Effect of gadolinium on microstructure characteristics and strengthening mechanisms of Mg(‐Gd)‐Nd‐Zn‐Zr alloys by hot treatment

In this study, a quantitative analysis was performed to assess the respective contributions of gadolinium (Gd) addition and heat treatment to the strengthening of the Mg–3Nd–1Zn–0.5Zr alloy. The results indicate that gadolinium addition not only refines the grain structure but also suppresses grain growth, while simultaneously promoting precipitate formation, thereby enhancing the overall strength. Moreover, as the gadolinium concentration increases, both solid‐solution strengthening and the aging response are improved, resulting in higher peak‐aging hardness and an extended incubation period. Notably, the solution‐treated GNZ931K alloy exhibits ultimate tensile strength (UTS), yield strength (YS), and elongation (EL) values of 227.8 MPa, 168.7 MPa, and 11.92 %, respectively. Furthermore, the peak‐aged GNZ931K alloy exhibits excellent room‐temperature mechanical properties, with the ultimate tensile strength, the yield strength, and the elongation values of 312.7 MPa, 219.7 MPa, and 3.34 %, respectively. Additionally, analysis of the strengthening mechanisms reveals that second‐phase strengthening predominates in the as‐cast state, solution strengthening becomes dominant after solution treatment, whereas precipitation strengthening plays a dominant role in the peak‐aged alloy.