# Macro- and micro-mechanical behaviour of a γ′ strengthened Ni-based superalloy at cryogenic temperatures Journal article, 2021

In-situ neutron diffraction was performed during tensile deformation of Ni-base superalloy, Haynes 282, at 20, 100 and 300 K. Two distinct uni-modal microstructures with fine (20 nm) and coarse (200 nm) $$\gamma^\prime$$ particles were investigated. On the macro-scale yield strength increased and ductility decreased with decreasing temperature, although most significant decrease in ductility occurred between 100 and 20 K. The work hardening differed between the two microstructures, but was independent of temperature for each microstructure. On the micro-scale intergranular elastic interactions mainly lead to a transfer of the load to grains with the $\left<200\right>$ parallel to the tensile axis. No further load re-distribution between matrix and particles occurred in the microstructure with fine $$\gamma^\prime$$, where shearing of precipitates lead to co-deformation at all temperatures. In the coarse $$\gamma^\prime$$ microstructure, the load was transferred intragranularly from matrix to particles, in addition to the intergranular load transfer. The particles initially behaved elastically while the matrix deformed plastically, but at higher stresses a change in load partitioning indicated that also the $$\gamma^\prime$$ phase underwent plastic deformation as a result of the elastic stress build-up from the load partitioning. The tendency for, and effect of, plastic deformation of $$\gamma^\prime$$ increased with decreasing temperature.

Cryogenic temperatures

Ni-base superalloy

Phase-specific response

In-situ neutron diffraction

## Author

Chalmers, Physics, Microstructure Physics

### Saurabh Kabra

ISIS Neutron and Muon Source

### Magnus Hörnqvist Colliander

Chalmers, Physics, Microstructure Physics

0264-1275 (ISSN)

Vol. 209 109954

### SwedNESS

Swedish Foundation for Strategic Research (SSF) (GSn15-0008), 2016-07-01 -- 2021-06-30.

Swedish Foundation for Strategic Research (SSF) (GSn15-0008), 2017-01-01 -- 2020-12-31.

### Driving Forces

Sustainable development

### Subject Categories

Materials Engineering

Other Materials Engineering

Metallurgy and Metallic Materials

Energy

Materials Science

### Infrastructure

Chalmers Materials Analysis Laboratory

### DOI

10.1016/j.matdes.2021.109954