One or more wax sprues will be attached to your model. Then, the sprue(s) and model will be attached to a wax tree, together with a bunch of other models. The tree is then placed in a flask and covered in fine plaster. The solidified plaster forms the mold for silver casting. It is then put in an oven where the wax is completely burned out.
Molten silver is poured to fill the cavities left behind by the wax. Once the silver has cooled and solidified, the plaster mold is broken (carefully!) to get at the silver models, which are removed manually. The model is then filed and sanded to lose the sprues and then sanded, polished, or sandblasted to achieve the appropriate finish. Silver, 3D printed in this way, is often used for jewelry, such as rings, cufflinks, bracelets, pendants, and earrings.
Here are some interesting things you may not know about silver:
- Pure silver is too soft for durable jewelry, so an alloy is added to harden it for longer wear.
- Due to lost-wax casting and printing being used in the production of silver, interlocking or enclosed parts are not possible.
- Sterling silver is a standard alloy used for jewelry purposes and, for this reason, is safe to wear on your skin.
- The fine quality of a 3D printed silver model is comparable to the kind of jewelry you can find in jewelry stores.
- Silver is made up of 93 percent silver, 4 percent copper, and 3 percent zinc.
It is actually possible to 3D print directly with silver and gold, but it costs tens of thousands of dollars, which is why the processes described are more cost-effective. It also allows for wax prototypes to be made before the casting is done in order to ensure that the design has full integrity before any silver or gold is used.
The company ZMorph has a superb article on Medium about a jeweler who 3D prints her designs to create a unique jewelry range. You can find ZMorph on Medium online. Simply search for the article on 3D printed jewelry. The figure shows you some of the ZMorph 3D printed jewelry designs that can be made.
The 3D printed jewelry range mentioned in the ZMorph article on Medium.com.