Study of the Combined Severe Plastic Deformation Techniques Applied to Produce Contact Wire for High-Speed Railway Lines

Abstract

This work considers the development and the application of combined severe plastic deformation (SPD) techniques to produce contact wire with an enhanced complex of physical, mechanical, and service properties used for high-speed railway lines. This type of processing can be used as an alternative to most conventional production methods, including rolling and drawing. The proposed technique is based on the combination of radial swaging and equal-channel angular pressing, bundled with the wire-forming process. Laboratory contact wire samples with an enhanced complex of physical, mechanical, and service properties were produced during physical experiments. The composition of processed alloy samples meets modern requirements for contact wires for high-speed railways. Ultimate tensile strength of 560 ± 20 MPa, electrical conductivity of 76 ± 2% IACS, and relative tensile elongation of 20 ± 2% are achieved through the formation of a band structure. Fragments of 300 ± 20 nm were formed inside strips with the precipitation of secondary phase particles of 20–100 nm along the fragment boundaries, mainly during the aging process.