Topographic Data on Structural Changes During Superplastic Deformation of Zn plus 22% Al Alloy.

Using the method of stereophotography of repliques from the surface of a rolled sample of Zn plus 22% Al alloy subjected to superplastic deformation at 250 degree C, a profile of this surface was plotted. The striated zones forming along the grain boundaries during superplastic deformation are inclined at various angles to the surface of the sample being strained, thus making it possible to regard them as the direct result of intergranular deformation. It is shown that intergranular deformation during superplastic flow of Zn plus 22% Al alloy develops preferentially at interphase boundaries and is also noted at boundaries between grains of the zinc solution. At boundaries between grains of the aluminum solution no topographic signs of intergranular deformation are observed.