Journal of Alloys and Compounds 471 (2009) 119–121
Journal of Alloys and Compounds
journal homepage: www.elsevier.com/locate/jallcom
Isothermal section of the phase diagram of the ternary system Y–Ni–V at 773 K
∗
Shunkang Pan, Huaiying Zhou , Qin Zhou, Qingrong Yao, Zhongmin Wang
Department of Information Materials Science and Engineering, Guilin University of Electronic Technology, Guangxi 541004, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
The isothermal section of the phase diagram of the ternary system Y–Ni–V at 773 K was investigated by
X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS)
techniques. It consists of 16 single-phase regions, 29 two-phase regions and 14 three-phase regions. At
Received 26 January 2008
Received in revised form 1 April 2008
Accepted 2 April 2008
773 K, the maximum solid solubility of V in Ni, Y2Ni17 , YNi5, Y2Ni7, YNi3, and YNi2, is about 17, 1, 2, 2, 2
Available online 30 June 2008
and 2 at.%, while Y in Ni, Ni3V, Ni2V, Ni2V3, NiV3 and V does not exceed 1 at.%. No ternary compound has
been observed in this work.
Keywords:
Rare earth alloys and compounds
Phase diagram
©
2008 Published by Elsevier B.V.
Crystal structure
X-ray diffraction
1. Introduction
2. Experimental
One hundred and twenty five samples were prepared. Each sample weighs 3 g.
The purities of yttrium, nickel, and vanadium used in this work were 99.9%, 99.95%,
and 99.9%, respectively. All samples were prepared by melting in an induction fur-
nace under high purity argon. Then, all alloys were sealed in evacuated quartz tubes
and put into an automatic controlled resistance heated furnace for homogeniza-
tion annealing. The heat treatment temperature was determined by the data based
on the previous work of Y–Ni and Ni–V binary systems. Some of the samples were
homogenized at 1125 K for 18 days and then cooled to 773 K for 12 days. The others
were kept at 773 K for a month. Finally, all alloys were quenched into an ice–water
mixture.
Hydrogen storage alloys have attracted considerable attention
in view of its potential as an energy storage material. Among
them, vanadium and V-based alloys with body-centered cubic
(BCC) structure are promising as negative electrode materials for
nickel–metal hydride batteries and hydrogen reservoirs for fuel
cells, because of their large hydrogen storage capacity per volume,
strong resistance to pulverization during hydriding–dehydriding
cycles, high-rate of diffusion and rapid activation [1–4]. However,
vanadium and V-based alloys are not commercially used because
of having poor electro-catalytic activity.
The samples were powdered and investigated by X-ray diffraction which was
carried out on a Rigaku D/Max 2500PC X-ray diffractometer using JADE5 software
◦ ◦
[
11]. The diffraction angles ranged from 2Â = 20 to 70 at a voltage of 40 kV and a
Thephasediagrams andthermodynamics arean importantbasis
for the study of the phase transformation of the materials perfor-
mance. This paper presents the 773 K isothermal section of the
Y–Ni–V ternary system phase diagram. The binary subsystems of
Y–Ni, Ni–V and Y–V have been widely investigated [5–10]. The
crystal structure data on Y–Ni and Ni–V binary compounds are pre-
sented in Table 1. The Y–Ni phase diagram was reported in Refs.
current of 250 mA. Some samples metallo graphy were analyzed by an S-570 scan-
ning electron microscope (SEM) or by differential thermal analysis (DTA). From all
these results, the phase relations in the Y–Ni–V ternary system were determined.
3. Results and discussion
3.1. Binary system
[
5,9,10]. There are nine intermetallic compounds in the Y–Ni sys-
tem, namely: Y Ni , YNi5, YNi , Y Ni7, YNi , YNi , YNi, Y Ni and
2
17
4
2
3
2
2
2
From the analysis of the X-ray diffraction (XRD) patterns of the
samples in the Y–Ni–V ternary system in our work at 773 K, we have
confirmed the existence of 13 binary compounds in our work. In the
Y3Ni. The V–Ni binary system is taken from Refs. [6,8], and exists in
four intermetallic compounds, namely: Ni V, Ni V, Ni V and NiV .
3
2
2
3
3
Ref. [7] reported the Y–V binary phase diagram and no binary com-
Y–Ni system, there are nine binary compounds: Y Ni17 , YNi5, YNi4,
2
Y Ni7, YNi , YNi , YNi, Y Ni and Y Ni at 773 K. In the Y–Ni system,
2
3
2
3
2
3
there are four binary compounds: Ni V, Ni V, Ni V and NiV3 at
3
2
2
3
773 K. No binary compound was found in the Y–V system at 773 K
in our work. All the results obtained concerning phase existence
and compositions are in perfect agreement with the binary phase
diagram reported by Refs. [5–7].
∗ Corresponding author.
0
925-8388/$ – see front matter © 2008 Published by Elsevier B.V.
doi:10.1016/j.jallcom.2008.04.002
Pan, Shunkang
