Mechanical properties of bulk- and hybrid nanocrystalline materials
Paper i proceeding, 2014

The compressive strength at elevated temperatures of a Cu/nano-Ni-Fe periodic cellular material and of nanocrystalline Ni-Fe samples was investigated. An unconstrained compression test was performed on a Cu/nano-Ni-Fe periodic cellular material (PCM) at 150C. Finite element analysis and SEM characterization revealed that major stress concentrations occurred at the nodes of the struts where cracks were formed. Also plastic wrinkling at the hinges of the PCM was observed. Compressive deformation of the nanocrystalline Ni-Fe samples was performed between room temperature and 275C. Without any deformation, the microstructure with an initial grain size of 31 nm was found to be thermally stable up to 275C. However, compression at an elevated temperature after annealing the sample for 30 minutes at the respective temperature led to deformation-induced grain growth; grains with 50 +/- 30, and 100 +/-50 nm in diameter were found after compression at 200 and 275C, respectively. The material exhibited considerable plasticity of >30% fracture strain at higher temperatures compared to <15% at room temperature. Characterization by use of TEM and transmission EBSD suggests that the coarser grains enable strain hardening by intragranular dislocation accumulation, and this is responsible for the larger fracture strains at higher temperatures.

FEM

nanocrystalline Ni-Fe

EBSD

PCM

SEM

compression test

Författare

Uta Klement

Chalmers, Material- och tillverkningsteknik, Yt- och mikrostrukturteknik

Nooshin Mortazavi Seyedeh

Chalmers, Material- och tillverkningsteknik, Yt- och mikrostrukturteknik

Johan Ahlström

Chalmers, Material- och tillverkningsteknik, Materialteknologi

Christer Persson

Chalmers, Material- och tillverkningsteknik, Materialteknologi

Glenn Hibbard

Proceedings of the Risø International Symposium on Materials Science

0907-0079 (ISSN)

349-355

Drivkrafter

Hållbar utveckling

Ämneskategorier

Materialteknik

Styrkeområden

Materialvetenskap

ISBN

978-87-92896-94-0

Mer information

Skapat

2017-10-07