Abstract
The influence of strontium modification on microstructure, pore characteristics and tensile properties of Al-Si-Cu castings produced by the expendable pattern casting (EPC) process has been investigated. Test castings have been produced at strontium concentrations varying from 0.0004%–0.03%. The castings have been analysed by microscopic and image analysis techniques. The results indicate that optimum strontium concentrations are between 0.01% and 0.015%. A coarsening of silicon particles is observed at strontium concentrations greater than 0.015%–0.02%. The addition of strontium to the melt also refines the iron- and copper-bearing phases in the casting. The amount of bulk porosity, average pore size and tensile properties of modified EPC castings are comparable to green sand castings. EPC castings are prone to surface porosity. Strontium modification has a significant effect on the pore distributions in EPC castings. The overall porosity and the maximum pore size increase with strontium modification.
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References
A. J. Clegg, Found. Trade J. Int. 9 (1986) 51.
H. J. Heine, Found. M T 114 (1986) 36.
G. del Gaudio, G. Serramoglia, G. Caironi and G. Tosi, Metall. Sci. Technol. 3 (1985) 76.
A. J. Clegg, Found. Trade J. 145 (1978) 393.
Idem, ibid., 145 (1978) 149.
E. J. Sikora, Trans. AFS 86 (1978) 65.
S. Shivkumar and B. Gallois, ibid. 95 (1987) 791.
Idem and B. Gallois, Ibid. 95 (1987) 801.
S. Shivkumar, L. Wang and B. Steenhoff, ibid. 97 (1989) 825.
L. Wang, S. Shivkumar and D. Apelian, ibid. 98 (1990) 923.
S. Shivkumar, L. Wang and D. Apelian, J. Metals 42 (1990) 38.
G. Sigworth, Trans. AFS 91 (1983) 7.
G. Sigworth, S. Shivkumar and D. Apelian, ibid. 97(1989) 811.
S. Shivkumar, S. Ricci, B. Steenhoff, D. Apelian and G. Sigworth, ibid. 97 (1989) 791.
S. Shivkumar, ibid. 101 (1993) 513–518.
G. Sigworth, Mod. Casting 77 (1987) 23.
R. Dasgupta, C. G. Brown and S. Marek, Trans. AFS 96 (1988) 297.
J. F. Major and J. W. Rutter, Mater. Sci. Technol. 5 (1989) 645.
B. Closset and J. E. Gruzleski, Trans. AFS 90 (1982) 453.
m. w. ozelton, g. r. turk and p. g. porter in “Proceedings of the Symposium on Technology for Premium Quality Castings”, Denver, CO, February 1987, edited by E. Dunn and D. R. Durham (The Metallurgical Society, 1988) p. 81.
J. R. Denton and J. A. Spittle, Mater. Sci. Technol. 1 (1985) 305.
J. Charbonnier, J. J. Perrier and R. Portalier, AFS Int. Cast Metals Res. J. 3 (1978) 17.
F. Dimayuga, N. Handiak and J. E. Gruzleski, Trans. AFS 96 (1988) 83.
H. Shahani, Scand. J. Metall. 14 (1985) 306.
K. Tynelius, PhD thesis, Drexel University, Philadelphia, March 1992.
Q. T. Fang and D. A. Granger, Trans. AFS 97 (1989) 989.
M. D. Hanna, S. Lu and A. Hellawell, Metal. Trans. 15A (1984) 459.
D. Argo and J. E. Gruzleski, Trans. AFS 96 (1988) 65.
s. shivkumar, l. wang and r. lavigne, in: “Proceedings of the Symposium on Light Metals”, TMS Annual Meeting, Denver, Colorado, February 1993, edited by Subodh K. Das (The Metallurgical Society, 1993) p. 829.
s. shivkumar, l. wang and c. keller, unpublished results (1993).
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Wang, L., Shivkumar, S. Strontium modification of aluminium alloy castings in the expendable pattern casting process. Journal of Materials Science 30, 1584–1594 (1995). https://doi.org/10.1007/BF00375269
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DOI: https://doi.org/10.1007/BF00375269