Superplastic Deformation of Zinc Sulfide Near Its Transformation Temperature [1020°

Abstract

Polycrystalline ZnS was deformed in compression to large strains (up to 100%), near its α⇄β transformation temperature (1020°), at strain rates that ranged from 10−5 to 3 × 10−3 s−1. The flow stress showed a minimum near 1020°. The strain rate sensitivity and the grain size dependence of the flow stress suggest a superplastic mechanism of deformation. There was some evidence of dynamic recrystallization and stress‐induced β (fcc) to α (hcp) phase transformation. The polycrystals had a tendency to form in tergranular cavities at the higher temperatures and at faster strain rates.