Formation of ultrafine grains and twins in the ?-phase during superplastic deformation of two-phase brasses

During superplastic deformation of microduplex-structured brasses, the strain is primarily localized in the beta-phase where deformation occurs by grain boundary sliding (GBS) and dislocation slip/creep mechanisms. Dynamic recrystallization and twinning were observed in the b.c.c. beta-phase leading to a transformation of the initial coarse beta-phase grains with average sizes of -4-5 mu m to ultrafine grains with sizes below 1 mu m. Alloying with Al refined the beta-grains, improved the superplastic behavior and reduced the occurrence of residual cavitation.

Automated summary

During superplastic deformation of microduplex-structured brasses, strain primarily occurs in the beta-phase through grain boundary sliding and dislocation slip/creep mechanisms. Dynamic recrystallization and twinning transform the initial coarse beta-phase grains into ultrafine grains, and alloying with Al improves superplastic behavior and reduces residual cavitation.