Large plasticity of a Mg42Li23Cu25Y10 multiphase composite

A novel Mg42Li23Cu25Y10 nanostructure-bcc ductile phase composite containing a Mg2Cu phase and amorphous zones has been obtained by injection casting. This alloy exhibits a large plastic engineering strain of 83% and plastic true strain of 177% with a flow stress at 4.3% deformation of 425 MPa. During compression, the deformation of the nanometer size bcc particles occurs by grain boundary sliding accommodated by flow controlled by grain boundary diffusion at room temperature. The hierarchical multiphase microstructure design allows for the operation and interaction of different shear deformation bands to provide large plastic strain at high strength.

► The alloys have a hierarchical microstructure with multiphase components.
► A novel Mg42Li23Cu25Y10 alloy exhibits a plastic engineering strain of 83%.
► The plastic deformation is favoured by grain boundary sliding of bcc particles.