J Mater Sci Technol ›› 2010, Vol. 26 ›› Issue (2): 136-140.

• High Temperature Structural Materials • Previous Articles     Next Articles

Microstructure Formation in Al-Bi-Co Immiscible Alloys Directionally Solidified with Different Melt Superheat Temperatures

Jie He, Chengyao Xing, Jiuzhou Zhao, Lei Zhao   

  1. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • Received:2009-04-16 Revised:2009-07-22 Online:2010-02-28 Published:2010-02-28
  • Contact: Jie He
  • Supported by:

    the Knowledge Innovation Program of the Chinese Academy of Sciences, the National Natural Science Foundation of China (No. 50704032)
    the Liaoning Province Natural Science Foundation of China (No. 20081009)

Abstract:

The directional solidification has been carried out for the Al-4Bi-2.5Co (wt pct) alloys with different melt superheat temperatures. The microstructure characterization and the quantitative metallographic analysis have been performed. The results indicated that the Bi-rich sphere size and cellular spacing decrease with increasing melt superheat temperature. The interaction between the advancing solidification interface and the Bi-rich spheres with different sizes was analyzed. The effect of the melt superheat treatment on microstructure evolution was discussed for the immiscible alloys. The microstructure development in ternary Al-Bi-Co alloys directionally solidified with different melt superheat temperatures was clarified.

Key words: Immiscible alloys, Directional solidification, Melt superheat, Solidification interface