We consider a non-conserved phase-field system which consists of two nonlin
early coupled hyperbolic integrodifferential equations. This model is deriv
ed from two basic assumptions: the heat flux law is of Gurtin-Pipkin type a
nd the response of the order parameter to the variation of the free energy
functional is delayed. These hypotheses might be a reasonable attempt to de
scribe, for instance, the melt of He-4 crystals. A suitable initial and bou
ndary value problem is then associated with the system and its well-posedne
ss is analyzed in detail. (C) 2001 Academic Press.