SEDL / STP / STP827-EB / STP37441S

Fractographic Analysis of Biaxial Failure in Ceramics

Mecholsky, JJ
Member Technical Staff, Sandia National Laboratories, Albuquerque, N.M.

Rice, RW
Head, Ceramics and Glass Materials Branch, Naval Research Laboratory, Washington, D.C.

Pages: 9    Published: Jan 1984

Download this paper for $25 PDF (164K)          View License Agreement
Abstract

Borosilicate and silica glass, Pyroceram 9606 glass ceramic, and polycrystalline magnesium fluoride ceramic disks were biaxially stressed and the fracture surfaces examined to determine the size of the fracture surface features. The fracture stress (σ)-fracture mirror radii (rj) relationship σjm=Mj where Mj are the mirror constants (j = 1, 2, 3) and m is constant, usually 0.5, is shown to hold for uniaxial, flexural, and biaxial loading conditions. This implies that any local differences of the stress state at the fracture-initiating site are dissipated by the time the crack-front forms mist, hackle, and crack branching, making measurement of the boundaries of these features a general fracture characteristic.