Different sectors of the precision investment casting industry place different requirements on the refractories used. Foundries making parts for turbines and medical applications demand much lower, potential contamination levels than in general commercial casting.

Similarly, refined precious metals place higher demands on the quality of their container than is allowable earlier in the production chain. Various types of crucible material are available to meet the preferences in terms of reaction, erosion and thermal shock.


Turbines and medical


The stringent specifications required of superalloy castings for aerospace turbines, land turbines and medical implants impose strict requirements on the refractories used for molten metal contact. Despite the use of filters during casting, chemical reaction and erosion of the refractory needs be minimised.

The least reactive oxide material for the containing crucible is zirconia. Its unique (non-) wetting characteristics make it especially suitable, but it does need a high degree of solid-state sintering during manufacture  to take advantage of this.

Magnesia has been found to offer good resistance to the Ni-based and Co-based alloys melted. It has a shorter service life than zirconia but is notably cheaper per unit crucible.