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The Effect of Casting Conditions on the Fluidity during Lost Foam Casting of Al Alloy  

Shin, Seung-Ryoul (Dept. of Materials Science and Engineering, KAIST)
Han, Sang-Won (Dept. of Materials Science and Engineering, KAIST)
Lee, Kyong-Whoan (Korea Institute of Industrial Technology)
Lee, Zin-Hyoung (Dept. of Materials Science and Engineering, KAIST)
Publication Information
Journal of Korea Foundry Society / v.24, no.1, 2004 , pp. 34-39 More about this Journal
Abstract
The effects of casting condition and hot melt glue during Lost Foam Casting were investigated on the fluidity of Al alloy melt. The fluidity increased linearly with increasing pouring temperature in thick castings but non-linearly in thin casting due to the difference in main heat flow direction. The metal flow velocity was in range of $0.5{\sim}2.7$ cm/s in no evacuation condition and the minimum value of it was measured after the melt flow through the hot melt barrier. The mold evacuation improved the metal flow velocity by around $0.5{\sim}1$ cm/s. And the reaction zone layer thickness was about 1 cm in no-evacuation conditions but about 0.6 cm in mold evacuation condition of 710 torr due to the easier removal of pyrolsis product of EPS. And hot melt barrier thickness of 0.6 mm increased the reaction zone layer thickness up to about 2.5 cm. The fluidity decreased remarkably with an enlarged thickness of hot melt due to a lot of pyrolysis products.
Keywords
lost foam casting; Al-alloy; fluidity; mold flask evacuation; hot melt glue; polystyrene;
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  • Reference
1 S. I. Bakhtiyarov, R. A. Overfelt and A. Alagarsamy, Proceeding of Lost Foam Casting in AFS lOOTH Casting Congress, 'Measurements of Decomposed EPS Gases Pressure and Molten Metal-Polymeric Foam Interface Velocity During Counter Gravity Lost Foam Casting', Dallas, Texas, USA, (2001), 3-16
2 S. R, Shin, H, J, Choi, K. W. Lee and Z. H. Lee; J. of the Korean Foundrymens Society, 'Hydrogen gas pick-up of AI-alloy Melt during Lost Foam Casting', 22 (2002), 167173
3 J. Fu, H. L. Tsai and D. R. Askeland, Transactions of the AFS, 'Mold Filling in Thin Section Castings produced by the Expandable Pattern Casting Process', 103 (1995), 817-828
4 T. R. Smith, 'Method of Casting , U.S. Patent No. 3,157,924, November 25 (1964)
5 E. N. Pan and K. Y. Liao, Transactions of the AFS, 'Study on F10wability of EPC A356 Alloy', 106 (1998),233-242
6 H. L. Tsai and T. S. Chen, Transactions of the AFS, 'Modeling of Evaporative Pattern Process, Part I : Metal Flow and Heat Transfer During the Filling stage', 96 (1988), 881-890
7 H. F. Shroyer, 'Cavityless Casting Mold and Method of Making Same', U.S.Patent No. 2,830,343, April 15 (1958)
8 C. E. Bates, J. Griffin and H. Littleton, 'Expandable pattern Casting, vol. I: Process Manual' edited by AFS Publication, ( 1994), 49
9 X. Liu, c. W. Ramsay and D. R. Askeland, Tranaactions of the AFS, 'Study onMold Filling Control Mechanisms in the EPC Process', 102 (1994), 903-914