Process for etching zirconium metallic objects
In a process for etching of zirconium metallic articles formed from zirconium or a zirconium alloy, wherein the zirconium metallic article is contacted with an aqueous hydrofluoric acid-nitric acid etching bath having an initial ratio of hydrofluoric acid to nitric acid and an initial concentration of hydrofluoric and nitric acids, the improvement, is described comprising: after etching of zirconium metallic articles in the bath for a period of time such that the etching rate has diminished from an initial rate to a lesser rate, adding hydrofluoric acid and nitric acid to the exhausted bath to adjust the concentration and ratio of hydrofluoric acid to nitric acid therein to a value substantially that of the initial concentration and ratio and thereby regenerate the etching solution without removal of dissolved zirconium therefrom; and etching further zirconium metallic articles in the regenerated etching bath.
- Assignee:
- Westinghouse Electric Corp., Pittsburgh, PA
- Patent Number(s):
- US 4738747
- OSTI ID:
- 7224121
- Country of Publication:
- United States
- Language:
- English
Similar Records
DISSOLUTION OF ZIRCONIUM AND ZIRCALOY-2 IN NITRIC-HYDROFLUORIC ACID MIXTURES AT REFLUX TEMPERATURES
CONCENTRATED NITRIC AND DILUTE HYDRO-FLUORIC ACID MIXTURES IN DISSOLUTION OF ZIRCONIUM METAL
Related Subjects
360101* -- Metals & Alloys-- Preparation & Fabrication
ACIDIFICATION
ALLOYS
AQUEOUS SOLUTIONS
DISPERSIONS
ELEMENTS
ETCHING
HYDROFLUORIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
METALLOGRAPHY
METALS
MIXTURES
NITRIC ACID
SOLUTIONS
SURFACE FINISHING
TRANSITION ELEMENTS
ZIRCONIUM
ZIRCONIUM ALLOYS