Precipitation behavior of Ti-45A1-3Fe-2Mo-0.5C intermetallics after creep tests at 750 degrees C

摘要

The addition of carbon can improve high temperature creep resistance of TiAl intermetallics. In this work, the precipitation behavior of Ti-45Al-3Fe-2Mo-0.5C during the creep process at 750 degrees C and 200 MPa has been investigated. The results show that the strain of C-doped TiAl is about 60% lower than that of the C-free TiAl at a creep time of 8 x 10(5) s. The precipitations, including phase, Ti3AlC phase and Ti2AlC phases, occurred in the lamellar structure of Ti-45Al-3Fe-2Mo-0.5C after creep tests. The formation of both Ti3AlC and Ti2AlC carbides is promoted at dislocations during creep tests.