ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
An expression for the lattice strains in a polycrystalline specimen under uniaxial stress field has been extended for all crystal systems. Apparent Miller indices (HKL) are introduced from Miller indices (hkl) and lattice parameters. The lattice strain ε(l1l2l3) of the direction l1l2l3, normal to the plane HKL, can be uniquely expressed for all crystal systems as follows: ε(l1l2l3)={αβ(l1l2l3)+(1−α)[1/(3KV)]}σ p+α(−(t/3)(1−3 cos2 ψ){(1/2)[3/E(l1l2l3) −β(l1l2l3)]})+(1−α){−(t/3)(1−3 cos 2 ψ)[1/(2GV) ]}, where β(l1l2l3) and E(l1l2l3) denote the linear compressibility and the Young modulus, respectively. Bulk modulus KV and shear modulus GV are values for isostrain model. Variable ψ is the angle between loading axis and the normal of the plane HKL. The first term is the strain caused by the hydrostatic stress component σp. The second and third term, strains caused by the differential stress t, correspond to the isostress and the isostrain model, respectively. The parameter α takes a value between 0 (isostrain) and 1 (isostress). A method to determine the hydrostatic stress component σp, differential stress t, and the parameter α from powder x-ray-diffraction is discussed. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.362920
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