An investigation on annealing process and strengthening mechanism of cold rolled Mg-10Li-3Al-2.8Zn alloy

In this study, we investigated the annealing process of a cold-rolled dual-phase Mg-10Li-3Al-2.8Zn alloy and used the crystal defect strengthening model to explain the strengthening mechanism of the annealed Mg-Li alloy. To maximize the strength of the alloy, it is annealed at 553 K for 1 h and then water quenched. The maximum yield strength is 321 MPa and the ultimate tensile strength is 346 MPa. Compared with the cold -rolled alloy, the yield strength is increased by 145 MPa and the ultimate tensile strength is increased by 139 MPa. The high strength of annealed alloy is the result of solution strengthening, fine grain strength-ening, second phase strengthening and dislocation strengthening, in which solution strengthening con-tributes the most. The size, content and distribution of the second phase AlLi and MgLi2Al have significant effects on the strength of the alloy. Higher annealing temperature and rapid cooling are all conducive to the dissolution of AlLi in the matrix, lower temperature and rapid cooling are conducive to the solid solution of MgLi2Al, and higher on the contrary, MgLi2Al will be precipitated quickly at a high temperature. Hard AlLi and MgLi2Al both cause the strengthening of the second phase, but their strengthening effect are far less than that of the second phase solid solution in & beta;-Li. & COPY; 2023 Elsevier B.V. All rights reserved.

Automated summary

In this study, the annealing process of a cold-rolled dual-phase Mg-10Li-3Al-2.8Zn alloy was investigated, and the strengthening mechanism of the annealed Mg-Li alloy was explained using the crystal defect strengthening model. To maximize the strength of the alloy, it was annealed at 553 K for 1 h and then water quenched. The high strength of the annealed alloy was attributed to solution strengthening, fine grain strengthening, second phase strengthening, and dislocation strengthening.