Heterogeneous deformation of multi-phase engineering materials - an in-situ neutron diffraction study
Licentiatavhandling, 2019

Gas turbines are complex power generation systems used in aerospace or land-based-power stations. Materials such as Ni-base superalloys are involved in the combustion zone of these machines, which continuously experiences harsh environments with loading at high temperatures. Moreover, the continuous demand for increasing operating temperature to achieve higher efficiencies and reduced emission levels opens the scene to new heat resistant materials like the state-of-the-art high entropy alloys (HEAs), which require a thorough understanding of the structure-process-property relationships. The microstructures of these advanced multi-phase, multi-component alloys are complex, and the deformation is generally heterogeneous both with respect to the different phases and to the crystallographic orientation within each phase. Hence, it is important to understand their behavior and performance during processing and service. In-situ neutron diffraction is a unique technique to probe the deformation behaviour during service/processing-like conditions, including plastic deformation at various temperatures, in order to provide insights into the structure-property relations.

In the first part of this work the deformation mechanisms of a newly developed Ni-base superalloy was investigated using in-situ neutron diffraction and electron microscopy at room temperature. In addition, elasto-plastic self-consistent (EPSC) crystal plasticity simulations are used to obtain insights into the operating deformation mechanisms. In the second part, the as-cast eutectic high entropy alloy AlCoCrFeNi2.1 was studied using in-situ neutron diffraction at temperatures from 77 to 673 K. These investigations provide unique insights into the complex heterogeneous deformation behavior of these high-performance multi-phase engineering materials.

Eutectic high entropy alloys

in-situ neutron diffraction

Deformation mechanisms


Electron microscopy

Luftbryggan A810, MC2, Kemivägen 9, Chalmers University of Technology
Opponent: Prof. Ru Peng, Linköping University


Nitesh Raj Jaladurgam

Chalmers, Fysik, Mikrostrukturfysik

Nitesh Raj Jaladurgam, Hongjia Li, Joe Kelleher, Christer Persson, Axel Steuwer and Magnus Hörnqvist Colliander, Microstructure-dependent deformation behaviour of a low gamma prime volume fraction Ni-base superalloy studied by in-situ neutron diffraction

Nitesh Raj Jaladurgam, Adrianna Lozinko, Sheng Guo, Tung Lik Lee and Magnus Hörnqvist Colliander, Temperature effects on the load and strain partitioning in AlCoCrFeNi2.1 eutectic high entropy alloy during tensile deformation

In-situ studies of microstructural evolution during processing and service of high-temperature materials

Stiftelsen för Strategisk forskning (SSF), 2017-01-01 -- 2020-12-31.



Bearbetnings-, yt- och fogningsteknik

Annan materialteknik

Metallurgi och metalliska material







Chalmers materialanalyslaboratorium



Luftbryggan A810, MC2, Kemivägen 9, Chalmers University of Technology

Opponent: Prof. Ru Peng, Linköping University

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