STP753

    Effect of Aging on Bulk Formability of Aluminum Alloys

    Published: Jan 1982


      Format Pages Price  
    PDF Version (380K) 16 $25   ADD TO CART
    Complete Source PDF (5.9M) 16 $55   ADD TO CART


    Abstract

    Forming limit lines (FLL) developed for the analysis of workability in bulk deformation processes have been used to evaluate the bulk formability of 2014, 2024, and 7075 aluminum alloys as a function of aging. Using the height (intercept) of FLL's as a workability index allowed bulk formability to be expressed quantitatively. In the three alloys studied, workability was poorest in the naturally aged condition. The workability index increased as the alloys were aged artificially; greatest workability was obtained in the highly overaged condition for all alloys.

    It was concluded that the low workability obtained in the naturally aged and peak-aged conditions resulted from localized shear failure. Tension test results on the 2014 alloy showed that shear localization was prevented in the overaged condition, leading to higher workability. Scanning electron microscope fractographs of fracture surfaces of upset cylinders in all conditions revealed dimples representative of microvoid coalescence. Vertical and 45-deg cracks, however, differed in fracture mode; the former showed features of fibrous tearing, while the latter exhibited shear failure characteristics.

    Keywords:

    bulk deformation processes, workability, forming limit lines, workability index, upset tests, bulk formability, ductile fracture, aluminum alloys, localized shear failure, formability


    Author Information:

    Ertürk, T
    Associate professor and former graduate student, Middle East Technical University, Ankara,

    Kazazoğlu, E
    Associate professor and former graduate student, Middle East Technical University, Ankara,


    Paper ID: STP28385S

    Committee/Subcommittee: E28.02

    DOI: 10.1520/STP28385S


    CrossRef ASTM International is a member of CrossRef.