Uniaxial and biaxial stretching of commercial-purity titanium and Ti–6Al–4V at 525°–725°C

Abstract

Ti–6Al–4V plate has been processed by hot rolling, cold rolling, and annealing to thin sheet, the mechanical behaviour of which has been evaluated in the temperature range 525°–725°C. Bands of primary α and transformed β can give rise to undesirable ridging effects during stretching. Ridging can be eliminated by hot rolling in the a-phase. Ductility in uniaxial and biaxial stretching increases rapidly in the temperature range 625°–725°C, with proportionate changes in the strain-rate sensitivity exponent m. Similar changes in commercial-purity titanium sheet occur over a somewhat lower temperature range. Anisotropic effects both on a microstructural scale and a macroscopic scale can have a strong influence on the biaxial stretching behaviour of Ti–6Al–4V sheet.