Uniaxial tensile deformation of uranium 6 Wt Pct niobium : A neutron diffraction study of deformation twinning

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 32; no. 9; pp. 2219 - 2228
• Main Authors: BROWN, D. W, BOURKE, M. A. M, DUNN, P. S, FIELD, R. D, STOUT, M. G, THOMA, D. J
• Format: Journal Article
• Language: English
• Published: New York, NY Springer 01-09-2001; Springer Nature B.V
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Deformation and plasticity (including yield, ductility, and superplasticity); Exact sciences and technology; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Metals. Metallurgy; Neutrons; Physics; Uranium; Binary alloys; Tensile stress; Neutron diffraction; Uniaxial stress; Niobium alloys; Uranium base alloys; Mechanical twin; Plastic properties; Experimental study
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-001-0197-4

The deformation of polycrystalline uranium 6 wt pct niobium (U6Nb) was studied in situ during uniaxial tensile loading by time-of-flight neutron diffraction. Diffraction patterns were recorded at incremental stresses to a maximum of 450 MPa (approx =4 pct macroscopic strain). Consistent with reorientation of the martensite variants by twinning, significant changes in the diffraction peak intensities, which were proportional to the plastic contribution of the macroscopic strain, were observed. Both the lattice parameters (a, b, c, and gamma ) and interplanar spacings (d sub hkl ) were determined as a function of applied stress. Phenomenologically, the highly anisotropic stress response of the lattice parameters as well as the individual lattice spacings can be related to deformation twinning. Preliminary transmission electron microscopy (TEM) studies identified the (130) and (172) as active deformation twinning systems of U6Nb in tension.