Etude des hétérogénéités de texture et de microstructure au sein de disques forgés en IMI834 : influence sur les propriétés en fatigue-dwel

Abstract : We have characterized in detail the strong heterogeneity of texture and microstructure (macrozones) by EBSD in areas, differently deformed, of a disk in IMI834 with a bimodal structure ?P/?S, used in aircraft engines. Specific samples have shown that the amplitude of back-scattered ultrasonic signals depended on the presence and organization of macrozones. Based on these observations, an analysis of back-scattered ultrasonic signals in parts of the disc subject to strong deformation during forging led to select a set of specimens with different microstructural features for fatigue-dwell tests. A high dispersion of lifetimes associated with these microstructures was observed. The fractographic analysis of fracture surfaces and their EBSD studies were used to locate crack initiation sites and propagation paths and their crystallographic characteristics. The results of fatigue-dwell tests showed that the lifetime reduction is strongly influenced by the presence of macrozones formed by agglomerates of grains elongated ?P associated with thicker ?S lamellae, organized in colonies and with c-axis predominantly at less than 30 ° of the solicitation axis
Document type :
Theses
Complete list of metadatas

Cited literature [27 references]  Display  Hide  Download

https://hal.univ-lorraine.fr/tel-01752939
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 2:02:26 PM
Last modification on : Monday, April 16, 2018 - 10:42:44 AM

File

Uta.Elena.SMZ0954.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01752939, version 1

Collections

Citation

Elena Uta. Etude des hétérogénéités de texture et de microstructure au sein de disques forgés en IMI834 : influence sur les propriétés en fatigue-dwel. Autre. Université Paul Verlaine - Metz, 2009. Français. ⟨NNT : 2009METZ054S⟩. ⟨tel-01752939⟩

Share

Metrics

Record views

29

Files downloads

16