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5.1 Introduction to Welding of Dissimilar Metals
Dissimilar metal joints are becoming increasingly important in automotive,
aerospace, electronics, and various other industrial applications. The reasons for
using a combination of dissimilar materials in a single product are based on several
considerations. Firstly, it is imperative to meet different technical requirements of the
product, such as (i) structural requirements like a combination of strength and rigidity
for static and fatigue loadings along with the reduction of weight, and (ii) operating conditions like local wear, corrosion and temperature resistance, etc. There are
many cases arising from the above requirements where limited choices exist to join
dissimilar materials. Second, combination of dissimilar metals provides designers
and manufacturers of components and sub-assemblies more flexibility in fulfilling
the functional requirement of the product or the component. Thirdly, the fabrication
of products, containing dissimilar metals can yield economic benefits. Therefore, this
strategy has found wide-scale applications in important sectors of manufacturing [1],
and it has been explained in detail in the subsequent sections.
5.1.1 Applications of the Structures of Dissimilar Metals
5.1.1.1 Automotive
As mentioned in the previous section, joints of dissimilar metals have found major
applications in the automotive industry. Light weighting is the main subject of automotive and transport manufacturing industries with the aim to improve the fuel
efficiency. Worldwide, stringent regulations are being imposed to control the carbon
footprint. In this regard, it is essential to implement multi-material concept, using
different materials with specific properties for different parts of an automotive body.
Automotive industry is thus attempting to come up with innovative solutions which
would make the automotive lighter in weight, without compromising with safety of
the passengers. A potential solution to this has been the tailor-welded blank (TWB)
technology, combining different metals to be welded together. Such combinations
aim at considering the most suitable properties of the materials which are then placed
within the part depending on the application. This tailoring is done with respect to
thickness, grades, strength, etc. [2].
5.1.1.2 Nuclear Reactor
Another area where the use of dissimilar materials is increasingly being explored
is the nuclear reactor. The reactor consists of different high temperature-resistant
materials present in the primary and secondary circuits. The performance of the
reactor is mainly determined by the properties of the materials. This further considers
S. Sahu et al.
5.1 Introduction to Welding of Dissimilar Metals
Dissimilar metal joints are becoming increasingly important in automotive,
aerospace, electronics, and various other industrial applications. The reasons for
using a combination of dissimilar materials in a single product are based on several
considerations. Firstly, it is imperative to meet different technical requirements of the
product, such as (i) structural requirements like a combination of strength and rigidity
for static and fatigue loadings along with the reduction of weight, and (ii) operating conditions like local wear, corrosion and temperature resistance, etc. There are
many cases arising from the above requirements where limited choices exist to join
dissimilar materials. Second, combination of dissimilar metals provides designers
and manufacturers of components and sub-assemblies more flexibility in fulfilling
the functional requirement of the product or the component. Thirdly, the fabrication
of products, containing dissimilar metals can yield economic benefits. Therefore, this
strategy has found wide-scale applications in important sectors of manufacturing [1],
and it has been explained in detail in the subsequent sections.
5.1.1 Applications of the Structures of Dissimilar Metals
5.1.1.1 Automotive
As mentioned in the previous section, joints of dissimilar metals have found major
applications in the automotive industry. Light weighting is the main subject of automotive and transport manufacturing industries with the aim to improve the fuel
efficiency. Worldwide, stringent regulations are being imposed to control the carbon
footprint. In this regard, it is essential to implement multi-material concept, using
different materials with specific properties for different parts of an automotive body.
Automotive industry is thus attempting to come up with innovative solutions which
would make the automotive lighter in weight, without compromising with safety of
the passengers. A potential solution to this has been the tailor-welded blank (TWB)
technology, combining different metals to be welded together. Such combinations
aim at considering the most suitable properties of the materials which are then placed
within the part depending on the application. This tailoring is done with respect to
thickness, grades, strength, etc. [2].
5.1.1.2 Nuclear Reactor
Another area where the use of dissimilar materials is increasingly being explored
is the nuclear reactor. The reactor consists of different high temperature-resistant
materials present in the primary and secondary circuits. The performance of the
reactor is mainly determined by the properties of the materials. This further considers