Localized shear deformation in magnesium alloy by four-point bending

We demonstrated the localized shear deformation of the Mg alloy after four-point bending tests using synchrotron-radiation (SR) white X-rays and transmission electron microscopy (TEM). In the case of a specimen size with 1-mm height for the four-point test, the results for the (0002) grain group by the SR white X-rays indicated the reduction of twin deformation, and the results for the (101¯0) grain group indicated a minimum lattice strain at a 0.4-mm local area from the compression surface side in the bent AZ31B Mg alloy. The TEM results revealed that twin deformation decreased at the local area along with the integrated intensity of the (0002) grain group, and dense dislocations between parallel twins were observed in the local area. Moreover, the slip activity in twin was found at 0.4 mm. Thus, localized shear deformation occurred at local area of the compression side.