Abstract
The effect of heat treatment and crystallographic orientation on creep behavior of aluminized Ni-base single crystal superalloy CM186LC has been investigated in the present study. The aluminized superalloy has a better creep rupture life after HT2 rather than after HT1 which is indicated by the reduction of the gamma' cuboidal precipitates size. The coating treatment resulted in a significant decrease in creep rupture lives for all specimens. Generally, the specimens with (001) side-surface had a longer creep rupture life than the specimens with (011) side-surface, which means the results were anisotropic with respect to the secondary orientation which is normal to the primary orientation. The anisotropic creep behavior was affected by the microstructural change and the different arrangement of {111}< 101 > slip systems. First, the microstructural change after creep rupture test which is designated by the formation of TCP phase with a preferential orientation and SDZ. Second, the different arrangement of {111}< 101 > slip systems between the two side-surface specimens where the operation of {111}< 101 > slip system would be more activated in (011) side-surface specimen than that in (001) side-surface specimen.