Synthesis of the Ti-Zr-Ni Alloys by the Hydride Cycle Method

Loading ...
Klee Irwin
Science
QGR Research papers
 
ISSN 1562-6016. ВАНТ. 2022. №1(137) 
 
 
 
 
 
 
 
 
            111 
https://doi.org/10.46813/2022-137-111 
 
SYNTHESIS OF THE Ti-Zr-Ni ALLOYS BY  
THE “HYDRIDE CYCLE” METHOD 
 
O.E. Dmytrenko
1
, I.V. Kolodiy
1
, T.B. Yanko
2
, V.M. Borysenko
1
, K. Irwin
3
, R.L. Vasilenko
1
 
1
National Science Center “Kharkov Institute of Physics and Technology”, Kharkiv, Ukraine; 
2
PJCS “Titanium Institute”, Zaporizhzhya, Ukraine; 
3
Quantum Gravity Research, Los Angeles, CA, USA 
E-mail: dmitrenko@kipt.kharkov.ua 
 
A comprehensive study of the technical parameters and conditions for the synthesis of ternary alloys in the Ti-
Zr-Ni system by the “hydride cycle” method was carried out. The influence on the synthesis process of such 
parameters as: temperature and annealing time, heating rate, cooling conditions, material composition, dispersion, 
hydrogen content in the hydrides used, the presence of impurities, mixing and pressing methods, and the degree of 
pressing of the starting components was determined. The alloys of the following compositions were synthesized and 
investigated: Ti40.5Zr31.9Ni27.6, Ti41.5Zr41.5Ni17, Ti40Zr40Ni20, Ti44Zr40Ni16. The optimal technological parameters and 
conditions for the synthesis of ternary alloys are determined. It has been established that the key factors in the 
process of compound formation during hydride dissociation are the dispersion and homogeneity of the initial 
compacted components. It was found that the synthesis of ternary alloys in the Ti-Zr-Ni system occurs during a 
short-term exothermic reaction in the “thermal explosion” mode, which begins in the temperature region 
corresponding to the α↔β polymorphic transformation of zirconium and titanium. 
PACS: 81.20.-n, 81.40.-z, 71.20.Lp 
 
INTRODUCTION 
 
Most zirconium alloys, including quasicrystalline 
(QC) materials and intermetallic compounds based on 
the Laves phase C14 L-TiZrNi, are capable of 
reversibly absorbing a significant amount of hydrogen 
and are promising materials for hydrogen energy. 
However, the production of these materials, due to the 
high melting point and chemical activity of the starting 
components, is a complex and energy-intensive task. 
Traditional methods for producing metal alloys, in this 
case, are significantly limited. It is necessary to use 
sophisticated vacuum equipment, which allows for non-
crucible melting since molten titanium and zirconium 
actively interact with crucible materials. In this case, 
saturation with interstitial impurities also occurs, 
primarily with oxygen and nitrogen, which prevents the 
formation of a given structure due to the precipitation of 
phases stabilized by dissolved gas impurities [1–4]. 
Thus, the main methods for producing bulk Ti-Zr-Ni 
alloys are vacuum-arc and electron-beam melting. If it 
is necessary to obtain a QC material, additional heat 
treatment is required – quick quenching (melt spinning) 
[5] or long-term annealing, which allows one to finally 
obtain QC samples. Synthesizing large volumes of 
homogeneous samples in this way is technically 
difficult and expensive, which in turn limits further 
practical application. 
The technology of the “hydride cycle” is based on 
the interaction of the products of thermal dissociation of 
hydrides of the starting components with the formation 
of systems and phases characteristic of these materials 
with significantly lower energy consumption. As shown 
in [6–12], this technique is successfully used for the 
synthesis of various binary and ternary alloys of 
refractory metals of the zirconium group. Including 
complex intermetallic compounds of the Ti-Zr-Ni 
system. Thus, the possibility of synthesizing stable     
Ti-Zr-Ni quasicrystals was shown in [6]. For the 
successful synthesis of Ti-Zr-Ni system alloys with the 
given structural characteristics using this technology, it 
is necessary to establish a number of technological 
parameters. The main influencing factors are: 
1. Heat treatment parameters: annealing temperature, 
annealing time, heating rate, pressure during annealing, 
cooling conditions. 
2. The parameters of the starting components: 
material composition, dispersion, hydrogen content in 
the hydrides used, the presence of impurities. 
3. Compaction parameters: method of mixing the 
starting components, method of compaction/pressing, 
degree of compression. 
The aim of this work is to determine the optimal 
parameters and conditions for the synthesis of QC 
materials and intermetallic alloys of the Ti-Zr-Ni 
system. 
 
1. MATERIALS AND METHODS 
 
To conduct a study on the synthesis of QC materials 
and intermetallic alloys of the Ti-Zr-Ni system, samples 
of the following starting compositions (in at.%) have 
been prepared: 
1) Ti40.5Zr31.9Ni27.6 – this composition have been 
shown to strongly interact with H2 gas [4]; 
2) Ti41.5Zr41.5Ni17 – composition with experimentally 
confirmed formation of quasicrystals during melt 
spinning [5]; 
3) Ti40Zr40Ni20 – theoretically calculated optimal 
composition for the formation of the QC phase [13]; 
4) Ti44Zr40Ni16 – corresponds to the quasicrystals 
obtained by the technology of the “hydride cycle” [10]. 
Initial studies were carried out on samples of the 
composition Ti40.5Zr31.9Ni27.6. As the ranges, modes and 
indicators were refined, the study of samples of 
composition Ti41.5Zr41.5Ni17 and then Ti40Zr40Ni20/ 
Ti44Zr40Ni16 began. The following powders were used 
 
112 
 
 ISSN 1562-6016. ВАНТ. 2022. №1(137) 
for all compositions under investigation: Ti – titanium 
powder Grade 1; TiH2 – titanium hydride powder (from 
TG-90, hydrogen content 3.6 wt.%); Zr – zirconium 
powder PCRK-1; ZrH2 – zirconium hydride powder 
(from PCRK-1, hydrogen content 2.0 wt.%); Ni  nickel 
powder 
electrolytic PNE-1; Ni – nickel 
powder 
carbonyl PNC. The powders were mixed by three 
different methods: 
a) “drunk barrel” mixer for 60…120 min at the 
rotational speed of ~ 30…40 rpm; 
b) hand rubbing/mixing in alundum mortar;  
c) high-energy grinding/mixing in a ball mill. 
The obtained mixture of powders was compacted 
with the different degree of pressing: from 3 to 80 t in 
the briquettes Ø 15…30 mm in diameter and height 
6…25 mm. Heat treatment in hydrogen (in the “thermal 
explosion” mode) was carried out by: heating to 450 °C 
in vacuum, hydrogen supply, holding for 1.5 h in a 
hydrogen atmosphere 
(2…5 atm) at a constant 
temperature of 450 °C. Cooling to room temperature 
under a hydrogen atmosphere for 2 h. Annealing of all 
samples was carried out in a vacuum (1...5)∙10
-3
 Pa at 
700…950 °C. 
The structure and composition of the samples were 
studied by SEM and EDX microanalysis, using 
scanning electron microscope JSM 7001F with an 
accelerating voltage of 20 kV. Observation of the 
structure was carried out both in the secondary electron 
(SEI) mode and in the backscattered electron (COMPO) 
mode forming the composite image contrast. The 
composition was analyzed using the INCA PentaFET*3 
detector and the Oxford Instruments INCA 4.11 
program. To calibrate the quantitative analysis, a 
standard of cobalt with a purity of 99.99% was used. 
The mapping mode is used to determine the degree of 
distribution of elements over the sample. XRD studies 
of the sample were carried out using DRON-4-07 X-ray 
diffractometer 
in Cu-Kα 
radiation. The 
initial 
components of the samples, as well as samples of Ti-Zr-
Ni alloys after heat treatment in hydrogen (in the 
“thermal explosion” mode)/vacuum annealing, were 
investigated for desorption under vacuum heating in the 
temperature range 0...900 °C in a mass-spectrometer 
MX7203. The MX7203 mass-spectrometer is designed 
to determine the hydrogen present in alloys and the 
composition of the gas phase released from the material 
when heated in a vacuum. 
 
2. RESULT AND DISCUSSION 
2.1. HEAT TREATMENT 
The key to the hydride cycle technology is heat 
treatment. Accordingly, the most significant parameter 
is temperature, heating and cooling rate, and also 
annealing time. Therefore, it is advisable to initially 
determine the effect of temperature and annealing time 
on the final structure of the synthesized samples and 
establish optimal conditions for the formation of a given 
structure. To determine 
the optimal 
annealing 
temperature of 
samples 
for 
the 
synthesis of 
quasicrystals, the temperature ranges of hydrogen 
desorption from the used starting components and their 
mixtures were determined (Fig. 1). This made it 
possible to determine the upper and lower boundaries of 
the dissociation of hydrides and, accordingly, to 
establish the annealing temperature of the samples. 
From the literature data [14–17] it is known that 
hydrogen is able to saturate titanium to a limiting 
stoichiometric 
concentration 
of 
4.04 wt.%, 
and 
zirconium above 2 wt.%, this is accompanied by 
significant changes in the properties of the material. The 
H2 content in the starting hydrides affects the properties 
of the resulting binary and ternary alloys (porosity, 
phase composition). This is due to the fact that during 
the dissociation of hydrides during heating in vacuum, 
TiH2 and ZrH2 produce hydrogen, and a decrease in the 
concentration of hydrogen in their crystal lattices leads 
to a sequence of phase transformations: ZrH2 (ε) → 
ZrH2 (δ) → Zr (β) → Zr (α) and TiH2 (ε) → TiH2 (δ) → 
Ti (β) → Ti (α). During dehydrogenation, both materials 
undergo 
a 
chain 
of 
phase 
transformations 
MeH2 → β (bcc) → α (hcp) 
[10]. 
However, 
the 
temperature ranges of phase transformations in the 
process of dehydrogenation 
for 
zirconium are 
150…200 °C higher than for titanium (see Fig. 1). 
 
Fig. 1. Thermal desorption TiH2; ZrH2; 
(TiH2)40.5Zr31.9Ni27.6 + H2; Ti40.5Zr31.9Ni27.6 + H2  
 
In addition, it is necessary to take into account the 
allotropic (phase) transitions of each of the components 
of the sample, since they can affect the structure already 
formed during annealing. It is known that titanium 
exists in two crystalline modifications: hcp α-Ti and 
bcc β-Ti 
(transition 
temperature α ↔ β = 883 °C). 
Similarly, 
zirconium also has 
two 
crystalline 
modifications: hcp  α-Zr and bcc  β-Zr (transition 
temperature 
α ↔ β = 863 °C). Therefore, 
if 
the 
annealing temperature is higher than these values, then 
upon cooling of the sample, structural changes are 
possible due to polymorphic transformation. This will 
happen if Ti and Zr formed during “reductive” 
annealing did not fully interact with each other and with 
Ni. Residues of β-Ti and β-Zr, undergoing polymorphic 
transformation during cooling of the sample, can lead to 
a change in the structure of the formed triple alloy 
(quasicrystal). Therefore, the annealing time should be 
selected so that the reaction between the components is 
complete and a triple alloy is formed in the entire 
volume of the sample. This, in turn, is determined by 
diffusion processes (and, accordingly, the annealing 
temperature) and can be established empirically. 
It should be remembered that according to the 
literature [1, 2, 18, 19], the icosahedral quasicrystals of 
0
10
20
30
40
50
60
70
80
90
100
0
100
200
300
400
500
600
700
800
Temperature, °С
Pressure, mm.Hg.Sample 3: Ti30Zr45Ni25 + H2
Sample 2:(TiH2)30Zr45Ni25 + H2
ZrH2
TiH2
Pressure, mm Hg 
 
ISSN 1562-6016. ВАНТ. 2022. №1(137) 
 
 
 
 
 
 
 
 
            113 
the Ti-Zr-Ni system are stable at temperatures below 
700 °C; when heated above, the QC phase is converted 
to the Laves phase mixture L-TiZrNi, α-(Ti, Zr) and 
phases (Ti, Zr)2Ni. Therefore, the lower the sintering 
temperature, the greater the probability of maintaining 
the QC phase. In this case, the sintering regime should 
ensure that the process of the formation of the ternary 
alloy proceeds according to the solid-phase diffusion 
mechanism in full. 
Thus, to choose the optimal annealing mode means 
to determine the heat treatment conditions under which: 
– there was a complete dissociation of the starting 
hydrides; 
– hydrogen is removed as much as possible from the 
material; 
– hydride 
dissociation 
products 
completely 
interacted with each other and with the other 
components of the sample; 
– formed a structural phase state characteristic of 
this composition; 
– the processes of high-temperature evolution of the 
material 
are 
limited 
(aging, 
polymorphic 
transformations, precipitation of secondary phases, 
diffusion segregation, etc.). 
From the graphs of thermal desorption shown in 
Fig. 1, it can be seen that the active evolution of 
hydrogen from TiH2 begins at 400 °C and practically 
ends above 650 °C with a maximum at 570 °C. ZrH2 
decomposition occurs in a wider temperature range of 
300...700 °C and has a two-stage character with peaks at 
430 and 650 °C. The graphs of thermal desorption from 
powder samples No. 2, 3 are similar and have several 
maxima, which represent the superposition of the 
decomposition processes of TiH2 and ZrH2, which is 
clearly visible on the general graph. Thus, it can be 
concluded that the main evolution of hydrogen from 
hydrides ends at 700 °С; however, it is necessary to take 
into account that a certain amount of hydrogen is stored 
in Ti and Zr above 1000 °С [17]. Since the composition 
of Ti40.5Zr31.9Ni27.6 samples is eutectic, the upper limit of 
the annealing temperatures will be in the region of the 
eutectic formation. According to the double state 
diagrams for Ti-Ni and Zr-Ni, the minimum eutectic 
temperature is 942 and 960 °С, respectively. Thus, the 
temperature range for research is 700…950 °C. 
2.2. ANNEALING TEMPERATURE 
Initial 
studies 
were 
carried 
out 
on 
(TiH2)40.5Zr31.9Ni27.6 and Ti40.5Zr31.9Ni27.6 samples treated 
in hydrogen in the “thermal explosion” mode followed 
by vacuum annealing at different temperatures. The 
XRD results of a series of samples of No. 1 after 
annealing at different temperatures showed that the 
minimum temperature required for the interaction of the 
starting components and the formation of ternary phases 
is 910 °C (with an annealing time of 1 h). Previous 
experiments showed that the upper temperature is 
limited to 950 °C, above which eutectic fusion of Ti and 
Zr with Ni occurs. Thus, the optimum temperature for 
sintering Ti-Zr-Ni samples with electrolytic nickel using 
the “hydride cycle” technology is 920...930 °С. Electron 
microscopy of the (TiH2)40.5Zr31.9Ni27.6 sample before 
and after heat treatment at different temperatures is 
presented in the COMPO mode in Fig. 2. It should be 
noted that in the No.1c diffraction pattern there are lines 
that can be attributed to the QC phase (at angles 
diffraction 2θ = 36.5° and 38.5°). But due to the weak 
intensity of the quasicrystal lines in the diffractogram, it 
is impossible to select a 5th order line to unambiguously 
confirm the QC phase in the sample. X-ray diffraction 
patterns of the samples are presented in Fig. 3. The 
results of the phase composition are summarized in 
Table 1. 
The low nickel content in the starting powders is due 
to the uneven distribution of the starting components 
during transportation, due to a significant difference in 
the dispersion of the starting TiH2, Zr (up to 10 μm) and 
electrolytic Ni (up to 100 μm) (see Fig. 2,a). The 
mismatch of the initial composition during the XRD 
study does not affect the final composition of the 
synthesized sample, since, during the preparation of the 
samples, the mixing of the starting components occurs 
immediately before pressing. And the powder mixture is 
not compacted during transportation and the associated 
uneven distribution of components of different 
dispersion. However, the discovered phenomenon led to 
the study of the effect of the degree of dispersion of the 
components and mixing methods on the synthesis of the 
Ti-Zr-Ni ternary alloy and the formation of the 
structure. 
 
 
      a 
 
 
 
     b 
 
 
 
  c 
 
Fig. 2. Electron microscopy of the sample (TiH2)40.5Zr31.9Ni27.6 + H2 before and after heat treatment:  
a – powder sample No. 1a; b – sample No. 1c after annealing at 700 °C for 1 h + 910 °C for 1 h;  
c – sample No. 1d after annealing at 920 °C for 1 h 
 
 
 
 
114 
 
 ISSN 1562-6016. ВАНТ. 2022. №1(137) 
Table 1 
Phase composition of the studied samples Ti40.5Zr31.9Ni27.6 
 
Sample 
Heat 
treatment 
mode 
Phase 
Weight content, 
wt.% 
Lattice parameters, Å 
No. 1a (TiH2)40.5Zr31.9Ni27.6, 
TiH2, Zr, PNE-1 
powder + H2 
TiH2 
28.6 
a = 4.452 
ZrH2-ε 
62.9 
a = 3.515; c = 4.475 
Ni 
8.5 
a = 3.524 
No. 1b (TiH2)40.5Zr31.9Ni27.6, 
TiH2, Zr, PNE-1 
910 °С, 1 h 
Ti-α 
19.9 
a = 2.962; c = 4.740 
Zr-α 
45.2 
a = 3.245; c = 5.169 
Ni 
5.2 
a = 3.526 
ZrH2-δ 
24.1 
a = 4.780 
NiTiO3 
5.6 
a = 5.469; α = 55.37° 
No. 1c (TiH2)40.5Zr31.9Ni27.6, 
TiH2, Zr, PNE-1 
700 °С, 1 h + 
910 °С, 1 h 
Ni 
– 
a = 3.524 
Zr-α 
– 
a = 3.232; c = 5.147 
(Ti,Zr)2Ni 
– 
a = 11.899 
QC-? 
– 
– 
No. 1d (TiH2)40.5Zr31.9Ni27.6, 
TiH2, Zr, PNE-1 
920 °С, 1 h 
(Ti,Zr)2Ni 
74.2 
a = 11.813 
L-TiZrNi 
25.8 
a = 5.222; c = 8.537 
No. 1e Ti40,5Zr31,9Ni27,6, 
Ti, Zr, PNE-1 
powder + H2 
TiH2 
30.6 
a = 4.453 
ZrH2-ε 
55.2 
a = 3.518; c = 4.462 
Ni 
14.2 
a = 3.524 
No. 1f Ti40.5Zr31.9Ni27.6, 
Ti, Zr, PNE-1 
920 °С, 1 h 
(Ti,Zr)2Ni 
93.6 
a = 11.820 
L-TiZrNi 
6.4 
a = 5.218; c = 8.545 
No. 1g Ti40.5Zr31.9Ni27.6, 
Ti, Zr, PNE-1 
930 °С, 1 h 
(Ti,Zr)2Ni 
79.6 
a = 11.864 
L-TiZrNi 
20.4 
a = 5.223; c = 8.556 
No. 1h Ti40.5Zr31.9Ni27.6, 
Ti, Zr, PNE-1 
940 °С, 1 h 
(Ti,Zr)2Ni 
92.1 
a = 11.845 
L-TiZrNi 
7.9 
a = 5.232; c = 8.558 
No. 1j 
(TiH2)40.5(ZrH2)31.9Ni27.6, 
TiH2, ZrH2, PNE-1 
920…930 °С, 
1 h 
(Ti,Zr)2Ni 
72.8 
a = 11.791 
 
 
 
Fig. 3. X-ray diffraction patterns of samples (TiH2)40.5Zr31.9Ni27.6: a – powder sample No. 1a; b – sample No. 1c after 
annealing at 700 °C for 1 h + 910 °C for 1 h; c – sample No. 1d after annealing at 920 °C for 1 h 
 
2.3. DISPERSION OF INITIAL COMPONENTS 
Fine samples of TiH2, ZrH2, Zr with a size of 
(0.1...10 μm) and two types of nickel powder were used 
to prepare the samples. The first is electrolytic nickel of 
the PNE-1 brand, which was sieved through a series of 
sieves, for separation into fractions, the fine and coarse 
fractions were used separately (less than 40 and more 
than 100 μm, respectively). The second is carbonyl 
nickel with a particle size of 0.1...10 μm. Studies have 
shown that the difference in the dispersion of Ti, Zr, Ni 
leads to local inhomogeneities, which give a significant 
deviation from a given composition in small areas of the 
analysis. Therefore, it is necessary to use the initial 
components of the same dispersion and minimum size. 
This will allow to achieve uniform distribution of 
elements along the sample, increase contact zones and 
accelerate the process of formation of a triple alloy. 
Thus, the use of finely dispersed nickel made it possible 
a 
b 
c 
 
ISSN 1562-6016. ВАНТ. 2022. №1(137) 
 
 
 
 
 
 
 
 
            115 
to achieve greater phase homogeneity of the samples 
and to lower the sintering temperature of the samples 
with the formation of the alloy by 50 °C.  
Further studies were conducted on samples of a 
different composition. According to published data [5], 
the 
composition 
of Ti41.5Zr41.5Ni17 
is 
optimal 
(experimentally confirmed) for the synthesis of stable 
quasicrystals in the Ti-Zr-Ni system. In addition, ZrН2 
powder (instead of zirconium powder) and the sieved 
fine fraction of nickel PNE-1 (less than 40 μm in size) 
were used as starting components. X-ray diffraction 
patterns of the samples are presented in Fig. 4, the 
results of the phase composition are summarized in 
Table 2. Electron microscopy of the cleavage of the 
(TiH2)41.5(ZrН2)41.5Ni17 sample after annealing at 930 °C 
for 1 h is presented in Fig. 5. 
 
 
Fig. 4. X-ray diffraction patterns of samples (TiH2)40Zr40Ni20: No. 4a, 4b, 4c 
 
 
Fig. 5. Electron microscopy samples (TiH2)41.5(ZrН2)41.5Ni17 after annealing at 930 °С, for 1 h  
 
As can be seen from the XRD analysis data 
presented in Table 2, the use of a finely divided fraction 
of electrolytic nickel (samples No. 2a-2d) led to a 
noticeable decrease in the temperature of the solid phase 
sintering. However, a change in the composition to the 
optimal one for the synthesis of the QC phase did not 
affect the phase composition of the samples. X-ray 
diffraction analysis confirmed only the presence of 
crystalline phases: L-TiZrNi, (Ti,Zr)2Ni and α-(Ti,Zr). 
In sample 2c, a halo is present in the diffraction pattern 
in the range of angles 2θ ≈ 30…42°, which indicates the 
presence of an X-ray amorphous phase in the sample. 
No hydrides were detected in the sample, i.e., hydrogen 
left the sample, but this temperature is not enough for 
synthesis. Also on this diffraction pattern, there are lines 
that can be interpreted as a quasicrystal, but the 
presence of a halo prevents unambiguous identification. 
Therefore, the presence of a QC phase is not given. 
2.4. HYDROGEN CONTENT IN THE HYDRIDES 
The use of TiH2 as initial components with different 
hydrogen contents (2...3.6 wt.%) did not affect the 
structural phase composition of the final samples. As 
well as the combined use of TiH2 and ZrH2 (series 
No. 2). Regardless of the weight content of hydrogen in 
hydrides (or one/both hydrides are present in the 
mixture), a similar alloy structure is formed after 
annealing in a vacuum. The amount of hydrogen in the 
initial hydrides significantly affects the time it takes to 
reach the heat treatment mode. The more hydrogen in 
the initial charge, the longer the dehydrogenation 
process before sintering the sample. 
2.5. DURATION OF ANNEALING 
Experiments were carried out to study the effect of 
the duration of isothermal annealing in a vacuum on the 
structural phase state of the obtained samples. The 
duration of annealing ranged from 2 to 15 h at a 
temperature of 800 °C. From the data given in Table 2 
(No. 4a, 4d, and 6a, respectively), it follows that this 
temperature is not sufficient for the synthesis of a 
ternary alloy, regardless of the annealing duration. After 
prolonged annealing in vacuum, the samples are a 
mixture of Ti, Zr, Ni with a small amount of (Ti,Zr)2Ni. 
 
116 
 
 ISSN 1562-6016. ВАНТ. 2022. №1(137) 
Table 2 
Phase composition of samples Ti41.5Zr41.5Ni17/Ti40Zr40Ni20/Ti44Zr40Ni16  
under various synthesis conditions 
 
Sample 
Heat treatment 
mode 
Phase 
Weight content, 
wt,% 
Lattice parameters, Å 
No. 2a 
(TiH2)41.5(ZrН2)41.5Ni17, 
 TiH2, ZrH2, fine PNE-1 
930 °С, 1 h 
(Ti,Zr)2Ni 
89.9 
a = 11.965 
L-TiZrNi 
10.1 
a = 5.226; c = 8.622 
No. 2b 
(TiH2)41.5(ZrН2)41.5Ni17, 
 TiH2, ZrH2, fine PNE-1 
920 °С, 1 h 
(Ti,Zr)2Ni 
70.8 
a = 12.004 
L-TiZrNi 
8.8 
a = 5.238; c = 8.675 
(Ti,Zr)-α 
20.4 
a = 3.076; c = 4.918 
No. 2c 
(TiH2)41.5(ZrН2)41.5Ni17, 
 TiH2, ZrH2, fine PNE-1 
850 °С, 1 h 
Ni 
– 
a = 3.521 
Zr-α 
– 
a = 3.232; c = 5.148 
Ti-α 
– 
a = 2.951; c = 4.686 
No. 2d 
(TiH2)41.5(ZrН2)41.5Ni17, 
 TiH2, ZrH2, fine PNE-1 
870 °С, 1.5 h 
(Ti,Zr)2Ni 
84.1 
a = 11.970 
L-TiZrNi 
2.9 
a = 5.231; c = 8.578 
(Ti,Zr)-α 
13.0 
a = 3.064; c = 4.910 
No 3a (TiH2)40Zr40Ni20, 
 TiH2, Zr, carbonyl Ni, 
mechanical activation 
910…915 °С, 
2 h 10 min 
(Ti,Zr)2Ni 
62.4 
a = 11.970 
L-TiZrNi 
32.3 
a = 5.233; c = 8.568 
(Ti,Zr)-α 
5.3 
a = 3.088; c = 4.898 
No. 3b (TiH2)44Zr40Ni16, 
 TiH2, Zr, carbonyl Ni, 
mechanical activation 
910…915 °С, 
2 h 10 min 
(Ti,Zr)2Ni 
52.7 
a = 11.974 
L-TiZrNi 
26.3 
a = 5.240; c = 8.560 
(Ti,Zr)-α 
21.0 
a = 3.073; c = 4.896 
No. 4a (TiH2)40Zr40Ni20, 
 TiH2, Zr, carbonyl Ni, 
mechanical activation 
800 °С, 2 h 
Ti-α 
~ 60 
a = 2.975; c = 4.698 
Zr-α 
~ 27 
a = 3.238; c = 5.152 
Ni 
~ 13 
a = 3.524 
X 
– 
??? 
No. 4b (TiH2)Zr40Ni20, 
 TiH2, Zr, carbonyl Ni, 
mechanical activation 
870 °С, 2 h 
(Ti,Zr)2Ni 
57.6 
a = 11.935 
L-TiZrNi 
31.1 
a = 5.230; c = 8.560 
(Ti,Zr)-α 
11.3 
a = 3.069; c = 4.824 
No. 4c (TiH2)Zr40Ni20, 
TiH2, Zr, carbonyl Ni, 
mechanical activation  
800 °С, 2 h + 
EBM 
(Ti,Zr)2Ni 
29.9 
a = 11.907 
L-TiZrNi 
53.7 
a = 5.230; c = 8.548 
(Ti,Zr)-α 
16.4 
a = 3.054; c = 4.898 
No. 4d (TiH2)44Zr40Ni16, 
TiH2, Zr, carbonyl Ni, 
mechanical activation 
830 °С, 2.5 h 
Ti-α 
~ 35 
a = 2.975; c = 4.698 
Zr-α 
~ 50 
a = 3.232; c = 5.147 
Ni 
~ 15 
a = 3.514 
X 
- 
??? 
No. 4e (TiH2)44Zr40Ni16, 
TiH2, Zr, carbonyl Ni,  
mechanical activation 
830 °С, 2.5 h  
+ EBM 
(Ti,Zr)2Ni 
16.0 
a = 11.965 
L-TiZrNi 
61.0 
a = 5.251; c = 8.589 
(Ti,Zr)-α 
23.0 
a = 3.087; c = 4.906 
No. 5a (TiH2)41.5Zr41.5Ni17, 
 TiH2, Zr, carbonyl Ni 
900 °С,  
2 h 10 min 
(Ti,Zr)2Ni 
72.8 
a = 11.985 
L-TiZrNi 
11.0 
a = 5.237; c = 8.581 
(Ti,Zr)-α 
16.2 
a = 3.075; c = 4.894 
No. 5b (TiH2)41.5Zr41.5Ni17, 
 TiH2, Zr, carbonyl Ni 
900 °С, 3 h 
(Ti,Zr)2Ni 
60.2 
a = 11.978 
L-TiZrNi 
12.6 
a = 5.231; c = 8.590 
(Ti,Zr)-α 
27.2 
a = 3.067; c = 4.872 
No. 5c (TiH2)41.5Zr41.5Ni17, 
 TiH2, Zr, carbonyl Ni 
870…880 °С, 
2.5 h 
(Ti,Zr)2Ni 
51.8 
a = 11.964 
L-TiZrNi 
19.2 
a = 5.241; c = 8.577 
(Ti,Zr)-α 
29.0 
a = 3.073; c = 4.853 
No. 6a Ti44Zr40(Ni-Pd)16, 
TiH2, Zr, fine PNE-1 with 
chemically precipitated  
Pd ~ 1 wt.% 
680…800 °С, 
~ 15 h 
Ti-α 
23.2 
a = 2.942; c = 4.679 
Zr-α 
42.0 
a = 3.229; c = 5.141 
Ni 
23.7 
a = 3.507 
(Ti,Zr)2Ni 
11.1 
a = 11.964 
 
With increasing annealing temperature to 910 °С, 
there is no significant difference in the structure (after 2 
and 3 h of isothermal annealing in a vacuum). The 
resulting samples have a similar structure. This is 
confirmed by XRD data on the example of sample 
Ti41.5Zr41.5Ni17 (see Table 2, No. 5a, 5b). Thus, based on 
the XRD results of all synthesized samples, we can 
conclude that in the temperature range of 870…900 °C, 
an isothermal exposure of 60 min is sufficient for the 
complete formation of the final structure. When using 
the initial finely dispersed components with a size of 
1…10 m, it is first of all important to use finely 
 
ISSN 1562-6016. ВАНТ. 2022. №1(137) 
 
 
 
 
 
 
 
 
            117 
dispersed nickel. When using coarse particles, for 
example, electrolytic nickel larger than 100 m, for the 
formation of a ternary alloy, it is necessary to increase 
the sintering temperature to 920…930 °C. 
2.6. HEATING RATE 
The heating rate significantly affects the dissociation 
temperature of titanium and zirconium hydrides. The 
higher the heating rate, the stronger the peak of thermal 
desorption shifts from the initial TiH2 and ZrН2 to the 
region of higher 
temperatures. As 
shown by 
experiments with rapid heating at a rate of more than 
10 °C/min after 400 °C, intense gas evolution from the 
samples begins and the vacuum pumping system cannot 
cope with the released hydrogen. In addition, the intense 
release of Н2 upon rapid heating leads to the formation 
of large pores in the sample and its swelling. 
Conversely, with slow heating at a rate of not more than 
5 °C/min, the sample after sintering has a significantly 
lower porosity with a pore size of less than 0.5 mm 
(unlike large pores with a size of up to 5 mm with rapid 
heating). Thus, it was found that the optimum heating 
rate is 5 °C/min. 
2.7. PRESSURE DURING ANNEALING 
The pressure in the chamber during sintering is also 
directly related to the dissociation rate of hydrides and 
the removal of hydrogen from the samples and, 
consequently, to the formation of a ternary alloy. The 
better the vacuum during heat treatment, the faster the 
cast structure is formed. In addition, the best vacuum 
conditions favorably affect the cleaning of the processed 
material from volatile impurities. Accordingly, by 
improving vacuum conditions, it is possible to reduce 
the level of interstitial impurities, primarily from 
oxygen. It was shown in [15, 16] that under certain 
conditions, partial purification of the material from 
oxygen is observed due to the fact that atomic hydrogen 
released during the decomposition of titanium and 
zirconium hydrides actively interacts with the oxygen of 
the oxide layer on the surface of the powders with the 
formation of the H2O molecule, which then leaves the 
material and is removed by a vacuum pumping system. 
And this process takes place the more intensively, the 
better the vacuum in the chamber. 
2.8. COOLING CONDITIONS 
The influence of the cooling conditions of the 
samples after sintering in vacuum was investigated in 
two versions. The first mode is cooling the sample from 
sintering temperature to room temperature together with 
the furnace for 20 h. The second mode is the lowering 
of the sample from the heating zone and rapid cooling to 
room temperature in 30 min (No. 3a, 3b). As shown by 
XRD/SEM/EDX studies in both modes, a similar 
structure is formed. 
 
2.9. COMPACTING. METHOD OF MIXING THE 
ORIGINAL COMPONENTS 
In this study, the following methods of mixing the 
starting components were tested in the manufacture of 
samples: 
a) “drunk barrel” mixer for 60…120 min at a 
rotational speed of ~ 30…40 rpm; 
b) hand rubbing/mixing in alundum mortar; 
c) high-energy grinding/mixing in a ball mill. 
The results of SEM/EDX studies showed that 
manual mixing and mixing in a “drunk barrel” gives an 
inhomogeneous distribution of components over the 
sample, which 
after 
sintering 
leads 
to 
local 
heterogeneity in elemental and phase composition. This 
is especially noticeable when using the starting 
components of different dispersions. The best result is 
obtained when using short-term joint mechanical 
activation of components with the same dispersion. 
After sintering, such samples showed the composition 
corresponding 
to 
the given one, without 
local 
heterogeneities and deviations. 
2.10. METHOD OF COMPACTION/PRESSING. 
THE EXTENT OF PRESSING 
The obtained mixture of powders was compacted 
with a different degree of unilaterally pressing: from 3 
to 80 t into cylindrical briquette Ø 15…30 mm in 
diameter and height 6…25 mm. The data obtained after 
the sintering of samples with different degrees of 
compaction show that the degree of compaction mainly 
affects the porosity of the final material and does not 
significantly affect its structural-phase state. In the 
course of the work, the optimal pressing parameters 
were empirically selected. Given the high fragility of 
TiH2 and ZrН2, as well as their low ductility, the 
pressing of these samples presents a certain technical 
difficulty:  
a) at low load (1...10 t), the mixture of the starting 
powders is not compressed and the sample crumbles; 
b) at high pressure (40...80 t), re-pressing cracks 
occur in the sample and the samplecrumbles when 
pressed out of the mold. 
The mode for pressing samples weighing 35...50 g 
was selected experimentally, the load is optimal 
(3.3...7.2 t/cm
2
). 
Further studies on the synthesis of quasicrystals in 
the Ti-Zr-Ni system were carried out on samples of the 
composition Ti40Zr40Ni20/Ti44Zr40Ni16. The first is the 
theoretically calculated optimal composition for the 
formation of the QC phase, according to the literature 
[13]. The second corresponds to the composition of 
quasicrystals obtained by the hydride cycle technology 
at the Institute of Macrokinetics [10]. 
Samples No. 3a, 3b were synthesized under equal 
heat treatment conditions (samples were sintered at the 
same time) using finely divided initial components and 
selected mixing/pressing parameters. As can be seen 
from the data presented, the composition of the samples 
affected the final structural phase state. The phase ratio 
and lattice parameters have slightly changed. According 
to published data, the presence of a certain amount of 
the Laves phase of L-TiZrNi and α-(Ti, Zr) is 
characteristic of QC materials of the Ti-Zr-Ni system. 
Therefore, subsequent studies were carried out with the 
same compounds, but aimed at reducing the oxygen 
content. The use of finely dispersed starting components 
and mechanical activation grinding in a planetary mill 
made it possible to lower the sintering temperature with 
the formation of a triple alloy to 870 °C. However, as 
can be seen from the above XRD data, sintering does 
 
118 
 
 ISSN 1562-6016. ВАНТ. 2022. №1(137) 
not occur at lower temperatures. Samples that were 
annealed at low temperature and in which there was no 
interaction between the components were subjected to 
vacuum refining in an electron beam melting unit in 
order to reduce the content of interstitial impurities 
(primarily oxygen). 
2.11. EFFECT OF IMPURITIES 
As it turned out during the research, this is the most 
important parameter affecting the formation of a QC 
structure. Regardless of carefully selected optimal 
parameters of the heat treatment modes using the 
hydride cycle technology, the presence of interstitial 
impurities (O2, N2, C) adversely affects the formation of 
quasicrystals. Thus, with oxygen content in the sample 
exceeding 3000 ppm (0.3 wt.%), the formation of the 
QC phase is leveled due to the stabilization of the 
(Ti, Zr)2Ni phase by oxygen and the formation of the 
Laves phase L-TiZrNi instead of quasicrystals. Given 
that active metals such as titanium and zirconium, 
which have a high affinity for oxygen, are used, it is 
extremely difficult to reduce the concentration of O2 in 
the samples. Especially considering that the initial raw 
materials are finely divided powders with a highly 
developed surface on which a significant amount of gas 
impurities is adsorbed. This is currently the main 
problem in obtaining stable quasicrystals in the Ti-Zr-Ni 
system using the proposed hydride cycle technology. At 
this point, attention was repeatedly paid to publications 
on quasicrystals synthesis by other methods. Thus, the 
use of the fast quenching method allows one to slightly 
increase the limiting oxygen content in the samples, and 
high cooling rates suppress the precipitation of the 
(Ti, Zr)2Ni phase and the Laves phase of L-TiZrNi 
forming quasicrystals [5]. It was theoretically proved 
[18, 19] that quasicrystals is a low-temperature stable 
phase in the Ti40Zr40Ni20-Ti41.5Zr41.5Ni17 system, while 
the Laves phase L-TiZrNi is stable at high temperatures 
(at T > 700 °C). 
To confirm the significant effect of interstitial 
impurities on the final structure of alloys of the Ti-Zr-Ni 
system, we studied the effect of refining electron-beam 
remelting 
of 
samples No. 4a, 4d 
annealed 
at 
temperatures insufficient to obtain a ternary alloy. An 
important result of this study is that a favorable effect of 
refining remelting on the structural state of the alloy 
was established. As can be seen from Table 2, the phase 
composition of the samples after electron beam melting 
No. 4c, 4e dramatically differs in the ratio of the phases 
L-TiZrNi and (Ti, Zr)2Ni compared with samples of the 
same composition after 
sintering 
(for example 
No. 3a, 3b). An increase in the amount of the L-TiZrNi 
phase is proportional to a decrease in the amount of the 
(Ti, Zr)2Ni phase. This indicates that, during the melting 
in a vacuum, the oxygen content in the sample 
decreases, which is responsible for the appearance of 
the (Ti, Zr)2Ni phase in the composition region 
corresponding to the L-TiZrNi phase (high-temperature 
phase of the Ti-Zr-Ni system). In addition, it was found 
that in samples No. 4a, 4d annealed at temperatures of 
800 and 830 °C, in which dehydrogenation occurred, 
but the alloy did not form, the self-propagating high-
temperature synthesis in the layer-by-layer combustion 
mode started at the beginning of the EBM. In this case, 
the sample was heated above the melting point and 
began to melt. Therefore, a small addition of electron 
beam power led to the complete melting of the sample. 
The discovered phenomenon led to additional studies 
aimed at testing the feasibility of synthesizing samples 
of the Ti-Zr-Ni system in the SHS mode. In Ti-Ni and 
Zr-Ni binary systems, a solid-phase interaction reaction 
in the SHS mode is possible due to their negative heats 
of mixing     
    (Ti-Ni) = -35 kJ/mol [20] and         
    
(Zr-Ni) = -49 kJ/mol, respectively. Those, it is quite 
possible that such processes can occur in the ternary    
Ti-Zr-Ni system.  
Fig. 6 shows the appearance of (TiH2)40Zr40Ni20 
samples after pressing and heat treatment in a vacuum 
under various conditions. The above images clearly 
show the changes that the samples undergo, depending 
on the selected modes. 
 
 
      a 
 
 
       b 
 
 
             c 
 
 
     d 
Fig. 6. Appearance of samples (TiH2)40Zr40Ni20: a – initial after pressing; b – No. 4a after annealing in vacuum at  
T = 800 °С; c – No. 4b after annealing in vacuum at T = 870 °С for 2 h; d – No. 4c after annealing in vacuum at  
T = 800 °С + SHS on EBM 
 
According to the Tamman-Hedwal theory of 
mechanisms of solid-phase interaction, supplemented by 
Wagner's theory, it follows that activated states 
significantly accelerate the course of solid-phase 
reactions. As indicated above, in the process of hydride 
dissociation, diffusion processes are activated. Due to 
an increase in the defect of the crystal structure due to 
phase transformations and volume effects during 
thermal desorption of hydrogen, as well as active 
diffusion of hydrogen, the processes of solid-phase 
interaction are significantly activated. Accordingly, the 
temperatures of the onset of the interaction of the 
particles of the starting components with each other can 
be lower than during fusion by traditional methods. In 
addition, according to Hedwal, if one substance can 
undergo a polymorphic transformation, then this 
transformation is a very favorable moment for the 
reaction of the interaction of two solids. Or in other 
 
ISSN 1562-6016. ВАНТ. 2022. №1(137) 
 
 
 
 
 
 
 
 
            119 
words, in the case of a polymorphic transformation of 
one of the components of the mixture at a relatively low 
temperature, the chemical reaction begins and proceeds 
intensively 
at 
the point of 
this polymorphic 
transformation. In the case of the Ti-Zr-Ni system, there 
are two components with a polymorphic transition in the 
temperature range 863...883 °C for Zr and Ti, 
respectively. As further studies showed, in the synthesis 
of samples of composition (TiH2)41.5Zr41.5Ni17 (in at.%, 
powder TiH2, Zr, fine PNE-1, without mechanical 
activation), thermocouples in direct contact with the 
sample recorded a sharp jump in temperature from 865 
up to 954 °C, ΔT = 89 °C. This indicates the occurrence 
of an exothermic reaction of solid-phase interaction in 
the “thermal explosion” mode. This was confirmed by 
visual observation during the heating of samples in a 
quartz ampoule. A graph of the temperature dependence 
of the sample during synthesis is shown in Fig. 7. 
 
Fig. 7. The temperature change of the pressed sample 
(TiH2)41.5Zr41,5Ni17 upon heating in vacuum 
Thus, it turned out that, in fact, the synthesis of a 
ternary Ti-Zr-Ni alloy does not occur by the mechanism 
of slow diffusion solid-phase sintering, but in the 
process of a short-term exothermic reaction between 
particles of Ti, Zr, and Ni, occurring in the thermal 
explosion mode. It is also possible to synthesize in a 
layer-by-layer combustion mode during preliminary 
annealing in the temperature range 800…830 °С to 
remove hydrogen and subsequent local initiation of 
SHS. However, for the successful synthesis of a ternary 
alloy, it is necessary to use finely dispersed starting 
components with a size of 1…10 μm, since in the case 
of different dispersion the temperature of initiation of 
the SHS reaction increases significantly and local 
heterogeneities in composition arise. The structural 
phase state of the final material depends on the presence 
of interstitial impurities, primarily on the oxygen 
content. Because in this study, the total amount of 
oxygen in the starting components exceeded 3000 ppm, 
and samples with a QC structure were not obtained. To 
form a QC structure using the hydride cycle technique, 
it is necessary to reduce the oxygen content in the 
samples. The following options are possible for this: 
– use of starting high-purity components (powders 
of Ti, Zr, Ni); 
– hydrogenation of Ti and Zr with high-purity 
hydrogen; 
– use of deoxidizing / microalloying Al, Y, Sc. 
3. CONCLUSIONS 
In this work, the main key parameters of the 
formation of intermetallic compounds of the Ti-Zr-Ni 
system by the “hydride cycle” method are established. 
The optimal modes of the technological chain of sample 
production were selected. The heat treatment parameters 
are empirically selected and their influence on the 
structural state of the synthesized alloys is determined. 
The influence of various factors on the synthesis process 
and on the final structural phase state of materials has 
been established. It has been established that the key 
factors in the formation of ternary compounds of the  
Ti-Zr-Ni system during hydride dissociation are the 
dispersion and homogeneity of the initial compacted 
components. 
The causes of the destruction of the QC phase and 
the formation of substituent phases are determined: the 
Laves phase of L-TiZrNi and the phase (Ti, Zr)2Ni 
arising from the high oxygen content. Regardless of the 
initial composition, all samples of Ti40.5Zr31.9Ni27.6, 
Ti41.5Zr41.5Ni17, Ti40Zr40Ni20, Ti44Zr40Ni16 contained the 
dominant phase (Ti, Zr)2Ni and a smaller amount of L-
TiZrNi and (Ti, Zr)-α. Mechanisms for reducing the 
oxygen content are proposed and the efficiency of using 
refining remelts in vacuum to reduce interstitial 
impurities is shown. 
It was found that during the “hydride cycle” the 
synthesis of ternary alloys in the Ti-Zr-Ni system occurs 
during a short-term exothermic reaction related to SHS 
and proceeding in the “thermal explosion” mode. SHS 
begins in the temperature region corresponding to the 
α↔β polymorphic transformation of titanium and 
zirconium. 
 
FUNDING 
 
This work was supported by non-profit corporation 
Quantum Gravity Research, CA, USA. 
 
REFERENCES 
 
1. R.M. Stroud, 
A.M. Viano, 
E.H. Majzoub, 
P.C. Gibbons, K.F. Kelton. Ti-Zr-Ni quasicrystals: 
structure and hydrogen storage // Materials Research 
Society. Symp. Proc. 1996, N 400, p. 255-260. 
2. R.M. Stroud, K.F. Kelton, S.T. Misture. High-
temperature x-ray and calorimetric studies of phase 
transformations in quasicrystalline Ti-Zr-Ni alloys // J. 
Mater. Res. 1997, N 12(2), p. 434-438. 
3. I. Zavaliy, G. Wojcik, G. Mlynarek, I. Saldan, 
V. Yartys, M. Kopczyk. Phase-structural characteristics 
of (Ti1-xZrx)4Ni2O0.3 alloys and their hydrogen gas 
and electrochemical absorption-desorption properties // 
Journal of Alloys and Compounds. 2001, N 314, p. 124-
131. 
4. O.Ye. Dmytrenko, I.V. Kolodiy. Influence of the 
hydrogen saturation temperature on the structure of 
melt-spun Ti30Zr45Ni25 alloys // Problems of Atomic 
Science and Technology. Series “Vakuum, Pure 
materials, Superconductors” (22). 2018, N 1(113), 
p. 162-168. 
5. V.M. Azhazha, A.M. Bovda, S.D. Lavrinenko, 
L.V. Onishchenko, S.V. Malykhin, A.T. Pugachev, 
M.V. Reshetnyak, A.N. Stetsenko, B.A. Savitsky. 
Synthesis and stability of Ti-Zr-Ni quasicrystals // 
0
100
200
300
400
500
600
700
800
900
1000
0
5000
10000
15000
20000
25000
30000
Time, sec
Temperature, °Сime, s 
 
120 
 
 ISSN 1562-6016. ВАНТ. 2022. №1(137) 
Problems of Atomic Science and Technology. Series 
“Vacuum, Pure materials, Superconductors”. 2007, 
N 4, p. 82-87. 
6. S.K. Dolukhanyan, A.G. Aleksanyan, V.Sh. She-
khtman, A.A. Mantashyan, D.G. Mailyan, O.P. Ter-
Galstyan. A new method for producing alloys based on 
transition metals // Chemical Journal of Armenia. 2007, 
N 60(4), p. 545-569. 
7. S.K. Dolukhanyan, A.G. Aleksanyan, O.P. Ter-
Galstyan, V.Sh. Shekhtman, M.K. Sakharov, G.E. Ab-
rosimova. Specifics of the formation of alloys and their 
hydrides in the Ti-Zr-H system // Russ. J. Phys. Chem. 
B. 2007, N 2(6), p. 563-569. 
8. A.G. Aleksanyan, S.K. Dolukhanyan, A.A. Man-
tashyan, D.G. Mailyan, O.P. Ter-Galstyan, V.Sh. She-
khtman. A new technique for producing alloys based on 
transition metals // Carbon nanomaterials in clean 
energy hydrogen systems. Springer, 2008, p. 783-794. 
9. S.K. Dolukhanyan, A.G. Aleksanyan, V.Sh. She-
khtman, H.G. Hakobyan, D.G. Mayilyan, N.N. Agha-
djanyan, K.A. Abrahamyan, N.L. Mnatsakanyan, 
O.P. Ter-Galstyan. Synthesis of 
transition metal 
hydrides and a new process for production of refractory 
metal alloys 
// 
International Journal of Self-
Propagating High-Temperature 
Synthesis. 
2010, 
N 19(2), p. 85-93. 
10. V.Sh. Shekhtman, H.G. Hakobyan, A.G. Alek-
sanyan, 
S.K. Dolukhanyan, O.P. Ter-Galstyan, 
M.K. Sakharov. The formation of quasicrystals and their 
hydrides in Ti-Zr-Ni system // International Journal of 
hydrogen energy. 2011, N 36, p. 1206-1208. 
11. D.G. Savvakin, M.М. Gumenyak. Synthesis of 
alloys based on the binary Zr-Ti system using dispersed 
zirconium hydride // Metallophysics and the Latest 
Technology. 2013, N 35(3), p. 349-358. 
12. O.M. Ivasishin, V.N. Voyevodin, P.E. Mar-
kovsky, M.M. Pylypenko, D.G. Savvakin, S.D. Lav-
rinenko, O.P. Karasevska. The microstructure and 
characteristics of the Zr-1% Nb alloy synthesized from 
heterogeneous powder mixtures // Problems of Atomic 
Science and Technology. 2015, N 2(96), p. 65-72. 
13. J.B. Qiang, Y.M. Wang, D.H. Wang, 
M. Kramer, P. Thiel, C. Dong. Quasicrystals in the Ti-
Zr-Ni alloy system // Journal of Non-crystalline Solids. 
2004, N 334&335, p. 223-227. 
14. О.М. Ivasishin, А.В. Bondarchuk, M.М. Gu-
menyak, D.G. Savvakin. Surface phenomenon upon 
heating of titanium hydride powder // Physics and 
Chemistry of Solid State. 2011, N 12(4), p. 900-907. 
15. О.М. Ivasishin, D.G. Savvakin, M.М. Gume-
nyak. Dehydrogenation of titanium hydride powder and 
its role in sintering activation // Metallophysics and 
Latest Technologies. 2011, v. 33, N 7, p. 899-917. 
16. D.G. Savvakin, N.M. Humenyak, M.V. Mat-
viychuk, O.G. Molyar. The role of hydrogen in sintering 
of titanium powders // Physicochemical Mechanics of 
Materials. 2011, N 5, p. 72-81. 
17. О.М. Ivasishin, D.G. Savvakin. Synthesis of 
alloys based on zirconium and titanium using their 
hydrides // Physicochemical Mechanics of Materials. 
2015, N 4, p. 27-35. 
18. R.G. Hennig, A.E. Carlsson, K.F. Kelton, 
C.L. Henley. Ab initio Ti-Zr-Ni phase diagram predicts 
stability of icosahedral TiZrNi quasicrystals // Physical 
Review B. 2005, N 71, p. 144103-1-10. 
19. R.G. Hennig, A.E. Carlsson, K.F. Kelton, 
C.L. Henley. Icosahedral Ti-Zr-Ni: A groundstate 
quasicrystal? eprint arXiv:cond-mat/0205202 [cond-
mat.mtrl-sci]. May 2002. 
20. É. Fazakas, L.K. Varga. Effect of valence 
electron concentration on the glass-forming ability in 
Al-based alloys // International Journal of Engineering 
and Applied Sciences (IJEAS). 2015, N 2(11), p. 115-
121. 
Article received 24.11.2021 
 
 
СИНТЕЗ Ti-Zr-Ni-СПЛАВОВ МЕТОДОМ «ГИДРИДНОГО ЦИКЛА» 
 
А.Е. Дмитренко, И.В. Колодий, Т.Б. Янко, В.М. Борисенко, К. Ирвин, Р.Л. Василенко 
 
Проведены комплексные исследования технических параметров и условий синтеза тройных сплавов в 
системе Ti-Zr-Ni методом «гидридного цикла». Определено влияние на процесс синтеза таких параметров, 
как: температура и время отжига, скорость нагрева, условия охлаждения, состав материала, дисперсность, 
содержание водорода в используемых гидридах, наличие примесей, способы смешивания и прессования, а 
также степень прессования исходных компонентов. Синтезированы и исследованы сплавы следующих 
составов: Ti40,5Zr31,9Ni27,6, Ti41,5Zr41,5Ni17, Ti40Zr40Ni20, Ti44Zr40Ni16. Определены оптимальные технологические 
параметры и условия синтеза тройных сплавов. Установлено, что ключевыми факторами в процессе 
образования соединений при диссоциации гидридов являются дисперсность и однородность исходных 
спрессованных компонентов. Установлено, что синтез тройных сплавов в системе Ti-Zr-Ni происходит в 
ходе кратковременной экзотермической реакции в режиме «теплового взрыва», которая начинается в 
области температур, соответствующей полиморфному превращению α↔β циркония и титана. 
 
 
СИНТЕЗ Ti-Zr-Ni-СПЛАВІВ МЕТОДОМ «ГІДРИДНОГО ЦИКЛУ» 
 
О.Є. Дмитренко, І.В. Колодій, Т.Б. Янко, В.М. Борисенко, К. Ірвін, Р.Л. Василенко 
 
Проведено комплексне дослідження технічних параметрів та умов синтезу потрійних сплавів у системі 
Ti-Zr-Ni методом «гідридного циклу». Було визначено вплив на процес синтезу таких параметрів, як: 
 
ISSN 1562-6016. ВАНТ. 2022. №1(137) 
 
 
 
 
 
 
 
 
            121 
температура і час відпалу; швидкість нагрівання; умови охолодження; склад матеріалу; дисперсність; вміст 
водню в гідридах, що використовуються; наявність домішок; способи змішування і пресування, а також 
ступінь пресування вихідних компонентів. Синтезовано та досліджено сплави наступних складів: 
Ti40,5Zr31,9Ni27,6, Ti41,5Zr41,5Ni17, Ti40Zr40Ni20, Ti44Zr40Ni16. Визначено оптимальні технологічні параметри та 
умови синтезу потрійних сплавів. Встановлено, що ключовими факторами в процесі утворення сполук при 
дисоціації гідридів є дисперсність та однорідність вихідних спресованих компонентів. Встановлено, що 
синтез потрійних сплавів у системі Ti-Zr-Ni відбувається в ході короткочасної екзотермічної реакції в 
режимі «теплового вибуху», яка починається в області температур, що відповідає поліморфному 
перетворенню α↔β цирконію та титану.