A PHASE INTERFACE DYNAMIC MODEL OF INTERNAL FRICTION IN THE PROCESS OF PHASE TRANSFORMATION

Abstract
The moving interface in the process of phase transformation (PT) causes a viscoelastic internal friction (IF) and a modulus defect, if some coupling between moving interface and stress exists. Starting with the IF and PT thories, an expression relating IF and modulus defect ƊM/M during the process of PT with phase interface dynamic function (the general relationship between average velocity of interface and the effective PT driving force ƊG') V=φ(ƊG'), temperature varying rate T, angular frequency of IF measurement ω, shear modulus M and the rate of PT dF/dT were obtained as Q^-1 = (n² / 2) (dlnφ(ƊG') / dƊG') dF / dT M[MATH] / ω (1) (ƊM/M = n ε_o(dlnφ(ƊG') / dƊG') dF/dT M[MATH] / ω (2) and (ƊM/M) / Q^-1_p = 2ε_o/n (3) where n is coupling coefficient and ε_o is PT strain. By utilizing equ. (1) and the experimental date of Q^-1_p (as a fuinction of T/ω), an explicit function relationship of V=φ (ƊG') cas be obtained.