Creep deformation of a sixth generation Ni-base single crystal superalloy at 800°C

The interrupted creep tests (ε=0.1%) of a fourth and a sixth generation Ni-base single crystals, i.e. MX-4/PWA 1497 and TMS-238, were conducted at 800 °C and 735 MPa along [001]. TMS-238 had a creep time more than sixty times longer than MX-4/PWA 1497. Microstructural observations showed that stacking faults (SFs) sheared both the γ matrix and γ΄ precipitates in MX-4/PWA 1497, however, SFs sheared only the γ matrix in TMS-238. The factors that...