Creep eutektika NiAl-Mo

Bc. Marie Dudová

Master's thesis

Creep in NiAl-Mo eutectics

Abstract:

Tato diplomová práce se věnuje studiu creepové deformace směrově krystalizovaného eutektika NiAl-Mo (in-situ kompozit) a intermetalika NiAl s nominální­m složení­m Ni-45.5Al-9Mo (v at.%) pro in-situ kompozity a Ni-45.2Al (v at.%) pro intermetalikum. Creepové experimenty byly provedeny při teplotách v rozmezí­ od 1073 K do 1173 K při aplikaci konstantní­ho napětí­. Výsledky jednoznačně prokázaly, že pří­tomnost termodynamicky stabilní­ch Mo vláken v NiAl matrici vede ke snížení rychlosti creepu, a to o ví­ce než 5 řádů. Pro aplikovaná napětí 150 MPa a 300 MPa byla stanovena zdánlivá aktivační­ energie creepu intermetalické matrice a in-situ kompozitu.

Abstract:

In this diploma thesis, a creep strain accumulation in directional solidified eutectic NiAl-Mo (in-situ composite) and intermellic NiAl is investigated. These materials had a nominal composition Ni-45.5Al-9Mo (in at.%) for the in-situ composite and Ni-45.2Al (in at.%) for the intermetallic. Creep experiments were performed in a temperature range between 1073 K and 1173 K and under constant applied stresses. Results clearly show that a distribution of long Mo fibers, that are thermodynamically stable in the NiAl matrix, results in a remarkable decrease of the composite creep rate representing more than 5 orders of magnitude. Apparent activation energy of creep has been determined for applied stresses of 150 MPa (NiAl matrix) and 300 MPa (in-sit composite).

Keywords

in-situ kompozity, vysokoteplotní deformace, intermetalikum, in-situ composties, high temperature deformation, intermetallicum

Language used: Czech

Date on which the thesis was submitted / produced: 14. 5. 2012

Thesis defence

• Date of defence: 14. 6. 2012
• Supervisor: prof. RNDr. Antonín Dlouhý, CSc.

Masaryk University

Faculty of Science

Master programme / field:
Physics / Condensed Matter Physics