The time-resolved X-ray diffraction synchrotron radiation technique was used in combination with E-field microwave heating to study in situ the kinetics of intermetallic phase formation in the Ti-Al system. The reaction of Ti with Al is triggered by the melting and spreading of Al onto the surface of Ti particles. The tetragonal TiAl3 phase is the primary reaction product, formed by instantaneous nucleation at the interface between the unreacted Ti cores and the Al melt. The growth of TiAl3 layers is diffusion-controlled. These preliminary results demonstrate that microwave heating can be used to rapidly synthesise intermetallic phases from high-purity elemental powders. (C) 2010 Elsevier B.V. All rights reserved.