The effect of grain boundary orientation on creep and rupture of IN-738 and nichrome

Improvement of grain structure and mechanical properties of a land based gas turbine blade directionally solidified with liquid metal cooling process

“…It can be seen that the DS blades show much higher rupture life and creep elongation than the CC ones (in the order of two times for the rupture life and three times for the creep elongation). Although Woodford and Frawley 13 and later Peterson 14 have reported that directional solidification offers marginal or no improvement in creep properties compared to the CC IN738LC, the present work is in agreement with the results of Quested et al 15 and McLean et al, 16 and clearly shows this improvement through using the high thermal gradient (LMC) process. The only difference between the present results and the results of McLean el al.…”

Directional Solidification of René 80

“…These previous studies indicate that in every case the ductility improvement, thermal shock resistance, and fatigue life extension are promised by directional solidification (DS) processing, but improvements in high temperature strength measured in tensile strength and the creep rupture life are not always ensured (9). The strength improvement, if any, is given to a different extent for different alloys, and there seems no indirect way of knowing the degree of improvement from the composition of an alloy although the amount of elements to contribute the intrinsic (bulk) strength is considered to be important (1).…”