Superplastic Behavior at Lower Temperatures of High‐Strength Ultrafine‐Grained Al Alloy 7475. Issue 1 (30th April 2018)

• Record Type: Journal Article
• Authors: Bobruk, Elena V.; Murashkin, Maxim Y.; Kazykhanov, Vil U.; Valiev, Ruslan Z.
• Is Part Of: Advanced engineering materials. Volume 21:Issue 1(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-04-30
• Subjects: Aluminium alloys -- High‐strength state -- Mechanical properties -- Severe plastic deformation -- Superplasticity -- Thermo‐mechanical treatment -- Ultrafine‐grained materials; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.201800094
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : This study aims to achieve high ductility at lower temperatures (170 and 200 °C) while retaining enhanced mechanical strength in the ultrafine‐grained high‐strength Al‐based alloy 7475. The ultrafine grain structure is formed by high pressure torsion (HPT) at room temperature. Isochronous annealing in a range of temperatures from 80 to 450 °С demonstrated that the high hardness values are retained or change insignificantly up to 200 °С. Static testing was performed at 120–200 °С and strain rates from 10 −2 to 10 −4 s −1 to determine the ductility and strain rate sensitivity. Elongations of 500% is achieved at 170 °С and a strain rate of 10 −3 s −1, and of 700% at 200 °С and a strain rate of 5 × 10 −4 s −1 . Abstract : The work focuses on deformation behavior of UFG 7475 alloy in terms of thermal stability of the high‐strength state to detect the signs of superplastic deformation exhibited by the material. Elongations of 500% at 170 °С and 700% at 200 °С have been registered as well as a strain rate of 10 −3 s −1 and that of 5 × 10 −4 s −1 .