×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Soft magnetics Ni alloy

Soft magnetics Ni alloy

Soft magnetics Ni alloy

(OP)
Hi. I have a problem identifying this alloy (material) . It should be soft magnetics material made in Germany (1940-1960) . Thanks

Ni-58%
Fe-26.3%
Cr-6.6%
Cu-3.7%
Mn-1.1%
Al-1.2%
Na-1%
Si-0.7%
Co-0.3%

RE: Soft magnetics Ni alloy

This looks like a constant (wrt field strength) permeability alloy similar to Permivar or Mumetal.
It will not have a very high saturation but will be very constant.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: Soft magnetics Ni alloy

(OP)
Thanks, i'm confused with 58% Ni percentage. Since the results are from X-ray flurescence spectrometry, is it possible that Lab made error or some manufacturers use smaller amount of Ni in their Mumetal mixtures ??? Sorry for dumb question.

RE: Soft magnetics Ni alloy

The Cr, Cu and Al are added to increase electrical resistance.
There is no Na in it. Was it cleaned and freshly polished? Might be surface contamination messing with the analysis.
You are correct, the 60% Ni/25% Fe is an odd ratio.
It does make me wonder how close their reference standard was.....

But if this material was used in the 40's, it may be a design from the 20's.
The alloy may not be for maximum perm but rather for either constant perm with field strength or constant perm with temperature.
It could have been used as a tuning shunt on a magnetic circuit. Bleed off more field at room temp and less at high temp so that the working field stays more consent.

What kind of device what this used in?

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: Soft magnetics Ni alloy

(OP)
Thanks for answers. Well, it looks like some variation of Mumetal since it was used for output audio transformer (small signal and power), lamination 0.35mm thickness. I'm not sure about cleaning since I was not in the lab during Xray but it's possible that it's contaminated somehow. Sheet says "No sample preparation" so it must be over the years. I would really like to know history of this material and possibility or reproducing the same since it works great under the application.

RE: Soft magnetics Ni alloy

since it was used for audio transformer, most probably this is something like Perminvar (=permeability invariable) with 50%nickel, 25%cobalt, 25%iron. Is that for telecommunication? the constant permeability at low magnetic field will minimize the signal distortion, so high sound quality.
nowadays, people like to use mumetal or permalloy for audio transformer, since one of main goals is to decrease the exciting current in primary to negligible level, high permeabiltiy is obviously beneficial. Also, since harmonci distortion is inversely proportional to permeability, high permeability means low distortion.
constant permeability is beneficial either, but if you can design a transformer to operate at a low flux density such that mumetal is more in the linear portion of curve, you will obtain benefit for a constant permeability.

RE: Soft magnetics Ni alloy

(OP)
As I can see there is no Co inside this alloy. Of course, this material can be substituted with similar "modern" but I was interested in exact (or few % up/down) chemical composition. Unfortunately I have no idea where to start from .

RE: Soft magnetics Ni alloy

It seems there are different version of perminvar, and no Co is possbile (see the paper publishedin 1930: Perminvar, an alloy of nickel, copper, and iron, used in proposed trans-Atlantic telephone cable, J. Chem. Educ., 1930, 7 (1), p 176).

A full wet chemistry analysis would give you an accurate composition of the alloy. But an electrical steel might be able to do a better job if you could design the transformer properly. And Si steel is cheap too.

RE: Soft magnetics Ni alloy

(OP)
According to Woldman's Engineering alloys Bell Labs produce only Co Perminvar Alloys. Not sure about other manufacturers.

RE: Soft magnetics Ni alloy

I am not in my office to check, but Perminvar was called other names by other companies.
Who knows what the Germans did.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: Soft magnetics Ni alloy

(OP)
Please post when you check, I'm sure that Germans had a different name for that alloy.

RE: Soft magnetics Ni alloy

(OP)
Polite bump ;)

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources