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Indexed by:会议论文

Date of Publication:2009-06-07

Included Journals:EI、CPCI-S、Scopus

Page Number:45-52

Key Words:mathematical modeling; supertight magnesium alloy; direct chill casting; temperature field; butt curl

Abstract:A mathematical model describing the direct chill (DC) casting process for a supertight Mg-Li-Al alloy (LA141) slab has been developed using the finite differential method (FDM). In this study, boundary conditions correspond to the primary and secondary cooling were considered to be the function of slab surface temperature. Especially, because of the formation and development of the butt curl of the slab bottom, the air gap between the slab and dummy block plays an important role during the DC casting process. An equation was proposed, and the heat-transfer coefficient between the slab and dummy block was considered as a function of the time and the slab deformation in this paper. Moreover, the temperature distributions on the slab section which considering the butt curl or not were compared. By calculating the temperature field of the LA141 alloy slabs, the influences of the main casting parameters including casting speed, cooling water flow rate and superheat of melt on the solidification process were analyzed. Calculated results indicated that the impact of increasing the pour temperature in the mold cooling zone is greater than that in the secondary zone. And it has a larger impact at the edge of the slab than that at the center of the slab. Moreover, in order to reduce or eliminate the butt curl, a non-uniform cooling water spiracle was proposed and compared with the conventional cooling method.