Structural changes in the alloys of the Mg-1%Zn-xCa system during HPT

Abstract

Structure and mechanical properties of magnesium alloys of the Mg-1%Zn-xCa system subjected to severe plastic deformation via high pressure torsion were studied. It was revealed that the chemical composition of the alloy influenced significantly the formation of the nanocrystalline structure. It was shown that the average grain size of the Mg-1%Zn-0.005%Ca alloy after HPT was 250 nm. HPT of the alloy with the increased content of Ca up to 0.2% led to a formation of the nanostructure with an average grain size of 90 nm. Microhardness measurements showed that all samples subjected to HPT possessed high values of microhardness. It was revealed that the formation of fine particles of Mg2Ca contributed to an increase in thermal stability of the alloy’s structure.