On Non-Dendritic Microstructure Formation during Sand Casting of A356 Alloy

Abstract:

The purpose of this study was to develop a new method for formation of non-dendritic microstructure during sand casting of aluminum alloys without any previous special processing. For this purpose, sand molds with three different types of running systems were designed. The first design included a traditional reverse tapered vertical sprue. The second design was similar to the first one except for a conical sand core placed inside the lower half portion of the sprue creating a narrow gap for the flow of the melt into the mold. In the third design, the core was fitted with metal chills. Molten A356 alloy was then cast from fully liquid state under gravity and centrifugal casting conditions in the molds and the microstructures of the castings were studied. The results showed that non-dendritic microstructure could be achieved by using the last design under low superheat temperature and centrifugal casting conditions. The findings can pave the way for small quantity production of semisolid castings in expendable molds.

• Periodical: Solid State Phenomena (Volumes 192-193)
• Pages: 433-440
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.192-193.433
• Online since: October 2012
• Authors: Mehdi Kaskani, BEHZAD NIROUMAND
• Keywords: A356 Aluminum Alloy, Centrifugal Casting, Expendable Mold, Gravity Casting, Non-Dendritic Structure

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