6. Cast superalloys

6.1 Lost wax foundry

The lost-wax casting process is a non-permanent ceramic mold and pattern process. It comprises several stages: wax model production, clustering, shell production, dewaxing, sintering and finally casting of the part (figure 23 ). This process provides optimum surface finish and maximum dimensional accuracy – which has earned it the name of "investment casting" – combined with excellent internal health and the ability to produce thin zones. The lost-wax process is therefore ideally suited to the casting of alloys with very high melting points, such as superalloys. Moreover, the process can be applied to all types of alloy (aluminum, Inconel, copper, steel, titanium) and to...