To systematically investigate the microstructural evolution and mechanical property response of AZ41M magnesium alloy TIG welded joints, alternating-current TIG welding is employed to perform butt welding on AZ41M sheets with 3 mm-diameter AZ81 filler wire. Sound welds with uniform formation, free of apparent surface defects and achieving full penetration, are acquired under optimized process parameters. The microstructure and mechanical properties of the joints are systematically characterized using optical microscopy, room-temperature tensile testing, bending testing, and fatigue testing. The results demonstrate that the welded joint yields a yield strength of 124 MPa, an ultimate tensile strength of 231 MPa, and an elongation of 17.4%, with its strength reaching 89.9% of the base metal. The joint successfully passes 180° face-bend and root-bend tests, indicating favorable ductility. The fatigue limit of the joint is determined as 65.2 MPa. High-cycle fatigue cracks preferentially initiate at or near the specimen surface, and the fatigue crack propagation zone exhibits clear radial striation features.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |