Like all other precious metal casting several design considerations are also specific to the process of casting of the metal palladium. Like gold and platinum, palladium also has got unique flow properties. However, the designs cannot be equal or identical for all three as despite all their similarities they also have some basic differences.
For example, the lighter and filigree designs do not work well for platinum while the medium and heavy designs work very well. Though the scientists, engineers and designers are yet to find out the exact reasons for this, the difference with palladium that supports lighter designs do exist.
Most of the problems relating to casting palladium have been addressed by keeping the purity level of palladium to 95% instead of 100%. Long term research and experiments have revealed that for proper casting of palladium the following principles may be useful –
- Casting models should have thickness of 0.75 mm or less.
- The rings should be at least 25% larger than the normal size to allow shrinkage.
- 95% pure palladium could be made from injection and carving wax or other outputs from CAD/CAM procedures.
- Investment mold should not be brittle to avoid cracking during the burnout.
- The diameter of the gate should be a bit larger than the cross section.
Proper designing can eliminate most of the palladium casting problems including all types of defects that are normal and also the no-fill problems.
