title: Two different types of age-hardening behaviors in commercial dental gold alloys.
abstract: Age-hardening behavior during continuous heating in commercial dental casting gold alloys was investigated by means of electrical resistivity measurements, hardness tests and X-ray diffraction. Two distinguishable behaviors were detected. It is considered that the difference was attributed to the amount of platinum, and the atomic ratio of gold and copper in each alloy. The phase transformations during continuous heating progressed into two steps (stages I and II). Increase of the platinum addition in gold-based alloys retards the rate of the reaction and decreases remarkably the amount of stage I.
authors.affiliation: Division of Dental and Biomedical Materials Science, Department of Developmental and Reconstructive Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8588, Japan. hisatune@net.nagasaki-u.ac.jp
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Hisatsune
authors.forename: Takanobu
authors.initials: T
authors.lastname: Shiraishi
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Takuma
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Rhodora H
authors.initials: RH
authors.lastname: Luciano
mesh_terms: D003300:Copper / Q000737:chemistry; D003722:Dental Alloys; D017097:Electric Impedance; D006046:Gold / Q000737:chemistry*; D006047:Gold Alloys / Q000737:chemistry*; D006244:Hardness; D006245:Hardness Tests; D008420:Manufactured Materials / Q000032:analysis*; D008422:Materials Testing; D010984:Platinum / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D003722:Dental Alloys; D006047:Gold Alloys; D010984:Platinum; D006046:Gold; D003300:Copper