J Mater Sci Technol ›› 2009, Vol. 25 ›› Issue (02): 273-276.

• Articles • Previous Articles     Next Articles

Preparation of Semisolid A356 Alloy Feedstock Cast via a Pipe Consisting of Partial Inclined and Partial Vertical Sections

Xiaorong Yang1,2) and Weimin Mao1)†   

  1. 1) School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
    2) School of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China
  • Received:2007-10-29 Revised:2008-01-30 Online:2009-03-28 Published:2009-10-10
  • Contact: Weimin Mao
  • Supported by:

    the National Key Basic Research Foundation of China under grant No. 2006CB605203
    the National Hi-Tech Research Foundation of China under grant No. 2006AA03Z115 
    the National Natural Science Foundation of China under grant No.50774007

Abstract:

In the present work, the microstructures of A356 feedstock cast via a pipe consisting of partial inclined and partial vertical sections were investigated. The experimental results indicate that semisolid feedstock with ideal microstructures can be obtained at higher temperatures 645°C and above by the proposed process, and the solid shell inside the pipe can be avoided at the optimum pouring temperature. Thus the process is attractive for industrial applications. The slanted angle of inclined section has an influence on the optimum pouring temperature. That is, the bigger the slanted angle, the higher the optimum pouring temperature, but accordingly, the greater the possibility of solid shell occurring inside the pipe. Therefore, small slanted angle should be considered first on the premise of ensuring a certain nucleation. The formation of semisolid feedstock is owed to the coactions of wall nucleation and stirring resulting from fluid flow. The inclined section greatly affects nucleation, and the vertical section has an important effect on both nucleation and generating stirring.

Key words: Semisolid, Microstructure, Inclined pipe, Vertical pipe, Primary α-Al