Embedded-atom interatomic potentials for hydrogen in metals and intermetallic alloys

Interatomic potentials of the embedded-atom type have been developed for H in metals. The potentials are constructed through a fitting procedure involving the thermodynamic heat of solution of H in the various metals and the volume expansion of the host lattice upon the dissolution of H. The potentials have been developed in such a way that the same functions for hydrogen are used for all the metals considered and the resulting set of potentials is suitable for the study of hydrogen effects in alloys. The pure metals considered are Ni, Al, Ti, Zr, and Fe. The heats of solution of hydrogen in various intermetallic alloys formed by these metals (TiAl, Ti3Al, NiAl, Ni3Al, NiTi, and FeAl) have been studied using the developed potentials in conjunction with existing potentials for the intermetallic systems. The effects of increasing hydrogen absorbed in the host are also simulated for the case of Ni.