Effect of Heat Treatment on Microstructure and Properties of Rolled Mg-4Y-3Nd-1.5Al Alloy (18 Mar, 10.1007/s11665-024-09342-5, 2024)

Mg-4Y-3Nd-1.5Al alloy sheets were prepared by multi-pass rolling. The effects of the heat treatment process on the microstructure and mechanical properties of the as-rolled alloy were studied. The results showed that during the solution treatment at 520 degrees C, with the increase of solution time, the grain size of the alloy gradually increased, and the Mg-RE phase in the microstructure gradually dissolved. After aging treatment at 200 degrees C, the strengthening phase in the alloy precipitated evenly, and the number of precipitated phases in the solid solution aging alloy was more than that in the direct aging alloy. Under this alloy system, the aging strengthening effect dominates. Through the exploration of the heat treatment process, the alloy sheet with the best mechanical properties was obtained at 520 degrees C solution for 6 h + 200 degrees C aging for 16 h (T6), and the elongation of 12.6% was obtained while satisfying the tensile strength of 302.3 MPa. Compared with the alloy after direct aging treatment, the elongation of the alloy after solid solution aging was greatly improved, which could be attributed to the fact that the solid solution treatment eliminated the residual stress of the alloy sheet and reduced the proportion of the hard-brittle Mg-RE phase.