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Contemporary Machining Processes
Electron beam welding (EBW) is a fusion welding process based on heat generated by a beam of high-energy electrons, so that edges of a workpiece are fused and
joined forming a weld after solidification. EBW is often performed in vacuum conditions to prevent dissipation of the electron beam (Kalaiselvan et al., 2021). EBW is
successful in welding of composites, especially SiCp/Al composites. In this material, the huge difference between the properties of SiC particles and matrix alloys
causes great difficulties to joining processes. Conventional fusion welding methods
are prone to generating defects such as voids and harmful Al 4 C 3 phases formed in
the reaction between the SiC particles and the matrix in the molten pool, which
prevents from meeting the performance requirements of the composite joint (Zuo
et al., 2020). Another example of EBW application to composites is TiB 2p reinforced
aluminum. No obvious pores or cracks were reported in the weld seam with homogenous distribution of TiB 2 particles. Moreover, hardness of the fusion zone and heataffected zone (HAZ) both increased in comparison with that of the base metal, with
no interface reactions between TiB 2 particle and Al matrix (Cui et al., 2010). EBW
proved effective at joining SiCp/Al composite with Ti-6Al-4V, welding of Al-Al 2 O 3
composites, etc. (Kalaiselvan et al., 2021).
An interesting application of electron beam machining was described by Drobny
(2013). EBM can be used to perform the cross-linking process improving bonds
between individual layers to hold a laminate together. Cross-linking increases
cohesive strength of an adhesive and consequently the bond strength in laminates.
Laminated materials, opaque to ultraviolet and visible light, may be cross-linked by
EB since high-energy electrons penetrate paper, foils, and fabrics. Laminates of thin
films or thin-film overlays can be processed by low-energy EBs. For setting adhesive bonds between thicker substrates, higher energy or even X-ray radiation may
be used. Materials with very different coefficients of expansion can be bonded by
EB-curable adhesives without interfacial stresses that are created when using thermal curing. EB curing is used for curing laminating adhesives in flexible packaging
and this application has been growing rapidly since the introduction of low-voltage
compact EB processors. Below are listed some other advantages of EB curing of
laminating adhesives:
• Adhesives do not require solvents
• An adhesive is one part chemistry (no mixing needed)
• Long shelf-life (more than six months)
• An adhesive remains unchanged until it is cured
• No multiroll coating is needed
• No complex tension controls are needed
• The adhesive bond is established almost instantly
• Real-time quality control
• In-line processing; immediate shipment is possible
• Easy cleanup (Drobny, 2013)
Figure 1.11 shows basic features of an EBM unit. It consists of a pulse energy source
(1), electron gun (4) where a high-power electron beam is formed, a vacuum chamber
Contemporary Machining Processes
Electron beam welding (EBW) is a fusion welding process based on heat generated by a beam of high-energy electrons, so that edges of a workpiece are fused and
joined forming a weld after solidification. EBW is often performed in vacuum conditions to prevent dissipation of the electron beam (Kalaiselvan et al., 2021). EBW is
successful in welding of composites, especially SiCp/Al composites. In this material, the huge difference between the properties of SiC particles and matrix alloys
causes great difficulties to joining processes. Conventional fusion welding methods
are prone to generating defects such as voids and harmful Al 4 C 3 phases formed in
the reaction between the SiC particles and the matrix in the molten pool, which
prevents from meeting the performance requirements of the composite joint (Zuo
et al., 2020). Another example of EBW application to composites is TiB 2p reinforced
aluminum. No obvious pores or cracks were reported in the weld seam with homogenous distribution of TiB 2 particles. Moreover, hardness of the fusion zone and heataffected zone (HAZ) both increased in comparison with that of the base metal, with
no interface reactions between TiB 2 particle and Al matrix (Cui et al., 2010). EBW
proved effective at joining SiCp/Al composite with Ti-6Al-4V, welding of Al-Al 2 O 3
composites, etc. (Kalaiselvan et al., 2021).
An interesting application of electron beam machining was described by Drobny
(2013). EBM can be used to perform the cross-linking process improving bonds
between individual layers to hold a laminate together. Cross-linking increases
cohesive strength of an adhesive and consequently the bond strength in laminates.
Laminated materials, opaque to ultraviolet and visible light, may be cross-linked by
EB since high-energy electrons penetrate paper, foils, and fabrics. Laminates of thin
films or thin-film overlays can be processed by low-energy EBs. For setting adhesive bonds between thicker substrates, higher energy or even X-ray radiation may
be used. Materials with very different coefficients of expansion can be bonded by
EB-curable adhesives without interfacial stresses that are created when using thermal curing. EB curing is used for curing laminating adhesives in flexible packaging
and this application has been growing rapidly since the introduction of low-voltage
compact EB processors. Below are listed some other advantages of EB curing of
laminating adhesives:
• Adhesives do not require solvents
• An adhesive is one part chemistry (no mixing needed)
• Long shelf-life (more than six months)
• An adhesive remains unchanged until it is cured
• No multiroll coating is needed
• No complex tension controls are needed
• The adhesive bond is established almost instantly
• Real-time quality control
• In-line processing; immediate shipment is possible
• Easy cleanup (Drobny, 2013)
Figure 1.11 shows basic features of an EBM unit. It consists of a pulse energy source
(1), electron gun (4) where a high-power electron beam is formed, a vacuum chamber