|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys II
||Mechanical Properties of Co-based Superalloys with FCC+L12 Two-phase Microstructures
||Haruyuki Inui, Norihiko Okamoto
|On-Site Speaker (Planned)
The creep properties of ‘Co-base superalloys’ consisting of FCC solid-solution based on Co and L1<SUB>2</SUB>-(Co<SUB>3</SUB>(Al,W) cuboidal precipitates have recently been reported to be not so high, being only comparable to that of the Ni-base superalloy of the 1 st generation. There may be many factors for this such as the low γ’-solvus temperature and the low CSF (complex stacking fault) energy of the γ’ phase, both of which are related to the phase stability of the L1<SUB>2</SUB> phase. We believe that the insufficient high-temperature mechanical properties of Co-based superalloys are due to the low strength of the constituent L12 compound at high temperatures, which comes from the very low CSF energy, as is evident from the four-fold dissociation of <110> dislocations. We will discuss some strategies for strengthening Co-based alloys with L1<SUB>2</SUB> cuboidal precipitates in the lights of our experimental findings.