High temperature compression of Mo(Si,Al)2-Al2O3 composites
Journal article, 2023

The aim of this study was to investigate the effect on high temperature of mechanical properties of adding Al2O3 particles to polycrystalline Mo(Si,Al)2. Mo(Si,Al)2-Al2O3 composites, containing 0–25 wt% Al2O3 particles have been compression tested at 1300 °C, and the microstructure after deformation was studied using electron backscatter diffraction. It was shown that even small amounts (5 wt%) of Al2O3 particles resulted in a grain-refined material through inhibition of grain growth during sintering, which lead to lower flow stresses compared to the coarse-grained Al2O3-free material. The inverse grain size effect and post-test microstructure investigations suggest that creep-like deformation mechanisms dominate in fine grained Mo(Si,Al)2-Al2O3 composites at 1300 °C. In the materials containing 5–15 wt% Al2O3, the maximum stress decreased with increasing Al2O3 content. In materials with higher Al2O3 additions, the maximum stress increased with the Al2O3 addition, but did not reach the strength levels in the Al2O3-free reference material. It is suggested that the deformation behaviour is affected by electroplasticity effects as resistive heating was used. Electroplasticity contributes to the decrease in maximum stress observed in the lower Al2O3 containing materials, while this is outweighed by particle strengthening at higher Al2O3 contents.

Particle strengthening

High temperature compression


Mo(si,Al) 2

Electron backscatter diffraction


Aina Edgren

Chalmers, Physics, Microstructure Physics

Kanthal AB

Erik Ström

Kanthal AB

Lars Frisk

Luleå University of Technology

Farid Akhtar

Luleå University of Technology

Magnus Hörnqvist Colliander

Chalmers, Physics, Microstructure Physics

Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

0921-5093 (ISSN)

Vol. 865 144583

Developing next generation high temperature MoSi2 materials

Swedish Foundation for Strategic Research (SSF) (ID18-0064), 2019-10-01 -- 2023-09-30.

Subject Categories

Other Materials Engineering


Chalmers Materials Analysis Laboratory



More information

Latest update