P. Delobelle et P. Robinet, VISCOPLASTIC BEHAVIOR AND MODELIZATION OF A RECRYSTALLIZED ZIRCALOY-4ALLOY UNDER UNIAXIAL AND MULTIAXIAL LOADINGS, Journal de physique. III, 4(8), 1994, pp. 1347-1382
Citations number
47
Categorie Soggetti
Material Science","Phsycs, Fluid & Plasmas","Physics, Applied
The results of experiment performed on a recrystallized zircaloy 4 all
oy in the intermediate temperature domain 20 less-than-or-equal-to T l
ess-than-or-equal-to 400-degrees-C are presented. To characterize the
anisotropy, especially at 350-degrees-C, the tests were made under bot
h monotonic and cyclic uni- and bidirectional loadings, i.e. tension-c
ompression, tension-torsion and tension-internal pressure tests. The d
ifferent anisotropy coefficients and especially [GRAPHICS] seem to be
temperature independent. An important feature of the behavior of this
alloy in the neighbourhood of 300-degrees-C is attributed to the dislo
cations-point defects interactions (dynamic strain aging), phenomena o
ften observed in the solid solutions. For the 2D cyclic non proportion
al loadings it is shown that a weak supplementary hardening appears, w
hich is a function of the degree of the phase lag. We propose to parti
cularize and to apply a unified viscoplastic model with internal varia
bles to the considered alloy, as the model as already been developed a
nd identified elsewhere for other isotropic materials. From a general
point of view the introduction of the anisotropy in the model is made
by four tensors of rank 4; [M] is assigned to the flow directions, [N]
to the linear parts of the kinematical hardening variables and [Q], [
R] respectively to the dynamic and static recoveries of these tensoria
l variables. This phenomenological formulation leads to a correct repr
esentation of the set of the experimental results presented at 350-deg
rees-C, which provides an a posteriori confirmation of the formalism u
sed.