Numerical calculation and experimental evaluation of counter-gravity investment casting of Ti-48Al-2Cr-2Nb alloy

• Published in: International journal of advanced manufacturing technology Vol. 96; no. 9-12; pp. 3295 - 3309
• Main Authors: Yang, Jieren, Wang, Hu, Wu, Yulun, Zhang, Keren, Wang, Xuyang, Hu, Rui
• Format: Journal Article
• Language: English
• Published: London Springer London 01.06.2018; Springer Nature B.V
• Subjects: CAE) and Design; Casting; Casting alloys; Casting defects; Computer simulation; Computer-Aided Engineering (CAD; Engineering; Finite element method; Gravitation; Heating; Industrial and Production Engineering; Investment casting; Mathematical models; Mechanical Engineering; Media Management; Molds; Morphology; Original Article; Phase composition; Pressure casting; Pressure effects; Rapid prototyping; Size effects; Solidification; Superheating; Three dimensional models; Titanium base alloys; Numerical calculations; Temperature field; Counter-gravity casting; Microstructure; Titanium aluminide
• ISSN: 0268-3768; 1433-3015
• DOI: 10.1007/s00170-018-1784-5

In this work, counter-gravity investment casting was used to fabricate TiAl parts with different cross-sections. A three-dimensional finite element model of counter-gravity investment casting was established based on ProCAST simulation software. The filling capacity and solidification behaviour during the counter-gravity investment casting of the Ti-48Al-2Cr-2Nb alloy were numerically investigated, and the effects of filling pressure, melt superheating temperature and mould preheating temperature were experimentally evaluated in terms of the filling integrity and casting defects. The results show that the filling pressure plays an important role in the filling capacity. Elevating properly the mould preheating and melt superheating temperatures can also improve the filling capacity. Then, counter-gravity investment casting was performed using the parameters optimised through numerical simulations, and sound Ti-48Al-2Cr-2Nb casting parts with different section sizes and shapes were produced. The as-cast microstructure of the Ti-48Al-2Cr-2Nb alloy indicates that the phase composition and morphology are largely affected by the size effect. Graphical abstract Counter-gravity investment casting was applied to fabricate TiAl parts. A FE model was established to calculate the filling capacity and solidification behaviour during the counter-gravity casting of the Ti-48Al-2Cr-2Nb alloy. The effects of filling pressure, melt superheating and mould temperature were evaluated. Based on the numerical results, sound Ti-48Al-2Cr-2Nb casting parts with different section sizes and shapes were produced with an optimised processing window. The as-cast microstructure of the Ti-48Al-2Cr-2Nb alloy indicates that the phase composition and morphology are largely affected by the size effect.