화학공학소재연구정보센터
Journal of Materials Science, Vol.31, No.4, 843-849, 1996
Topographic Study of Superplastically Formed Aa7475 Hemispherical Domes
Sliding of grain groups occurs during superplastic stretching of 7475 aluminium alloy with a spherical punch. Such co-operative grain boundary sliding (CGBS) is accompanied by cavity formation in intersection sites of CGBS surfaces, formation of striated bands and migration of sliding grain boundaries. Fibres were observed evolving from the striated bands between grains separated due to CGBS. This fibring process anticipates extreme ductility of the material and could be considered as "microsuperplasticity" originating from operation of a diffusion-like process or incipient melting.