Guinier–Preston zone explained

A Guinier–Preston zone, or GP-zone, is a fine-scale metallurgical phenomenon, involving early stage precipitation.^{[1] [2]}

GP-zones are associated with the phenomenon of age hardening, whereby room-temperature reactions continue to occur within a material through time, resulting in changing physical properties. In particular, this occurs in several aluminium series, such as the 6000 and 7000 series alloys.

Physically, GP zones are extremely fine-scaled (on the order of 3–10 nm in size) solute enriched regions of the material, which offer physical obstructions to the motion of dislocations, above that of the solid solution strengthening of the solute components. In 7075 aluminium for example,^[3] Zn–Mg clusters precede the formation of equilibrium MgZn₂ precipitates.

The zone is named after André Guinier and George Dawson Preston who independently identified the zones in 1938.^{[4] [5]}

Further reading

• G.D Preston, Structure of age-hardening aluminium–copper alloys, Nature 142 (1938) 570, September 24

Notes and References

1. Book: Guinier-Preston zone evolution in 7075 Aluminium.
2. Web site: A. Guinier - Personal Reminiscences.
3. Web site: Microstructural Evolution and Age Hardening in Aluminium Alloys: Atom Probe Field-Ion Microscopy and Transmission Electron Microscopy Studies. 2016-01-13. https://web.archive.org/web/20160304111841/http://www.nims.go.jp/apfim/pdf/MatCharAl.pdf. 2016-03-04. dead.
4. Web site: Notable Scientists at Dundee University : Museum : University of Dundee. 2018-01-16. 2016-08-30. https://web.archive.org/web/20160830202715/http://www.dundee.ac.uk/museum/exhibitions/madetomeasure/scientists/#preston. dead.
5. Web site: The Preston of the Guinier-Preston Zones . O.B.M. . Hardouin Duparc . 2020-01-25.