Discoloration when annealing BeCu
A discussion started in 2001 but continuing through 20192001
Q. I am a quality engineer, and work with Be Cu contacts that are annealed, we are experiencing discoloration following this process. Can you tell me what could contribute to this condition?Jennifer Carr
- Harrisburg, Pennsylvania
A. Hello Jennifer!
Are you sure it is annealing that you are doing? This would be done at 1450 °F or maybe 1700 °F (depending on the alloy) and quenching in water. Aging is done at 600 °F or 900 °F (again, alloy dependent), and if you are doing that in air you can easily get some discoloration. If you are using an atmosphere, you might have a leak, you might be getting impure cover gas, or you might have contamination, like an oil film that wasn't cleaned off completely.
It's actually good that there are so many things that can go wrong- it keeps us engineers employed.
Q. This is to the respondent. What process would you use to remove the oxide from beryllium copper heat treated at 600 °F for 3 hours?Deborah Graves
- San Juan Capistrano, California, USA
A. Hi Deborah Graves,
I used to work with this kind of Cu Be annealing process about six years ago, and I remember we used to use a chemical with sulfuric acid base to remove the oxide from the copper. Ask around to chemical supply companies about this chemical. Good luck!
- Valencia, Calif, U.S.A.
A. Hello Deborah!
I agree with Reynaldo that sulfuric acid based formulations work well, and we have used them to clean our oxidized BeCu parts. Yet also effective are citric acid based cleaners. We haven't added them to our shop because our environmental folks are loath to add another waste stream, but they work wonders in the lab. Check with Lee Kremer at Stellar Solutions [a finishing.com supporting advertiser], who is wise enough to advertise here.
May 25, 2019
Q. I have copper beryllium thickness 0.20 mm and having hardness of 200 HV1. I want to reduce the hardness of that material to 100 HV1. Please suggest method from which I can achieve the required hardness.Abhishek Jain
Manufacturing - Udaipur, India
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