Technologie přesného lití přizpůsobená slitinám TiAl

Investment Casting Technology Tailored to Near-Gamma TiAl Alloys

presentation

en

The present study reports on the investment casting of near-gamma TiAl intermetallics. The attention is paid mainly to the minimization of thermal mismatch strains generated in an intermetallic cast and a ceramic shell mould during cooling to room temperature. The mismatch strains stem from different thermal expansion coefficients of near-gamma TiAl alloy and the mould ceramics. A numerical modeling and optimization helped to spot those process parameters that are most influential with respect to the stress state in the cast-mould system. The optimization based on a sequential technique and on a modified random search routine yielded a processing window in which sound casts can be fabricated.

V práci je uveden 1D model vedení tepla v soustavě odlitek TiAl – keramická skořepinová forma a na něj navazující 1D model vzniku napjatosti v odlitku. Vytvořené modely umožňují optimalizaci základních licích parametrů (počáteční teplota formy, licí teplota, režim ochlazování odlitků) poskytujících minimální napětí v odlitku během ochlazování.

The present study reports on the investment casting of near-gamma TiAl intermetallics. The attention is paid mainly to the minimization of thermal mismatch strains generated in an intermetallic cast and a ceramic shell mould during cooling to room temperature. The mismatch strains stem from different thermal expansion coefficients of near-gamma TiAl alloy and the mould ceramics. A numerical modeling and optimization helped to spot those process parameters that are most influential with respect to the stress state in the cast-mould system. The optimization based on a sequential technique and on a modified random search routine yielded a processing window in which sound casts can be fabricated.

TiAl Intermetallics, Investment casting

2005

30.05.2005

University of Applied Sciences Aargau

Aargau

First Invited COST 526 Conference on Automatic Process Optimization in Materials Technology

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