The effects of heat treatments on the microstructure and electrochemical properties of the ZrCr0.7Ni1.3 multiphase alloy

Qualitative and quantitative X-ray analysis using the Rietveld method of th e as cast ZrCr0.7Ni1.3 alloy, shows an average phase abundance of 62.7% C15 -Laves phase, 36.6% of Zr7Ni10 and less than 1% of chromium. The annealed a lloy at 1373 K reveals a complete disappearance of pure Cr with an importan t reduction of the amount of the Zr,Ni,,, phase based on EDS/SEM and XRD re sults. Pressure-Composition-Temperature(PCT) measurements show that the all oy behaves as a single phase with faster kinetics. Electrochemical measurem ents shows a relatively high discharge capacity of the cast alloy, c = 320 mAhg(-1) after 20 cycles. Contrary to that, the discharge capacity of the a nnealed alloy decreases by about a factor of 2 with c = 156 mAhg (1). (C) 2 001 Elsevier Science B.V. All rights reserved.