Characterising Correlations between Electric Conductivity and Structural Features in Rotary Swaged Al/Cu Laminated Conductors

Abstract

This study aims to characterize the correlations between electric characteristics and selected structural features of newly designed Al/Cu laminated conductors manufactured via room temperature rotary swaging. After swaging, the laminates with diameters of 15 mm were subjected to two different post-process annealing treatments. Structure analyses performed to evaluate the effects of thermomechanical processing were performed via scanning and transmission electron microscopies. Electric conductivity and resistivity of the laminates were experimentally measured and numerically simulated using models designed according to the real conditions. The results showed that the electric resistivity was affected by the grain size, bimodal grains’ distribution (where observed), the presence of twins, and, last but not least, dislocation density. Among the influencing factors were the area fractions of Al and Cu at the cross-sections of the of the laminated conductors, too. The results revealed that fabrication of the laminate via the technology of rotary swaging introduced more advantageous combinations of electric and mechanical properties than fabrication by conventional manufacturing techniques. The lowest specific electric resistivity of 20.6 Ωm × 10−9 was measured for the laminated conductor subjected to the post-process annealing treatment at 350 °C, which imparted significant structure restoration (confirmed by the presence of fine, equiaxed, randomly oriented grains).

Optimizing Thermomechanical Processing of Bimetallic Laminates

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Enhancement of Creep Lifetime of Aluminum through Severe Plastic Deformation

“…The microstructures processed by low value of imposed plastic strain usually contain cells or subgrains with low-angle grain boundaries. However, in the case that extremely large strain is imposed on the material, the transformation of coarse-grained microstructure to ultrafine-grained one (grain size 100 nm-1 µm) occurs [3][4][5][6][7]. Nevertheless, the transformation of microstructure using SPD methods proceeds subsequently.…”

Case study of advanced processed OFHC copper by dry sliding wear test

“…The forging force is concentrated on a small local area of the workpiece in contact with the tilted die. The dies are then moved to deform successive small areas of the workpiece until a final shape is formed, which can improve metal flowing and decrease forging load [37][38][39][40][41]. The problem of the fatigue strength and wear resistance of advanced materials, particularly ultra-fine-grained containing voids (pores), defects or inhomogeneities, is significant both from the theory and practical point of view [42][43][44][45][46].…”