Improving the mechanical properties of duplex Mg-Li-Zn alloy by mixed rolling processing

The microstructure and mechanical properties of a dual-phase Mg-9Li-1Zn (LZ91) alloy after 80% rolling at 250 degrees C and then additional 10% room temperature rolling are studied. After the rolling process, the Mg-rich phase (alpha phase) is squashed and stretched, and Li-rich phase (beta phase) is refined. A large number of small ellipsoidal secondary Mg-rich phases are precipitated in beta phase after rolling process. In addition, Zn-containing phases are precipitated surrounding alpha phase and in beta phase. Under the combined precipitation strengthening of the secondary phases, fine-grain strengthening and processing strengthening in room temperature rolling, the strength of Mg-9Li-1Zn alloy is greatly enhanced. The tensile strength and yield strength of Mg-9Li-1Zn alloy reach 251 MPa and 233 MPa, respectively, and the elongation is over 20%.

Automated summary

The microstructure and mechanical properties of a dual-phase Mg-9Li-1Zn (LZ91) alloy after rolling are studied. The rolling process leads to squashing and stretching of the Mg-rich phase and refinement of the Li-rich phase, with precipitation of secondary Mg-rich phases and Zn-containing phases. The strength of the alloy is greatly enhanced due to the combined effects of precipitation strengthening, fine-grain strengthening, and processing strengthening.