D. Baskin et al., ELEVATED-TEMPERATURE MECHANICAL-BEHAVIOR OF COSI AND PARTICULATE-REINFORCED COSI PRODUCED BY SPRAY ATOMIZATION AND CODEPOSITION, Journal of materials research, 9(2), 1994, pp. 362-371
Monolithic CoSi and TiB2 reinforced CoSi materials were produced by sp
ray atomization and co-deposition. The creep behavior of both material
s at elevated temperature was investigated. The unreinforced material
of grain size approximate to 25 mu m exhibited a stress exponent of th
ree, activation energy for creep of 320 kJ/mole, dislocation substruct
ure of homogeneously distributed dislocations, and inverse creep trans
ients upon stress increases. These results suggest that the creep beha
vior of CoSi is controlled by a dislocation glide mechanism. In contra
st, the reinforced material of a finer grain size (approximate to 10 m
u m) exhibited a stress exponent of unity, activation energy for creep
of 240 kJ/mole, and negligible creep transients upon stress increases
, suggesting that the creep behavior of the reinforced material is con
trolled by a diffusional creep mechanism. The creep resistance of the
reinforced material was lower than that for the unreinforced material.
This is a result of the finer grain size and higher porosity in the r
einforced material.