Abstract
Investment casting is an effective way to produce very thin and most complex components with very high-dimensional accuracy and surface finish. A wax pattern is repeatedly dipped into ceramic slurry, and coarse stucco is sprinkled over it to develop a ceramic shell. Very fine ingredients are used to achieve smooth internal surface in the ceramic shell. These fine ingredients of the inner coat reduce the shell permeability, which lead to porosity defects on the cast part. In the present work, an attempt is made to enhance the permeability of ceramic shell by mixing fine needle coke and coarse needle coke powders to inner and outer coat slurries, respectively. After firing, fine needle coke and coarse needle coke got burnt and left some microspores and macrospores in the inner and outer layers of the shell, respectively. These pores improved the shell permeability to a considerable extent. Modified ceramic slurry with needle coke offered higher slurry retention rate as compared to the conventional slurry. Modified shell also possesses sufficient flexural strength and fair inner surface roughness. Field-emission scanning electron microscope (FE-SEM) is used to examine the microstructure of conventional and modified shells, and it is found that some pores are developed at the inner and outer layers of the modified shell, which lead to increment in permeability.
Similar content being viewed by others
References
S. Pattnaik, D.B. Karunakar, P.K. Jha, J. Mater. Process. Technol. 212(11), 2332–2348 (2012)
O. Bemblage, D.B. Karunakar, in Proceedings of the world Congress on Engineering, London, U.K., (2011)
A.S. Sabau, S. Viswanathan, Mater. Sci. Eng. 362(1–2), 125–134 (2003)
V.F Okhuysen, K. Padmanabhan, R.C. Voigt, in Investment Casting Institute: 46th Annual Technical Meeting, Orlando, Florida. (1998)
P.R. Johnson, E.S. Lassow, U.S. Patent. 4,966,225 (1990)
D. Liao, Z. Fan, W. Jiang, E. Shen, D. Liu, J. Mater. Process. Technol. 211(9), 1465–1470 (2011)
S. Jones, C. Yuan, J. Mater. Process. Technol. 135(2–3), 258–265 (2003)
C. Yuan, S. Jones, S. Blackburn, J. Eur. Ceram. Soc. 25(7), 1081–1087 (2005)
R. Doles, D. Viers, Nalco Company LLC, U.S. Patent 10,942,451, (2006)
S. Amira, D. Dube, R. Tremblay, J. Mater. Process. Technol. 211(8), 1336–1340 (2011)
B.S. Sidhu, P. Kumar, B.K. Mishra, J. Mater. Eng. Perform. 17(4), 489–498 (2008)
F. Wang, F. Li, B. He, B. Sun, Ceram. Int. 40(1), 479–486 (2014)
W. Everhart, S. Lekakh, V. Richards, J. Chen, H. Li, K. Chandrashekhara, Int. J. Metalcasting 7(1), 21–27 (2013)
M. Xu, S.N. Lekakh, V.L. Richards, Int. J. Metalcasting 10(3), 329–337 (2016)
J. Bundy, S. Viswanathan, Int. J. Metalcasting 3(1), 27–37 (2009)
Y.G. Jung, E. Tumenbayar, H.H. Choi, H.Y. Park, E.H. Kim, J. Zhang, Ceram. Int. 44(2), 2223–2230 (2018)
Y. Li, X. Liu, K. Lű, X. Du, Int. J. Metalcasting (2019). https://doi.org/10.1007/s40962-019-00323-2
Z. Li, X. Liu, K. Lv, Int. J. Metalcasting (2019). https://doi.org/10.1007/s40962-019-00362-9
C.W. Park, S. Yoon, S.M. Oh, Carbon 38(9), 1261–1269 (2000)
H.G. Kang, J.K. Park, B.S. Han, H. Lee, J. Power Sources 153(1), 170–173 (2006)
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Kumar, S., Karunakar, D.B. Characterization and Properties of Ceramic Shells in Investment Casting Process. Inter Metalcast 15, 98–107 (2021). https://doi.org/10.1007/s40962-020-00421-6
Published:
Issue Date:
DOI: https://doi.org/10.1007/s40962-020-00421-6