Is there a metal (or any machinable material) that can be magnetized but exhibits no residual magnetism?

Answer 1

There are two separate physical paramters you are talking about. Permitivity is the property which allows a magnetic field to permeate a material. Retentivity is the property that enables a material to hold a magnetic field. It sounds like you want a metal alloy with a high permitivity but low retentivity.

To help you understand the difference: imagine a simple coil of wire, multiple loops wound around some non-conducting form, like a cardboard tube. Pass a current through the coil and it becomes an electromagnet. Put a piece of ferromagnetic metal (an alloy containing one of the three metals, iron, nickel or cobalt) into the tube, and you now have a stronger electromagnet, because all the imaginary line of force in the magnetic field want to pass through the metal. It has a high permitivity; it concentrates them magentism; think of the way a lens focuses light.

Turn off the current. The coil is no longer energized, and it is no longer generating a magnetic field. Measure the magnetic field of the metal core, now. If it is insignificant, it has low retentivity. If it is significant, it has high retentivity.

So you can think of retentivity of magnetic field as being analogous to temporary phosphorescence after the exciting light source is turned off.

This is now permanent magnets are made. They are put into a big electromagnet (usually while they are still hot, almost molten.) That way, more of the atoms line up with the magnetic field. When it cools off, the atoms are all lined up in the same directin, and you have a strong magnet. If the material has a low retentivity, as soon as the external magnetic field is taken away, the atoms go back to being lined up in random directions.

This is somewhat of an oversimplification, but I hope it helps you understand what you are asking. Try searching for different alloys with different characteristics, as I mentioned. If you run across any terms you don't understand, look them up.

Try searching on the magnetic properties of 'cermets'; they are ceramic-metal compounds. Some of them are 'ferrites', which are used for high-frequency magnetic cores for transformers. I think they might have the properties you want, only you would have to have them made to the shape you want as they are fragile and cannot be machined. Good luck!

Answer 2

I agree with Bikeguy. There are no commercially available materials that I know of that would satisfy your request.

The key question is what cdf_rom posted. How much magnetism response and how little? If you really mean NO retained magnetic signature, you will probably have to go for laboratory specimens of exotics.

former machinist

Answer 3

Magnetism could be reason by ability of electricity flowing via an merchandise. This supply the article a fee. additionally specific metals earnings a fee from the earths organic magnetic circulate. The molecules slowly grow to be aligned in a manner that provides them magnetic fee. this additionally ability that gadgets close to magnetized gadgets could additionally earnings a magnetic fee from the interior of sight magnet

Answer 4

Any metal above its curie point cannot retain its magnetism.

Gadolinium is a ferro magnetic which has curie point at 292K which is little below room temperature.

I don't know about its machinability though. Being a metal, i assume it is machinable.

Answer 5

Yes, I believe the alloy known as "mumetal" may have this property- but I'm not sure. I worked with some of it 30 years ago- good luck

Answer 6

no, not that i'm aware of