Liquid phase separation の履歴(No.3)

Liquid phase separation†

Multi-step liquid phase separation†

Figure 1
Schematic illustration of the multi-step liquid phase separation [1,5].

Figure 2
Various-size Cu-globules dispersed Fe-based metallic glass. The unique fractal structure was formed through the multi-step liquid phase separation [4,5].

REFERENCES
Recently, two-phase amorphous alloys have been obtained through liquid phase separation in La-Zr-Al-Ni-Cu[1], Y-Ti-Al-Co[2], and Ni-Nb-Y[3] by means of rapid solidification. In a multi-component alloy system, phase separation in a liquid state occurs first, after which each liquid region undergoes a liquid-to-glass transition, resulting in the formation of a two-phase amorphous alloy. These alloys systems also show an unique behavior of "multi-step liquid phase separation". Figure 1 shows the schematic illustration of multi-step liquid phase separation. We try to develop new metallic materials based on the concept of multi-step liquid phase separation in Fe-Cu and Co-Cu based alloys [4,5]. Figure 2 shows the typical example of Fractal-like structure formed by multi-step liquid phase separation in Fe-Zr-B-Cu alloys [4,5].
REFERENCES
[1] A.A Kundig, M. Ohnuma, D.H. Ping, T. Ohkubo, K. Hono, Acta Mater. 52, 2441 (2004).
[2] B.J. Park, H.J. Chang, D.H. Kim, W.T. Kim: Appl. Phys. Lett. 85, 6353, (2004).
[3] N. Mattern, U. Kuhn, A. Gebert, T. Gemming, M. Zinkevich, H. Wendrock, L. Schultz: Scripta Mater. 53, 271, (2005).
[4] T. Nagase, A. Yokoyama and Y. Umakoshi: Mater. Trans, 47, 1105-1114 (2006). http://www.jim.or.jp/journal/e/47/04/1105.html
[5] T. Nagase, A. Yokoyama and Y. Umakoshi: J. of alloys and compounds, 494, 295-300 (2010). http://dx.doi.org/10.1016/j.jallcom.2010.01.015