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Segregation and grain refinement in cast titanium alloys

Published online by Cambridge University Press:  31 January 2011

M.J. Bermingham ,
S.D. McDonald ,
D.H. StJohn  and
M.S. Dargusch
M.J. Bermingham*
Affiliation:
CAST Cooperative Research Centre, School of Engineering, The University of Queensland, Brisbane, Queensland, Australia
S.D. McDonald
Affiliation:
CAST Cooperative Research Centre, School of Engineering, The University of Queensland, Brisbane, Queensland, Australia
D.H. StJohn
Affiliation:
CAST Cooperative Research Centre, School of Engineering, The University of Queensland, Brisbane, Queensland, Australia
M.S. Dargusch
Affiliation:
CAST Cooperative Research Centre, School of Engineering, The University of Queensland, Brisbane, Queensland, Australia
*
a) Address all correspondence to this author. e-mail: [email protected]
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Abstract

The growth restriction factor is a parameter derived from binary phase diagrams and is a useful predictor for the grain refining response when a solute is added to a base alloy. This work investigates the relevance of growth restriction theory to titanium alloys where solidification rates are an order of magnitude faster than previous studies in aluminum- and magnesium-based systems. In particular, the segregation of Fe and Cr in titanium is investigated and the effects on grain size studied. It was found that the Scheil equation reasonably modeled solidification of titanium where cooling rates approach 120 °C/s, and the growth restriction factors for Fe and Cr were useful in predicting prior-β grain refinement. However, it was found that caution must be used when calculating growth restriction factors from binary phase diagrams.

Keywords

CastingGrain sizeTi
Type
Articles
Information
Journal of Materials Research , Volume 24 , Issue 4 , April 2009 , pp. 1529 - 1535
Copyright
Copyright © Materials Research Society 2009

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References

1Semiatin, S.L., Seetharaman, V., and Weiss, I.: Thermomechanical processing of alpha/beta titanium alloys. JOM 49, 33 (1997).CrossRefGoogle Scholar
2Weiss, I. and Semiatin, S.L.: Thermomechanical processing of alpha titanium alloys: An overview. Mater. Sci. Eng., A 263, 243 (1999).CrossRefGoogle Scholar
3Weiss, I. and Semiatin, S.L.: Thermomechanical processing of beta titanium alloys: An overview. Mater. Sci. Eng., A 243, 46 (1998).CrossRefGoogle Scholar
4Singh, A.K. and Schwarzer, R.A.: Texture and anisotropy of mechanical properties in titanium and its alloys. Z. Metallkd. 91, 702 (2000).Google Scholar
5Boyer, R., Welsch, G., and Collings, E.W.: Materials Properties Handbook: Titanium Alloys (ASM International, Materials Park, OH, 1994).Google Scholar
6Samsonov, G.V., Kashchuk, V.A., and Cherkashin, A.I.: Effect of transition metals on the grain size of titanium. Metalloved. Term. Obrab. Met. 11, 30 (1970).Google Scholar
7Crossley, F.A.: Grain refinement of titanium alloys. U.S., Patent No. 4 420 460, December 13, 1983.Google Scholar
8Whitsett, C.R., Sastry, S.M.L., O'Neil, J.E., and Lederich, R.J.: Influence of Rare-Earth Additions on Properties of Titanium Alloys Microstructures and Room-Temperature Tensile Properties of Ti-6Al-4V with Yttrium, Erbium and Mischmetal Additions (McDonnell Douglas Research Labs, St. Louis, 1977).Google Scholar
9McCartney, D.G.: Grain refining of aluminium and its alloys using inoculants. Int. Mater. Rev. 34, 247 (1989).CrossRefGoogle Scholar
10Easton, M.A. and StJohn, D.H.: An analysis of the relationship between grain size, solute content, and the potency and number density of nucleant particles. Metall. Mater. Trans. A 36, 1911 (2005).CrossRefGoogle Scholar
11Greer, A.L., Cooper, P.S., Meredith, M.W., Schnider, W., Schumacher, P., Spittle, J.A., and Tronche, A.: Grain refinement of aluminium alloys by inoculation. Adv. Eng. Mater. 5, 81 (2003).CrossRefGoogle Scholar
12Murty, B.S., Kori, S.A., and Chakraborty, M.: Grain refinement of aluminium and its alloys by heterogeneous nucleation and alloying. Int. Mater. Rev. 47, 3 (2002).CrossRefGoogle Scholar
13StJohn, D.H., Qian, M.A., Easton, M.A., Cao, P., and Hildebrand, Z.: Grain refinement of magnesium alloys. Metall. Mater. Trans. A 36, 1669 (2005).CrossRefGoogle Scholar
14Easton, M.A. and StJohn, D.H.: A model of grain refinement incorporating alloy constitution and potency of heterogeneous nuleant particles. Acta Mater. 49, 1867 (2001).CrossRefGoogle Scholar
15Greer, A.L., Bunn, A.M., Tronche, A., Evans, P.V., and Bristow, D.J.: Modelling of inoculation of metallic melts: Application to grain refinement of aluminium by Al-Ti-B. Acta Mater. 48, 2823 (2000).CrossRefGoogle Scholar
16Lee, Y.C., Dahle, A.K., and StJohn, D.H.: Role of solute in grain refinement of magnesium. Metall. Mater. Trans. A 31, 2895 (2000).CrossRefGoogle Scholar
17Easton, M.A. and StJohn, D.H.: The effect of alloy content on the grain refinement of aluminium alloys, in 2001 Light Metals Proceedings of Sessions, TMS Annual Meeting (Warrendale, PA, 2001), p. 927.Google Scholar
18StJohn, D.H., Easton, M.A., Cao, P., and Qian, M.: New approach to analysis of grain refinement. Int. J. Cast Met. Res. 20, 131 (2007).CrossRefGoogle Scholar
19Easton, M.A. and StJohn, D.H.: Improved prediction of the grain size of aluminum alloys that includes the effect of cooling rate. Mater. Sci. Eng., A 486, 8 (2008).CrossRefGoogle Scholar
20Tamirisakandala, S., Bhat, R.B., Tiley, J.S., and Miracle, D.B.: Grain refinement of cast titanium alloys via trace boron addition. Scr. Mater. 43, 1421 (2005).CrossRefGoogle Scholar
21Cheng, T.T.: The mechanism of grain refinement in TiAl alloys by boron addition: An alternative hypothesis. Intermetallics 8, 29 (2000).CrossRefGoogle Scholar
22Bermingham, M.J., McDonald, S.D., Dargusch, M.S., and St.John, D.H.: The mechanism of grain refinement of titanium by silicon. Scr. Mater. 58, 1050 (2008).CrossRefGoogle Scholar
23Bermingham, M.J., McDonald, S.D., Nogita, K., St. John, D.H., and Dargusch, M.S.: Effects of boron on microstructure in cast titanium alloys. Scr. Mater. 59, 538 (2008).CrossRefGoogle Scholar
24Bermingham, M.J., McDonald, S.D., Dargusch, M.S., and St. John, D.H.: Grain-refinement mechanisms in titanium alloys. J. Mater. Res. 23, 1 (2008).CrossRefGoogle Scholar
25E 112-96 standard test methods for determining average grain size, in Annual Book of ASTM Standards, Vol. 03.01 (ASTM International, Baltimore, MD, 2005), p. 267.Google Scholar
26Bania, P.J.: Beta titanium alloys and their role in the titanium industry. JOM 46, 16 (1994).CrossRefGoogle Scholar
27Zollinger, J., Lapin, J., Daloz, D., and Combeau, H.: Influence of oxygen on solidification behaviour of cast TiAl-based alloys. Intermetallics 15, 1343 (2007).CrossRefGoogle Scholar
28Jacobson, L.A. and McKittrick, J.: Rapid solidification processing. Mater. Sci. Eng., R 11, 355 (1994).CrossRefGoogle Scholar
29Sobolev, S.L.: Rapid solidification under local nonequilibrium conditions. Phys. Rev. E 55, 6845 (1997).CrossRefGoogle Scholar
30Flemings, M.C.: Solidification Processing (McGraw-Hill, New York, 1974).CrossRefGoogle Scholar
31Kurz, W. and Trivedi, R.: Rapid solidification processing and microstructure formation. Mater. Sci. Eng., A 179-180, 46 (1994).CrossRefGoogle Scholar
32Okamoto, H.: Desk Handbook Phase Diagrams for Binary Alloys (ASM International, Materials Park, OH, 2000).Google Scholar