Deformation behavior in Zr702 processed by equal-channel angular pressing at room temperature

The microstructural evolution of commercial parity zirconium Zr702 with an initial grain size of ∼40 μm during equal channel angular pressing (ECAP) was investigated. ECAP was carried out at room temperature via route BC, in which the sample was rotated 90° in the same sense in each pass. After four ECAP passes, the microstructure of Zr702 revealed that the grain size decreased to ∼0.5 μm without fracture. Deformation twins were found in all the grains after the first pass of ECAP. Transmission electron micrographs of the ECAP-processed Zr702 revealed that the strain imposed during ECAP is accommodated mainly by {1 1 2¯ 1} deformation twinning.