 15 hours. For exact determination of pre-combustion reactions temperature, powder mixtures were DTA analyzed. According to Scanning Electron Microscopy and X-ray Diffraction Analysis the first phase forms in the Al-Ti interface is TiAl3 for all of powder mixtures. However, with the complete consumption of Al, Ti3Al is the second intermetallic phase forms in the TiAl3-Ti interface. Also type and amount of intermetallic compounds were considered by the time. Finally, effect of pre-combustion reactions on the high-temperature combustion synthesis products was studied. Results indicated that pre-combustion products have no negative effect on amount and type of final intermetallic compounds.

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