Fragmentation process of platelet Al3Ti particles in compressed Al-Al3Ti alloy observed by serial sectioning and EBSD analysis

The fragmentation mechanism of platelet Al3Ti particles in Al-Al3Ti alloy during compression was investigated by combining serial sectioning and electron backscatter diffraction (EBSD) analysis. To observe the fragmentation process of a platelet Al3Ti particle in detail, same-area observation of the platelet Al3Ti particles was performed. When the Al-Al3Ti alloy was compressed up to a nominal strain of 5%, a twin boundary parallel to the {112} Al3Ti trace was observed inside the platelet Al3Ti particle. Subsequently, when a nominal strain up to 8% was reached, a crack was generated in the same platelet Al3Ti particle. From three-dimensional imaging and the results of crystallographic analysis for the fragmented Al3Ti particle, it is found that the crystal plane orientation on the fracture surface was {112} Al3Ti . Because {112} Al3Ti is a twin boundary plane of Al3Ti, the crack in the platelet Al3Ti particle propagated along this boundary. Therefore, it is concluded that fragmentation of platelet Al3Ti particles in Al–Al3Ti alloy preferentially occurs at twin boundaries after twinning deformation.