Enhanced Ductility in Ultrafine-Grained Al Alloys Produced by SPD Techniques
In this work ultrafine-grained (UFG) structure was successfully produced in the commercial Al 6061 and Al-30%Zn alloys using new modifications of two severe plastic deformation (SPD) techniques, namely equal channel angular pressing (ECAP) with parallel channels (PC) and high pressure torsion (HPT) with enhanced load. Variation of SPD processing regimes made it possible not only to perform strong grain refinement but also to modify the phase composition through the formation of grain boundary (GB) segregations and precipitations. This enabled to achieve a unique combination of high strength and ductility in the Al 6061 alloy and demonstrate super-ductility in the Al-30%Zn alloy, when elongation to failure exceeded 150% at room temperature.
Yonghao Zhao and Xiaozhou Liao
R. Valiev et al., "Enhanced Ductility in Ultrafine-Grained Al Alloys Produced by SPD Techniques", Materials Science Forum, Vols. 633-634, pp. 321-332, 2010