ASTM D2674-72(2021)

Annotation of standard text ASTM D2674-72(2021) :

These methods offer a means for controlling the effectiveness of the etchant which is normally used for preparing the surface of aluminum alloys for subsequent adhesive bonding. As the etchant reacts with the aluminum, hexavalent chromium is converted to trivalent chromium; a measure of the two and the difference can be used to determine the amount of dichromate used. The sulfochromate solution can be replenished by restoring the sodium dichromate and the sulfuric acid to the original formulation levels. Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the requirements specified. Unless otherwise indicated, references to water purity shall be understood to mean reagent water conforming to the requirements specified. The procedure and calculations for sulfochromate etch solution analysis are presented in details.


Keywords:
acid etch, aluminum, chromate, sodium dichromate,, ICS Number Code 71.060.50 (Salts)