In view of the structure features that narrow slots and thin blades appearing alternately

and difficult to forming

the process of investment casting was made from trial-and-error experiments.In making wax mould process

the mould was composed of whole ceramic core and separated wax pattern.During smelting

needle blanket was used to parcel the thin blades area for insulation

and heat the shell at high temperature and pour also at high temperature and tilted.Through this process

the requirement of skill level and labor strength of works could be decreased.Meanwhile

the production efficiency could be improved with stable quality.