Phase Equilibria of the Al-Mn-Sn System at 450 and 800 °C

Phase equilibria of the Al-Mn-Sn system were investigated by means of x-ray powder diffraction, scanning electron microscopy and energy dispersive spectroscopy. Two isothermal sections of the Al-Mn-Sn system at 450 and 800 °C were experimentally established. No ternary compound was found at those two temperatures. The low-temperature phase Mn3Sn2 was observed at 450 °C. The solubility of Al in Mn3Sn, Mn3Sn2, MnSn2 and that of Sn in Al8Mn5 at 450 °C is about 3.1, 2.9, 0.6, and 1.7 at.%, respectively. The high-temperature phase Mn2-xSn was observed at 800 °C. The solubility of Al in Mn3Sn, Mn2−xSn and that of Sn in Al8Mn5 at 800 °C was measured to be 2.8, 3.6 and 1.0 at.%, respectively. Al12Mn, also named G phase, was proved to be stable at 450 °C.