Fractography and tensile strength of glass wool fibres

Mechanical reliability such as strength and brittleness is of great interest for application of brittle materials, i.e. glasses and glass fibres. In this paper we study the fracture behaviour and the tensile strength of glass wool fibres (GWFs) of both basalt and E-glass compositions, which play an important role in both transportation and application of GWFs (as insulation material). GWFs are tested in uniaxial tension. The surfaces of the fractured fibres are imaged using scanning electron microscopy. Three main types of fracture surfaces produced in tensile stress are observed, all of which include fracture mirror, mist and hackle features comparable to fracture surfaces of bulk glass and continuous fibres. The three types are: a) surface without visible origin; b) surface with visible origin; c) surfaces originated from internal pores. The relations between the fracture mirror size and the mechanical strength shown for bulk glass and continuous glass fibres are also valid for GWFs. Relation between the fractographic observations and the strength Weibull distributions are discussed in relation to chemical composition and homogeneity. (C) 2008 The Ceramic Society of Japan. All rights reserved.