|About this Abstract
||2019 TMS Annual Meeting & Exhibition
||Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys III
||Creep Deformation Mechanisms and Compositional Changes in SX Co-base Superalloys Studied by Means of EM and APT
||Malte Lenz, Yolita Eggeler, Julian Müller, Dorota Kubacka, Surendrar Makineni, Christopher Zenk, Nicklas Volz, Steffen Neumeier, Peter Felfer, Philip Wollgramm, Gunther Eggeler, Mathias Göken, Baptiste Gault, Dierk Raabe, Erdmann Spiecker
|On-Site Speaker (Planned)
In this work a multinary SX Co-based superalloy (ERBOCo-1) was creep deformed at 850°C in tension and compression. At different creep stages corresponding to plastic strains of 0.3% and 5% characteristic defect processes are activated giving rise to a tension-compression asymmetry. The nature of planar faults and dislocations are characterized using conventional TEM and large-angle convergent beam electron diffraction (LACBED). Moreover, HR-STEM imaging combined with geometric phase analysis (GPA) was utilized to study the atomic structure of these defects. The chemical composition of twins, superlattice intrinsic/extrinsic stacking faults and superpartial dislocations was studied by combining STEM-EDXS and atom probe tomography (APT). A site-specific preparation method was applied to prepare APT-tips containing single planar defects. HR-STEM and EDXS investigations show that the local crystal structure in SISFs changes from L12 to D019 accompanied by localized compositional changes. We also investigated the influence of defects on the microstructural degradation.
||Planned: Supplemental Proceedings volume