No registration or passwords; no pop-up ads -- just aloha, fun, & answers.
(as an eBay Partner & Amazon Affiliate earns from qualifying purchases).
Home /
Site 🔍
pub  Where the
world gathers for metal finishing
Q&As since 1989


Removing Oxidation from Kovar

Q. Hi, I would like to ask how to remove the oxide layer from Kovar material.
Thank you in advance,

Sukru Baha Baydir
- Ankara, Turkey

A. Hello, Sukru. The oxide can probably be removed either mechanically or chemically depending on what the sheet or parts look like and what you want to do with them after removing the oxide. Can you provide a bit more context please?

Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

Q. Hi,

After heat treatment with N2 I got brownish surface on my Kovar material. Since my apparatus need to be dimensional accuracy I want to remove the oxide layer chemically. If there is a solution to remove the oxide layer from material it'll be better. There is no next step for my project except removing oxide layer.

Thank you in advance,

Best Regards,

Sukru Baha Baydir [returning]
- Ankara, Turkey

A. Kovar® can be pickled in inhibited, 50 vol% hydrochloric acid (~16 wt% HCl); a suitable inhibitor is available from GALKIM in Istanbul.

This alloy is usually annealed in dry hydrogen. Water vapor may be added (dewpoint 20-30 °C) for decarburization or to slightly oxidize the surface for (some believe) improved adhesion to borosilicate glass.

Ken Vlach [deceased]
- Goleta, California

contributor of the year honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at, continue to benefit from.


A. Reheating the Kovar in a nitrogen/hydrogen mix will remove your oxide.

Richard Browning
- Southampton England
August 31, 2010

Q. Kovar pieces have oxidation on them after heat treating. This component needs to have glass put onto it for assembly. How can we remove the oxidation and prepare the piece for the glass-to-metal seal? Thanks.

Beth Reynolds
- Chicago, Illinois, USA
January 21, 2013

Q. Which Chemicals are recommended for cleaning of KOVAR after Fabrication (slurry)? Actually we are going to do Experiment with N2 Gas.

isro - Banglore Karnataka India
June 26, 2019

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully 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 might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

Chemicals &
Consult'g, Train'g
& Software

About/Contact  -  Privacy Policy  -  ©1995-2024, Pine Beach, New Jersey, USA  -  about "affil links"