Atomic-resolution imaging of the nanoscale origin of toughness in rare-earth doped SiC.
Ultrahigh-resolution transmission electron microscopy and atomic-scale spectroscopy are used to investigate the origin of the toughness in rare-earth doped silicon carbide (RE-SiC) by examining the mechanistic nature of the intergranular cracking events which we find to occur precisely along the RE-decorated interface between the SiC grains and the nanoscale grain-boundary phase. We conclude that, for optimal toughness, the relative elastic modulus across the grain-boundary phase and the interfacial fracture toughness are the most critical material parameters; both can be altered with judicious choice of rare-earth elements.
Kueck
Aaron M
AM
Materials Sciences Division, and National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Kim
Do Kyung
DK
Ramasse
Quentin M
QM
De Jonghe
L C
LC
Ritchie
R O
RO