Journal of Dental Research, Vol 56, 335-345, Copyright © 1977 by International & American Associations for Dental Research Online Journals
Hardening of gold-based alloys
K. F. Leinfelder and D. F. Taylor
The relationships between composition, heat treatment, hardness, and
microstructure have been investigated for a number of commercial dental
casting alloys and for several series of experimental gold-silver-copper
compositions. The hardnesses and typical microstructures found are
reported. The results indicate that at least two distinct hardening
mechanisms must occur in these alloys. The ternary alloys outside the
two-phasr region of the gold-silver-copper system harden by ordering. The
commercial alloys and those within the two-phase region may harden in part
by ordering, but some other mechanism in required to explain the observed
hardening. This mechanism is not due to the observed grain boundary
precipitates. It may be associated with the intragranular needlelike
structures seen, but reasons exist to question the sufficiency of that
structure as an explantation of the hardening.
