ENTHALPIES OF FORMATION OF L1(2) INTERMETALLICS DERIVED FROM HEATS OFRECORDING

A new method is proposed for estimating the enthalpies of formation of L1(2) (fec-ordered) intermetallics from the heat release measured dur ing ordering of their disordered polymorphs. The method is applied to Cu3Au, Ni3Al, and Ni3Si. The resulting estimates of enthalpies of form ation are close to values obtained by high temperature dissolution cal orimetry, They also appear to be more precise than estimates based on Miedema's correlations provided that care is taken to account properly for the magnetic and lattice stability contributions to the formation enthalpies in the ordered and disordered states.