ABSTRACT Recent studies have shown that using the cooling fins is one of the most appropriate methods to eliminate the shrinkage porosities in the castings. In fact, Fins play the role of heat exchangers during the solidification and their usage is the same as that of chills. The cooling effect of fins is directly related to their geometry. Also the effect of fin on decreasing the time of local freezing is a function of metal’s thermal conductivity, mould thermal conduction, superheating and fin dimensions. In this research, the effect of three types of fins on local solidification time of a casting of A356 and 6069 alloys as well as the effect of moisture content on cooling rate of sand moulds made of carboceramics have been studied. Results indicate that fin affects severely on solidification time and this influence is more severe in castings produced in moulding materials such as carboceramics which can absorb more moisture. The results show that carboceramics as a new refractory material decrease the solidification time significantly. This is particularly evident when the fins were used. Generally, using fins and carboceramics decrease the solidification time down to 45%. This is good news for casting industry in which the mechanical properties can be easily improved using simple ways.
Cite this paper
nullS. Boutorabi and M. Zandira, "Effects of Using Fins and Carboceramics on the Solidification Characteristics of Aluminum Casting Alloys?," Materials Sciences and Applications, Vol. 2 No. 7, 2011, pp. 891-898. doi: 10.4236/msa.2011.27119.
 R. C. Creese and A. R. Sarfaraz, “Effect of Fins at Design of Junction in Castings,” AFS Transactions, 1987, p. 689.
 V. S. Zolotorevsky, N. A. Belov and M. V. Glazoff, “Casting Aluminum Alloys,” Elsevier Ltd., Amsterdam, 2007.
 W. C. Erickson, “Computer Simulation of Solidification,” AFS Cast Metals, 1980, p. 30.
 R. M. Kotschi and C. R. Loper, “Effect of Chills and Cores on the Design of Junction in Simple Shape Castings,” AFS Transactions, 1976, p. 631.
 D. Dispinar et al., “Degassing, Hydrogen and Porosity Phenomena in A356,” Materials Science and Engineering, Vol. 527, No. 16-17, June 2010, pp. 3719-3725.
 H. Nguyen, “The Effects of Solidification Rates on Porosity Formation and Cast Microstructure of Aluminum Alloy A356,” Grand Valley State University, Allendale, 2005.
 M. H. Kim and J. T. Berry, “Some Experimental Observation of the Effect of Fins on the Solidification of Pure Lead, Zinc, and Copper,” Transactions of the American Foundrymen’s Society, Vol. 97, May 1989, pp. 329-334.
 H. M. Guo et al., “Pressurized Solidification of Semi-Solid Aluminum Die Casting Alloy A356,” Journal of Alloys and Compounds, Vol. 485, No. 1-2, 2009, pp. 812-816. doi:10.1016/j.jallcom.2009.06.083
 R. C. Creese and A. R. Sarfaraz, “Effect of Fins on Casting Junction Design,” AFS Transactions, 1987, p. 689.
 R. C. Creese and A. R. Sarfaraz, “Computer Wave Fronts Analysis of Fin Effect in L-shaped Castings,” AFS Transactions, 1988, p. 705.
 R. C. Creese and A. R. Sarfaraz, “Fin Size Determination for Producing Sound Casting,” AFS Transactions, 1989, p. 863.
 M. H. Kim, C. R. Loper and C. S. Kang, “Experimental Analysis of Wave Fronts in Standard Casting Sections and in Finned Castings,” AFS Transactions, 1985, p. 463.
 Y. A. Gengel, “Introduction to Thermodynamics and Heat Transfer,” Mc-Grawhill, New York, 1997.