Warm deformation behaviour of UFG CP-Titanium produced by I-ECAP

7th International Conference on Nanomaterials by Severe Plastic Deformation

Qarni, Muhammad Jawad^1 ; Rosochowski, Andrzej^2 ; Boczkal, Sonia^3

Advanced Forming Research Centre (AFRC), University of Strathclyde, Inchinnan, Renfrewshire

PA4 9LJ, United Kingdom^1

Design Manufacture and Engineering Management (DMEM), University of Strathclyde, Glasgow

G1 1XJ, United Kingdom^2

Institute of Non-Ferrous Metals in Gliwice, Light Metals Division, ul. Pilsudskiego 19, Skawina

32-050, Poland^3

关键词: Commercial purity titanium;    Cylindrical samples;    Deformation behaviour;    Hardening behaviours;    Isothermal conditions;    Steady-state response;    True stress strain curve;    Uni-axial compression tests;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/194/1/012038/pdf
DOI  :  10.1088/1757-899X/194/1/012038

来源: IOP

【 摘 要 】

The objective of the present study is to investigate the deformation behaviour of Ultrafine-grain (UFG) commercial purity Titanium (CP-Ti) at warm temperatures. Firstly, CP-Ti billets were processed through six passes of incremental equal channel angular pressing (I-ECAP) at 300° C using a die channel angle (Φ) of 120°. Uniaxial compression tests were then performed under isothermal conditions on cylindrical samples obtained from the UFG CP-Ti billets. A series of these tests were conducted at different temperatures of 400, 500 and 600 °C and at varying strain rates of 0.01, 0.1 and 1.0 s-1. In each test, the original height of the sample was deformed by ∼50% of its original value. The true stress-strain curves obtained, revealed that the flow stress was sensitive to both temperature and strain rate. In general, the flow stress was higher for lower temperatures and higher strain rates. For tests conducted at 400 and 500 °C, the flow stress quickly reaches a peak value, beyond which it exhibits a steady state response where there is no appreciable change in flow stress with increasing strain. The 600 °C tests however shows a strain hardening behaviour. Microstructure of the sample deformed at 600 °C and 0.01 s-1, exhibited significant grain growth.