CREEP BEHAVIOR OF AN EASY ORIENTED Ti-48Al PST CRYSTAL
(Department of Materials Science and Engineering,Beijing University of Aeronautics and Austronautics, Beijing100083)
Abstract: The creep deformation behavior of an easy oriented PST crystal was investigated at 800℃ in compression creep. The stress range was 120MPa to 200MPa. The creep curves showed a steady state stage. The application of a power-law equation led to a stress exponent n=6.6 and the creep activation energy Qc=282 kJ/mol, which indicated that dislocation climb controlls creep mechanism. TEM observation of the crept samples at steady state regime showed the formation of substructures in some γ plates.
Key words: TiAl alloy PST crystal creep behavior