The influence of adding samarium on the microstructure, mechanical performance and corrosion behavior of as-extruded AZ41 alloys

The effect of samarium (Sm) addition on the microstructure, mechanical performance and corrosion behavior of extruded AZ41-xSm (x = 0%, 1%, 2% and 3%) alloys has been investigated by using optical microscope (OM), X-ray diffusion (XRD), scanning electronic microscope (SEM) equipped with energy dispersive spectroscope (EDS), tensile testing, hydrogen evolved and electrochemical tests. It is observed that Sm alloyed AZ41 alloys consist of alpha-Mg substrate, beta-Mg17Al12 and Al2Sm intermetallic. The beta-phase is gradually inhibited with increasing Sm content. The tensile testing result shows that the appropriate amount of Sm addition slightly enhances the mechanical strength. 2Sm alloyed alloy (AZ41-2Sm) displays optimal tensile properties, with a yield tensile strength (YTS) of 216.4 MPa, ultimate tensile strength (UTS) of 295.9 MPa and elongation (EL) of 15.9%, which is the result of second phase strengthening. The addition of Sm significantly improved the corrosion resistance of AZ41 alloy. The AZ41-1Sm alloy exhibits the best corrosion resistance properties with a corrosion rate about one-half that of the AZ41 alloy based on the hydrogen evolved and electrochemical test.

Automated summary

The study found that adding an appropriate amount of Sm can inhibit the beta phase in AZ41 alloys, improve mechanical strength, and significantly enhance corrosion resistance. Among the different Sm content levels, the 2% Sm alloy showed the best tensile properties.