Superplastic characteristics and forming of LZ91 Mg-Li alloy sheet

Magnesium-lithium (Mg-Li) alloys, due to their high specific strength, have great potential in the modern aviation industry. The superplastic characteristics, microstructure evolution, mechanical properties, and forming process of LZ91 Mg-Li alloys at 200 degrees C-300 degrees C were studied in this paper. Tensile tests show that the optimal elongation of tensile specimens is 812.6% at 300 degrees C under a strain rate of 5 x 10(-4 )s(-1). The flow stress of the material increases with strain during the high-temperature tensile testing due to the grain coarsening . Meanwhile, low dislocation densities were observed during tension, which is not sufficient for dynamic recrystallisation to occur. The finite element method is used to investigate the forming schemes of a narrow-mouth box component. Finally, this component was manufactured by the powder pressure bulging process at 300 degrees C experimentally.

Automated summary

Magnesium-lithium (Mg-Li) alloys have great potential in the aviation industry due to their high specific strength. This paper studies the superplastic characteristics, microstructure evolution, mechanical properties, and forming process of LZ91 Mg-Li alloys at temperatures ranging from 200 to 300 degrees Celsius. Experimental results confirm the feasibility of using this alloy in aircraft components.