Journal of Materials Engineering and Performance

, Volume 14, Issue 1, pp 132–135 | Cite as

Mold-filling characteristics of AZ91 magnesium alloy in the low-pressure expendable pattern casting process

  • H. B. Wu
  • Z. T. Fan
  • N. Y. Huang
  • X. P. Dong
  • X. F. Tian
Processing

Abstract

The magnesium (Mg) alloy low-pressure expendable pattern casting (EPC) process is a newly developed casting technique combining the advantages of both EPC and low-pressure casting. In this article, metal filling and the effect of the flow quantity of inert gas on the filling rate in the low-pressure EPC process are investigated. The results showed that the molten Mg alloy filled the mold cavity with a convex front laminar flow and the metal-filling rate increased significantly with increasing flow quantity when flow quantity was below a critical value. However, once the flow quantity exceeded a critical value, the filling rate increased slightly. The influence of the flow quantity of inert gas on melt-filling rate reveals that the mold fill is controlled by flow quantity for a lower filling rate, and, subsequently, controlled by the evaporation of polystyrene and the evaporation products for higher metal velocity. Meanwhile, the experimental results showed that the melt-filling rate significantly affected the flow profile, and the filling procedure for the Mg alloy in the low-pressure EPC process. A slower melt-filling rate could lead to misrun defects, whereas a higher filling rate results in folds, blisters, and porosity. The optimized filling rate with Mg alloy casting is 140 to 170 mm/s in low-pressure EPC.

Keywords

expandable pattern casting low-pressure casting magnesium alloy 

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Copyright information

© ASM International 2005

Authors and Affiliations

  • H. B. Wu
    • 1
  • Z. T. Fan
    • 1
  • N. Y. Huang
    • 1
  • X. P. Dong
    • 1
  • X. F. Tian
    • 1
  1. 1.State Key Laboratory Plastic Forming Simulation and Mold TechnologyHuazhong University of Science and TechnologyWuhanPeople’s Republic of China

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