title: Difference in age-hardening mechanism in dental gold alloys.
abstract: TEM and SAED studies were conducted to clarify a difference in age-hardening mechanism with changes of gold content in Au-Cu-Ag ternary alloys, 18K, 16K, and 14K gold alloys, for which the ratio of copper to silver remained at 65 to 35 in weight. Age-hardening in the 18K alloy was attributed to the formation of the AuCu I type ordered platelets on the matrix (100). In the 16K and 14K alloys, a periodic antiphase domain structure of the AuCu II type ordered phase made a major contribution to age-hardening. An alternating coarse lamellar structure was formed by the mechanism of discontinuous precipitation in the 16K alloy, while a modulated structure by spinodal decomposition was observed in the 14K alloy.
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003300:Copper; D006046:Gold; D006047:Gold Alloys; D006244:Hardness; D006358:Hot Temperature; D008854:Microscopy, Electron; D012834:Silver; D013997:Time Factors
chemical_list: D006047:Gold Alloys; D012834:Silver; D006046:Gold; D003300:Copper