Determination of the non-chemical energy terms and the equilibrium transformation temperature ( T0) in CuAlNi poly- and single crystalline alloys

Abstract

Results of the analysis, developed in the author's group and applied in poly- and single crystalline Cu–20 at.%Al–2.2 at.%Ni–0.5 at.%B alloy, are reviewed and the dependence of the derivatives of the elastic and dissipative energy terms on the transformed fraction are presented. The T 0( σ) functions ( T 0 is the equilibrium transformation temperature and σ is the uni-axial tensile stress, respectively), calculated on the basis of the method, by uniform heating and cooling of the specimen, are also presented. Similarly, the stress dependences of the non-chemical contributions to the phase transformation are determined. It is shown that integrals of the differential values (the derivatives of the energy contributions by the transformed fraction) give self-consistent results with the (integral) quantities directly measured in differential scanning calorimetry or obtained from the area of the hysteresis loops.