Magnetic Material questions

[zenophryk]

So I'm wanting to process some pins in AP and there's a lot of warnings against processing Kovar. I get that. So when it comes to checking for Iron using a mgnet, I have found that almost all the pins I have (header pins, socket pins, cable pins, just about any pin) has some sort of attraction to a magnet. Sure, some are more than others. Using a neodymium magnet, some pins are very attracted, and some only a tiny bit. are the Kovar pins going to be the more attracted pins, and maybe the less attracted be a nickle alloy?

 

[maynman1751]

Use a magnet with less 'strength'. A weaker magnet will only attract the kovar/iron pins. Yes, nickel is slightly magnetic but it won't hurt to process in AP.

 

[Geo]

kovar pins can be processed in straight hcl. place the pins in a heat resistant container and cover with hcl and bring to a boil. keep level of hcl over pins, so add as needed until complete. usually a couple of hours is all thats needed and you will have clean foils.

 

[zenophryk]

Is it safe to assume that a strongly magnetic pin is going to be Kovar? I would think header pins, and maybe CPU pins would be. are there any other traights besides magnetic affinity that can help seperate them?

 

[Geo]

basically, thats it.other base metals range from copper,brass,steel and all the different metals that alloy with them.all Kovar pins are magnetic but not all magnetic pins are Kovar.nickel is magnetic, and even copper pins will have a slight magnetic effect with a really strong magnet. after you deal with this for some time you will learn whats what.

 

[maynman1751]

basically, thats it.other base metals range from copper,brass,steel and all the different metals that alloy with them.all Kovar pins are magnetic but not all magnetic pins are Kovar.nickel is magnetic, and even copper pins will have a slight magnetic effect with a really strong magnet. after you deal with this for some time you will learn whats what.

That's why, as it was suggested to me, to use a weaker magnet as to not 'attract' the non-ferrous metals. :mrgreen:

 

[stardust18]

kovar pins can be processed in straight hcl. place the pins in a heat resistant container and cover with hcl and bring to a boil. keep level of hcl over pins, so add as needed until complete. usually a couple of hours is all thats needed and you will have clean foils.

I usually use for the dissolution of Kovar mixture of dilute nitric and sulfuric acids (4/1). In the final heat the stage almost to a boil, heat the reaction to start (carefully!! A very rapid process). :roll:

 

[Geo]

as the saying goes "there more than one way to skin a cat". some members finds it hard to obtain nitric acid, plus just using straight hcl theres no need to incinerate before using hcl/Cl. you can re-use the hcl until the acid is neutralized.

 

[samuel-a]

Kovar will attach tightly to a strong magnet.
Copper based pins usually have a Nickel layer which makes them slightly magnetic.
Therefore, it is rather easy to seperate the two.


You can process Kovar based pins in: hot HCl / AP / hot dilue sulfuric acid. Cu⁺² ions will catalyze the reaction, though i can't really recommand you of a proper concentration.

Copper based pins are processed usually with AP.

In either cases, using nitric alone will not be a sound choice.


As Geo wrote, there are many ways to reach the same goal... experiment on small scale first, in time you will zoom in on your favorite choice.