Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-19T05:10:40.320Z Has data issue: false hasContentIssue false

Microstructural Investigation of Grain Growth in Cryomilled Inconel 625 Powder

Published online by Cambridge University Press:  17 March 2011

Kyung H. Chung
Affiliation:
Dept. of Chem., Biochem. Eng. and Mater. Sci., University of California at Irvine, Irvine, CA 92697-2575, USA
Jongsang Lee
Affiliation:
Dept. of Chem., Biochem. Eng. and Mater. Sci., University of California at Irvine, Irvine, CA 92697-2575, USA
Rodolfo Rodriguez
Affiliation:
Dept. of Chem., Biochem. Eng. and Mater. Sci., University of California at Irvine, Irvine, CA 92697-2575, USA
Enrique J. Lavernia
Affiliation:
Dept. of Chem., Biochem. Eng. and Mater. Sci., University of California at Irvine, Irvine, CA 92697-2575, USA
Get access

Abstract

The grain growth behavior of cryomilled nanocrystalline Inconel 625 powders was investigated during isothermal heat treatment at 600 ∼ 900 °C for 1 ∼ 4 hours. The grain size of cryomilled Inconel 625 remained under 250 nm following heat treatment in the temperature range of 600 ∼ 900 °C up to 4 hours, which represents an improved grain stability compared to that of conventional Inconel 625 and cryomilled pure Ni. Microstructural studies, using TEM, revealed the existence of oxide particles after cryomilling. The pinning effects on grain stability by oxide particles were quantitatively analyzed. The grain stability of cryomilled Inconel 625 powders at 900 °C was noted to be better than that at lower temperatures. This behavior was attributed to the presence of two types of precipitates found at this temperature, which were identified as spherical NbC and rod shaped Ni3Nb intermetallic precipitates. These precipitates promote grain growth resistance at this particular temperature via a grain boundary pinning mechanism. The preferred nucleation sites of those precipitates was noted to be at grain boundaries, thereby augmenting the grain boundary pinning effect.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

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

[1] Malow, T. R., and Koch, C. C. (1997). Acta, Mater. 45, 2177 Google Scholar
[2] Zhou, L. Z. and Guo, J. T. (1999). Scripta Mater. 40, 139 Google Scholar
[3] Perez, R. J. Huang, B. and Lavernia, E. J. (1996). NanoStructured Mater. 7, 565 Google Scholar
[4] Erb, U. (1995). NanoStruct. Mater. 5, 533 Google Scholar
[5] Gleiter, H. (2000). Acta Mater. 48, 1 Google Scholar
[6] Eckert, J. Holzer, J. C. and Johnson, W. L.J. (1993). Appl. Phys. 73, 131 Google Scholar
[7] Knauth, P. Charal, A. and Gas, P. (1993). Scripta Metall. Mater. 28, 325 Google Scholar
[8] Boylan, K. Ostrander, D. Erb, U. Palumba, G. and Aust, K. T. (1991). Scripta Metall. Mater. 25, 2711 Google Scholar
[9] Smith, C. S. (1948). Trans. AIME. 175 Google Scholar
[10] Humphreys, F. J. and Hatherly, M., Recrystallization and Related Phenomena, Pergamon Press, Oxford, England, 309 (1995)Google Scholar