Palladium Alloy

[pegz82]

I''m designing a new ring and was going to use palladium for the first time. The jeweller i''m using is going to be using a Palladium 950 with Copper and/or Gallium being used for the 5%. I''m struggling to find much information on what sort of properties Copper/Gallium bring to Palladium, pretty much all the info I can find is using ruthenium. Does anybody else know anything about Palladium being used with thesee metals?

Thanks very much for your help.

 

[neatfreak]

I don't, but you might want to have this thread moved to Rocky Talk (you can use the REPORT CONCERN button at the bottom of your post). That's the right place for it and that forum gets much more traffic. Good luck!

 

[pegz82]

Thanks for your advice.

 

[John P]

Date: 11/27/2008 9:25:24 AM
Author:pegz82
I'm designing a new ring and was going to use palladium for the first time. The jeweller i'm using is going to be using a Palladium 950 with Copper and/or Gallium being used for the 5%. I'm struggling to find much information on what sort of properties Copper/Gallium bring to Palladium, pretty much all the info I can find is using ruthenium. Does anybody else know anything about Palladium being used with thesee metals?

Thanks very much for your help.

It makes sense to use copper with palladium, just as with platinum, since they are both high-temperature metals. Copper will behave like cobalt in these alloys. The Europeans began using cobalt because the castings are smooth...when a piece is simply cast and there is no assembly or soldering afterwards these alloys are great; it’s why Stuller uses Plat-Cobalt in mass-manufacture. The drawback is that hand-application/soldering after casting discolors such alloys and makes them dull. Treatment and repolish are required to restore their luster.

I don't know about Gallium specifically. There are infinite variations of alloys so the choice depends on preferences and what effects the metalsmith is trying to achieve. Platinum/palladium are alloyed with other metals for two reasons: 1, to bring down the melting point and 2, because in pure form they are too soft. Pt or Pd alloyed with ruthenium will have the highest melting point of the common alloys but it’s more millable so it can be machined and grinded better. Many milled products are plat-ruth because they're harder and crisper at the bench. Pt or Pd alloyed with iridium has a lower flow point and is fabulous for casting, but more difficult to hand-tool and it wears softer. Alloying Pt or Pd with cobalt or copper is great for mass-production but outside the "noble" family of platinum alloys: Platinum, palladium, ruthenium & iridium (along with osmium & rhodium) are all members of the platinum family of metals.

In short, when a piece is simply cast and requires no assembly afterwards, 950 palladium with copper should be great. Be aware that the piece will require special treatment to restore luster after any heat application; including resizing.

 

[oldmancoyote]

Date: 11/28/2008 1:13:38 PM
Author: John Pollard

Date: 11/27/2008 9:25:24 AM
Author:pegz82
I''m designing a new ring and was going to use palladium for the first time. The jeweller i''m using is going to be using a Palladium 950 with Copper and/or Gallium being used for the 5%. I''m struggling to find much information on what sort of properties Copper/Gallium bring to Palladium, pretty much all the info I can find is using ruthenium. Does anybody else know anything about Palladium being used with thesee metals?

Thanks very much for your help.

It makes sense to use copper with palladium, just as with platinum, since they are both high-temperature metals. Copper will behave like cobalt in these alloys. The Europeans began using cobalt because the castings are smooth...when a piece is simply cast and there is no assembly or soldering afterwards these alloys are great; it’s why Stuller uses Plat-Cobalt in mass-manufacture. The drawback is that hand-application/soldering after casting discolors such alloys and makes them dull. Treatment and repolish are required to restore their luster.

I don''t know about Gallium specifically. There are infinite variations of alloys so the choice depends on preferences and what effects the metalsmith is trying to achieve. Platinum/palladium are alloyed with other metals for two reasons: 1, to bring down the melting point and 2, because in pure form they are too soft. Pt or Pd alloyed with ruthenium will have the highest melting point of the common alloys but it’s more millable so it can be machined and grinded better. Many milled products are plat-ruth because they''re harder and crisper at the bench. Pt or Pd alloyed with iridium has a lower flow point and is fabulous for casting, but more difficult to hand-tool and it wears softer. Alloying Pt or Pd with cobalt or copper is great for mass-production but outside the ''noble'' family of platinum alloys: Platinum, palladium, ruthenium & iridium (along with osmium & rhodium) are all members of the platinum family of metals.

In short, when a piece is simply cast and requires no assembly afterwards, 950 palladium with copper should be great. Be aware that the piece will require special treatment to restore luster after any heat application; including resizing.

I think small amounts of gallium are used to improve hardness in PGM alloys.

 

[John P]

Date: 11/28/2008 7:46:57 PM
Author: oldmancoyote
I think small amounts of gallium are used to improve hardness in PGM alloys.

Thanks OMC. Do you know if it''s employed with heat treatment/aging in the same manner as Pt-Tungsten, for instance?

 

[pegz82]

Thanks very much for everyone''s advice. Copper and gallium wasn''t something I knew much about but you guys have eased my mind now

 

[John P]

You may want further info on the Pd-Gallium alloy Pegz. If it''s being used in tandem with heat treatment to ''improve hardness'' it will probably behave more like tool steel than precious metals when finished.