#983 Alloy

Thank you for using UNITED'S alloys.

UNITED'S 983 ALLOY may be used for 18K white gold casting and fabrication, which produces a white finished color. #983 contains silicon, and boron deoxidizers.

You should obtain excellent results by following a few simple instructions.

MELTING

We highly recommend pre-graining all alloy and fine gold before casting to assure a uniform mixture.

FLASK TEMPERATURE
We suggest a slightly higher flask temperature for white gold.

QUENCH TIME
15 to 20 minutes.

FLUXING
Fluxing white gold is extremely important to pick-up oxides. Boric Acid is the recommended flux. Do not use carbon fluxes or any fluxes designed for refining; i.e., soda ash, saltpeter, etc. Fluxes make the oxides and impurities coagulate together which should be removed with a quartz or graphite rod. Avoid flux in bottom pour automatic casting units.

REMELTING
Use a 30% scrap to 70% fresh mix on nickel white gold alloys. White gold alloys have about 1/3 the re-usability of yellow gold alloys.

INVESTMENT REMOVAL
Most standard investment removers will successfully remove the
investment powder. Fluoric-based investment removers are the best for removing the silicon oxide invisible coating. UNITED'S Brite-Cast Investment Remover also works very well.

NOTES
Melt temperature may vary with type of unit.

FABRICATION
The metal ingot should be cleaned of all adhering oxide or fluxes before rolling. The ingot should be rolled or drawn to a 50% reduction in size before annealing. Too small of a reduction can cause ingot to crack during anneal. After annealing continue the reduction at 50% before annealing again. Clean the ingot after each anneal in hot pickle solution. Keep the rolls, dies, and metal clean to prevent defects in the finished stock

POURING TEMP. FOR INGOTS
18 K - 1015º C / 1860º F.

POURING
Metal should be poured into a preheated, vertical graphite, or lightly lubricated iron mold. A steady even pouring motion should be used, slowing down at the end of the pour to prevent shrinkage in the top of the ingot. Use a round rod mold for wire, and a 2 piece L shaped mold for plate and sheet.

DON'T QUENCH
Remove the ingot from the mold and allow to air cool - don't quench. Nickel white gold rolling alloys will be much softer if allowed to air cool after pouring and after annealing. Soak ingot in a hot pickle solution to remove surface oxides.

ANNEALING
Annealing temperature 704º C/ 1300º F for 20 minutes. DO NOT QUENCH INGOT, allow ingot to air cool. A boric acid fire coat should be applied before annealing in an open atmosphere oven to protect the metal from heavy oxidation. Clean the ingot in hot pickle solution to remove surface oxidation after annealing. Avoid over-annealing wire, plate or sheet stock as this can cause excessive grain growth creating orange peel surface or poor strength in finished goods.

TECHNICAL ASSISTANCE
Always available…
Call 1-800-999-3463 / 1-800-999-FINE
E-mail / doc@unitedpmr.com
Web-Site / www.unitedpmr.com