Stainless Steel Lost Wax Castings Process

The lost wax casting process, also called simply as precision-investment casting, has been used for many years by auto, marine and mechanical industries. Basically, the stainless steel lost wax casting method involves the use of expendable (heat disposable) pattern unrounded with a shell of refractory material to form the casting mould. Stainless steel cast parts are formed by putting the molten metal in the cavity. The wax pattern is melted and it is reusable.
The steps involved in this lost wax process are explained below: wax injection, assembly, shell building, dewax, conventional casting, knockout, cut-off, machining, test, and finished castings.
Stainless Steel Lost Wax Castings Process
(a) Wax patterns are usually made by injection molding
(b) Multiple Patterns are assembled in central wax sprue .
(c) The assembly is immersed in a liquid ceramic slurry. After that this structure is dipped into a bed of very fine sand. More than one layer of sand may be necessary.
(d) The ceramic becomes dry. The wax is then melted. To melt all the wax ceramic is fired.
(e) Simple gravity pouring is used for filling the mould. After solidification all the parts of the ceramic structure become casting. Hollow castings can be made by pouring out the extra metal before solidification.
(f) The metal cools to room temperature and after that the ceramic structure is broken off by water blasting or by applying vibration.
(g) The parts are separated by the high speed friction saw. Minor finishing is given to the parts.