Influence of TiCN addition on the microstructures and mechanical properties of the AZ31 alloy.

The microstructure and mechanical properties of extruded AZ31 + xTiCN (x = 0, 0.4, 0.8, 1.2 wt%) were investigated, and the strengthening mechanism was discussed. X-ray diffraction and energy dispersive spectroscopy (EDS) confirmed that the Al4C3 and Al2MgC2 duplex phase particles were generated in situ by TiCN and Al particles, which act as the nucleation precursors of Mg grains during solidification. The grain size decreased and then increased with increasing TiCN addition. The yield strength (YS) and ultimate tensile strength (UTS) increased with increasing TiCN addition reaching a maximum (217.5 MPa) at 0.4 wt%, and in contrast, the elongation index (EI) continuously decreased with increasing TiCN addition.