Evaluation of nano ceramic coating on radiographic defects of thin-walled AL4-4 aluminum alloy sand casting

  • Mansour Borouni
  • Behzad Niroumand
  • Mohammad Hossein Fathi
Keywords: AL4-1 Alloy, Nano-ceramic Coating, Thin-walled Parts, Gas Defects, Shrinkage Defect


Internal defects are among the problems in gravity casting of aluminum parts. The main internal volumetric defects are gas and shrinkage defects which form during solidification of the melt and drastically reduce the quality of the produced parts. These defects adversely affect the mechanical properties of thin walled castings parts. In this study, ceramic nanoparticles coatings were applied on the sand mold and the effect of mold coatings on the reduction of defects were investigated. X-ray radiography was used to detect defects in sand molds with ceramic nanoparticles coatings. For comparison, this test was performed on molds with micro-ceramic and graffiti coatings and uncoated sand mold. The results showed that the maximum amount of gas and shrinkage defects was observed in casting parts from AL4-1 alloy in uncoated molds. On the other hand, the minimum defects were found in molds coated with ceramic nanoparticles. It seems that the reduced defects in casting parts in molds coated with ceramic nanoparticles may be due to high thermal and chemical stability and higher heat transfer rate of the coating. These results can facilitate the production of high quality aluminum alloys parts using nanotechnology.


S. Vadim, A. Z. Nikolai: Casting Aluminum Alloy, first ed., Moscow Institute of Steel and Alloys–State Technical University, Elsevier Linacre House, Oxford, 2007.

GOST 1583–89, "Aluminum casting alloys", Moscow, 1993.

R W. Osorio, R.L. Garicia, R.P. Goulart, A. Garcia: Mater Chem Phys, 106 (2007) 343-349.

ASM Handbook Committee, Metals Handbook, Vol. 15, Casting, tenth ed., ASM International, 2008.

Military standard, MIL-STD-2175A, "Castings, Classification and inspection", Department of defense, USA, 1993.

J. Campbell, Castings, second ed., Elsevier Butterworth Heinemann publication, 2003.

A.K. Dahel, L. Baeckrund and L. Arnberg: "Castability of Aluminum foundry alloys", Final report for AFS, 1997.

M. C. Flemings, F. R. Mollard and H. F. Taylor: AFS Transactions, 69 (1961) 566-576.

M.D. Sabatino: "Fluidity of Aluminum Foundry Alloys", Ph.D. thesis, Norwegian University of Science and Technology, 2005.

M.D. Sabatino, L. Arnberg: Metall Sci Technol, 22(2004) 9-15.

K.R. Ravi, R.M. Pillai, K.R. Amaranathan, B.C. Pai, M. Chakraborty: J Alloys Compd, 456 (2008) 201-210.

J. Campbell and R.A. Hardning: "The Fluidity of Molten Metals", Training in aluminum application technologies, TALAT Lecture 3205, Birmingham, 1994.

P.R. Beely, Foundry Technology, Butterworth Scientific, 1972.

N.A. Goldstein: Handbook of Nanophase Materials, Marcel Dekker Inc., 1997.

G.J. Li, X.X. Huang and J.K. Guo: Mater Res Bull, 38(2003) 1591-1600.

L. Feng, Y. Gencang: J Non-Cryst Solids, 290 (2001) 105-114.

ASM Handbook Committee, Metals Handbook: Aluminum and Aluminum Alloys", ASM International, 1992.

J.E. Gruzleski, B.M. Closset: The Treatment of Liquid Aluminum-Silicon Alloys, American Foundry men's Society, 1990.

N. Hongjun, B. Sun, H. Jiang, W. Ding: J Mater Sci Eng A, 352(2003) 294-299.

Metal caster's reference and guide, 1st. ed., American Foundry men's Society, 1972.

D. Stuart, M. Donald, N. Kazuhiro, K. Arne, Dahle: J Alloys Compd, 442 (2006) 184-191.

A.K. Prasada Rao, K. Das, B.S. Murty, M. Chakraborty: Mater Lett, 62 (2008) 273-275.

M. Borouni, B. Niroumand, M.H. Fathi: Materiali in tehnologije, 48 (2014) 473-477.

D. Delaportas, P. Svarnas, I. Alexandrou, A. Siokou, K. Black, J.W Bradley: J Phys D: Appl Phys, 42.24 (2009) 245204.

B.D. Cullity, Elements of X-Ray Diffraction, second ed., Addison-Wesley, 1978.

N. P. Prasad, Nano photonics, John Willey & Sons Inc., 2004.

J.Y. Huang: Nano Lett, 7 (2007) 2335–2340.

A. Hamasaiid, M.S. Dargusch, C.J. Davidson, S. Tovar, T. Loulou, F. Rezaï-Aria and G. Dour: Metall Mater Trans A, 38 (2007) 1303-1316.

A.F. Ilkhchy, N. Varahraam, and P. Davami: Iran J Mater Sci Eng, 9 (2012) 11-20.

M. Nosonovsky. and B. Bhushan: Microsyst Technol, 11(2005) 535-549.

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