Lost-Wax Casting is a process of manufacturing moulds. It is similar to Investment Casting, whose dimensional accuracy and surface quality, however, is not reached.
The first step in this moulding process is the creation of a precise wax part that represents a negative of the desired casting. The wax part is then embedded in a ceramic material, which hardens at high temperatures. This ceramic mould forms the outer shell or expendable mould that will later hold the molten metal. The ceramic mould is heated to melt and remove the wax inside. This leaves a hollow mould that is the negative of the desired casting. The wax flows out of the mould, which is why the process is called lost-wax. Finally, the empty ceramic mould is heated in a furnace to bring it to the correct temperature for casting. Molten metal is poured into the mould. Once solidified, the ceramic mould is broken or chemically dissolved to retrieve the finished casting.
On the other hand Lost-Wax Casting surpasses Sandcasting regarding dimensional precision and surface quality. Because of the high intensity of labour resources needed, this process is, in practise, mainly carried out in Asian countries. It is suited for all standard metal materials.