STP745

    Precracking of Fracture Toughness Specimens by Wedge Indentation

    Published: Jan 1981


      Format Pages Price  
    PDF Version (160K) 11 $25   ADD TO CART
    Complete Source PDF (4.5M) 11 $55   ADD TO CART


    Abstract

    A technique devised for precracking single-edge notch beam KIc specimens of cemented carbides has been extended to several nonmetallic materials. The mechanism of formation and growth of a precrack under an indenter is discussed in terms of indentation theory, the material and geometry of the indenter, and the properties of the specimen material. For cemented carbides, the material's fracture toughness and the indenter angle appear to be the most important parameters governing the stability of a precrack, and this is probably true for other materials.

    In materials with very fine or poorly defined precracks, it has been shown that a compliance method can be combined with the wedge indentation precracking procedure to enable KIc to be determined without measuring the crack length.

    Keywords:

    fracture toughness, brittle materials, brittle materials testing, fracture (materials), indentation fracture, cracking (fracturing), cemented carbides, ceramics, magnesite refractory, crack propagation, composite materials


    Author Information:

    Almond, EA
    Principal and senior scientific officers, Division of Materials Applications, National Physical Laboratory, Teddington, Middlesex

    Roebuck, B
    Principal and senior scientific officers, Division of Materials Applications, National Physical Laboratory, Teddington, Middlesex


    Paper ID: STP28299S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP28299S


    CrossRef ASTM International is a member of CrossRef.