IN-SITU OBSERVATION OF CRACK PROPAGATION IN PST CRYSTALS OF Ti-49%Al ALLOY①
(Department of Materials Science and Engineering,Beijing University of Aeronautics and Astronautics, Beijing100083, P. R. China)
Abstract: The effects of loading axis to the lamellae on the fracture behavior of PST crystals have been investigated by SEM in-situ testing. The results show that the fracture behavior of PST crystals ofγ-TiAl base alloys depend on not only the angles between cracks and lamellae, but also the angles of loading axis to the lamellae, and the cracks propagating along different paths show different toughening mechanisms, crack resistance, corresponding fracture behavior and fractography.
Key words: PST crystal fracture behavior crack path toughness mechanism