Dynamic model of supersonic martensitic crystal growth
The basic features of martensitic transformations are reviewed using the fcc—bcc (bct) transformation in iron alloys as an example. Supersonic crystal growth is believed to be due to a master wave process initiated by an excited (oscillatory) state that arises in the elastic field of a dislocation. Topics discussed include the mechanism by which nonequilibrium electrons generate (amplify) master waves; the optimum range of parameters for wave generation; the dependence of the transformation onset temperature on the polycrystal size; and the formation of transformation twins due to the coordinated action of relatively short and relatively long wavelength waves. Future research prospects are briefly discussed.