TY - JOUR A1 - Garces, G. A1 - Perez, P. A1 - Cabeza, Sandra A1 - Lin, H. K. A1 - Kim, S. A1 - Gan, W. A1 - Adeva, Paloma T1 - Reverse tension/compression asymmetry of a Mg-Y-Zn alloys containing LPSO phases N2 - Room temperature mechanical behavior of extruded Mg–Y–Zn alloys with varying fractions of LPSO phase was studied in tension and compression along the extrusion direction. The microstructure is characterised by elongated LPSO fibers along the extrusion direction within the magnesium matrix. Moreover, the magnesium matrix presents a bimodal grain structure with dynamically-recrystallized grains and deformed, elongated grains with the basal plane parallel to the extrusion direction. The beginning of plasticity depends on the volume fraction of deformed and DRX grains. Alloys with low volume fraction of LPSO phase (<10 vol%), with a high volume fraction of deformed grains, show the typical behavior of extruded magnesium alloys where yield stress in tension is higher than in compression. This effect is, however, reversed as the volume fraction of the LPSO phase increases since DRX grains are majority. PY - 2015 DO - https://doi.org/10.1016/j.msea.2015.09.003 SN - 0921-5093 SN - 1873-4936 VL - 647 SP - 287 EP - 293 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-35175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pérez, P. A1 - Cabeza, Sandra A1 - Garcés, G. A1 - Adeva, Paloma T1 - Influence of long period stacking ordered phase arrangements on thecorrosion behaviour of extruded Mg97Y2Zn1 alloy N2 - The influence of second phase arrangements on the corrosion resistance of extruded Mg97Y2Zn1 alloy has been evaluated in a 0.1 M NaCl solution. The microstructure of the alloy consists of a high volume fraction of coarse elongated particles of a long period stacking ordered phase aligned along the extrusion direction. Corrosion rate of transversal sections is lower than that of longitudinal sections. Such difference is attributed to the different orientation of second phases in longitudinal and transversal sections. The corrosion front advances mainly perpendicular to the surface in transversal samples while perpendicular and lateral growth occur in longitudinal samples KW - passive films KW - Magnesium alloys KW - anodic dissolution PY - 2016 DO - https://doi.org/10.1016/j.corsci.2016.02.024 SN - 0010-938X VL - 107 SP - 107 EP - 112 PB - Elsevier Ltd. CY - Oxford, UK AN - OPUS4-36358 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Garcés, G. A1 - Perez, P. A1 - Cabeza, Sandra A1 - Lin, H.K. A1 - Kim, S. A1 - Gan, W. A1 - Adeva, Paloma T1 - Reverse tension /compression asymmetry of a Mg–Y–Zn alloys N2 - Room temperature mechanical behavior of extruded Mg–Y–Zn alloys with varying fractions of LPSO phase was studied in tension and compression along the extrusion direction. The microstructure is characterized by elongated LPSO fibers along the extrusion direction within the magnesium matrix. Moreover, the magnesium matrix presents a bimodal grain structure with dynamically-recrystallized grains and deformed, elongated grains with the basal plane parallel to the extrusion direction. The beginning of plasticity depends on the volume fraction of deformed and DRX grains. Alloys with low volume fraction of LPSO phase(o10vol%),with a high volume fraction of deformed grains, show the typical behavior of extruded magnesium alloys where yield stress in tension is higher than in compression. This effect is, however, reversed as the volume fraction of the LPSO phase increases since DRX grains are majority. KW - plasticity KW - Magnesium alloy KW - LPSO PY - 2015 DO - https://doi.org/doi:10.1016/j.msea.2015.09.003 VL - 647 SP - 287 EP - 293 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-36359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cabeza, Sandra A1 - Garcés, G. A1 - Pérez, P. A1 - Adeva, Paloma T1 - Properties of WZ21 (%wt) alloy processed by a powder metallurgy route N2 - Microstructure, mechanical properties and corrosion behaviour of WZ21 (%wt.) alloy prepared by a powder metallurgy route from rapidly solidified powders have been studied. Results were compared to those of the same alloy prepared through a conventional route of casting and extrusion. The microstructure of the extruded ingot consisted of α-Mg grains and Mg3Zn3Y2 (W-phase) and LPSO-phase particles located at grain boundaries. Moreover, stacking faults were also observed within α-Mg grains. The alloy processed by the powder metallurgy route exhibited a more homogeneous and finer microstructure, with a grain size of 2 µm. In this case W-phase and Mg24Y5 phase were identified, but not the LPSO-phase. The microstructural refinement induced by the use of rapidly solidified powders strengthened the alloy at room temperature and promoted superplasticity at higher strain rates. Corrosion behaviour in PBS medium evidenced certain physical barrier effect of the almost continuous arrangements of second phases aligned along the extrusion direction in conventionally processed WZ21 alloy, with a stable tendency around 7 mm/year. On the other hand, powder metallurgy processing promoted significant pitting corrosion, inducing accelerated corrosion rate during prolonged immersion times. KW - Magnesium KW - RE KW - Microstructure KW - Creep KW - Corrosion PY - 2015 DO - https://doi.org/10.1016/j.jmbbm.2015.02.022 SN - 1751-6161 SN - 1878-0180 VL - 46 SP - 115 EP - 126 PB - Elsevier Ltd. CY - Amsterdam [u.a.] AN - OPUS4-32704 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cabeza, Sandra A1 - Garces, G. A1 - Adeva, Paloma A1 - Kabra, S. A1 - Gan, W. T1 - Effect of Extrusion Temperature on the Plastic Deformation of an Mg-Y-Zn Alloy Containing LPSO Phase Using In Situ Neutron Diffraction N2 - The evolution of the internal strains during in situ tension and compression tests has been measured in an MgY2Zn1 alloy containing long-period stacking ordered (LPSO) phase using neutron diffraction. The alloy was extruded at two different temperatures to study the influence of the microstructure and texture of the magnesium and the LPSO phases on the deformation mechanisms. The alloy extruded at 623 K (350 °C) exhibits a strong fiber texture with the basal plane parallel to the extrusion direction due to the presence of areas of coarse non-recrystallised grains. However, at 723 K (450 °C), the magnesium phase is fully recrystallised with grains randomly oriented. On the other hand, at the two extrusion temperatures, the LPSO phase orients their basal plane parallel to the extrusion direction. Yield stress is always slightly higher in compression than in tension. Independently on the stress sign and the extrusion temperature, the beginning of plasticity is controlled by the activation of the basal slip system in the dynamic recrystallized grains. Therefore, the elongated fiber-shaped LPSO phase which behaves as the reinforcement in a metal matrix composite is responsible for this tension–compression asymmetry. KW - Mg-Y-Zn Alloy KW - LPSO Phase KW - Neutron Diffraction PY - 2017 DO - https://doi.org/10.1007/s11661-017-4284-6 VL - 48A IS - 11 SP - 5332 EP - 5343 PB - Spinger AN - OPUS4-42935 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -