Many mahince parts are simply or machine our of solid metal but parts with complex shapes or thin walls can be made that way they have to be cast using a technique called lost wax process casting. It takes anywhere from a week to a month to manufacture a cast metal part depensing on its complexity. . The first thing is to inject wax into a n aluminum die which is essentially a mold. Whos cavity is in the shape of the part . This creates a wax model slightly larger that the finished part that will be use. This model to make a modl our of ceramics that also has to be larger than the finished part because metal shirinks as it cools . Once the wax model is ready a code is stamped indicating to workers what kind of metal is to be used. Next using a hot iron they attach works components to create whats called a metal delivery system. Channels that will funned the molten metal into the mold cavity. Next they dip this wax assembly into a ceramic soulution called slurry. This is done by hand to prevent imperfection that would cause defects in the cast and to strengthen the slurry it’s coated in a fine zirconium sand. An automated process repeats the coating with coarse sand until the ceramic shell surrounding the wax is 7 mm thick. This takes 5 days. If the ceramic covered wax assembly is ready for what’s called the “D” Wax workers place it in a hot steam chamber called an autoclave for 10 minutes. This melts the wax right after the shelf creating the ceramic mold cavity is in the shape of the part.
Once the mold has dried out the workers can now begin to cast the part. First they put the cold mold into another fire to 2 to 3 hours. This prevents the mold from cracking from the shark with contact with molten metal at a scolding 1200 degrees celcuis. Molten metal is poured in mold cavity which then cools and hardens at room temperature . Once the metal solidifies the ceramic is broken using a vibrating hammer. The metal delivery system is sawn off . The surface is now ground into a smooth finishing. The final part is to make that the part is exact in dimension in the technical drawing this is called sizing.