Etude de la structure massive dans des alliages à base TiAl et de son évolution en cours de traitements thermiques

Abstract : Grain refinement and texture reduction in as-cast TiAl alloys are very important in order to improve their structural properties, and make them industrially viable, and offer a possible replacemen to Ni-based super alloys in many industrial applications. Thermo-mechanical route is not always preferred for grain refinement due to the high production cost and low treatability. Thermal treatment through massive phase tansformation could be a possible grain refinement route but it requires full understanding of the mechanisms of massive transformation, and of the evolution of microstructure and texture through subsequent heat treatments. In the Ph.D. research work, [gamma]-massive grains were obtained by rapid quenching of TiAl alloys from the high temperature single phase [alpha] field at 1365°C. Depending on the alloy composition and cooling rate, different volume fractions of [gamma]-massive grains were obtained. In order to address different objectives, samples with different volume fractions of the [gamma] grains were chosen and studied. After studying the mechanisns of massive transformation ( nucleation and growth), subsequent heat treatments were performed on the microstructures to study their microstructural and texture evolution. To understand the mechanisms development and evolution of these massive structures, morphological and crystallographic characterization were performed using different instruments, (DSc) and microscopy techniques (X-ray, electron microscopy)
Document type :
Theses
Complete list of metadatas

Cited literature [106 references]  Display  Hide  Download

https://hal.univ-lorraine.fr/tel-01752622
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 1:52:45 PM
Last modification on : Monday, April 16, 2018 - 10:42:19 AM

File

Sankaran.Ananthi.SMZ0908.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01752622, version 1

Collections

Citation

Ananthi Sankaran. Etude de la structure massive dans des alliages à base TiAl et de son évolution en cours de traitements thermiques. Autre. Université Paul Verlaine - Metz, 2009. Français. ⟨NNT : 2009METZ008S⟩. ⟨tel-01752622⟩

Share

Metrics

Record views

14

Files downloads

28