Metastable Precipitates and their Misfit Strains in a Cu-0.9wt%Be Single Crystal


Article Preview

The precipitation processes from G.P. zones to γ’ in a Cu−0.9wt%Be alloy single crystal containing only the G.P. zones parallel to the matrix (001)α plane are investigated by high-resolution electron microscopy. The precipitate phases follow a G.P. zone → γ” → γI + γ’ sequence. The G.P. zone to γI phase transformation occurs successively via γ” during aging, while the γ’ phase heterogeneously precipitates on the γI phase. From length-change measurements during aging, the misfit strains of γ’ precipitates in directions perpendicular and parallel to [001]α are estimated as ε11 =ε22 = −0.03 and ε33 = −0.09, respectively. The observation that the estimated absolute value of ε33 is much smaller than that of ε33 = −0.25 calculated using lattice parameters of the γ’ phase and Cu matrix is understood in terms of the relaxation of ε33 by interfacial misfit dislocations.



Materials Science Forum (Volumes 561-565)

Main Theme:

Edited by:

Young Won Chang, Nack J. Kim and Chong Soo Lee




R. Monzen et al., "Metastable Precipitates and their Misfit Strains in a Cu-0.9wt%Be Single Crystal", Materials Science Forum, Vols. 561-565, pp. 2297-2300, 2007

Online since:

October 2007




[1] R. Monzen, C. Watanabe, T. Seo and T. Sakai: Philos. Mag. Lett. Vol. 85 (2005), p.603.

[2] R. J. Rioja and D. E. Laughlin: Acta Metall. Vol. 28 (1980), p.1301.

[3] A. H. Geisler, J. H. Mallery and F. E. Steigert : Trans. Metall. AIME Vol. 4 (1952), p.307.

[4] W. Gruhl and G. Wassermnn: Metall Vol. 5 (1951).