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Contemporary Machining Processes
1. Adsorption theory
2. Chemical bonding
3. Diffusion theory
4. Electrostatic attraction
5. Mechanical interlocking
6. Weak boundary layer theory
However, the authors added that none of these theories were capable of providing a
comprehensive explanation for all types of adhesive interaction and joints. They also
listed several factors defining adhesive bond performance, such as lifetime or robustness (Martinsen et al., 2015):
• Physical and chemical properties of adhesives
• Nature of adherents whose materials are to be joined
• Type of bonding surface pre-treatment (preparation), very important for
joint quality
• Surface wettability
• Joint design, i.e., appropriate adhesive choice, which plays a crucial role in
the selection of an adhesive and curing method
Katnam et al. (2013) claim that the resulting bond strength must be sufficient to
ensure that stresses are safely transferred between the two adherents providing a
shear dominant stress state and inducing minimum peel (i.e., through-thickness normal) stresses in the adhesive layer. For bonded structural composite repair, single- or
double-sided doubler patches, scarf or stepped scarf patches can be bonded to a damaged structure. In general, bonded scarf patches can be considered the most efficient
joints for bonded repair, since they have no eccentricity of the load and produce
minimal peel stresses (Katnam et al., 2013).
Resistance spot welding (RSW) has been the mainstream solution for steel-dominated automotive bodies, but today it is applied to obtain dissimilar material joints
such as Al–steel, Mg–steel, glass–steel, Cu–Ni-plated steel, stainless steel–Ti, Ti–
Al, and Al–Mg combinations (Martinsen et al., 2015). The authors list among benefits of the method its flexibility and easy automation, and the fact that since the weld
gun electrodes are clamped, small gaps between the sheets can be leveled.
Hybrid joining techniques as a combination of adhesive bonding with a spotjoint, such as a resistance spot-weld or a clinched joint, are widely used in car body
manufacturing (Meschut et al., 2014). Application of heat-curing epoxy-based structural adhesives significantly increases joint strength and the adhesive layer also isolates and seals the joint area. The latter is a very important aspect for multi-material
design, where a difference in electrochemical potential of joined materials can result
in accelerated corrosion effects. Today, mechanical joining technologies like clinching and self-pierce riveting are often combined with adhesive bonding. Trying to
summarize the advances in hybrid joining technologies, the authors emphasized that
classic mechanical joining combined with local conditioning as well as some new
Contemporary Machining Processes
1. Adsorption theory
2. Chemical bonding
3. Diffusion theory
4. Electrostatic attraction
5. Mechanical interlocking
6. Weak boundary layer theory
However, the authors added that none of these theories were capable of providing a
comprehensive explanation for all types of adhesive interaction and joints. They also
listed several factors defining adhesive bond performance, such as lifetime or robustness (Martinsen et al., 2015):
• Physical and chemical properties of adhesives
• Nature of adherents whose materials are to be joined
• Type of bonding surface pre-treatment (preparation), very important for
joint quality
• Surface wettability
• Joint design, i.e., appropriate adhesive choice, which plays a crucial role in
the selection of an adhesive and curing method
Katnam et al. (2013) claim that the resulting bond strength must be sufficient to
ensure that stresses are safely transferred between the two adherents providing a
shear dominant stress state and inducing minimum peel (i.e., through-thickness normal) stresses in the adhesive layer. For bonded structural composite repair, single- or
double-sided doubler patches, scarf or stepped scarf patches can be bonded to a damaged structure. In general, bonded scarf patches can be considered the most efficient
joints for bonded repair, since they have no eccentricity of the load and produce
minimal peel stresses (Katnam et al., 2013).
Resistance spot welding (RSW) has been the mainstream solution for steel-dominated automotive bodies, but today it is applied to obtain dissimilar material joints
such as Al–steel, Mg–steel, glass–steel, Cu–Ni-plated steel, stainless steel–Ti, Ti–
Al, and Al–Mg combinations (Martinsen et al., 2015). The authors list among benefits of the method its flexibility and easy automation, and the fact that since the weld
gun electrodes are clamped, small gaps between the sheets can be leveled.
Hybrid joining techniques as a combination of adhesive bonding with a spotjoint, such as a resistance spot-weld or a clinched joint, are widely used in car body
manufacturing (Meschut et al., 2014). Application of heat-curing epoxy-based structural adhesives significantly increases joint strength and the adhesive layer also isolates and seals the joint area. The latter is a very important aspect for multi-material
design, where a difference in electrochemical potential of joined materials can result
in accelerated corrosion effects. Today, mechanical joining technologies like clinching and self-pierce riveting are often combined with adhesive bonding. Trying to
summarize the advances in hybrid joining technologies, the authors emphasized that
classic mechanical joining combined with local conditioning as well as some new