Effect of Nd addition on microstructures and mechanical properties of AZ80 magnesium alloys
(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
Abstract: The influence of Nd addition on the microstructures and mechanical properties of AZ80 magnesium alloys was investigated. The results show that the microstructure of as-cast AZ80 magnesium alloy is modified effectively with the addition of 1.0% Nd, the grain size is decreased from 448 to 125 μm, new rod-shaped Al11Nd3 phase and block-shaped Al2Nd phase are observed in the as-cast microstructure, and β-Mg17Al12 phases are refined and become discontinuous. The addition of Nd suppresses the discontinuous precipitations at grain boundaries during aging, and the time of reaching the peak hardness is delayed. With the addition of 1.0% Nd, the combined properties reach an optimum, the yield strength, tensile strength and elongation are 103.7 MPa, 224.0 MPa and 8.4%, respectively. After T6 heat treatment, the yield strength and tensile strength of the AZ80-1.0%Nd alloy are increased to 141.1 and 231.1 MPa, respectively.
Key words: AZ80 magnesium alloy; Nd; microstructure; mechanical properties