Structure and orientation relationship of new precipitates in a Cu–Cr–Zr alloy

ABSTRACT

The crystallography and morphology of the nano-sized precipitate particles in a ternary Cu–Cr–Zr alloy were studied by transmission electron microscopy. A new type of face-centred-cubic (f.c.c) Cr-rich precipitate was observed. This precipitate is ordered and solute enriched on alternate {110} f.c.c planes, with an ellipsoid-shaped morphology. The new orientation relationship (OR) between the precipitate and Cu matrix satisfies [211]M//[011]p and [100]M//[111]p, {-111}M//{200}p and {02-2}M//{02-2}p. The difference between this new OR and the Nishiyama–Wasserman OR between body-centred-cubic (b.c.c) Cr and the Cu matrix can be detailed by Δg vectors in the diffraction patterns. Furthermore, the precipitation strengthening effect is increased greatly with the formation of these new precipitate particles when compared to binary Cu–Cr alloys.

KEYWORDS:

• Copper alloy
• microstructure
• precipitates
• chromium
• transmission electron microscopy

Acknowledgements

The authors are grateful to the experimental assistance by Professor Y.-L. Ai and the valuable discussion with Professor W.-Z. Zhang.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financial supported by the Ministry of Science and Technology of the People Republic of China (2006DFA53240) and the Hunan Province Education Department (CX2011B109), as well as the Open-End Fund for the Valuable and Precision Instruments of Central South University (CSUZC20140010).