STP839

    Effects of Deformation Twinning on the Stress-Strain Curves of Low Stacking Fault Energy Face-Centered Cubic Alloys

    Published: Jan 1984


      Format Pages Price  
    PDF Version (592K) 24 $25   ADD TO CART
    Complete Source PDF (4.3M) 24 $55   ADD TO CART


    Abstract

    A quantitative metallographic study of the effects of mechanical twinning on the uniaxial stress-strain curves of Cu-3.1Sn, Cu-4.9Sn, Cu-30Zn, and Co-40Ni has shown that twinning produces identifiable deformation stages in these alloys. These deformation stages are (1) an interval without twinning, (2) twinning on a single crystallographic plane within a grain, (3) twinning on intersecting twinning planes, and (4) dynamic recovery. In Stage 2, in which twins apparently form on the primary slip plane, twinning decreases the work hardening rate, whereas in Stage 3 the development of intersecting twin arrays increases the work hardening rate by progressively decreasing the effective grain size. The increased work hardening in Stage 3 accounts for the unusually high ductility of those alloys that twin heavily. The strength of the effects of the twinning on the stress-strain curve increases with increasing solute concentration and decreasing temperature.

    Keywords:

    quantitative metallography, face-centered cubic (fcc) alloys, stacking fault energy, deformation twinning, tensile stress-strain curves, volume fraction of twins, ductility, strength


    Author Information:

    Krishnamurthy, S
    National Research Council associate, Air Force, Wright Aeronautical Laboratories, Wright-Patterson Air Force Base, Dayton, Ohio

    Qian, K-W
    professor, Fuzhou University, Fuzhou, Fujian,

    Reed-Hill, RE
    Professor, University of Florida, Gainesville, Fla.


    Paper ID: STP30214S

    Committee/Subcommittee: E04.14

    DOI: 10.1520/STP30214S


    CrossRef ASTM International is a member of CrossRef.