Mechanical Properties and Structures of Rapidly Solidified Mg-Al-Zn Alloy

Abstract

  Rapidly solidified Mg-Al-Zn alloys were prepared by the single role melt-spinning method. It is well known that Mg-Al-Zn alloys consist of quasi crystals. The rapidly solidified ribbon had a width of 700 μm and a thickness of 20 μm. The structure of the ribbons was investigated by XRD and TEM, and their thermal stability was analyzed using DSC. The mechanical properties of the ribbons were measured. Some ribbons were mechanically ground. The results of the DSC analysis indicate that Mg₃₂Al₁₃Zn₃₆ alloy ribbons consist of thermally stable quasicrystals. The strength of the Mg₃₂Al₁₆Zn₃₃ alloy ribbons consisting of both the metastable quasicrystals and approximants was found to be the highest. After milling, the Mg₃₂Al₁₃Zn₃₆ alloy ribbons remained in the quasicrystal state but the other ribbons were found to change into intermetallic compounds. The Mg₃₂Al₁₃Zn₃₆ alloy ribbons were consolidated at the condition of 573 K and 250 MPa by PCS. After sintering, the quasicrystal phase transformed into approximants.