INTRODUCTION

The objectives of the proposed research are to accurately determine heats of formation for aluminum-nickel-X ternary compounds and to use these data to develop thermodynamic models for ternary systems which are relevant to aluminum and nickel alloy processing and development. Such data are also of importance in providing benchmarks for first principles calculations. We will also exam the systematics of the alloying behavior through correlations between the hears of formation and atomic bonding parameters such as atomic number, valence electron/atom ratios and numbers of available s, p, d, and f electrons. The applicability of the Miedema model in its extended form for ternary compounds will be examined by comparison with our experimental data, as well as comparisons of several interpolation techniques for estimating ternary heats of formation. Application of the Wagner-Schottky defect model to selected compound heats of formation together, with density and x-ray data, will allow us to determine molar enthalpies of formation of various constitutional defects. Some phase equilibria data will also be generated in the course of the work and this will be used with the thermodynamic data to develop a self-consistent Al-Ni-X thermodynamic database.