Thermomechanical treatments of age-hardenable wrought aluminium alloys provoke microstructural changes that involve the movement, arrangement, and annihilation of dislocations, the movement of boundaries, and the formation or dissolution of phases. Cold and hot compression tests are carried out using a Gleeble® 3800 machine to produce flow data as well as deformed samples for metallography. Electron backscattered diffraction and light optical microscopy were used to characterise the microstructure after plastic deformation and heat treatments. Models based on dislocation densities are developed to describe strain hardening, dynamic recovery, and static recrystallisation. The models can describe both the flow and the microstructure evolutions at deformations from room temperatures to 450 °C. The static recrystallisation and static recovery phenomena are modelled as a continuation of the deformation model. The recrystallisation model accounts also for the effect of the intermetallic particles in the movements of boundaries.

Electron beam welding facilitates a very high energy density, which is a significant advantage when welding materials with a high thermal conductivity like copper. Nevertheless, in EBW of copper, unique root defects are observed in full penetration welding of thick components. Therefore, it is of scientific interest and relevant for applications to determine the reason and to develop countermeasures. A novel attempt to address this problem is using filler material. First, with a copper-tin alloy filler metal in form of sheets, a sufficient solidification range can be established. Second, a pure tin plasma-sprayed layer is applied to achieve an alloyed weld zone. With these approaches and in combination with proper welding parameters, defect free joints are established.

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