Research on Optimization Design of Cast Process for TiAl Case Casting

Abstract

The effect of the cast process procedure and pouring systems on several typical metallurgical defects for TiAl case casting was studied by numerical simulation and pouring test. The results indicated that gravity casting had much better melt-filling stability and synchronization, compared to centrifugal casting. Misrun defects in the upper edge of the thin-walled outer ring could be removed by increasing the bottom cross runners, and the negative effect of the overheated zone in the thick-walled flange could be reduced by designing a suitable inner-gate structure. The crack induced by stress concentration in the transition zone brought significant challenges for TiAl case casting and the issue would be effectively resolved through structural design and process optimization.

Keywords

• TiAl alloys
• case casting
• gravity casting
• centrifugal casting
• misrun
• crack