Formation of an 18R long-period stacking ordered structure in rapidly solidified Mg{sub 88}Y{sub 8}Zn{sub 4} alloy

Journal Article · Mon Aug 15 00:00:00 EDT 2016 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2016.06.032· OSTI ID:22689599

Garcés, Gerardo ^[1]; Requena, Guillermo ^[2]; RWTH Aachen, 52062 Aachen ^[3]; Tolnai, Domonkos ^[4]; Pérez, Pablo; Medina, Judit ^[1]; Stark, Andreas ^[4]; Schell, Norbert ^[5]; Adeva, Paloma ^[1]

---

1. Department of Physical Metallurgy, National Center for Metallurgical Research (CENIM-CSIC), Avda. Gregorio delAmo 8, 28040 Madrid (Spain)
2. Institute of Materials Research, German Aerospace Centre, Linder Höhe, 51147 Köln (Germany)
3. Germany
4. Institute of Materials Research, Helmholtz-ZentrumGeesthacht, Max-Planck-Str. 1, 21502 Geesthacht (Germany)
5. Structural Research on New Materials, Helmholtz-ZentrumGeesthacht Outstation at DESY, Hamburg (Germany)

The formation of the long-period stacking ordered structure (LPSO) in a Mg{sub 88}Y{sub 8}Zn{sub 4}(at%) ribbon produced by melt spinning was studied using high energy X-ray synchrotron radiation diffraction during in-situ isochronal heating and transmission electron microscopy. The microstructure of the rapidly solidified ribbons is characterised by fine magnesium grains with yttrium and zinc in solid solution and primary 18R LPSO-phase segregated at grain boundaries. Using differential scanning calorimetry, a strong exothermal peak was observed around 300 °C which was associated with the development of the 18R-type LPSO-phase in the magnesium grains. The apparent activation energy calculated using the Kissinger model was 125 KJmol{sup −1} and it is related to simultaneous diffusion of Y and Zn through magnesium basal plane. - Highlights: •The formation of the LPSO phase in rapidly solidified ribbons was studied. •The formation of the 18R LPSO starts at around 300 °C. •LPSO formation have to steps: Stacking faults along basal plane and then growth of 18R structure along the c direction.

• OSTI ID: 22689599
• Journal Information: Materials Characterization, Vol. 118; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
CALORIMETRY
DIFFRACTION
DIFFUSION
GRAIN BOUNDARIES
MAGNESIUM
MAGNESIUM ALLOYS
SOLID SOLUTIONS
STACKING FAULTS
SYNCHROTRON RADIATION
TEMPERATURE RANGE 0400-1000 K
TRANSMISSION ELECTRON MICROSCOPY
X RADIATION
YTTRIUM ADDITIONS
ZINC ADDITIONS