1. General information

1.1 History

Rosenham, Haughton, and Bingham were the first, in 1920, to demonstrate superplastic behavior by deforming a ternary zinc-aluminum-copper alloy. In 1928, Jenkins achieved a 400% elongation by tensile testing cadmium-zinc and lead-tin alloys heated to a high temperature (0.8 times the melting temperature expressed in kelvins). At that time, it was noted that these deformations were associated with delayed development of necking in the material. A record was set in 1934 by Pearson in Great Britain, who succeeded in elongating the eutectic bismuth-tin alloy by nearly 2,000%. In addition, Pearson showed, through metallographic observations, that the size and shape of the grains did not appear to change during deformation.

It was not until 1946 that the...