Microstructural characterization and creep behavior of dispersion strengthened MRI230D magnesium alloy

The microstructural changes following the dispersion of SiC nanoparticles (SiCnp) n p ) and its subsequent significance on the creep response of MRI230D alloy are examined. Nanocomposites (NCs) of MRI230D alloy are fabricated with a dispersion of 1.0SiCnp np (NC1SiC) and 2.0SiCnp np (NC2SiC) (wt.%) using squeeze-casting. The primary Mg (alpha-Mg), lamellar C36 (Mg,Al)2Ca, 2 Ca, as well as blocky Al8Mn5 8 Mn 5 phases, are observed in the MRI230D alloy and NCs. Additionally, SiC phase is detected in NCs. The additions of SiCnp np refine the grains of the NCs. The fraction of C36 increases with an increase in SiCnp np in MRI230D alloy. The alloy and NCs are exposed to impression creep tests under 450-500 MPa stress and 448-498 K temperature. The NCs exhibit better resistance to creep over MRI230D alloy, and NC2SiC is the most creep-resistant. The strengthening from the increased fraction of C36, along with Orowan strengthening from SiCnp np dispersion in the alpha-Mg matrix, give rise to improved creep strength of the NCs than the alloy. The creep in MRI230D alloy and NCs progressed by dislocation-climb with pipe diffusion.