Radial Additive Friction Stir Repairing of Mechanical Hole Out of Dimension Tolerance of AZ31 Magnesium Alloy Assisted by Stationary Shoulder: Process and Mechanical Properties

Radial additive friction stir repairing (R-AFSR) assisted by stationary shoulder was put forward in the present study, which can be employed to repair mechanical hole out of dimension tolerance AZ31 magnesium alloy sheet. The results show that has sealed-barrier, heat-sink and extra-forging effects. effect improves microstructure uniformity along zone (SZ) thickness surface appearance repaired hole, sealed-barrier effects eliminate super-fine grain band SZ. Therefore, these three improve formation quality region, thereby enhancing properties compared with conventional R-AFSR. tensile compressive shear strengths R-AFSR both increase first then decrease when rotating speed changes from 1200 1800 rpm, maximum values, respectively, reach 190 ± 3 MPa 64.5 2 at 1400 rpm. addition during obtain a higher-quality broaden process window.