Comparison of superplastic forming abilities of as-cast AZ91 magnesium alloy prepared by twin roll casting and WE43 magnesium alloy Vergleich der superplastischen Umformbarkeit einer gießgewalzten AZ91 Magnesiumlegierung mit einer gewalzten WE43 Magnesiumlegierung S. Taylor 1 , V. Janik 1 , R. Grimes 1 , E. Mogire 2 , R. Dashwood 3 This paper describes and compares the superplastic behaviour and microstructural evolution of twin roll cast AZ91 and WE43 rolled sheet alloys. Tests were carried out in uniaxial tension on both alloys across a range of temperatures (300 8C– 525 8C) and strain rates (1·10 -4 s -1 –1·10 -1 s -1 ). In the case of WE43 gas bulge test- ing was employed at 400 8C and 0.6 MPa to offer a better analogy to superplastic forming than uniaxial tensile testing. Elongations of over 400 % were observed within WE43 when tested at 450 8C and 1·10 -3 s -1 strain rate, and over 200 % within AZ91 when tested at 350 8C and 1·10 -3 s -1 strain rate. A peak cone height of 41 mm was achieved with WE43 at a temperature of 400 8C and pressure of 0.6 MPa. Electron back scattered detection technique was employed to analyse the micro- structural evolution of the two alloys during the forming process. Both WE43 and AZ91 were observed to undergo dynamic recrystallization during elevated temper- ature tensile testing and failed at low strain rates mainly by means of coalescence of cavitation, in the case of AZ91 at high strain rates cracking of Al 12 Mg 17 inter- metallic particles was the dominating failure mechanism. Both alloys were seen to achieve good levels of superplastic ductility over 200 % elongation, which would be industrially useful in niche vehicle and aerospace manufacturing. Keywords: Superplastic forming / electron back scattered detection / gas bulge testing / microstructure / AZ91 / WE43 Schlu ¨ sselwo ¨ rter: Superplastisches Umformen / Elektronenru ¨ ckstreubeugung / Gas- Bulgetest / Gefu ¨ge / AZ91 / WE 43 Corresponding author: S. Taylor, WMG, Advanced Manufacturing and Materials Centre, University of Warwick, CV4 7AL, COVENTRY, UNITED KINGDOM, E-Mail: ascott.taylor@warwick.ac.uk 1 WMG, Advanced Manufacturing and Materials Centre, University of Warwick, CV4 7AL, COVEN- TRY, UNITED KINGDOM 2 Buehler Centre of Excellence, International Manu- facturing Centre, University of Warwick, CV4 7AL, COVENTRY, UNITED KINGDOM 3 Coventry University, Vice Chancellor’s Office, Priory Street, CV1 5FB, COVENTRY, UNITED KINGDOM Materialwiss. Werkstofftech. 2018, 49, 1206–1212 DOI 10.1002/mawe.201700121 1206 © 2018 WILEY-VCH Verlag GmbH & CO. KGaA, Weinheim www.wiley-vch.de/home/muw