4. Phase selection modellingA powerful theoretical instrument to predict which phase canbe formed on solidification is the phase selection theory [6–8].The theory assumes abundant nucleation of all phases and thatthe phase with the higher interface temperature is kineticallyfavoured for growth. With a code written in MATLAB languagethe following equation based upon the Mullins and Sekerkaanalysis [9] of absolute stability of solidification front has beensolved numerically. The function f(ω) in Eq. (1) represents thevariation of the amplitude of the perturbation of the planar frontin time while the wave number ω is the inverse of the stabilitylength, that is the minimum wavelength corresponding to a sinusoidal morphological perturbation above which the planar front is broken