A Mg-Zn-Y-Zr alloy sheet containing icosahedral quasicrystalline particles and Zr-rich particles has been developed by the thermomechanical processes, i.e. hot extrusion and hot rolling. The grain size is found to be 5 μm. The superplastic deformation behavior of the alloy has been investigated. Under the test condition in the strain rate range of 5 × 10-4 to 5 × 10-2 s-1 and the temperature range between 300°C and 450°C, large elongation to failures are observed, especially around 600% at 450°C (5 × 10-4 s-1). During superplastic deformation, the concurrent grain growth rate is significantly retarded by the presence of I-phase particles, thermally stable at the temperature up to around 500°C. In addition, the formation of cavities is found to be negligible because of interfacial coherency between icosahedral quasicrystalline particles and the α-Mg matrix. Although superplastic deformation could be relatively prevented by the pinning effect of the distributed particles, microstructure stability can provide large elongation to failure in such an alloy.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering