The precipitation behavior under various heat treatment conditions in the as-cast and hot-rolled Mg-Zn-Y alloy has been investigated. While MgZn2 precipitates are distributed in the α-Mg matrix at 190°C, in the temperature range of 350-420°C, polygon-shaped icosahedral phase (I-phase) precipitates are mainly formed. The precipitated I-phase is mostly found to be localized near the eutectic region in the as-cast ingot, but it is randomly distributed throughout the refined α-Mg grains formed by dynamic recrystallization during the hot-rolling processes in the sheet. The I-phase precipitates have no specific orientation relationship with the α-Mg matrix and do not coarsen at high temperatures. An increase of the hardness value by I-phase precipitates is less significant than that by MgZn2 precipitates due to their relatively low number density and near-spherical morphology.
Bibliographical noteFunding Information:
This work is supported by Creative Research Initiatives of the Korean Ministry of Science and Technology.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering