Pressure–composition–temperature hysteresis in C14 Laves phase alloys: Part 3. Empirical formula

• Published in: Journal of alloys and compounds 2009-07, Vol.480 (2), p.440-448
• Main Authors: Young, K., Ouchi, T., Fetcenko, M.A.
• Format: Article
• Language: English
• Subjects: Alloys; Condensed matter: structure, mechanical and thermal properties; Electrodes; Empirical analysis; Exact sciences and technology; Gallium base alloys; Hydrogen absorbing materials; Hysteresis; Laves phase; Metal hydride; Metal hydrides; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Ternary alloys; Thermodynamic properties; Transition metal alloys and compounds
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2009.03.194

In Part 1 and Part 2 of this series of papers, the pressure–concentration–temperature (PCT) isotherms hysteresis was found to be closely related to the axial ratio a/ c for both simple ternary and more complicated multi-element C14 Laves phase based alloys. Furthermore, the particle pulverization rate, which is the major determining factor in the duration of metal hydride electrode cycling, was found to correlate well with PCT hysteresis. In the current Part 3, we discuss an empirical equation which was developed to predict the PCT hysteresis of battery alloys through the study of the lattice constant ratios of a series of ZrCr 2-based ternary alloys. The empirical formula can then be used to estimate the pulverization rate of metal hydride electrode. To fit the empirical formula, an equivalent number of outer shell electrons for some non-transition metals was calculated from the axial ratio of ZrCr 1.8M 0.2 ternary alloys, where M is an element from the group of Al, Si, Ga, Ge, and Sn. Other factors, such as the amount of substitution, the difference in A and B element electronegativities, atomic size, and the choice of A element, were also investigated.