Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-22T22:05:28.191Z Has data issue: false hasContentIssue false

The relationship between thermal history and microstructure in spray-deposited tin-lead alloys

Published online by Cambridge University Press:  31 January 2011

B.P. Bewlay
Affiliation:
Department of Metallurgy and Science of Materials, University of Oxford, Parks Road, Oxford OX13PH, United Kingdom
B. Cantor
Affiliation:
Department of Metallurgy and Science of Materials, University of Oxford, Parks Road, Oxford OX13PH, United Kingdom
Get access

Abstract

Gas-atomized spray deposition involves the creation of a spray of droplets by a gas atomizer and the consolidation and solidification of these droplets on a substrate. The present paper describes an investigation of the fundamental characteristics of heat transfer and solidification during spray deposition. Spray deposition was used to manufacture Sn-15 and 38 wt. % Pb preforms using atomizer-substrate distances of 180 and 360 mm, gas flow rates of 2.5 and 3.4 g/s, and melt flow rates of 61 and 35 g/s. Analytical and numerical models were developed to predict the thermal history of the spray deposit for a range of deposit-substrate heat transfer coefficients. A deposit-substrate heat transfer coefficient of ∼104 W m−2 K−1 was determined by comparing measured and calculated spray-deposit thermal histories both during and after spray deposition. Microstructural analysis of transverse sections of the spray deposits revealed maximum values of spray-deposit density and cell/grain size at specific distances from the deposit-substrate interface. The distance between the density and cell/grain-size maxima and the deposit-substrate interface increased from 0.9 to 10 mm for Sn–15 wt. % Pb and from 2.6 to 11.3 mm for Sn–38 wt. % Pb as the atomizer-substrate distance was increased from 180 to 360 mm and the melt to gas mass flow rate ratio was decreased from 24 to 10. The origin of these microstructural features is described in terms of heat transfer during spray deposition.

Type
Articles
Copyright
Copyright © Materials Research Society 1991

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Singer, A. R. E. and Evans, R.W., Met. Technol. 10, 61 (1983).CrossRefGoogle Scholar
2.Singer, A. R. E., Met. Mater. 4, 247 (1970).Google Scholar
3.Kim, M. H. and Jones, H., in Rapidly Quenched Metals, edited by Steeb, S. and Warlimont, H. (Elsevier North Holland, New York, 1985), p. 139.CrossRefGoogle Scholar
4.Read, P.J., Latimer, K.J., Reynolds, T.D.W., and Munson, D., British Patent 1 431895 (1976).Google Scholar
5.Bricknell, R. H., Metall. Trans. 17A (4), 561 (1986).Google Scholar
6.Fiedler, H.C., Sawyer, T.F., and Koop, R.W., General Electric CRD Report No. 85CRD073 (1985).Google Scholar
7.Bewlay, B. P. and Cantor, B., in Proc. Conf. on Rapidly Solidified Materials, San Diego, CA, 1986, edited by Lee, P. W. and Carbonara, R. S. (ASM, Metals Park, OH, 1986), p. 15.Google Scholar
8.Lavernia, E. J., Ando, T., and Grant, N. J., in Proc. Conf. Rapidly Solidified Materials, San Diego, CA (ASM, Metals Park, OH, 1986), p. 29.Google Scholar
9.Mathur, P., Apelian, D., and Lawley, A., Acta Metall. 37 (2), 429 (1989).CrossRefGoogle Scholar
10.Gutierrez-Miravete, E.M., Lavernia, E.J., Trapaga, G.M., and Szekely, J., Int. J. Rapid Solid. 4, 125 (1988).Google Scholar
11.Bewlay, B. P., D. Phil. Thesis, University of Oxford (1987).Google Scholar
12.Bewlay, B. P. and Cantor, B., Metall. Trans. 21B, 899 (1990).CrossRefGoogle Scholar
13.Smithells Metals Reference Book, edited by Brandes, E. A., 6th ed. (Butterworth's, London, 1983).Google Scholar
14.Schwarz, C., Arch. Eisenhütten. 5, 139 (1931).CrossRefGoogle Scholar
15.Geiger, G. H. and Poirier, D. R., Transport Phenomena in Metallurgy (Addison-Wesley, Reading, MA, 1980), p. 340.Google Scholar
16.Patankar, S. V., Numerical Heat Transfer and Fluid Flow (Hemisphere Books, New York, 1980).Google Scholar
17.Duflos, F., Ph.D. Thesis, University of Sussex (1980).Google Scholar
18.Gillen, A. G. and Cantor, B., Acta Metall. 33 (10), 1813 (1985).CrossRefGoogle Scholar
19.Bewlay, B. P. and Cantor, B., Int. J. Rapid Solid. 3, 30 (1987).Google Scholar
20.Flemings, M. C., Solidification Processing (McGraw-Hill, New York, 1974).CrossRefGoogle Scholar
21.Leatham, A. G., Ph.D. Thesis, University of Wales (1972).Google Scholar