MIG and CMT brazing of aluminum alloys and steel: A review

Abstract

In automobile industries production of lightweight vehicles to increase the performance of a vehicle, reduction in fuel consumption, and the low emission of toxic gases have generated the need for the fabrication of multi-material design. In recent years an effort was made to fabricate the automobile bodies with dissimilar metals like aluminium and stainless steel but welding or joining of these two different metals is very difficult due to non-identical thermo-physical properties, melting point, zero solubility, and the emergence of hard and brittle intermetallic compound (IMC) and phases at the interface of joint. Different welding and joining processes were attempted to join steel and aluminium to restrict the emergence and growth of hard and brittle IMC phases and their layer thickness at the interface through effective heat control input. Though MIG, CMT-MIG brazing is more effective than any other welding and joining processes due to their control on heat supply and synchronized transfer of molten metal. This study aims to examine the several welding factors in the joining of steel and aluminium by MIG, CMT, and other arc-based welding methods. Various factors such as the impact of heat input, process parameters, and different filler wires on the formation of IMC thickness and firmness of joint are analyzed and discussed.

Full text

MIG and CMT brazing of aluminum alloys and steel: A review
Gaurav Nandan
a,
⇑
, Girendra Kumar
a
, K.S. Arora
b
, Ashok Kumar
a
a
National Institiute of Technology Jamshedpur, Jamshedpur 831014, India
b
Research and Development, Tata Steel Limited, Jamshedpur 831001, India
article info
Article history:
Available online 21 February 2022
Keywords:
MIG
CMT
IMC layer
Joint strength
abstract
In automobile industries production of lightweight vehicles to increase the performance of a vehicle,
reduction in fuel consumption, and the low emission of toxic gases have generated the need for the fab-
rication of multi-material design. In recent years an effort was made to fabricate the automobile bodies
with dissimilar metals like aluminium and stainless steel but welding or joining of these two different
metals is very difficult due to non-identical thermo-physical properties, melting point, zero solubility,
and the emergence of hard and brittle intermetallic compound (IMC) and phases at the interface of joint.
Different welding and joining processes were attempted to join steel and aluminium to restrict the emer-
gence and growth of hard and brittle IMC phases and their layer thickness at the interface through effec-
tive heat control input. Though MIG, CMT-MIG brazing is more effective than any other welding and
joining processes due to their control on heat supply and synchronized transfer of molten metal. This
study aims to examine the several welding factors in the joining of steel and aluminium by MIG, CMT,
and other arc-based welding methods. Various factors such as the impact of heat input, process param-
eters, and different filler wires on the formation of IMC thickness and firmness of joint are analyzed and
discussed.
Copyright Ó2022 Elsevier Ltd. All rights reserved.
Selection and peer-review under responsibility of the scientific committee of the International Confer-
ence on Materials, Machines and Information Technology-2022.
1. Introduction
Material joining in the automobile industry requires rigorous
criteria. The increasing demand for fabricating lightweight struc-
tures has generated a substantial necessity to integrate different
materials such as aluminum and stainless steel. Currently, automo-
bile industries were interested to reduce the vehicle’s weight to
strengthen the overall working and performance of vehicles,
reduce fuel consumption, and control air pollution. Integrated
structures of aluminum alloy and stainless steel have also been
applied in the area of spacecraft and steamships to improve fly
range and fuel efficiency by reducing the weight [1,2,3]. In recent
years steel is being replaced with aluminum alloy in the fabrication
of vehicle bodies and it is the prime area of interest for research
development and industries. Since steel remains the dominant
material in the manufacturing of vehicle bodies some of the parts
of the structure can be replaced by aluminum alloys, the low den-
sity of the aluminum may be the effective solution for the light-
weight structure [4]. In recent times resistance spot welding
(RSW) is the most recommended welding technology in the assem-
bly line of the automobile sector for the joining of car bodies. But in
the previously available literature in RSW, high heat input during
the process was reported which causes the evaporation of the pro-
tective layer if the coated steel was used as the base material. Some
researchers have also used RSW for the joining of iron alloys and
aluminum alloys [5,6]. Several authors have reported the influence
of vibration in the weld pool during the welding process [7–10].
The vibration-induced during the SMAW welding process results
in the enhancement of mechanical properties such as yield
strength and tensile strength of the material [11,12]. This may be
attributed due to the refinement in the grain structures. Other con-
ventional welding method like arc welding also produces high heat
input during the process. So, to retain the strength, corrosion resis-
tance and the desired properties of the base material and joint,
welding process with low heat input and synchronized heat trans-
fer is required.
Joining different metals Al alloy and steel is very difficult due to
non-identical thermal-physical properties and the melting temper-
ature of both metals. In the welding or joining process of the Al
https://doi.org/10.1016/j.matpr.2022.02.166
2214-7853/Copyright Ó2022 Elsevier Ltd. All rights reserved.
Selection and peer-review under responsibility of the scientific committee of the International Conference on Materials, Machines and Information Technology-2022.
⇑
Corresponding author.
E-mail address: 2017rsmm002@nitjsr.ac.in (G. Nandan).
Materials Today: Proceedings 56 (2022) 481–488
Contents lists available at ScienceDirect
Materials Today: Proceedings
journal homepage: www.elsevier.com/locate/matpr

alloy and iron alloys, the prime issue is with the emergence and
growth of hard and brittle IMC layer and phases at the interface
of the joint which may reduce mechanical characteristics of the
obtained dissimilar joint. When the fusion process takes place
the noted weak miscibility between the aluminum alloy and iron
alloy produces imperfect weld metallurgical compatibility which
is further worsened by non-identical thermal and physical proper-
ties. The formation of intermetallic compound phases is distinctly
dependent on the temperature and the cooling period of the weld-
ing and joining process [13–15]. The growth of the intermetallic
compound layer thickness and phases can be restricted by the
low and controlled heat input during the process. Both Murakami
et al. [15] and Mathieu et al. [16] depicted that temperature during
the welding process governs the IMC thickness at the interface of
joint and suggested the application of low heat supply to get the
intact joint. It was noticed that if the IMC and phase thickness is
below 10 mm the mechanical properties of the joint will be more
enhanced as compared to the thicker IMC layer and it can be
achieved by the low and controlled heat input and synchronized
transfer of molten metal [17–19].
In recent years many joining processes were attempted to join
steel and aluminum alloys, but the abundant generation of hard
and brittle IMC was the main issue during the joining which arose
due to the uncontrolled heat input and molten metal transfer. In
the last decade, industries have started replacing the conventional
welding method with the MIG-brazing and Cold metal transfer
(CMT) process which provides less heat input and is very much
reliable than any other conventional joining process and became
an exemplary process for the industrial application [20–25]. MIG-
brazing is the exemplary welding process for different metals join-
ing because of low and controlled heat input and very little spatter
formation during the process. MIG-brazing technique has the ben-
efit of both welding and brazing, it provides high welding speed
and high deposition rate while brazing will provide welded parts
without any severe fusion and any significant variation of mechan-
ical properties of the base material. In the MIG-brazing process,
many researchers have investigated to further decrease the effect
of heat and to restrict the growth of the IMC layer and phases to
achieve a quality and sound joint. The different types of dissimilar
welding processes are represented in Fig. 1.
The cold metal transfer (CMT) joining method is an upgraded
version of the MIG technique developed by Fronius in 2005 which
provides less heat supply and is very much reliable than any other
conventional joining process. The schematic sketch of the CMT
setup is shown in Fig. 2. CMT process is the exemplary joining tech-
nology for the welding of coated thin steel sheets and dissimilar
metals which provides negligible spatter formation, porosity, and
better stability of arc and controlled transfer of the molten metal
[20,26–29]. The problem of the emergence and growth of hard
and brittle IMC at the interface of a joint can be minimized by
using the CMT technique. Due to the decreased heat energy, the
emergence of these intermetallic phases is restricted which
enhances the joint quality [15,16]. The basic theory of this
approach is that the filler wire movements have been incorporated
into the welding cycle and digitally control the overall process.
When a short circuit happens, the digitally controlled process
holds up the power source and governs the mechanically backward
movement of the welding wire. A schematic diagram as shown in
Fig. 3 portrays the short-circuiting, current waveform, and droplet
detachment. Throughout the short-circuiting phase, the mechani-
cal retraction of wire supports the separation of the metal droplet,
thereby significantly reducing the heat input throughout the pro-
cess [20,23,24,30,31]. The main objective of this review focuses
on the effect of various factors in MIG brazing and CMT process
viz. effect of process parameters, heat supply, and influence of filler
wire which affect the joint properties of steel and aluminum alloys.
1.1. Problems in joining dissimilar metal aluminum and steel
The most explored dissimilar metal for welding and joining is
aluminium alloy and steel due to the novel incorporation of the
toughness and high strength of the steel and formability and light-
weight of the aluminium alloys, which has remarkable develop-
ment in automobile and marine industries [32–35].
The joining of these two different metals is complex. Several
non-identical aspects of thermo-physical properties and mechani-
cal characteristics were presented by Mathers [36,37], which
includes melting, and boiling point, their oxides, coefficient of ther-
mal expansion, coefficient of thermal conductivity, and specific
heat. These discrepancies are expected to cause deformation, met-
allurgical precipitation, and defects, especially in the weld area.
[38,39]. The predominant reason for the inadequate workaround
steel-aluminium joining is primarily due to the near-zero solubility
of both metals [40–42]. The circumstances arise due to the zero
solubility resulting in the emergence of hard and brittle inter-
metallic compounds between the two non-identical metals. The
IMC layer has been intensively investigated, with many research-
ers claiming that it is the weakest zone, a crack propagation point,
and the cause of degradation of the joint’s mechanical properties
[43–48]. However, during their investigation, Borrisutthekul et al.
[49] and Zhang et al. [50,51] observed that the weakest zone and
crack propagation point is the heat-affected zone (HAZ) in the alu-
minium region, which is corroborated by the tensile test that indi-
cated fracture occurred in this location.
Joining of steel-aluminium incorporates welding-brazing inter-
activity because the meltdown temperature of the aluminium
(welding joint) is lower than welding temperature whereas the
meltdown temperature of steel (brazing joint) is higher than the
welding temperature. As previously stated, an IMC layer will form
at the joint interface due to the near-zero solubility of the metals.
Fe
x
Al
y
brittle phases such as Fe
4
Al
13
,Fe
2
Al
5
, FeAl
3
, and FeAl may be
found in the IMC layer [19,52,53]. It is very well may be noted from
the Gibbs free energy and Al-Fe phase diagram (Fig. 4) that ther-
modynamically intermetallic compound FeAl
3
is more coherent
than the Fe
2
Al
5
,Fe
3
Al. Hence, there is a possibility of an abundant
amount of FeAl
3
throughout the joint interface. The emergence of
these IMC layers was due to the diffusion-controlled growth of
Fe atoms as reported by S Kobayashi and Yakou [54,55]. Therefore,
the growth of a stable monoclinic FeAl
3
is propagated due to the
dispersed iron in aluminium and vice-a-versa. Also, it is expected
that FeAl
3
and Fe will react with each other to form Fe
3
Al due to
the prevailing cooling rate. The IMC layer, which is a result of the
diffusion control process, its thickness can be calculated by the fol-
lowing equations:
X¼Kptð1Þ
K¼KoexpðQ=RTÞð2Þ
In the above-stated equation, Xis the IMC layer thickness in
mm, tis the diffusion time in seconds, K
o
is constant, Q(J) is the
minimum energy required for the formation of the IMC layer, R
is gas constant whereas Tis the absolute temperature in kelvin
[56–58].
The growth of these IMC at the interface of joint by diffusion
control process affects as well as degrades strength and quality
of joint. Previously, several authors have pointed out the conse-
quences of brittle IMC on joint strength. Kreimeyer and Sepold
[19] observed that if the IMC thickness is below 10
l
m, the quality
of the joint would be mechanically robust. Hence, for a sound and
enhanced dissimilar metal weld joint strength thinner IMC layer is
considered [39,56,59–62].
G. Nandan, G. Kumar, K.S. Arora et al. Materials Today: Proceedings 56 (2022) 481–488
482

2. Effect of heat generated on the growth of intermetallic
compounds and weld joint strength
The joining of dissimilar metals is extremely challenging due to
the growth and formation of brittle IMC at the interface of the
joint. These brittle IMC phases were the main cause of the low joint
strength. One of the most important factors determining joint
characteristics, particularly the formation of the IMCs layer, is
the brazed joint interface. In most cases, the phase composition
of IMCs produced at the brazed interface, or the formation of IMCs
was studied under various conditions. The formation of IMC is
mainly affected by the welding current and the heat input through-
out the process. As we already discussed in section 1.1 the forma-
tion of intermetallic phases mainly occurs due to the diffusion
Fig. 1. Various process for dissimilar welding.
Fig. 2. Schematic sketch of cold metal transfer (CMT) setup.
G. Nandan, G. Kumar, K.S. Arora et al. Materials Today: Proceedings 56 (2022) 481–488
483

between the metals at the joint interface and it is largely depen-
dent on the cooling rate and the temperature provided during
the joining. Therefore, heat supplied during the process plays a
critical role in the emergence and expansion of the IMC layer and
its adverse effect on the joint quality. It was reported that with
high heat input or at high welding current the thickness of the
IMC layer becomes thicker and brittle due to which the strength
of the joint decreased. M Roulin et al. [63] and M. Mohammadpour
et al. [64] in their study noted that the critical thickness value of
the IMC layer is 10 mm and for sound joint strength layer thickness
should not exceed 10 mm. If the thickness of the layer exceeds the
critical value, it will become brittle, and the joint strength will
Fig. 3. Schematic diagram of the current waveform of CMT welding.
Fig. 4. Phase diagram of Al-Fe.
G. Nandan, G. Kumar, K.S. Arora et al. Materials Today: Proceedings 56 (2022) 481–488
484

decrease desperately. Cao et al. [65] concluded that infusion braz-
ing of steel and Al alloy, the joint attained the highest tensile
strength when the IMC layer thickness was around 5
l
m, while
the joint strength starts decreasing and failed at the braze interface
when IMC thickness exceeds 5 mm. Murakami et al. [66] in their
research paper found that when the thickness of the IMC was
around 2.5 mm the tensile strength of the joint was highest and
approximately 70% of that of Al base metal. The HAZ in the Al side
of the joint was shattered in this instance. But the joint strength
starts decreasing as IMC layer thickness exceeds 2.5 mm. Su et al.
[67] reported that fracture may develop at the steel-Fe
2
Al
5
sub-
layer interface. Because the IMC layer is thick, it becomes hard
and brittle, increasing the chances of fracture at the aluminum-
steel interface. Table 1 shows the heat generated and correspond-
ing strength and IMC thickness.
3. Effect of process parameters
In the joining of materials, process parameters are extremely
important. Process parameters like welding speed, wire feed rate,
energy input are some of the important parameters which can
affect the desired properties of the joint. Filler wire tip diameter
and composition, as well as the type of shielding gas used, are
defined parameters that cannot be altered once the joining process
has begun, whereas welding current, arc voltage, and welding
speed, as well as gas flow rate, are adjustable parameters that
can be adjusted during the process. The quality of the weld joints
was decided by the good penetration, better bead profile (shown
in Fig. 5), and heating rate, and these features were influenced by
the arc voltage, welding current, welding speed, and protective
gas parameters. Choosing the optimal combination of process
parameters will enhance the quality of weld bead and sound weld
can be obtained. Different heat inputs during the brazing process
have a significant effect on the bead geometry like height, width,
wetting length, and wetting angle. S. Basak et al. [68] in their study
employed three sets of welding current 70 A, 80 A, 100 A at a con-
stant welding speed of 350 mm/min which corresponds to heat
energy of 155235 J/mm. They observed that when the current
value is increased, the bead height decreases from 3.45 m to
2.9 mm, and the wetting angle decreases from 61°to 37°, but the
wetting length increases from 9.4 mm to 12.58 mm, showing bet-
ter wettability of molten metal. The increase in heat input also
affected the hardness value which increases from 771 HV to 985
HV when heat energy was increased from 155 J/mm to 235 J/
mm. The reason for the rise in the hardness is due to the formation
of an abundant amount of Fe
2
Al
5
IMC at the interface which
results from the high heat input value during the brazing. The
higher hardness value of Fe
2
Al
5
was also reported by Kobayashi
et al. [55]. Murakami et al. [15] has reported that with an increase
in welding speed IMC layer thickness decreased. It was observed
that at a welding speed of 0.2, 0.4, 0.6 m/min the IMC thickness
was obtained 11.1, 2.5, and 0.9 mm respectively. They also reported
that the average microhardness of the IMC region and without the
IMC region was higher than the hardness of the filler wire which
shows that dynamic load capacity was low and weld joints were
brittle.
Process parameters also have a significant effect on heat inputs
during the brazing process which may affect the bead geometry
like height, width, wetting length, cross-sectional area, and contact
angle. Therefore, the selection of the best combination of process
parameters is very important for enhancing the quality of weld
bead and sound weld can be obtained.
Table 1
The heat generated during the joining of Al alloys-steel and corresponding IMC layer thickness and strength.
Process Heat
Input (J/
mm)
Filler Wire Materials Used Strength IMC layer thickness (
l
m) Reference
CMT – AA1080 AA6016 and GI – 2.3 Agudo et al
200 AA4043 AA6061 and GI 200 MPa 3–5 Cao et al
– AA4043 AA1060 and GI 83 N mm
1
4 Zhang et al.
55–91 AA4043 Al alloy and GI steel 96 MPa 7–40 Zhang et al.
111 AA4043, AA4047,
AA5183, AA5356
AA5052 and Al-
coated and GI
75–188 MPa 5 (Filler-Al-Si), 12–13
(Filler-Al-Mg)
Kang and Kim
– AA4043 AA4047,
Al-Si3-Mn
AA5754 and GI 188 N mm
1
– Milani et al.
110–140 AA4043 AA6061 and Dual
Phase steel
440 N mm
1
1.23–3.02 Madhavan
et al.
Pulsed GMA 170–255 AA4047 Al alloy and
Uncoated steel
80 MPa 0.9–2.5 Murakami
et al.
63–120 AA4043 Al alloy and GI 168–194 N mm
1
5–15 Zhang and Liu
– AA4043, AA5356 AA5052 and GI steel 199 N mm
1
(AA4043), 188 N mm
1
(AA5356)
– Shi
et al.37,38),
Shao et al)
62.75 AA4043 Al 6061 and GI, GA
and uncoated steel
110–180 MPa – Yagati et al.
– AA2319, AA5087 AA6061 and UHSS 128 MPa (AA2319), 65 MPa (AA5087) 2–4 (AA2319), 6–18
(AA5087)
Chang et al
54.6–
110.5
AA4043 AA6061 and GI 162 MPa 1–10 Ma et al.
GMA (AC
Pulsed)
– AA4043 Al 6021 and
Uncoated steel
173 MPa 1.14–3.2 Park et al.
Cold Arc 36–126 AA4043 AA5754 and AA5052
and GI and GA
210 N mm
1
(GA),73 N mm
1
(GA) 0.8–4.5 Das et al.
AC Double-
pulsed
GMA
111 Pure Al, AA4043,
AA4047, AA5356
AA5052 and GI 112 N mm
1
(AA5356), 165 N mm
1
(Pure
Al), 201 N mm
1
(AA4043, AA4047)
1–7 (AA4047, AA4043),
30 (AA5356, pure Al,)
Su et al.
Double-sided
arc joining
85.8 AA4043 Al 5052 and Low
carbon steel
148.1 N mm
1
2.03 Ye et al.
G. Nandan, G. Kumar, K.S. Arora et al. Materials Today: Proceedings 56 (2022) 481–488
485

4. Effect of filer wire on weld joint and IMC formation
The most used filler wire for joining of steel and Al alloys are Al-
based filler wire such as pure aluminum, Al-Si, Zn-Al, and Al-Mg. In
previous literature when AA4043 filler wire was employed the
reported IMC layer thickness was found to be in the band of 1–
20
l
m and the strength of the joint was in the range of 83–200
MPa. Usually, in pure Al-based filler wire, growth of the IMC layer
was reported between 2.3 and 7
l
m and strength of the welded
joint was reported approximately 165 MPa. The IMC thickness
and welded joint’s strength in the range of 0.9–12
l
m and 80–
200 MPa respectively were reported in the case of AA4047 filler
wire. In the case of filler wire AA5183 and AA5356, the reported
thickness of the IMC layer was around 7–3
l
m and the strength
of the joint was around 112–188 MPa. Table 2 shows the effect
of different filler wires on the joint’s strength and growth of the
IMC layer.
5. Use of laser power in MIG and CMT brazing in dissimilar
metals
To overcome the problems of MIG brazing of dissimilar metals,
laser-MIG hybrid fusion welding was introduced to supply ade-
quate heat energy for diffusion and good wettability and spread-
Fig. 5. Schematic representation and cross-section of the CMT brazed joint.
Table 2
Influence of filler wire on the formation of IMC layer thickness and joint strength.
Filler Wire Process Strength IMC layer thickness (
l
m) Reference
AA4043 CMT 200 MPa 3–5 Cao et al.
Cold Arc 210 MPa 0.8–4.5 Das et al.
AC double pulsed GMA 188 MPa 4–7 Su et al.
Pulsed GMA 194 MPa 5–15 Zhang and Liu
Pulsed GMA 173 MPa 1.14–3.2 Park et al.
Pulsed GMA 199 MPa – Shi et al.37,38), Shao et al.
CMT 83 MPa 4 Zhang et al.
CMT 96 MPa 7–20 Zhang et al.
CMT 162 MPa 1–10 Ma et al.
Double side arc joining 148 MPa 2.03 Ye et al
Laser 162 MPa 1.5–13 Zhang et al.
Laser 174.6 4 MPa 1.8–6.2 Sun et al.
AA4047 Pulsed GMA 80 MPa 0.9–2.5 Murakami et al.
GMA (AC double pulsed) 201 MPa 1–4 Su et al.
CMT 175 MPa 5 Kang and Kim
Laser 190 MPa 2 Sierra et al.
Laser 180 MPa 2–3 Saida et al.
Laser - GMA hybrid 180 MPa 4–12 Thomy et al.
Laser - GMA hybrid 130 MPa 3–6.5 Gao et al.
Zn-30 %Al and Zn-15 %Al Laser 193–230 N mm
1
5 Mathieu et al.
Laser 200 MPa 8–12 Dharmendra et al.
Laser 190 MPa 10 Shabadi et al.
AA5183 and AA5356 GMA (AC double pulsed) 112 MPa 30 Su et al.13,
CMT 188 MPa 12–13 Kang and Kim
Pure Al CMT – 2.3 Agudo et al.
AC double pulsed GMA 165 MPa 2–7 Su et al.
G. Nandan, G. Kumar, K.S. Arora et al. Materials Today: Proceedings 56 (2022) 481–488
486

ability. Recent investigation about the use of laser power in the
MIG brazing process reveals that the introduction of laser power
enhances the mechanical characteristics and features of joints.
Mei et al. [69] reported the use of IPG YLR-6000 laser source for
joining of Al and stainless steel by laser-CMT hybrid welding pro-
cess. In the tensile test of the specimen, the strength of the joint
was 165 ± 18 MPa which was much higher when compared to
the TIG weld joints (120 MPa) in previous studies. The enhance-
ment of the mechanical properties was due to the controlled and
uniform growth and serrated shape of the IMC. The IMC layer’s
average thickness was confined to 3 mm which is below the critical
thickness of 10 mm and has a significant impact on the joint’s
mechanical properties. The restricted growth of the IMC layer
was due to the improved convection in the molten pool caused
by laser–arc interaction.
Xue et al. [70,71] discuss the effect of laser power on the dissim-
ilar laser-MIG hybrid welding-brazing of 6061-T6 Al alloy and 304
SS. During the experiment, it was discovered that as the laser
power was increased from 800 W to 1200 W, the tensile strength
increased. When the laser power was 1200 w and the IMC layer
thickness ranged from 3 to 5.5 m, which was less than the critical
thickness, the highest tensile strength of 150 MPa was achieved. As
laser power was further raised to 1400 W tensile strength of the
welded joint rapidly declined due to the thick (10 mm), hard and
brittle layer of IMC. The immense energy input to the welding pro-
cess resulted in the high thickness of the IMC layer. So, it can be
observed that the thickness of the IMC layer has a significant
impact on the joint’s mechanical properties.
6. Conclusion
With the advent of dissimilar welding and non-conventional
welding process, the welding industry was uplifted. Recent pro-
gress in dissimilar welding has indicated notable ability to bring
down the production cost and time, especially in shipbuilding
and automobile industries. The design of welding parameters, fil-
ler, base metals, and other primary variables of dissimilar welding
remains a major area for research.
A brief review has been discussed on the joining of dissimilar
metal aluminum and steel using MIG and CMT brazing-based pro-
cesses. Based on the previous literature on dissimilar welding, the
influence of welding parameters, shielding gases, filler wire, and
heat generated on the growth of hard and brittle IMC layer at the
interface of the joint and strength of the welded joint is discussed
in detail. The investigations in the previous literature showed that
the heat generated during the joining process mainly influences
the growth of the IMC layer at the interface of the joint which
affects the strength of the obtained jointly. Though, in the litera-
ture, it remains indecisive about the critical value of the heat sup-
plied to restrict the growth of the IMC layer thickness. Recently
laser and hybrid joining processes with controlled metal transfer
and very low heat input have provided an option to employ this
joining process to obtain a sound weld between steel and
aluminum.
CRediT authorship contribution statement
Gaurav Nandan: Conceptualization, Visualization, Writing –
original draft. Girendra Kumar: .K.S. Arora: Supervision. Ashok
Kumar: Supervision.
Declaration of Competing Interest
The authors declare that they have no known competing finan-
cial interests or personal relationships that could have appeared
to influence the work reported in this paper.
References
[1] W.S. Miller, L. Zhuang, J. Bottema, A.J. Wittebrood, P. De Smet, A. Haszler, A.
Vieregge, Recent development in aluminium alloys for the automotive
industry, Mater. Sci. Eng. A 280 (1) (2000) 37–49.
[2] S. Basak, T.K. Pal, M. Shome, High-cycle fatigue behavior of MIG brazed
galvanized DP600 steel sheet joint-effect of process parameters, Int. J. Adv.
Manuf. Technol. 82 (2016) 1197–1211.
[3] M. Ró_
zan
´ski, Joining elements of zinc-coated steel with aluminium elements
using binders with high-zinc content and modern low energy power sources,
Weld. Int. 27 (11) (2013) 848–852.
[4] A. Kouadri-David, Study of metallurgic and mechanical properties of laser
welded heterogeneous joints between DP600 galvanised steel and aluminium
6082, Mater. Des. 54 (2014) 184–195.
[5] R. Qiu, H. Shi, K. Zhang, Y. Tu, C. Iwamoto, S. Satonaka, Interfacial
characterization of joint between mild steel and aluminium alloy welded by
resistance spot welding, Mater. Char. 61 (7) (2010) 684–688.
[6] Z. Wan, H. Wang, N. Chen, M. Wang, B.E. Carlson, Characterization of inter-
metallic compound at the interfaces of Al-steel resistance spot welds, J. Mater.
Process. Technol. 242 (2017) 12–23.
[7] A.S.M.Y. Munsi, A.J. Waddell, C.A. Walker, The effect of vibratory stress on the
welding microstructure and residual stress distribution, Proc. Inst. Mech. Eng.,
Part L: J. Mater.: Des. Appl. 215 (2) (2001) 99–111.
[8] A. Mostafapour, V. Gholizadeh, Experimental investigation of the effect of
vibration on mechanical properties of 304 stainless steel welded parts, Int. J.
Adv. Manuf. Technol. 70 (5–8) (2014) 1113–1124.
[9] K. Balasubramanian, D. Kesavan, V. Balusamy, Studies on the effect of vibration
on hot cracking and grain size in AA 7075 aluminum alloy welding, Int. J. Eng.
Sci. Technol. 3 (1) (2011).
[10] A. Krajewski, W. Włosin
´ski, T. Chmielewski, P. Kołodziejczak, Ultrasonic-
vibration assisted arc-welding of aluminum alloys, Bull. Polish Acad. Sci.
Techn. Sci. 60 (4) (2012) 841–852.
[11] P.K. Singh, D. Patel, S.B. Prasad, Development of vibratory welding technique
and tensile properties investigation of Shielded metal arc welded joints, Ind. J.
Sci. Technol. 9 (35) (2016) 1–6.
[12] P.K. Singh, S.B. Prasad, D. Patel, Effect of vibrations on solidification behavior
and mechanical properties of shielded metal arc weld, in: Next Generation
Materials and Processing Technologies 2021, Springer, Singapore, pp. 209–219.
[13] W.B. Lee, M. Schmuecker, U.A. Mercardo, G. Biallas, S.B. Jung, Interfacial
reaction in steel-aluminum joints made by friction stir welding, Scr. Mater. 55
(2006) 355–358.
[14] K.J. Lee, S. Kumai, T. Arai, T. Aizawa, Interfacial microstructure and strength of
steel/aluminum alloy lap joint fabricated by magnetic pressure seam welding,
Mater. Sci. Eng. A. 471 (2007) 95–101.
[15] T. Murakami, K. Nakata, H. Tong, M. Ushio, Dissimilar metal joining of
aluminum to steel by MIG arc brazing using flux cored wire, ISIJ Int. 43 (10)
(2003) 1596–1602.
[16] A. Mathieu, J. Viala, E. Cicala, S. Matte, D. Grevey, Laser brazing of a steel /
aluminium assembly with hot fiiler wire(88% Al, 12% Si), Mater. Sci. Eng. A 436
(2006) 19–28.
[17] C.R. Radscheit, Laserstrahlfügen von Aluminium mit Stahl. BIAS; 1997, ISBN 3-
9805011-3-2.
[18] R. Lison, Zur Problematik der Schweißverbindungen zwischen
unterschiedlichen Werkstoffen unter besonderer Berücksichtigung des
Schmelzschweißens. Schweißen und Schneiden, Jahrgang 30, Heft 2.
Düsseldorf: DVS-Verlag, 1976, 45–47.
[19] M. Kreimeyer, G. Sepold, Laser steel joined aluminium-hybrid structures, in:
Proceedings of International Congress on Applications of Lasers and Electro-
Optics 2002 (ICALEO’02), Jacksonville, USA, 2002.
[20] S. Meco, G. Pardal, A. Eder, L. Quintino, Software development for prediction of
the weld bead in CMT and pulsed-MAG processes, Int. J. Adv. Manuf. Technol.
64 (2013) 171–178.
[21] R. Cao, J.H. Chang, X.H. Zhu, G.J. Mao, Q.W. Xu, Y. Shi, J.H. Chen, P.C. Wang,
Investigation of wire selection for CMT plug joining Mg AZ31-to-galvanized
steel, J. Manuf. Process. 32 (2018) 65–76.
[22] P. Wang, R. Cao, J.H. Sun, J.H. Chen, Cold metal transfer joining of aluminum
AA6061-T6-to- galvanized boron steel, J. Manuf. Sci. Eng. 136 (2016) 1–10.
[23] H.T. Zhang, J.C. Feng, P. He, Interfacial phenomena of cold metal transfer (CMT)
welding of zinc coated steel and wrought aluminium, Material Sci. Technol. 24
(11) (2008) 1346–1349.
[24] C.G. Pickin, K. Young, Evaluation of cold metal transfer (CMT) process for
welding aluminium alloy, Sci. Technol. Weld. Join. 11 (2006) 583–586.
[25] G. Mou, X. Hua, D. Wu, Y. Huang, W. Lin, P. Xu, Microstructure, and mechanical
properties of cold metal transfer welding-brazing of Titanium alloy (TC4) to
stainless steel (304L) using V-shaped groove joints, J. Mater. Process. Technol.
266 (2018) 696–706.
[26] H.T. Zhang, J.C. Feng, P. He, B.B. Zhang, J.M. Chen, L. Wang, The arc
characteristics and metal transfer behaviour of cold metal transfer and its
G. Nandan, G. Kumar, K.S. Arora et al. Materials Today: Proceedings 56 (2022) 481–488
487

use in joining aluminium to zinc-coated steel, Mater. Sci. Eng. A 499 (2009)
111–113.
[27] R. Cao, G. Yu, J.H. Chen, P.C. Wang, Cold metal transfer joining aluminium
alloys-to-galvanized mild steel, J. Mater. Process. Technol. 213 (2013) 1753–
1763.
[28] K. Furukawa, New CMT arc welding process-welding of steel to aluminium
dissimilar metals and welding of super-thin aluminium sheets, Weld. Int. 20
(6) (2006) 440–445.
[29] S. Basak, H. Das, T.K. Pal, M. Shome, Corrosion behavior of MIG brazed and MIG
welded joints of automotive DP600-GI steel sheet, J. Mater. Eng. Perform. 25
(2016) 5238–5251.
[30] P. Wang, R. Cao, J.H. Sun, J.H. Chen, Cold metal transfer joining of aluminium
AA6061-T6-to- galvanized boron steel, J. Manuf. Sci. Eng. 136 (2016) 1–10.
[31] G. Mou, X. Hua, D. Wu, Y. Huang, W. Lin, P. Xu, Microstructure and mechanical
properties of cold metal transfer welding-brazing of Titanium alloy (TC4) to
stainless steel (304L) using V-shaped groove joints, J. Mater. Process. Technol.
266 (2018) 696–706.
[32] S.M. Chan, L.C. Chan, T.C. Lee, Tailor-welded blanks of different thickness ratios
effects on forming limit diagrams, J. Mater. Process. Technol. 132 (1-3) (2003)
95–101.
[33] S. Fukumoto, H. Tsubakino, K. Okita, M. Aritoshi, T. Tomita, Amorphization by
friction stir welding between 5052 aluminium alloy and 304 stainless steel,
Scr. Mater. 42 (2000) 807–812.
[34] H. Zhang, J. Liu, Microstructure characteristics and mechanical property of
aluminium alloy-stainless steel lap joints fabricated by MIG welding-brazing
process, Mater. Sci. Eng., A 528 (2011) 6179–6185.
[35] M. Staubach, S. Juttner, U. Fussel, M. Dietrich, Joining of steel–aluminium
mixed joints with energy-reduced GMA processes and filler materials on an
aluminium and zinc basis, Weld. Cutt. 7 (2008) 30–38.
[36] G. Mathers, The Welding of Aluminium and Its Alloys, 4–14, Woodhead,
Cambridge, 2002, 32, 97.
[37] N.R. Mandal, Welding and Distortion Control, Narosa Publishing House,
Kharagpur, 2004, pp. 95–98.
[38] S. Kou, Welding Metallurgy, second ed., John Wiley, New Jersey, Hoboken,
2003.
[39] C. Dharmendra, K.P. Rao, J. Wilden, S. Reich, Study on laser welding–brazing of
zinc coated steel to aluminium alloy with a zinc based filler, Mater. Sci. Eng., A
528 (3) (2011 Jan 25) 1497–1503.
[40] R. Qiu, C. Iwamoto, S. Satonaka, The influence of reaction layer on the strength
of aluminium/steel joint welded by resistance spot welding, Mater. Charact. 60
(2) (2009 Feb 1) 156–159.
[41] J.L. Song, S.B. Lin, C.L. Yang, G.C. Ma, H. Liu, Spreading behavior and
microstructure characteristics of dissimilar metals TIG welding–brazing of
aluminium alloy to stainless steel, Mater. Sci. Eng., A 509 (1–2) (2009) 31–40.
[42] H. Bang, H. Bang, G. Jeon, I. Oh, C. Ro, Gas tungsten arc welding assisted hybrid
friction stir welding of dissimilar materials Al6061-T6 aluminium alloy and
STS304 stainless steel, Mater. Des. 1 (37) (2012) 48–55.
[43] S.B. Lin, J.L. Song, C.L. Yang, C.L. Fan, D.W. Zhang, Brazability of dissimilar
metals tungsten inert gas butt welding–brazing between aluminium alloy and
stainless steel with Al–Cu filler metal, Mater. Des. 31 (5) (2010 May 1) 2637–
2642.
[44] J.L. Song, S.B. Lin, C.L. Yang, C.L. Fan, Effects of Si additions on intermetallic
compound layer of aluminium–steel TIG welding–brazing joint, J. Alloy.
Compd. 488 (1) (2009 Nov 20) 217–222.
[45] M.V. Akdeniz, A.O. Mekhrabov, T. Yilmaz, The role of Si addition on the
interfacial interaction in Fe-Al diffusion layer, Scr. Metall. Mater. 31 (12)
(1994) 1723–1728.
[46] M. Pourali, A. Abdollah-Zadeh, T. Saeid, F. Kargar, Influence of welding
parameters on intermetallic compounds formation in dissimilar steel/
aluminium friction stir welds, J. Alloy. Compd. 25 (715) (2017) 1–8.
[47] T. Murakami, K. Nakata, H. Tong, M. Ushio, Dissimilar metal joining of
aluminium to steel by MIG arc brazing using flux cored wire, ISIJ Int. 43 (10)
(2003) 1596–1602.
[48] L. Agudo, N. Jank, J. Wagner, S. Weber, C. Schmaranzer, E. Arenholz, J. Bruckner,
H. Hackl, A. Pyzalla, Investigation of microstructure and mechanical properties
of steel-aluminium joints produced by metal arc joining, Steel Res. Int. 79 (7)
(2008) 530–535.
[49] R. Borrisutthekul, P. Mitsomwang, S. Rattanachan, Y. Mutoh, Feasibility of
using TIG welding in dissimilar metals between steel/aluminium alloy, Energy
Res. J. 1 (2) (2010) 82–86.
[50] H. Zhang, J. Liu, Microstructure characteristics and mechanical property of
aluminium alloy/stainless steel lap joints fabricated by MIG welding–brazing
process, Mater. Sci. Eng., A 528 (19–20) (2011) 6179–6185.
[51] H.T. Zhang, J.C. Feng, P. He, H. Hackl, Interfacial microstructure and mechanical
properties of aluminium–zinc-coated steel joints made by a modified metal
inert gas welding–brazing process, Mater. Charact. 58 (7) (2007) 588–592.
[52] G. Sierra, P. Peyre, F. Deschaux Beaume, D. Stuart, G. Fras, Galvanised steel to
aluminium joining by laser and GTAW processes, Mater. Charact. 59 (12)
(2008) 1705–1715.
[53] H. Dong, W. Hu, Y. Duan, X. Wang, C. Dong, Dissimilar metal joining of
aluminium alloy to galvanized steel with Al–Si, Al–Cu, Al–Si–Cu and Zn–Al
filler wires, J. Mater. Process. Technol. 212 (2) (2012 Feb 1) 458–464.
[54] L. Agudo, D. Eyidi, C.H. Schmaranzer, E. Arenholz, N. Jank, J. Bruckner, A.R.
Pyzalla, Intermetallic Fe x Al y-phases in a steel/Al-alloy fusion weld, J. Mater.
Sci. 42 (12) (2007) 4205–4214.
[55] S. Kobayashi, T. Yakou, Control of intermetallic compound layers at interface
between steel and aluminium by diffusion-treatment, Mater. Sci. Eng., A 338
(1–2) (2002) 44–53.
[56] R. Borrisutthekul, T. Yachi, Y. Miyashita, Y. Mutoh, Suppression of intermetallic
reaction layer formation by controlling heat flow in dissimilar joining of steel
and aluminium alloy, Mater. Sci. Eng., A 467 (1–2) (2007) 108–113.
[57] A. Bouayad, C. Gerometta, A. Belkebir, A. Ambari, Kinetic interactions between
solid iron and molten aluminium, Mater. Sci. Eng., A 363 (1–2) (2003) 53–61.
[58] K. Murakami, N. Nishida, K. Osamura, Y. Tomota, T. Suzuki, Aluminization of
high purity iron and stainless steel by powder liquid coating, Acta Mater. 52
(8) (2004) 2173–2184.
[59] H. Shi, S. Qiao, R. Qiu, X. Zhang, H. Yu, Effect of welding time on the joining
phenomena of diffusion welded joint between aluminium alloy and stainless
steel, Mater. Manuf. Processes 27 (12) (2012) 1366–1369.
[60] H. Springer, A. Kostka, J.F. Dos Santos, D. Raabe, Influence of intermetallic
phases and Kirkendall-porosity on the mechanical properties of joints between
steel and aluminium alloys, Mater. Sci. Eng., A 528 (13–14) (2011) 4630–4642.
[61] S.P. Pradhan, An investigation into the friction stir welding of aluminium pipe
with stainless steel plate (Doctoral dissertation).
[62] N.R. Jesudoss Hynes, P. Nagaraj, J.A. Jennifa Sujana, Investigation on joining of
aluminium and mild steel by friction stud welding, Mater. Manuf. Processes 27
(12) (2012) 1409–1413.
[63] M. Roulin, J.W. Luster, G. Karadeniz, A. Mortensen, Strength and structure of
furnace-brazed joints between aluminium and stainless steel, Weld. Res. 1
(78) (1999) 151–155.
[64] M. Mohammadpour, N. Yazdian, G. Yang, H.P. Wang, B. Carlson, R. Kovacevic,
Effect of dual laser beam on dissimilar welding-brazing of aluminium to
galvanized steel, Opt. Laser Technol. 1 (98) (2018) 214–228.
[65] R. Cao, J.H. Chang, H.X. Zhu, G.J. Mao, Q.W. Xu, Y. Shi, J.H. Chen, P.C. Wang,
Investigation of wire selection for CMT plug joining Mg AZ31-to-galvanized
steel, J. Manuf. Processes 1 (32) (2018) 65–76.
[66] T. Murakami, K. Nakata, H. Tong, M. Ushio, Dissimilar metal joining of steel to
aluminum by lap joint MIG arc brazing, Trans. JWRI. 32 (1) (2003) 35–37.
[67] Y. Su, X. Hua, Y. Wu, Quantitative characterization of porosity in Fe–Al
dissimilar materials lap joint made by gas metal arc welding with different
current modes, J. Mater. Process. Technol. 214 (1) (2014) 81–86.
[68] S. Basak, H. Das, T.K. Pal, M. Shome, Characterization of intermetallics in
aluminium to zinc coated interstitial free steel joining by pulsed MIG brazing
for automotive application, Mater. Charact. 1 (112) (2016) 229–237.
[69] S.W. Mei, M. Gao, J. Yan, C. Zhang, G. Li, X.Y. Zeng, Interface properties and
thermodynamic analysis of laser–arc hybrid welded Al/steel joint, Sci. Technol.
Weld. Joining 18 (4) (2013) 293–300.
[70] J.Y. Xue, Y.X. Li, C.H. Hui, Z.T. Zhu, Wettability, microstructure and properties of
6061 aluminium alloy/304 stainless steel butt joint achieved by laser-metal
inert-gas hybrid welding-brazing, Trans. Nonferr. Metals Soc. China 28 (10)
(2018) 1938–1946.
[71] J. Xue, Y. Li, H. Chen, Z. Zhu, Effects of heat input on wettability, interface
microstructure and properties of Al/steel butt joint in laser-metal inert-gas
hybrid welding-brazing, J. Mater. Process. Technol. 1 (255) (2018) 47–54.
G. Nandan, G. Kumar, K.S. Arora et al. Materials Today: Proceedings 56 (2022) 481–488
488