The Two Advantages of lost wax casting (investment casting)
Compared to the traditional casting process, the lost wax casting can obtain
relatively accurate shape. The investment casting process is to make fusible
pattern, coat several refractory layer, to get a shell after drying and hardening
process, then to use steam or hot water melt the pattern from shell, to put the shell
in sand box for modeling purpose, the last step is to bake model in high
temperature, then pour melt metal to get casting parts.
Nowadays, lots of mechanical parts are made by lost wax casting (investment
casting) process cause by two advantages:
1, investment casting (investment casting) process is suitable for complex shape,
especially for alloy material casting parts who work in high temperature. For
example, the jet-propeller engine impeller, which has streamline outer contour
and cavity for cooling. It can be made by precision casting (investment casting)
process for batch production, to ensure consistency, the most important is it
wouldn't left concentrated press after machining, so it couldn't be made by
machining process.
2, investment casting (investment casting) have good surface finish and accuracy
dimension, which can reduce machining workload, only need to machine local
surface where require highly accuracy. Even some parts only need grind and shot
blasting, total no need further machining.
We can get a conclusion according to above points, lost wax casting (investment
casting) process can save tool facilities, machining work hours, and raw material.