Mg-Zn-Nd准晶合金显微组织和电化学性能研究

Mg70.8Zn28Nd1.2 alloy containing icosahedral quasicrystal phase was prepared under conventional casting conditions. The microstructures and phases structure of quasicrystal alloy were investigated by means of SEM and XRD. There is not change in morphology and structure for icosahedral phase after being annealed at 600k for 48h. The Mg7Zn3 matrix phase transformed into a kind of honeycombed eutectic organization which is Mg and MgZn eutectic phase.The hydrogen storage capacity of Mg70.8Zn28Nd1.2 quasicrystal alloy was investigated by electrochemical testing. The result shows that the as-cast alloy has low discharge capacity when quasicrystal phase is enclosed by Mg7Zn3 phase. After the heat treatment, Mg7Zn3 phase changed into Mg and MgZn phase, and the maximum discharge capacity was 36mA/g. Because the ratio of the volume fraction of icosahedral phase is only about 45%, and the other phases can't react with hydrogen, the icosahedral quasicrystal phase has high electrochemical hydrogen storage capacity.