Equal-Channel Angular Pressing (ECAP) and High- Pressure Torsion (HPT) ECAP and HPT are used to fabricate ultrafine- grained microstructures with grain sizes <1000 nm. Hardness measurements demonstrate the development of homogeneity after processing: illustrations (right) show an inhomogeneous microstructure after 1 turn of HPT (upper) and a more homogeneous microhardness after 5 turns (lower). Materials processed by ECAP and HPT are under evaluation for use in superplastic forming operations. Creep and Superplasticity Creep and Superplasticity in Materials with Ultrafine Grain in Materials with Ultrafine Grain Sizes Sizes Terence G. Langdon, University of Southern California, DMR 0243331 M. Kawasaki, C. Xu and T.G. Langdon, “An Investigation of Cavity Growth in a Superplastic Aluminum Alloy Processed by ECAP,” Acta Materialia 53 , 5353 (2005). C.Xu, Z. Horita and T.G. Langdon, “The Evolution of Homogeneity in Processing by High-Pressure Torsion,” Acta Materialia 55 , 203 (2007). M. Kawasaki and T.G. Langdon, “Properties of Superplasticity in Ultrafine-Grained Materials,” Journal of Materials Science 42 , 1782 (2007). Al-6061: P = 4 GPa, 5 turns Al-6061: P = 4 GPa, 1 turn