Nanoscale investigation of deformation characteristics in a polycrystalline silicon carbide

Research output: Contribution to journalArticlepeer-review


  • D. Zhang
  • L. G. Zhao
  • A. Roy
  • Y. L. Chiu

Colleges, School and Institutes

External organisations

  • Loughborough University
  • EPSRC Centre for Doctoral Training in Physical Sciences for Health


In this paper, we study the mechanical behaviour of silicon carbide at the nanoscale, with a focus on the effects of grain orientation and high-dose irradiation. Grain orientation effect was studied through nanoindentation with the aid of scanning electron microscopy (SEM) and EBSD (electron backscatter diffraction) analyses. Mechanical properties such as hardness, elastic modulus and fracture toughness were assessed for different grain orientations. Increased plasticity and fracture toughness were observed during indentations on crystallographic planes which favour dislocation movement. In addition, for SiC subjected to irradiation, increases in hardness and embrittlement were observed in nanoindentations at lower imposed loads, whereas a decrease in hardness and an increase in toughness were obtained in nanoindentations at higher loads. Transmission electron microscopy (TEM) analyses revealed that the mechanical response observed at a shallow indentation depth was due to Ga ion implantation, which hardened and embrittled the surface layer of the material. With an increased indentation depth, irradiation-induced amorphization led to a decrease in hardness and an increase in fracture toughness of the material.


Original languageEnglish
JournalJournal of the Australian Ceramic Society
Publication statusAccepted/In press - 1 Jan 2019


  • Focused ion beam, Fracture toughness, Irradiation damage, Nanoscale deformation, Silicon carbide