Effect of Al particle size on the reaction kinetics and densification of TiAl intermetallics

The present investigation deals with response of the particle size of aluminum on the reactive sintering of Ti-Al intermetallics and subsequently on their reaction kinetics and densification behavior. Aluminum powders of initial average particle size of 44 mu m were milled for various durations in a planetary ball mill to produce average particles sizes of 100, 28 and 7 mu m. These aluminum powders of various particle sizes i.e. 100, 28 and 7 mu m were mixed with titanium powder of average particles size of 44 mu m in the ratio of 1:1 corresponding to the Ti-Al intermetallic composition. The reactive sintering temperatures of the mixtures were determined by DTA and the effect of change in particle Al particle size has been determined for the activation energy ofthe self-propagating reaction. The effect of Al particle size on the sintering was determined by studying density and microstructure.