We systematically investigate the inteal friction properties of a Fe-(43 at.％)Al powder mixture compact during the heating process with the expectation to understand the phase formation and transition process.Three inteal friction peaks are successively observed during the heating process from room temperature to 750℃,but almost completely disappear in the subsequent cooling process.Three inteal friction peaks exhibit obvious measuring frequency dependence,which increases with decreasing the frequency.The first inteal friction peak originates from the micro-sliding of weak bonding interface between Al particles corresponding to a recrystallization process of deformed Al particles.The second inteal friction peak is attributed to a phase formation process associated with the formation of the intermediate phase Fe2Al5.The third inteal friction peak is considered to result from the formation of the FeAl intermetallic compound owing to the reaction of Fe2Al5 and residual Fe initiated by a dramatic thermal explosion reaction.