The work reviews some preliminary recent micromechanical tests aimed at the evaluation of the fracture toughness of silicon. Pre-cracked nano specimens and alternatively notched nano specimens combined with the theory of critical distances (TCD) are compared. The results show that the fracture toughness of silicon is approximately 1 MPa·m0.5, regardless of the procedure involved (i.e., pre-cracked samples or TCD). This value agrees with macro counterpart, i.e., 0.75-1.08 MPa·m0.5, and therefore the KIC is independent of the size and crystal orientation. However, by employing the TCD, the accurate control of the final crack tip which is currently very challenging, is overcome by using notched specimens. Additionally, the results give information about the crack propagation at the nanoscale. It seems that although the specimen axis deviates from the (011), the crack propagates along the cleavage plane (011) and the process develops very fast by breaking covalent bond at the crack tip. A brief discussion on beyond the breakdown of continuum theory and challenges toward nanometer scale fracture mechanics concludes the paper.
How to Cite
Authors are allowed to retain both the copyright and the publishing rights of their articles without restrictions.
Open Access Statement
Frattura ed Integrità Strutturale (Fracture and Structural Integrity, F&SI) is an open-access journal which means that all content is freely available without charge to the user or his/her institution. Users are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles in this journal without asking prior permission from the publisher or the author. This is in accordance with the DOAI definition of open access.
F&SI operates under the Creative Commons Licence Attribution 4.0 International (CC-BY 4.0). This allows to copy and redistribute the material in any medium or format, to remix, transform and build upon the material for any purpose, even commercially, but giving appropriate credit and providing a link to the license and indicating if changes were made.