Analyzing crack-tip dislocations and their shielding effect on fracture toughness

K. Higashida, M. Tanaka, A. Hartmaier, Y. Hoshino

研究成果: ジャーナルへの寄稿学術誌査読

26 被引用数 (Scopus)


With the aim of experimental clarification of the interaction between a crack and dislocations, crack-tip dislocations in two kinds of plastic zones in silicon crystals were directly observed by high-voltage electron microscopy to analyse by their detail characterisation. Three-dimensional analysis on crack-dislocation interaction revealed that they were shielding type dislocations in both 45°-shear-type and hinge-type plastic zones, which accommodate mainly mode I stress intensity at the crack tip. The crack-tip shielding fields due to dislocations also have been visualised by photoelasticity. In specimens without pre-deformation, photoelastic images due to the mode I crack-tip field were observed when an external load was applied at room temperature. In specimens pre-deformed at high temperatures, photoelastic images corresponding to the dislocation shielding were observed. The shielding field has an effect of accommodating the tensile stress concentration due to the applied load, which increases the critical stress intensity factor for crack extension.

ジャーナルMaterials Science and Engineering A
1-2 C
出版ステータス出版済み - 6月 15 2008

!!!All Science Journal Classification (ASJC) codes

  • 材料科学(全般)
  • 凝縮系物理学
  • 材料力学
  • 機械工学


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