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Nano-scale Shell in Phase Separating Gd-Ti-Al-Co Metallic Glass

  • Chang, Hye Jung (Advanced Analysis Center, Korea Institute of Science and Technology) ;
  • Park, Eun Soo (RIAM, Department of Materials Science and Engineering, Seoul National University) ;
  • Kim, Do Hyang (Center for Non-Crystalline Materials, Yonsei University)
  • Received : 2013.06.12
  • Accepted : 2013.06.20
  • Published : 2013.06.30

Abstract

In the present study, formation of yard and shell has been investigated in as-melt-spun $Gd_{30}Ti_{25}Al_{25}Co_{20}$ alloy using a variety of transmission electron microscopy techniques. The phase separation during cooling leads to the formation of the microstructure consisting of amorphous droplets with different size scales embedded in the amorphous matrix. Due to the interdiffusion at the interface after the first-step phase separation, ~50 nm-thick yard develops on the surface of the primary droplet particle. Due to the critical wetting phenomenon, ~5 nm thickness shell enveloping the droplet forms. The sell is enriched in Co and Ti, implying that the composition is close to that of the droplet.

Keywords

References

  1. Cahn J W (1977) Critical point wetting. J. Chem. Phys. 66, 3667. https://doi.org/10.1063/1.434402
  2. Chang H J, Yook W, Park E S, Kyeong J S, and Kim D H (2010) Synthesis of metallic glass composites using phase separation phenomena. Acta Mater. 58, 2483-2491. https://doi.org/10.1016/j.actamat.2009.12.034
  3. Hays C C, Kim C P, and Johnson W L (2000) Microstructure controlled shear band pattern formation and enhanced plasticity of bulk metallic glasses containing in situ formed ductile phase dendrite dispersions. Phys. Rev. Lett. 84, 2901-2904. https://doi.org/10.1103/PhysRevLett.84.2901
  4. Jayaraj J, Park J M, Gostin P F, Fleury E, Gebert A, and Schultz L (2009) Nano-porous surface states of Ti-Y-Al-Co phase separated metallic glass. Intermetallics 17, 1120-1123. https://doi.org/10.1016/j.intermet.2009.05.008
  5. Johnson W L (1996) Fundamental aspects of bulk metallic glass formation in multicomponent alloys. Mater. Sci. Forum 225-227, 35-50. https://doi.org/10.4028/www.scientific.net/MSF.225-227.35
  6. Kim S Y, Jee S S, Lim K R, Kim W T, Kim D H, Lee E S, Kim Y H, Lee S M, Lee J H, and Eckert J (2011) Replacement of oxide glass with metallic glass for Ag screen printing metallization on Si emitter. Appl. Phys. Lett. 98, 222112-222112-3. https://doi.org/10.1063/1.3596469
  7. Kim Y C, Na J H, Park J M, Kim D H, Lee J K, and Kim W T (2003) Role of nanometer-scale quasicrystals in improving the mechanical behavior of Ti-based bulk metallic glasses. Appl. Phys. Lett. 83, 3093-3095. https://doi.org/10.1063/1.1616198
  8. Lee M H, Bae D H, Kim D H, and Sordelet D J (2003) Synthesis of Nibased bulk metallic glass matrix composites containing ductile brass phase by warm extrusion of gas atomized powders. J. Mater. Res. 18, 2101-2108. https://doi.org/10.1557/JMR.2003.0295
  9. Lee M H, Lee J Y, Bae D H, Kim W T, Sordelet D J, and Kim D H (2004) A development of Ni-based alloys with enhanced plasticity. Intermetallics 12, 1133-1137. https://doi.org/10.1016/j.intermet.2004.04.027
  10. Lee M H and Sordelet D J (2006a) Nanoporous metallic glass with high surface area. Scripta Mater. 55, 947-950. https://doi.org/10.1016/j.scriptamat.2006.07.024
  11. Lee M H and Sordelet D J (2006b) Synthesis of bulk metallic glass foam by powder extrusion with a fugitive second phase. Appl. Phys. Lett. 89, 021921-021921-3. https://doi.org/10.1063/1.2221882
  12. Lim K R, Kim W T, Lee E S, Jee S S, Kim S Y, Kim D H, Gebert A, and Eckert J (2012) Oxidation resistance of the supercooled liquid in Cu50Zr50 and Cu46Zr46Al8 metallic glasses. J. Mater. Res. 27, 1178-1186. https://doi.org/10.1557/jmr.2012.23
  13. Mattern N, Kuhn U, Gebert A, Gemming T, Zinkevich M, Wendrock H, and Schultz L (2005) Microstructure and thermal behavior of two-phase amorphous No-Nb-Y alloy. Scripta Mater. 53, 271-274. https://doi.org/10.1016/j.scriptamat.2005.04.018
  14. Park B J, Chang H J, Kim D H, and Kim W T (2004) In situ formation of two amorphous phases by liquid phase separation in Y-Ti-Al-Co alloy. Appl. Phys. Lett. 85, 6353-6355. https://doi.org/10.1063/1.1842360
  15. Park B J, Chang H J, Kim D H, Kim W T, Chattopadhyay K, Abinandanan T, and Bhattacharyya S (2006) Phase separating bulk metallic glass: A hierarchical composite. Phys. Rev. Lett. 96, 245503. https://doi.org/10.1103/PhysRevLett.96.245503
  16. Park E S, Kim D H, Ohkubo T, and Hono K (2005) Enhancement of glass forming ability and plasticity by addition of Nb in Cu-Ti-Zr-Ni-Si bulk metallic glasses. J. Non-cryst. Solids 351, 1232-1238. https://doi.org/10.1016/j.jnoncrysol.2005.02.019
  17. Park E S, Jeong E Y, Lee J K, Bae J C, Kwon A R, Gebert A, Schultz L, Chang H J, and Kim D H (2007) In situ formation of two glassy phases in the Nd-Zr-Al-Co alloy. Scripta Mater. 56, 197-200. https://doi.org/10.1016/j.scriptamat.2006.10.020
  18. Xing L Q, Li Y, Ramesh K T, Li J, and Hufnagel T C (2001) Enhanced plastic strain in Zr-based bulk amorphous alloys. Phys. Rev. B 64, 180201. https://doi.org/10.1103/PhysRevB.64.180201