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International Journal of Modern Applied Physics, 2013, 2(1): 1-14
International Journal of Modern Applied Physics
ISSN: 2168-1139
Florida, USA
Journal homepage: www.ModernScientificPress.com/Journals/ijmep.aspx
Article
Using Melt-spinning Technique with Calcium Addition on the
Ternary Pb-Sb-Sn Alloys for Storage Battery Grids
Mustafa Kamal, Abu-Bakr El-Bediwi and Mohammed .S. Jomaan*
Metal Physics Lab. Physics Department, Faculty of Science –Mansoura University, Egypt.
*on leave, M.sc student, Ministry of Higher Education, Yemen.
* Author to whom correspondence should be addressed; Emails (in the order of the name list):
[email protected] , [email protected] , [email protected]
Article history: Received 5 December 2012, Received in revised form 26 December 2012, Accepted
27 December 2012, Published 2 January 2013.
Abstract: The aim of this study was to evaluate the role of alloying and rapid solidification
processing in direct structural control in lead base batteries. A detailed investigation on
rapid solidification of liquid lead base alloys for high performance storage battery
applications was made in order to search for suitable lead grid alloys for lead acid batteries
as melt-spun ribbons. This paper provides a comprehensive review of the physical
metallurgy and mechanical properties of the melt-spun ordered alloy based on (Pb-12%Sb8%Sn, Pb-14%Sb-6%Sn) and (Pb-11.5%Sb-7.5%Sn-1%Ca, Pb-13.5%Sb-5.5%Sn-1%Ca)
for storage battery applications. The results indicate that the composition of alloys plays an
important role on grid batteries performance. It was found that Pb-11.5%Sb-7.5%Sn-1%Ca
is a good candidate for making the grids of ribbon grid lead-acid batteries.
Keywords: Rapid solidification, Lead battery grids, Resistivity, Elastic Moduli, Internal
Friction, Thermal Diffusivity, X-Ray diffraction, Pb-Sb-Sn alloys.
1. Introduction
Lead-antimony alloys have been widely used as the grid metal for lead acid batteries for many
years [1]. The alloys used in lead-acid battery systems have varied remarkably over the years with
wide-ranging experimentation with new composition [2]. In general, the rationale for the usage of
common alloying elements (Sb, Sn, Ca) was determined empirically. Antimony is alloyed with lead in
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Int. J. Modern App. Physics. 2013, 2(1): 1-14
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amounts typically ranging from 4 to 10 wt.% of Sn in battery alloys with the Pb-Sb eutectic point at
11.1 wt.% [2,3]. The primary purpose of Sb additions is to produce strength in terms of solid solution
strength in the Pb-rich phase, as well as to be used for final coating to the grids of lead acid batteries in
electrodeposition process because it promotes the initial corrosion process during plate formation and
gives rise to a highly adhesive oxide layer [4]. The high-antimony alloys offer excellent fluidity,
uniform grain structure, high initial and aged mechanical properties for ease in processing, and
uniform (although relatively high) corrosion rates [11]. The disadvantage of the binary lead antimony
alloys is when they are corrode; antimony is released during the corrosion process and, during
recharge, is transferred to the negative plate where it causes unacceptable loss of water, particularly in
high heat environments [5]. Pb-Sb binary alloys are used widely in the chemical industry. They are
commonly modified by adding small amount of other alloying elements, most often Sn. Tin is
generally considered to add a favorable solid solution strengthening effect, and perhaps to play some
favorable electrochemical role [6]. The grid can be encapsulated by a corrosion resistant pure Pb–Sn
outer layer, which prevents the grid from being dissolved in the battery electrolyte throughout the
battery life [4]. These alloys, however, have lower cast-ability and a reduced ability to age-hardening.
The addition of small amount of tin improves the fluidity and cast-ability. The limits of the solubility
of antimony and tin at 20 0C are not known very well. For tin , the following value have been reported:
1.9wt.% [7] ; 2-3 wt.% [8] : 1.3wt.% [9,10]. The purpose of this paper is to discuss the precipitated
phase in ternary Pb-Sb-Sn alloys. Lead–calcium alloys have replaced lead antimony alloys in a number
of applications, in particular, storage battery grids and casting applications. They represent a classical
precipitation – hardening binary system, with the maximum solubility of Ca in Pb being 0.10wt. % at
the peritectic temperature of 328 0C and diminishing to 0.01wt.% at room temperature [12]. Storage
battery alloys usually contain less than 0.08 wt.% of Ca, in order to minimize corrosion phenomena
due to the grain refining effect of Ca [13]. We added to the ternary alloy 1wt.% of Ca to reduce the
gassing batteries [11].
2. Scope of This Study
The present work is attended to explore the effect of rapid solidification from melt and addition
of 1 wt.%
of Ca on ternary Pb-Sb-Sn alloys for storage battery application through chemical
composition and structural control. Presently used alloys and several new systems are examined from
the standpoint of useful composition ranges, strengthening mechanisms, structure, electrical, and
mechanical behavior of two systems (Pb-12%Sb-8%Sn, Pb-14%Sb-6%Sn) and (Pb-11.5%Sb-7.5%Sn1%Ca, Pb-13.5%Sb-5.5%Sn-1%Ca) (numbers are in weight percent) melt-spun ribbons as grid of
lead/acid battery in the industry.
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3. Material and Methods
The materials used in the present work are Pb, Sb, and Sn fragments. The starting purity was
better than 99.99%. The two systems (Pb-12%Sb-8%Sn, Pb-14%Sb-6%Sn), (Pb-11.5%Sb-7.5%Sn1%Ca, Pb-13.5%Sb-5.5%Sn-1%Ca) and (Pb-11%Sb-7%Sn-1%Ca-1%Al, Pb-13%Sb-5%Sn-1%Ca1%Al) melt-spun alloys (composition are all in weight percent) were produce by single copper roller
(200mm in melt diameter) spinning technique[14]. The process parameters such as the ejection
temperature, and the linear speed of the wheel were fixed at (550-750k) and 30.4ms-1 respectively. The
resulting melt spun alloys had long ribbon forms of about 50µm thick and about 0.4cm in width.
Estimated cooling rates were 105 ks-1. The structure of these melt-spun alloys was examined by the xray diffraction (XRD) technique (DX-30), using cu kα radiation (λ=1.5406A0) with Ni-filter. Electrical
resistivity values and the temperature dependence of resistivity values were calculated using double –
bridge circuit with heating rate 5k min-1. The detail of the double bridge method was as described in
reference [15]. The values of dynamic young's modulus E, and the internal friction Q-1 were calculated
using the dynamic resonance from the following relationship [1, 2]:
E  38.32
 L4 f 2
t2
………………. (1)

f
Q 1  0.5773
f …………………. (2)
where ρ is the density of the sample test, L is the length of the vibrated of the melt-spun ribbon, f is the
resonance frequency of the sample and t is the sample's thickness. In particular, shear modulus, G and
bulk modulus, B may be estimated from the young's modulus, E and Poisson's ratio, σ:
B
E
3 (1  2 ) …………………………. (3)
G
E
2 (1   ) ………………………….(4)
For Pb-Sb-Sn alloys, Poisson's ratio was calculated from equation (5). The thermal diffusivity can be
measured from f, at which the peak damping occurs, the thermal diffusivity D, can be obtained directly
from the frequency relation:
Poisson's ratio  (E/2G)-1 .................... (5)
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Int. J. Modern App. Physics. 2013, 2(1): 1-14
D
4
2 t2 f

.......................................... (6)
Hardness measurements were carried out using the Vickers micro-hardness tester. Fifteen
measurements were taken for each melt-spun ribbon using a load of 10 grams of force for 5 seconds.
4. Results and Discussions
4.1 Structural Analysis
Figure 1 shows the X-ray diffraction patterns for (Pb-12%Sb-8%Sn, Pb-14%Sb-6%Sn) and
(Pb-11.5%Sb-7.5%Sn-1%Ca, Pb-13.5%Sb-5.5%Sn-1%Ca), melt-spun alloys. The patterns show the
existence of five types of phases: f.c.c., structure of α-Pb solid solution, γ-Sb phase, β-Sn phase, SbSn
phase, SnSb phase.
(a)
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Int. J. Modern App. Physics. 2013, 2(1): 1-14
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(b)
(c)
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Int. J. Modern App. Physics. 2013, 2(1): 1-14
6
(d)
Fig. 1. X-ray diffraction patterns of melt-spun alloys (a, b, c and d)
The lattice parameters were determined from each peak and an average value was calculated.
The value of lattice spacing for α-Pb phase in the two systems increases continuously with increasing
antimony content as show in table 1. The particle size of Pb was calculated using Debye-Scherrer
formula in reference [16]. Particle size was decreased due to increasing Sb content and decreasing Sn
content as show in table 1. The measured density for two systems rapidly solidified decreasing with
adding calcium and work melt-spinning for these alloys.
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Int. J. Modern App. Physics. 2013, 2(1): 1-14
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Table 1. Calculated particle sizes from d-spacing
(tables a, b, c and d corresponding to a, b, c, and d of X-ray patterns in Fig. 1)
d-spacing
(A0)
3.06558
2.92175
2.85745
2.79454
2.4758
2.17716
2.06617
2.01787
1.75193
1.6622
1.53694
1.4858
1.46006
1.44395
1.4286
1.37682
1.30474
1.29545
1.25138
1.20601
1.13589
1.10678
1.09783
1.04199
1.03362
1.02867
particle size
(A0)
320.8704613
321.9687207
419.2073488
299.9928901
424.7819196
269.7512011
155.3984118
272.9816301
321.1137129
253.1585282
194.4291482
295.1067832
264.0999458
341.0259799
0.039949079
152.2409455
277.6920782
358.8047439
160.1348387
437.3570233
457.9571368
351.6012158
472.4109346
374.9863462
378.7329637
104.0473922
(a) Pb80-Sb12-Sn8
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Int. J. Modern App. Physics. 2013, 2(1): 1-14
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d-spacing
(A0)
3.08638
2.85667
2.479
2.16775
1.75216
1.54326
1.49417
1.42973
1.29048
1.25555
1.2391
1.13699
1.10827
1.04707
1.04721
1.01124
1.00748
particle size
(A0)
347.3390047
220.6525365
353.8758385
359.85482
236.5980972
194.1623711
336.6195094
399.3610486
838.7882242
182.6654896
368.3217981
457.5801744
624.38619
444.2573127
816.7402625
392.997436
570.6215655
(b) Pb80-Sb14-Sn6
d-spacing
(A0)
3.07982
2.85737
2.47366
2.19067
2.16527
1.77206
1.75138
1.53988
1.49404
1.42966
1.37195
1.253
1.23817
1.13711
1.10693
particle size
(A0)
463.3152024
381.0641548
326.8367126
359.3137084
359.9144918
320.2461416
408.6535242
333.1033413
589.2087268
599.3073518
243.9978496
182.8911975
515.8586039
784.2600989
460.9105289
(c) Pb80-Sb11.5-Sn7.5-Ca 1
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Int. J. Modern App. Physics. 2013, 2(1): 1-14
d-spacing
(A0)
3.08955
2.85827
2.47459
2.20096
2.17009
1.75156
1.54743
1.49375
1.42974
1.37331
1.3079
1.29705
1.25876
1.23913
1.21079
1.13638
1.10667
9
particle size
(A0)
260.5140097
279.4659635
223.5930936
215.4826862
392.5377549
264.409237
193.9888401
294.5312485
281.9154858
271.0152061
312.29337
418.2225512
159.5649632
468.6896919
163.5813018
392.4856862
288.133899
(d) Pb80-Sb13.5-Sn5.5-Ca 1
Using the following equation [12],
n
 V
1.6602 A
, where n is the number of atoms per unit cell, A is the atomic weight,  is the
0
measured density in g/cm3 and V is the volume of the unit cell in A 3. The number of the atoms per
unit cell was calculated to be 3.88 which must be 4 for Pb–I. Therefore, some of the atoms may be
missing from a certain fraction of those lattice sites, which they would be expected to occupy as table
2.
From the above results it can be seen that the solid solubility of Sb in Pb has been increased
from maximum of 9 wt.% Sb to 14 wt.%. The solubility increase indicates that about 14 wt.% of Sb
can be retained in the Pb rich fcc phase by melt-spinning. Increasing Sb content causes the formation
of intermetallic compound phase (SbSn). The calculate lattice parameters of SnSb phase the c/a equals
0.95. This value is very close to 1; it means this phase tend to be f.c.c phase. So spinning technique
decreases the density of the metal.
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Int. J. Modern App. Physics. 2013, 2(1): 1-14
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Table 2. Lattice parameters
System
a (Å)
Pb-12%Sb-8%Sn
Pb-14%Sb-6%Sn
Pb-11.5%Sb-7.5%Sn-1%Ca
Pb-13.5%Sb-5.5%Sn-1%Ca
4.949
4.956
4.950
4.953
Cell
Volume (Å3)
121.213
121.728
121.346
121.545
n
3.88
3.67
3
2.9
4.2. Electrical Properties
Electrical properties of rapidly solidified alloys depend sensitively on the structure state of
material as well as on composition of the alloys. So, the temperature dependence of electrical
resistivity might be a useful tool for studying the process of any phase transformation of the material.
It is found in this study that the electrical resistivity of the studied melt-spun alloys increase with the
rise of temperature as indicated in figure 2 for (Pb-12%Sb-8%Sn, Pb-14%Sb-6%Sn) and (Pb11.5%Sb-7.5%Sn-1%Ca, Pb-13.5%Sb-5.5%Sn-1%Ca) systems alloys.
400
Pb-12b-8n
Pb-14b-6n
Pb-11.5b-7.5n-1a
Pb-13.5b-5.5n-1a
350
Resistivity(..cm)
300
250
200
150
100
50
280
300
320
340
360
380
400
420
440
460
Temperature(K)
Fig. 2. The resistivity of two systems alloys
In the ternary system we noted that the resistivity of Pb-14%Sb-6%Sn alloy is lower than that
of Pb-12%Sb-8%Sn alloy. This may be resulting from increase number of atoms in the first alloy
which increases the charge carriers in this alloy. Quaternary system resistivity is lower than ternary
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system because of the disruption of the orderly atomic arrangement is removed during the
solidification of these alloys. So a net increase in the conductivity occurs, and the resistivity decreases
with the increasing of antimony content in all these alloys may be resulting from high bonding among
antimony and tin atoms which create appropriate channels for moving of charge carriers.
4.3. Thermal Diffusivity
Thermal diffusivity, Dth is transport coefficient which is related to microscopic transport of
heat. This value is directly associated with the change of temperature of material. It is noted from table
3 that the thermal diffusivity of the melt-spun ribbons used in this work is a non-linear increase or
decrease of thermal diffusivities with or without calcium contend observed in all cases. The thermal
diffusivity of first system is higher than that of other systems. So the thermal diffusivity in this case
is a function of Ca addition or the composition.
Table 3. Thermal diffusivity
Dth x 10-8
Alloy
m2/sec
Pb-12%Sb-8%Sn
37.121
Pb-14%Sb-6%Sn
7.0602
Pb-11.5%Sb-7.5%Sn-1%Ca
8.4972
Pb-13.5%Sb-5.5%Sn-1%Ca
1.6785
4.4. Elastic Constants
Young’s modulus is one of the important characteristics that reﬂect strongly the interaction and
the bonding nature among constituent atoms [17]. The elastic constants of the metallic alloys which
were fundamental physical properties especially for the mechanical properties such as strength, plastic
deformation and fracture were reported previously using single crystals [18]. Poisson’s ratio, deﬁned
as the lateral contraction per unit breadth divided by the longitudinal extension per unit length in
simple tension, is reported to provide more information about the character of the bonding forces than
any other elastic coefficients [19, 20]. Poisson’s ratio (ν) is related to Young’s modulus (E), shear
modulus (G) and bulk modulus by equations (3) and (4). The dynamic Young’s modulus (E) was
calculated according to equation (1). Fig. 3 shows the resonance curves for two systems of melt spun
alloys. Table 4 shows Young’s modulus, shear modulus, bulk modulus and Poisson’s ratio for two
systems of melt-spun alloys. Addition of 1 wt% of Ca on the ternary alloy shows great increase in the
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Int. J. Modern App. Physics. 2013, 2(1): 1-14
12
internal friction while a slightly decrease in the thermal diffusivity has been measured as shown in
tables 3 and 4. The unit-cell volume of phase (Pb-phase) is indicated in table 2.
Table 4. Elastic properties of alloys
System
Pb-12%Sb-8%Sn
Pb-14%Sb-6%Sn
Pb-11.5%Sb-7.5%Sn-1%Ca
Pb-13.5%Sb-5.5%Sn-1%Ca
Young's
modulus
E G Pa
5.91
9.22
8.49
5.90
Shear modulus
G G Pa
Bulk modulus
B G Pa
Poisson's ratio
2.20
3.44
3.16
2.20
6.20
9.66
8.90
6.18
0.340
0.340
0.343
0.340
12
Pb80-sb12-sn8
Pb80-sb14-sn6
10
Pb80-sb11.5-sn7.5-ca1
Pb80-sb13.5-sn5.5-ca1
Amplitude(cm)
8
6
4
2
0
8
10
12
14
16
18
20
22
24
Frequency(HZ)
Fig. 3. The resonance carve of alloys
It can be seen that the unit-cell volume of phase (Pb-phase) in these Pb-12%Sb-8%Sn and Pb11.5%Sb-7.5%Sn-1%Ca alloys is expanded with the addition of Ca content. This means that the
increased unit-cell volume with Ca content normally leads to decrease elastic modulus of the studied
alloy in this study. But, it was found that Ca atoms may serve as filled among atoms in the lattice.
Therefore a small amount of calcium is added to melt in this study to improve the resistivity. Hence, it
is reported to increase the elastic modulus of the Pb-Sb-Sn melt-spun alloys with the addition of 1 wt%
of Ca.
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4.5. Hardness Measurement
The average hardness values indicated table 5, Hv increases slightly with the addition of
the calcium, indicating that the bonding of the calcium atoms as filled among atoms is much
stronger than bonding force between antimony and tin which work together to withstand any
deformation.
Table 5. The hardness of used alloys
System in Wt. %
pb80-sb12-sn8
pb80-sb14-sn6
Pb-11.5%Sb-7.5%Sn-1%Ca
Pb-13.5%Sb-5.5%Sn-1%Ca
Hardness Hv Mpa
141.691787
145.123768
191.700653
185.817257
5. Conclusion
Based on observations described in the present paper, the following conclusions may be
formulated.
(a) The patterns shows the existence of five types of phases: f.c.c., structure of α-Pb solid solution,
γ-Sb phase, β-Sn phase, SbSn phase, SnSb phase. The calculated lattice parameters of SnSb
phase the c/a equals 0.95 (very close to 1), which means this phase tend to be f.c.c phase. Meltspinning technique decreases the density of the metal.
(b) In terms of the electrical properties, the ternary alloy is better than quaternary because the
increasing impurities work as scattering centers resist motion of the charge carriers.
(c) In terms of mechanical properties, the addition of calcium to the Pb-Sb-Sn ternary alloy causes
the increase of the hardness.
(d) Intermetallic compound which gives good mechanical properties was present because the meltspinning technique is capable to stop the alloy in the same state of its solid solution.
Therefore, it is concluded that the melt-spinning technique is successfully used in fabrication
grids of lead acid battery.
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