Effect of extrusion ratio on microstructures, mechanical properties, and high cycle fatigue behavior of Mg–5Zn–1Mn alloy

• DOI: 10.1016/j.jmrt.2024.03.128
• Publication Date: 2024-03-24T06:45:19Z
• Authors: Tong Mu; Jiawei Yuan; Kai Zhang; Yongjun Li; Xinggang Li; Minglong Ma; Guoliang Shi; Zhaoqian Sun; Kui Zhang
• Keywords: Dislocation slip; Extrusion ratio; Mining engineering. Metallurgy; 0203 mechanical engineering; Twinning/detwinning; TN1-997; Mg-5Zn–1Mn alloy; 02 engineering and technology; Microstructure evolution; High cycle fatigue

The effects of extrusion ratio (ER) on the microstructures, static mechanical properties, and tension-compression high cycle fatigue (HCF) behavior as-extruded Mg–5Zn–1Mn (ZM51) alloy was investigated systematically, HCF mechanism discussed. results show that texture weakening grain refinement caused by increasing ER can effectively enhance properties alleviate tensile-compressive asymmetry alloy. strength at 107 cycles is 124 ± 5, 138 4, 142 5 MPa for ER8, ER11.5, ER23, respectively, corresponding approximately 0.45, 0.49, 0.50, which means ZM51 possesses outstanding resistance. failure analysis microstructure evolution post-fatigued samples demonstrated stress amplitudes characteristics strongly influence At high-stress load, close to tensile yield 160–180 MPa, abundant {101¯2} residual twin bands were observed near fracture surface. Twinning/detwinning deformation dominant due plastic incompatibility between matrix twins. low-stress 125–145 crack initiation transits from twinning/detwinning dislocation slip. Grain inhibit activation twins, twin-dislocation interaction, promote slip dominate deformation, thereby enhancing life This work provides new insight into design development resistance wrought Mg ensure long-term service safety structural materials.