STP556: Investigation of the Plastic Fracture of High-Strength Aluminum Alloys

    Van Stone, RH
    Instructor, research assistant, and professor, Carnegie-Mellon UniversityQueens University, PittsburghKingston, Pa.Ont.

    Merchant, RH
    Instructor, research assistant, and professor, Carnegie-Mellon UniversityQueens University, PittsburghKingston, Pa.Ont.

    Low, JR
    Instructor, research assistant, and professor, Carnegie-Mellon UniversityQueens University, PittsburghKingston, Pa.Ont.

    Pages: 32    Published: Jan 1974


    Abstract

    In a study of plastic fracture in five high-strength aluminum alloys (2014, 2024, 2124, 7075, and 7079), it has been shown that fracture toughness is affected primarily by the size and volume fraction of the larger (2 to 10 μm) second-phase particles. Certain of these particles crack at small plastic strains, nucleating voids which, with further plastic strain, coalesce to cause fracture. Not all second-phase particles crack at small plastic strains, and qualitative analysis of those which are primarily responsible for void nucleation shows that they contain iron or silicon or both. This result suggests that a reduction in the iron and silicon impurity content of the alloys should improve fracture toughness without loss of strength.

    Keywords:

    fracture properties, fracture strength, toughness, fractures (materials), rupture (materials), second-phase particles, voids, aluminum alloys, evaluation, tests


    Paper ID: STP33125S

    Committee/Subcommittee: E08.07

    DOI: 10.1520/STP33125S


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