BCC single crystal plasticity modeling and its experimental identification

2008-12-01
Yalçınkaya, Tuncay
Geers, M.G.D.
A crystal plasticity model for body-centered-cubic (BCC) single crystals, taking into account the plastic anisotropy due to non-planar spreading of screw dislocation cores is presented. In view of the longstanding contradictory statements on the deformation of BCC single crystals and their macroscopic slip planes, recent insights and developments are reported and included in this model. The flow stress of BCC single crystals shows a pronounced dependence on the crystal orientation and the temperature, mostly due to non-planar spreading of a/2 < 1 1 1 > type screw dislocation cores. The main consequence here is the well-known violation of Schmid's law in these materials, resulting in an intrinsic anisotropic effect which is not observed in, for example, FCC materials. Experimental confrontations at the level of a single crystal are generally missing in the literature. To remedy this, uniaxial tension simulations are done at material point level for alpha-Fe, Mo and Nb single crystals and compared with reported experiments. Material parameters, including non-Schmid parameters, are calibrated from experimental results using a proper identification method. The model is validated for different crystal orientations and temperatures, which was not attempted before in the open literature.
Modelling and Simulation in Materials Science and Engineering

Suggestions

Thermal and mechanical properties of Cu-Au intermetallic alloys
Kart, HH; Tomak, Mehmet; Cagin, T (IOP Publishing, 2005-07-01)
The thermal and mechanical properties of Cu, Au pure metals and their ordered intermetallic alloys of Cu3Au(L1(2)), CuAu(L1(0)) and CuAu3(L1(2)) are studied by using the molecular dynamics simulation. The effects of temperature and concentration on the physical properties of CuxAu1-x, are analysed. Sutton-Chen (SC) and quantum Sutton-Chen (Q-SC) many-body potentials are used. The simulation results such as cohesive energy, density, elastic constants, bulk modulus, heat capacity, thermal expansion, melting p...
Titanium-magnesium based composites: Mechanical properties and in-vitro corrosion response in Ringer's solution
ESEN, ZİYA; Dikici, Burak; Duygulu, Ozgur; Dericioğlu, Arcan Fehmi (Elsevier BV, 2013-06-20)
Ti-Mg composite rods exhibiting both bioinert and biodegradable characteristics have been manufactured by hot rotary swaging from elemental powders of titanium and magnesium. As a result of processing, spherical magnesium powders elongated in the direction of deformation and the dendritic structure in starting magnesium powders transformed into highly equiaxed grains. Magnesium particles in the outer layer of the composites were decorated by thin layer of MgO while the interior parts were free from oxides. ...
Heterojunction solar cells with integrated Si and ZnO nanowires and a chalcopyrite thin film
KARAAĞAÇ, Hakan; Parlak, Mehmet; YENGEL, Emre; Islam, M. Saif (Elsevier BV, 2013-06-15)
ZnO nanowires (NWs) have been successfully synthesized using a hydrothermal technique on both glass and silicon substrates initially coated with a sputtered ZnO thin film layer. Varying ZnO seed layer thicknesses were deposited to determine the effect of seed layer thickness on the quality of ZnO NW growth. The effect of growth time on the formation of ZnO NWs was also studied. Experimental results show that these two parameters have an important effect on formation, homogeneity and vertical orientation of ...
Surfactant-modified multiscale composites for improved tensile fatigue and impact damage sensing
Yesil, Sertan; Winkelrnann, Charles; Bayram, Göknur; La Saponara, Valeria (Elsevier BV, 2010-10-25)
This paper documents the mechanical and electrical performance of self-sensing conductive polymer composites prepared with a low-cost technique and small hardware, able to considerably improve the dispersion and the surface adhesion of multi-walled carbon nanotubes (CNTs) in epoxy resin with respect to amine-modified CNTs and as-received CNTs. Surface treatment of the CNTs is performed using hexamethylene diamine, or a mix of sulfuric and nitric acid, and one of two surfactants (for the diamine treatment on...
Crystal data, photoconductivity and carrier scattering mechanisms in CuIn5S8 single crystals
Qasrawi, AF; Hasanlı, Nızamı (Wiley, 2001-01-01)
The X-ray diffraction has revealed that CuIn5S8 is a single phase crystal of cubic spinet structure. The value of the unit cell parameter for this crystal is 1.06736 nm. The crystal is assigned to the conventional space group Fd3m. The photocurrent is found to have the characteristic of monomolecular and bimolecular recombination at low and high illumination intensities, respectively. The electrical resistivity and Hall effect of CuIn5S8 crystals are measured in the temperature range of 50-400 K. The crysta...
Citation Formats
T. Yalçınkaya and M. G. D. Geers, “BCC single crystal plasticity modeling and its experimental identification,” Modelling and Simulation in Materials Science and Engineering, pp. 0–0, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/37350.