Low temperature plasticity enhancement mechanisms which are operative in bo
dy-centered cubic metals and BZ ordered alloys can be observed in MoSi2 in
appropriate stress-temperature-strain rate regimes. We illustrate effects o
f surface films (ZrO2) and dispersoids (TiC) in enhancing plasticity of MoS
i2 in the ductile-to-brittle transition range of temperatures, 900-1400 deg
rees C. We also show, through experiments involving high temperature (1300
degrees C) prestrain, that effective operation of dislocation generation pr
ocesses can extend the low temperature range to which polycrystalline MoSi2
can be plastically deformed. The dislocation substructures of polycrystall
ine MoSi2 deformed over this temperature range have also been characterized
. The overall results illustrate that approaches to enhance toughness of Mo
Si2 need not be limited to ductile phases characterized by weak interfaces.
(C) 1999 Published by Elsevier Science S.A. All rights reserved.