Journal of Dental Research, Vol 64, 62-66, Copyright © 1985 by International & American Associations for Dental Research Online Journals
The response of dental amalgam to dynamic loading
E. J. Sutow, D. W. Jones, G. C. Hall and E. L. Milne
A conventional (gamma 2-containing) dental amalgam was fatigue-tested at
1800 and 80 cycles/min, employing uni-axial, sinusoidal loading, with R =
-8. Compressive, tensile, and creep tests were conducted to characterize
the alloy's static mechanical behavior. Tests were performed at 37 degrees
C on specimens which were aged for seven days, at 37 degrees C.
Fatigue-tested specimens were microscopically examined for fracture surface
appearance and crack path. The amalgam demonstrated a frequency dependence
and a significant reduction in fracture strength due to fatigue loading.
The fatigue crack path was primarily intergranular in the gamma 1 phase and
inclined at approximately 45 degrees to the principal stress axis. These
observations are characteristic of some metals when subjected to
low-frequency, elevated temperature testing where significant grain
boundary sliding occurs, and therefore suggest a creep-fatigue interaction
for this alloy.
