Microstructure evolution of Zn–0.2Mg–0.8Mn(wt-%) alloys with different initial textures during room-temperature compression

Abstract

Zn–0.2Mg–0.8Mn alloys extruded at 300 and 150°C exhibited similar grain size, second phases, but different textures which were basal and non-basal texture, respectively. The initial textures affected the yielding and strain hardening stages. Non-basal texture was not conducive to the slipping of dislocations, causing high yield strength of 378 MPa but low strain hardening rate. Average grain size decreased from 2.2 ∼ 2.3 μm to 0.7 ∼ 0.8 μm by the formation of low angle grain boundaries. Deformation texture with (CD: compressive direction) was introduced by deformation. Dynamic recrystallisation (DRX) occurred as strain exceeded 0.16 and caused softening for both of the alloys. The DRXed grains exhibited average size of 0.7 ∼ 0.8 μm and texture with 〈0001〉 deviating 15° ∼ 30° away from CD.