The work performed is covered by next 2 publications in open access Journals with the first one being the main one:
1. R. Lapovok, et.al Architectured Hybrid conductors: Aluminium with embedded copper helix, Materials & Design, (2019), (
https://doi.org/10.1016/j.matdes.2019.108398(si apre in una nuova finestra))
Abstract: This study is inspired by the potential of application-designed aluminium-copper conductors. This work combines
recently discovered advantages of hybrids with one constituent having a helical architecture with the benefits
provided by severe plastic deformation (SPD)methods. The hybrids are made by embedding copper helixes
in melted aluminium and subjecting cast hybrid ingots to different SPD techniques. The electrical conductivity,
microstructure features and strength of the produced samples are discussed in relation to effect of SPD and annealing
on both constituents and an interface zone formed during the hybrids' production. Itwas shown that between
all processing techniques the reciprocal extrusion (RE) has the great potential for production of
lightweight conductors with high conductivity and enhanced strength. A new model describing the effective
electrical conductivity of hybrid samples, consisting of an aluminium matrix with an embedded copper helix
and intermetallic containing interface, is developed and justified by experimental data.
The model is shown to be instrumental for analysis of the effect of the helix's parameters and interfacewidth on effective conductivity of
the hybrid samples and could be used for optimal design of hybrid conductors.
2. R. Lapovok, et.al Effect of Severe Plastic Deformation on the Conductivity and Strength of Copper-Clad Aluminium
Conductors, Metals, Special Issue Severe Plastic Deformation and Thermomechanical Processing: Nanostructuring and Properties, 9:9 (2019), Article Number: 960.
Abstract: Aluminium rods with dierent copper sheath thicknesses were processed by severe plastic
deformation at room temperature and then annealed, to join the constituent metals and produce a
nanocrystalline microstructure. A study of the eects of the deformation parameters, copper cladding
thickness and annealing temperature on the electrical conductivity and hardness of the conductors
is reported. It is shown that an interface forms between constituents because of intermixing in
the course of severe shear deformation under high hydrostatic pressure and diusion during the
subsequent annealing. The eective conductivity of the aluminium copper-clad conductor dropped
after deformation, but was recovered during annealing, especially during short annealing at 200 C,
to a level exceeding the theoretically predicted one. In addition, the annealing resulted in increased
hardness at the interface and copper sheath.
