title: Isothermal age-hardening behaviour in a multi-purpose dental casting gold alloy.
abstract: The isothermal age-hardening behaviour of a multi-purpose dental casting gold alloy was investigated by means of hardness testing, X-ray diffraction study, scanning electron microscopic observations and energy dispersive spectroscopy. By ageing of the solution-treated specimen at 400-500 degrees C, two phases of the Au-rich alpha 1 phase with an f.c.c. structure and the alpha 2 phase with an ordered f.c.c. structure based on Pt3In were transformed into three phases of the alpha 1 phase, the alpha 2 phase and the beta phase with an ordered f.c.t. structure based on PtZn. Hardening was attributed to the fine nodular precipitation resulting from the formation of the beta phase in the alpha 1 matrix. Softening was due to the coarsening of the fine nodular precipitates as the result of consumption of the alpha 2 phase.
authors.affiliation: Department of Dental Materials, College of Dentistry, Pusan University, Korea.
authors.forename: H I
authors.initials: HI
authors.lastname: Kim
authors.forename: H K
authors.initials: HK
authors.lastname: Ahn
authors.forename: H K
authors.initials: HK
authors.lastname: Lee
authors.forename: K
authors.initials: K
authors.lastname: Hisatsune
authors.forename: H J
authors.initials: HJ
authors.lastname: Seol
authors.forename: Y
authors.initials: Y
authors.lastname: Takuma
mesh_terms: D003300:Copper; D003343:Corrosion; D003735:Dental Casting Technique; D004577:Electron Probe Microanalysis; D006047:Gold Alloys / Q000737:chemistry*; D006244:Hardness; D006245:Hardness Tests; D006358:Hot Temperature; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010984:Platinum; D012834:Silver; D013816:Thermodynamics; D013997:Time Factors; D014961:X-Ray Diffraction; D015032:Zinc
chemical_list: D006047:Gold Alloys; D012834:Silver; D010984:Platinum; D003300:Copper; D015032:Zinc