Effect of yttrium addition on microstructure and properties of M60B magnesium alloy

The S4800 scanning electron microscope with energy spectrometer, D8 Focus X-ray diffractometer, AG-10TA electronic universal testing machine and electrochemical station were employed to investigate systematically the effects of Y addition on the microstructure, the mechanical properties at room temperature and high temperature (175°C) and corrosion resistance of AM60B magnesium alloy. Experimental results indicate that the thermodynamically stable new phase Al 2Y is formed after Y addition to the AM60B alloys, and distribution of Mg 17Al 12 is changed from reticulation to dispersed state. When the addition amount of Y was 0.6%, both the mechanical properties and corrosion resistance of the alloy were enhanced. There were obviously diffraction peaks of Al 2Y phase in XRD patterns when the addition amount of Y was 1.2%, the high temperature (175°C) tensile strength of the alloy reaches 147 MPa and the room-temperature tensile strength also reached the best. At the same time, the corrosion potential of alloy increased to -1.02V. With Y content increasing from 1.2% to 1.8%, the corrosion potential of alloy had no obvious change while the mechanical properties decreased.