Investment casting, also known as lost-wax casting, is one of the processes of manufacturing metal parts that go back more than a thousand years. In this method, the mold is formed using a wax model corresponding to the desired piece. Then the mold is immersed in a ceramic slurry to form a shell around the mold. After the shell drying, the mold and shell are placed in the oven and the wax melts and comes out of the shell. Finally, the molten metal is poured into the ceramic shell and the part is manufactured.
Most parts that are usually made by investment casting include objects that have complex geometry. High working temperatures are also common in this process, which is suitable for Cast metals with high melting temperatures that cannot be molded into plaster or metal. This method is used for automotive, aircraft and military industries.
The material which is used for the shell needs to be shock resistant, resistant to melt corrosion, chemically and stable at high temperatures and provide good surface quality in the cast part. For this application ALPHA offers different grades of calcined alumina with precise particle size distributions, soda content and specific surface area.