Manufacturing Methods
Wax Injection
Using a low pressure, injection system, semi-molten wax is forced into the silicone cavity of a two-part resin mold until full. The cavity is then chilled until the wax has fully solidified. The wax is then removed from the cavity and the process will be repeated.
Wax Sprue Assembling
Wax patterns are typically attached to a wax “sprue” for mass production as it is uneconomical to make small parts individually. The sprue provides a mounting surface to assemble multiple patterns into a single mold, which will be filled with alloy. The sprue also provides a flow path for the molten alloy to fill the void created by the wax patterns.
Shell Building
A fire-resistant ceramic coating is created by plunging the wax tree into a fluid sludge multiple times and then applying multiple layers of ceramic powder on to the surface. After the application of every ceramic layer, the casting mold must be dried in a drying chamber under atmospheric conditions.
Dewaxing
After drying the multiple ceramic layers, the wax within the ceramic mold will be melted in an autoclave using steam. The wax model disappears; the product shape is then taken over by the ceramic coating.
Casting
The desired steel alloy is melted in a smelting furnace and brought up to a casting temperature of (approximately) 1600 °C. The hot mold is then removed from the kiln and filled with molten steel. Heating the ceramic mold prevents a thermal shock during casting. After the molten steel is poured into the hot mold, the mold will then be left for the steel to solidify.
Knockout
The ceramic exterior is removed from the steel casting molds by manually breaking the shell with a hammer. This removes the majority of the ceramic. The cast pieces are then sawed off or vibrated away from the steel tree.
Cut Off
The steel tree is cut off for the grinding process.
Grinding & Minor Finishing
Any edges remaining on the cast piece are sanded by sanding mold.
Vibratory Finishing
Vibratory finishing process is used for the cast pieces to deburr, radius, descale, burnish, clean, and brighten.