FP6 priority
1.1.3   Nanotechnologies and Nanosciences, Knowledge-based Multifunctional Materials and New Production Processes and Devices
Title of the proposal

Reliability of cast TiAl-based components for applications in gas turbine industry

Slovak Academy of Sciences, Institute of Materials and Machine Mechanics
Racianska 75, 83102 Bratislava, Slovak Republic
Dr. Juraj LAPIN
+421 2 49268290

Research subject for a potential FP6 project

In recent years ordered TiAl based intermetallic alloys have been extensively studied as potential high-temperature materials in gas turbine industry. The low density, high stiffness, good oxidation resistance and interesting mechanical properties have made TiAl based alloys attractive candidate for use in low-pressure stage of gas turbine engines or for turbocharger of diesel engines. Of the numerous microstructures that can be developed in TiAl based alloys, the fully lamellar or nearly lamellar microstructure consisting of TiAl and small volume fraction of Ti3Al exhibits better creep resistance than duplex material. However, large cast components such as turbine blades may exhibit various microstructures ranging from fully or nearly lamellar in columnar grain regions to duplex ones in the equiaxed grain region. In addition, cast components contain cast defects that have to be eliminated by a hot isostatic pressing. The microstructural changes and cast defects significantly affect the reliability of the cast components.
The project is based on a complex approach including fundamental and applied research of solidification behaviour, phase transformations, nano-scale layer protection coatings and mechanical behaviour of TiAl-based alloys with the aim to create basic knowledge for processing, reproducibility and reliability of large investment cast TiAl-based components for applications in gas turbine industry. Microstructure, room and high temperature tensile properties, creep, fatigue, hardness, thermocycling creep properties, oxidation behaviour will be characterised and finite element analysis modelling of the cast components based on the obtained data will be performed.

Recent international cooperation of the research team

Alstom Power, Baden, Stwitzerland; Alstom Power, Finspang, Sweden; IPM, Academy of Sciences of Czech Republic, Czech Republic; University of Northumbria, Newcastle, United Kindgom; Polish Academy of Sciences, Poland; Universite catholique de Louvain, Belgium; IRC, University of Birmingham, Birmingham, United Kindgom; CENIM, Madrid, Spain; CNR-IENI, Milano, Italy; ITC, Povo, Italy; Imperial College, London, United Kingdom; NLR, Nederland

Proposer´s relevant publications related to the research subject

1. LAPIN, J. – ONDRUS, L.: Microstructure and some mechanical properties of titanium based intermetallic alloy after directional solidification. In: 7th International Conference Technology 2001. Slovenska technicka univerzita, Vydavatelstvo STU, Bratislava, Vol. 1, 2001, pp. 129-132.
2. LAPIN, J. – PELACHOVA, T.: Microstructure and creep of g-TiAl alloy. Submitted to 7th Liege Conference Materials For Advanced Power Engineering, Liege 2002, Belgium.
3. LAPIN, J. – ONDRUS, L.: Formation of ceramic particles in intermetallic Ti-46Al-2W-0.5Si alloy during directional solidification. Submitted to Kovove Mater.
4. LAPIN, J.: Creep of intermetallic Ti-46Al-2W-0.5Si alloy. Submitted to International Conference Metal 2002, Czech Republic.
5. LAPIN, J. – ONDRUS, L. – NAZMY, M.: Directional solidification of Ti-46Al-2W-0.5Si alloy in alumina moulds. Intermetallics, in preparation.