Studies of Ti1.5Zr5.5V0.5(MxNi1-x)9.5 (M = Cr, Mn, Fe, Co, Cu, Al): Part 1. Structural characteristics

In Part 1 of this two part series of papers, the structural characteristics of quinary alloys Ti1.5Zr5.5V0.5(MxNi1-x)(9.5) with M = Cr, Mn, Fe, Co, Cu, or Al and x=0.1 or 0.2 are reported All 12 alloys are composed of Laves phases (C14 or C15) and non-Laves Zr-Ni phases Only partial Cu-substitution retains a Zr7Ni10-dominated microstructure. Substitutions of elements with fewer outer shell electrons, such as Al, Mn, and Cr, were found to promote more C14 phase while Fe- and Co-substitutions favored the C15 structure Average electron density was found to have a determining role in the predilection toward C14/C15 phases As the NI-content in the alloy decreases, the structure of non-Laves phase changes from Zr7Ni10 to Zr7Ni10 + Zr9Ni11, then to Zr9Ni11, and finally to Zr9Ni11 + ZrNi. The solubilities of V and Cr in the Zr7Ni10 and Zr9Ni11 phases are very low and the contents of other substitutional elements in these phases are lower than in the Laves phases (C) 2010 Elsevier B.V. All rights reserved.