ALBERT

Description: To explore the effect of neodymium (Nd) on the deformation mechanisms of Mg–Zn alloys, texture and lattice strain developments of hot-rolled Mg–Zn (Z1) and Mg–Zn–Nd (ZN10) alloys were investigated using in situ synchrotron diffraction and compared with elasto-viscoplastic self-consistent simulation under tensile loading. The Nd-containing ZN10 alloys show much weaker texture after hot rolling than the Nd-free Z1 alloy. To investigate the influence of the initial texture on the texture and lattice strain evolution, the tensile tests were carried out in the rolling and transverse direction. During tension, the {002} texture components develop fast in Z1, which was not seen for ZN10. On the other hand, fiber // loading direction (LD) developed in both alloys, although it was faster in ZN10 than in Z1. Lattice strain investigation showed that // LD-oriented grains experienced plastic deformation first during tension, which can be related to basal slip activity. This was more apparent for ZN10 than for Z1. The simulation results show that the prismatic slip plays a vital role in the plastic deformation of Z1 directly from the beginning. In contrast, ZN10 plastic deformation starts with dominant basal slip but during deformation prismatic slip becomes increasingly important.

Description: By applying cold extrusion, an elemental metal powder composite Al60Mg40 was prepared. The texture gradient was measured over the cross-section of the extrusion profile using synchrotron radiation while the bulk texture was obtained by neutron diffraction. The aluminum phase shows a typical texture component of plane-strain deformation in the middle part of the sample and a uniaxial deformation texture at the surface. In the central region of the extruded bar, the (0002) Mg pole figure shows a split along the extrusion direction (±ED), which also has been observed in rare-earth containing magnesium alloys. These two poles twist towards the transverse direction on moving towards the surface of the extruded bar; one pole moves to +TD and the other one to −TD. The angle of twist increases towards the TD surface.

Description: Anisotropic behavior is a key characteristic for understanding eccentricity in tubes. In this paper, the effect of using a tilted die during tube drawing on eccentricity, texture, dislocation density, and mechanical properties is shown. Copper tubes were drawn with a ±5° tilted die for two passes. The increase or decrease in eccentricity can be controlled by controlling the angle of the tilted die. Two types of textures have been developed during tube drawing, namely plane strain and uniaxial types. Plain strain type texture is mainly characterized by the β fiber with a dominant copper component {112}. The uniaxial deformation type is dominated by the fiber, as commonly found by wire drawing. Texture sharpness increases with increasing drawing strain, and the texture varies significantly between the maximum and minimum wall thickness. This texture variation between maximum and minimum wall thickness has no significant influence on mechanical properties, which are more or less similar, but the increase in strength after each drawing pass is apparent. The dislocation density is low for the as-received tubes due to recovery and recrystallization. This is consistent with the as-received texture dominated by the cube component {001}. During tube drawing, dislocation density increases as a function of the deformation strain. The variation of dislocation density between the maximum and minimum wall thickness in the tube deformed with −5° tilted die is higher than the variation in the tube deformed with +5° tilted die.