Abstract:Suitable heat treatment processes were adopted to regulate the precipitation of the lamellar LPSO phase and β′ phase in Mg-Gd-Y-Zn-Zr-Nd alloy. The effects of lamellar LPSO phase and β′ phase on the mechanical properties and damping capacity of the alloy were studied systematically. Experimental results demonstrate that the lamellar LPSO phase is more conducive to dynamic recrystallization processes, leading to a high degree of recrystallization and a weak texture intensity, resulting in a higher plasticity and damping capacity. After aging treatment, the β′ precipitates exhibit pronounced aging strengthening and increase the number of mobile interfaces, thus enhancing the strength and damping capacity at the same time. Through regulating lamellar LPSO and aged β′ phase, the alloy achieves high strength and high damping capacity: ultimate tensile strength of 498 MPa, yield strength of 371 MPa and damping capacity of 0.02 at strain amplitude of 1×10^-3.

Key words: Mg-Gd-Y-Zn-Zr-Nd alloy; strength; damping capacity; β'' precipitates; LPSO phase