Surface Segregation and Oxidation Behavior of Superalloy Powders Fabricated by Argon Atomization

Article Preview

Abstract:

Particle surface component and valence state of nickel-based superalloy FGH96 powders fabricated by argon gas atomization have been measured by X-ray phoelectron spectrometer (XPS) to recognize the effect of powder size, surface segregation and heat treating on the oxidation behavior of powders. Type and phase structure of prior particle boundaries (PPBs) precipitated in HIPed superalloy have been studied also. The results showed that prior particle surface segregation and oxidation happened during the powder collection and storage with the C, O, Ti elements enrichment and Ti, Cr, Al, Zr elements oxidation in the surface respectively. During the heat treating of 1150/2h, normal segregation element Ti and Zr enriched more apparently in the particle surface, on the contrary, negative segregation elements Ni, Al and Co diffused into the particle inner. Furthermore, the higher oxygen level on particle surface enhanced to form much more oxides such as ZrO2, TiO2 and Cr2O3. During HIP process of 1150/2h/150MPa, the oxide ZrO2 as the nuclei accelerated the preferential precipitation of MC-type carbides which forms the continuous harmful PPBs. Definitely, PPB precipitation depended on the prior particle surface segregation and oxidation, surface elements Ti, Cr and Nb enrichment and oxidation reaction enhancement in high temperature such as 1150. Small powders always had little segregation in the surface and thin oxidation layer, but had more oxygen content per weight for its higher specific surface. So using some powders with optimum particle size and lower oxygen content can help to reduce the PPB precipitation.

You might also be interested in these eBooks

Info:

Periodical:

Materials Science Forum (Volumes 747-748)

Pages:

518-525

Citation:

Online since:

February 2013

Export:

Price:

[1] N.K. Park, I.S. Kim. Hot forging of nickel-base superalloy, Journal of Materials Processing Technology. 111 (2001) 98-103.

DOI: 10.1016/s0924-0136(01)00489-7

Google Scholar

[2] Y.C. Li, S.Y. Wang. Development on manufacture of turbine disk from superalloy powder in China, Chinese Journal of Rare Metals. 25 (2001) 226-230.

Google Scholar

[3] S. Rqujol, F. Pettinari, D. Locq. Creep straining micro-mechanisms in a powder-metallurgical nickel-based superalloy, Materials Science and Engineering A. 387 (2004)678-683.

DOI: 10.1016/j.msea.2004.02.091

Google Scholar

[4] J.M. Silva, R.A. Claudio, B.A. Sousae. Characterization of powder metallurgy (PM) nickel base superalloys for aeronautical applications, Materials Science Forum. 514-516 (2006) 495-499.

DOI: 10.4028/www.scientific.net/msf.514-516.495

Google Scholar

[5] M. Carol, F. Gillels, K.K. Ashok. Prior particle boundary precipitation in Ni-base superalloys, The International Journal of Powder Metallurgy. 25 (1989) 301-305.

Google Scholar

[6] R. Thamburaj, W. Wallace, Y.N. Chary, T.L. Prakash. Influence of processing variables on prior particle boundary precipitation and mechanical behavior in PM superalloy APL1, Powder Met. 27 (1984) 169-180.

DOI: 10.1179/pom.1984.27.3.169

Google Scholar

[7] R. Thamburaj, A.K. Koul, W. Wallace, M.C. de Malherbe, in: E.N. Aqua C.I. Whitman (Eds. ), Modern Developments in Powder Metallurgy, vol. 16, Metal Powder Industries Federation, Princeton, NJ. (1985) 635-673.

Google Scholar

[8] P.K. Galenko, O. Funke, J. Wang, et al., Kinetics of dendritic growth under the influence of convective flow in solidification of undercooled droplets, Mater. Sci. Eng. A. 375-377 (2004) 488-492.

DOI: 10.1016/j.msea.2003.10.021

Google Scholar

[9] A.F. Norman, K. Eckler, A. Zambon, et al., The application of microstructure-selection maps to droplet solidification, Mater. Sci. Eng. A. 226-228 (1997) 48-52.

DOI: 10.1016/s0921-5093(96)10587-6

Google Scholar

[10] P.S. Grant. Solidification in Spray Forming, Metallurgical and Materials Transactions A. 38A (2007) 1520-1527.

Google Scholar

[11] S.E. Shamblen , D.R. Chang. Effect of inclusions on LCF life of HIP plus heat treated powder metal Rene95, Metallurgical Transaction B. 168 (1985) 775-781.

DOI: 10.1007/bf02667513

Google Scholar

[12] D.R. Chang, D.D. Krueger, et al. Superalloy powder processing, Properties and turbine disk applications, Conference: Superalloys. (1984) 245-251.

DOI: 10.7449/1984/superalloys_1984_245_273

Google Scholar

[13] N. Liu, H. Yuan, W. Xu, Y. Zhang, G. Zhang. The oxidation characteristics of nickel-based superalloy powders prepared by argon gas atomization, Chinese Journal of Rare Metals. 35 (2011) 481-484.

Google Scholar

[14] Z. Li, G. Zhang, Y. Zhang, H. Yuan, R. Yao, S. Xu, S. Tian. Structures and properties of argon-gas atomized superalloy powders, The Chinese Journal of Nonferrous Metals. 15 (2005) 335-338.

Google Scholar

[15] Z. Gao, G. Zhang, Z. Li, H. Yuan, W. Xu, Y. Zhang, N. Liu. Microstructure characteristics of superalloy powders during rapid solidification prepared by argon atomization, Powder Metallurgy Technology. 29 (2011) 93-97.

Google Scholar

[16] G.A. Rao, P.K. Satya, M. Kumar, M. Srinivas, D.S. Sarma. Characterisation of hipped nickel base superalloy IN718, Materials Science and Technology. 19 (2003) 313-317.

DOI: 10.1179/026708303225010605

Google Scholar

[17] M. Liu, Y. Zhang, P. Liu, Y. Zhang. Study on the PPB defect of P/ M superalloy FGH95, Powder Metallurgy Industry. 16 (2006) 1-5.

Google Scholar

[18] G.A. Rao, M. Srinivas, D.S. Sarma. Effect of oxygen content of powder on microstructure and mechanical properties of hot isostatically pressed superalloy Inconel 718, Materials Science and Engineering A. 435-436 (2006) 84-89.

DOI: 10.1016/j.msea.2006.07.053

Google Scholar

[19] J. Liao, M. Hotta, A. Koshi. Effect of oxygen content on impact toughness of a fine-grained magnesium alloy, Materials Letters. 65 (2011) 2995-3001.

DOI: 10.1016/j.matlet.2011.06.028

Google Scholar

[20] J.F. Radavich, D.J. Meyers, in: M. Gill, C.S. Kortovich, R.H. Bricknell, W.B. Kent, J.F. Radavich (Eds. ), Proceedings of the Fifth International Symposium on Superalloys 1984, TMS, Wrrendale, PA, AIME. (1984) 347-356.

DOI: 10.7449/1984/superalloys_1984_347_356

Google Scholar

[21] E.A. Loria, in: E.A. Loria (Ed. ), Proceedings of the First International Symposium on Superalloy 718—Metallurgy and Applications, TMS, Warrendale, PA. (1989) 427-436.

Google Scholar

[22] F.J. Rizzo, J. Radavich, in: E.A. Loria (Ed. ), Proceedings of the Second International Symposium on Superalloy 718, 625, 706 and Various Derivatives, TMS, Warrendale, PA. (1991) 297-308.

Google Scholar

[23] J.E. Flinn, K.S. Shin, T.F. Kelly, in: E.A. Loria (Ed. ), Proceedings of the Second International Symposium on Superalloy 718, 625, 706 and Various Derivatives, TMS, Warrendale, PA. (1991) 251-260.

Google Scholar

[24] Z. Gao, G. Zhang, Z. Li, H. Yuan, W. Xu, Y. Zhang, N. Liu. Effect of size distribution and oxygen content of powder on microstructure of HIPed superalloy FGH96, Chinese journal of rare metals. 36 (2012) 665-670.

Google Scholar

[25] R.G. Menzies, R.H. Bricknell, A.J. Craven. STEM microanalysis of precipitates and their nuclei in a nickel-base superalloy, Philosophical Magazine A. 41 (1980) 493-508.

DOI: 10.1080/01418618008239328

Google Scholar