Effect of Nano-AlN Particles on the Microstructure and Mechanical Properties of Mg-Al-Nd-Mn Alloy

The addition of AlN particles effectively refined the α-Mg grain size of Mg-4Al-2Nd-0.3Mn (AE42) alloy, as well as the size of acicular Al11Nd3 and blocky Al2Nd phases, while promoting the precipitation of the Al8Mn5 phase. The 2.0 wt.% AlN/AE42 composite exhibited optimal room- and high-temperature mechanical properties. At room temperature, the ultimate tensile strength (UTS), yield strength (YS), and fracture strain (ε) of AE42 alloy and 2.0 wt.% AlN/AE42 composite were 191 MPa, 86 MPa, 12.1% and 219 MPa, 107 MPa, and 13.8%, respectively. At 150 °C, 200 °C, and 250 °C, the UTS values of the 2.0 wt.% AlN/AE42 composite were 178 MPa, 152 MPa, and 139 MPa, respectively. At high temperatures, AlN particles synergistically enhanced the strength and plasticity of the composite by suppressing grain boundary sliding and promoting twinning.