Textures of Materials - ICOTOM 14

Paper Title Page

Authors: Nikolay Y. Zolotorevsky, D.M. Vasiliev, Yuri Titovets
Abstract: The material studied was commercial pearlitic steel deformed by cold drawing. Internal stresses appearing due to the plastic interaction of cementite and ferrite phases of the lamellar pearlite (interphase stresses) were examined in order to clarify the mechanisms controlling plastic behavior of the lamellar pearlite. It was shown that, while the interphase stress level is high at relatively small drawing strain, it is significantly reduced with true strain increasing up to e = 2. The high level of the interphase stress is restored after annealing of the heavily drawn wire and its repeated straining. This result is considered to support a suggestion that the reduction of interphase stress under severe cold drawing is caused by a transformation of the cementite lamellae substructure.
Authors: Tom Walde, Hermann Riedel
Abstract: In this paper we describe a rolling simulation considering the main sources of plastic anisotropy, namely the Bauschinger effect and crystallographic texture. For this purpose we coupled the VPSC-model of Lebensohn and Tomé [1] with the hardening model of Peeters et al. [2]. The combined model is implemented in the Finite-Element code ABAQUS/Explicit®. With the combination of finite-element method, VPSC-texture model and the hardening model a rolling process is simulated and the nfluence of the Bauschinger effect on the texture evolution is studied.
Authors: Dierk Raabe, Franz Roters, Yan Wen Wang
Abstract: We present a numerical study on the influence of crystallographic texture on the earing behavior of a low carbon steel during cup drawing. The simulations are conducted by using the texture component crystal plasticity finite element method which accounts for the full elastic-plastic anisotropy of the material and for the explicit incorporation of texture including texture update. Several important texture components that typically occur in commercial steel sheets were selected for the study. By assigning different spherical scatter widths to them the resulting ear profiles were calculated under consideration of texture evolution. The study reveals that 8, 6, or 4 ears can evolve during cup drawing depending on the starting texture. An increasing number of ears reduces the absolute ear height. The effect of the orientation scatter width (texture sharpness) on the sharpness of the ear profiles was also studied. It was observed that an increase in the orientation scatter of certain texture components entails a drop in ear sharpness while for others the effect is opposite.
Authors: Svetlana Ristić, S. He, Albert Van Bael, Paul van Houtte
Abstract: An explicit integration algorithm using a texture-based plastic potential and isotropic hardening has been developed and implemented into a commercial explicit finite-element software program through a user material subroutine (VUMAT in ABAQUS/Explicit). Simulations of cup drawing of an IF-steel are presented and compared to both experimental data and calculation results obtained with a previously developed fully implicit approach (UMAT in ABAQUS/Standard). The explicit formulation has the advantage of being more stable, but local sheet thickness variations cannot be reproduced with the same accuracy.
Authors: Z.J. Li, Grethe Winther, Niels Hansen
Abstract: The effect of microstructure and texture on the flow stress anisotropy in aluminium and IF steel has been investigated. The samples are recrystallized commercial purity aluminium (AA1050) cold rolled to prestrains of 0.05, 0.11 and 0.2, and recrystallized IF steel cold rolled to a prestrain of 0.28. The flow stress anisotropy was measured by tensile testing of specimens cut along different directions in the rolling plane. Pronounced anisotropy was found in both materials in spite of weak textures. The yield stress increases with increasing angle between the tensile direction and the rolling direction at all prestrains. The effect of microstructure and texture on the flow stress anisotropy was modelled by incorporating into a full-constraint Taylor model the strengthening effect of dislocation boundaries. The modelling and experimental results agree well, leading to a discussion of effect of the microstructure and texture on the flow stress anisotropy.
Authors: Shouichi Ochiai, Takeshi Murakami, Keizo Hashimoto, Nobuo Ishii, Koichi Hasegawa
Abstract: In Pt-10mass%Rh alloys which were recrystallized using full annealing at or above 1273K after the cold rolling with the reduction ratio of both 90% and 98%, the formation of cube texture has already been found. When these primary recrystallized alloys are subjected to the further annealing at higher temperatures, the occurrence of the secondary recrystallization can be expected. In this study, the development of the cube texture and the process in the coarsening of crystal grains during the secondary recrystallization were investigated. In addition, the creep tests were carried out for the secondary recrystallized alloys and resultant creep properties were compared with those for the primary recrystallized alloys. It became clear that the cube texture which further developed during the secondary recrystallization in 98% rolled specimens exhibits the greater thermal stability than that in secondary recrystallized 90% rolled ones. During the secondary recrystallization, it was confirmed that the grains coarsened according to the law of tm, where t and m show time and a constant, respectively. The higher development of the cube texture and the coarsening of grains during the secondary recrystallization were found to have remarkable effects of improving the creep resistance.
Authors: E.C. Oliver, Mark R. Daymond, Philip J. Withers
Abstract: The influence of texture and anisotropy on the generation of intergranular stresses in clock-rolled zirconium is investigated using neutron diffraction and elastoplastic self-consistent modelling. Comparison between experimental data and model calculations indicates that the operation mainly of prismatic and basal slip explains the trends in intergranular stress evolution during in-plane tensile and through-thickness compressive deformation, whilst twinning plays a significant role during in-plane compression.
Authors: Xin Ming Zhang, Yao Zongyong, De Guang Liu
Authors: Jürgen Hirsch
Abstract: The texture evolution during hot and cold rolling of AlMg1Mn1 can body sheet is described and the related anisotropy effects during deep drawing are analysed quantitatively. The typical textures of rolled aluminium show the transition between ß-fibre orientations and cube recrystallization texture, depending on rolling temperature and strain. These correlate with transitions between 45° and 0°/90° ear heights in deep drawn cups which are described by a new method of Fourier series expansion. Processing parameters to achieve low anisotropy are discussed.

Showing 231 to 240 of 260 Paper Titles