-- The Home Page of the Finishing Industry
Serious Education & the most FUN
you can have in metal finishing smiley

No popups, spam, registration or passwords
on this site
current topics
topic 7974

Anodizing 7175 Aluminum


We are having difficulty hardcoat anodizing 7175 aluminum. We have been able to get 1.2 mils of coating thickness but even this has required considerable amperage and time. The part is a 2-ft disc (approx. 6 sq. ft.). We anodized in a series of 3 steps to ramp up current: 45 minutes a 15 ASF, + 45 minutes at 30 ASF, + 45 minutes at 75 ASF. We would like to get approx. 2 mils and hopefully achieve that in less time with less current. Racking material is aluminum; connection is good. Bath is 300 g/L H2SO4 at 35 degrees F. Is there some special trick to anodizing 7175? We've been successful with 7075 which has nearly the same chemistry.


Brian Dougherty
- Keyport, Washington, USA


Although I have never dealt with this particular alloy, 300 gr/liter bath concentration sounds awfully high for hardcoat to me, I would think that coating dissolution rate would be way up there, and perhaps you are reaching a point where you are removing as much of coating as you are putting on. My suggestion would be to lower your concentration, by at least 100 gr/liter.

Marc Green
Marc Green
anodizer - Idaho

If you have a question in mind which seems off topic, please Search the Site

ADD a Comment to THIS thread START a NEW threadView CURRENT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2018, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.