Keller's reagent (metallurgy)

In metallurgy, Keller's reagent is a mixture of nitric acid, hydrochloric acid, and hydrofluoric acid, used to etch aluminum alloys to reveal their grain boundaries and orientations.[1] It is also sometimes called Dix–Keller reagent, after E. H. Dix, Jr., and Fred Keller of the Aluminum Corporation of America, who pioneered the use of this technique in the late 1920s and early 1930s.[2][3]

Keller's reagent
Identifiers
Hazards
GHS labelling:
GHS03: OxidizingGHS05: CorrosiveGHS06: ToxicGHS07: Exclamation mark
Danger
H272, H290, H300, H310, H314, H330, H335
P210, P220, P221, P234, P260, P262, P264, P270, P271, P280, P284, P301+P310, P302+P350, P305+P351+P338, P310, P320, P321, P322, P330, P361, P363, P370+P378, P403+P233, P405, P406, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability (yellow): no hazard codeSpecial hazards (white): no code
4
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Safety

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Keller's reagent contains oxidizing nitric acid and toxic hydrofluoric acid. The reagent and its fumes may be lethal via contact, inhalation of its fumes, etc. Hydrogen produced on contact with some metals may pose a fire hazard.[4]

See also

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References

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  1. ^ Vander Voort, George F. (1999), Metallography, Principles and Practice, ASM International, p. 197, ISBN 978-0-87170-672-0.
  2. ^ Mondolfo, Lucio F. (2007), Metallography of Aluminum Alloys, Read Books, p. 169, ISBN 978-1-4067-3672-4
  3. ^ Dix, E.H. Jr.; Keller, Fred (1929), "Keller's reagent", Mining and Metallurgy, 9: 327, ISSN 0096-7289
  4. ^ "Keller's Reagent-Safety Data Sheet" (PDF). 18 November 2024.