STP1413: Ductile Thin Foils of Ni3Al

    Demura, M
    National Research Institute for Metals, Ibaraki,

    Kishida, K
    National Research Institute for Metals, Ibaraki,

    Umezawa, O
    National Research Institute for Metals, Ibaraki,

    George, EP
    Oak Ridge National Laboratory, Oak Ridge, TN

    Hirano, T
    National Research Institute for Metals, Ibaraki,

    Pages: 14    Published: Jan 2001


    Abstract

    Ni3Al thin foils with 315 to 357 μm thickness were successfully fabricated by cold rolling. X-ray pole figures showed the formation of {110} rolling textures with various rolling directions in the foils cold rolled over 83% reduction. The deformation microstructure consists of fine slip traces and coarse and wavy shear bands. Banded deformation structure was observed in some foils. In the foils cold rolled to 83% reduction, the Vickers hardness number reached over 600 and the ultimate tensile strength over 1.7 GPa, irrespective of rolling texture and deformation microstructure. The cold rolled foils showed no tensile elongation, but it was possible to bend the foils. The foils recrystallized at temperatures over 1273 K had some tensile ductility (3.0 to 14.6%), though the polycrystalline Ni3Al is known to be brittle due to severe grain boundary fracture. Electron backscatter diffraction measurements revealed that the large amount of total grain boundary area consists of low angle (LAB) and ∑3 coincidence lattice boundaries. This large fraction is probably a chief cause of the observed ductility.

    Keywords:

    intermetallic compounds, Ni, 3, Al, foil, cold rolling, texture, microstructure, mechanical properties, recrystallization, ductility


    Paper ID: STP10993S

    Committee/Subcommittee: E08.01

    DOI: 10.1520/STP10993S


    CrossRef ASTM International is a member of CrossRef.