Zhikun Qu

Microstructure and mechanical properties of Mg–8Li–(1, 3)Al–(0, 1)Y alloys

Abstract The microstructure and mechanical properties of Mg–8Li–(1, 3)Al–(0, 1)Y alloys were studied. Y refines and spheroidises the microstructures of alloys, and it causes the decrease in α phase percentage. Blocky AlY exists in α and β phases. When Al content is 3 wt-%, AlLi and MgLi2Al form in β phase. The Al content solid soluted in the α phase appears larger than that in the β phase, while the Y content solid soluted in the α phase is less than that in the β phase. The addition of Al and Y brings about a combination of good strength and elongation for the Mg–8Li alloy.

EFFECTS EVALUATION FOR DIFFERENT RARE EARTH ELEMENTS IN MAGNESIUM-LITHIUM ALLOY

1 wt.% different rare earth elements (Ce, Y, Gd, misch metal, Nd) are added into the alloy of Mg6Li-1.5Al, respectively. The different effects on the microstructure and mechanical properties are evaluated. The additions of these elements produce granular and rod-like precipitated phases, which are Al2Ce, Al2Y, AlGd, Al3La, Al2Nd, respecitvely. All the rare elements have refining effects in the alloys. Misch metal and Nd have the best refining effects, while Y and Ce have the least obvious refining effects. All the elements are favorable for the improvement of strength and elongation. Mg6Li-1.5Al-1Ce possesses the highest strength, and Mg-6Li-1.5Al-1Y possesses the highest elongation. If considering the different yield of elements, Mg-6Li-1.5Al-1Y possesses both the highest strength increase per rare earth yield and elongation increase per rare earth yield.

Microstructures and corrosion resistance of three typical superlight Mg–Li alloys

Abstract Three typical superlight Mg–Li alloys (Mg-5Li-3Al-2Zn, Mg-8Li-3Al-2Zn and Mg-14Li-3Al-2Zn) with the matrixes of alfa(Mg), alfa(Mg) + beta(Li) and beta(Li), respectively, are prepared. The microstructures of the alloys are characterized using optical microscopy and X-ray diffraction. The corrosion resistant properties of the alloys are characterized by means of hydrogen evolution, weight loss and potentiodynamic polarization. The alloys are also oxidized at elevated temperature. The microstructure and corrosion resistant property of the alloys after oxidation are also characterized.