ISSN: 0090-3973
Page Count: 10

In Situ Fracture Toughness Measurement Using Scanning Electron Microscopy

Yawny, AA
Institut für Werkstoffe, Ruhr Universität Bochum,

Perez Ipiña, JE
Grupo Mecánica de Fractura. Universidad Nacional del Comahue/CONICET,

(Received 15 August 2002; accepted 23 April 2003)

Abstract

In situ tests were developed to measure fracture toughness (K^Ic, J^Ic, CTOD, R-curves) in small samples, simultaneously observing details of the crack blunting, initiation, and propagation by using scanning electron microscopy (SEM). A small load frame was employed for this purpose and in situ tests were performed in a Philips 515 SEM with a small chamber. A load-load line displacement record could be obtained from the different types of tests in order to calculate any fracture mechanics parameter, determine the initiation and amount of stable crack growth, measure directly the CTOD or Schwalbe's δ⁵ and correlate any of these parameters with the observed micromechanisms. The applicability of the proposed in situ fracture toughness measurement technique has been exemplified making use of a wide set of materials, and its limitations were also evaluated.

Keywords:
in situ test, fracture toughness, micromechanisms, scanning electron microscopy

Paper ID: JTE12367J
DOI: 10.1520/JTE12367J
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