Microprobe analysis of a Au-containing alloy and its amalgam. 1976

D B Mahler, and J D Adey, and J van Eysden

Under near-equilibrium conditions, an alloy ingot containing approximately 64% Ag, 26% Sn, and 10% Au was found by X-ray diffraction to consist of large grains demonstrating the gamma (Ag-Sn) structure. Microprobe analysis of these grains showed a 64.2% Ag, 25.3% Sn, and 10.5% Au composition with very small amounts of AuSn2 and AuSn4 segregated at the grain boundaries. When this alloy is manufactured in the form of rapidly colled spherical particles, X-ray diffraction shows both beta (Ag-Sn) and gamma (Ag-Sn) structures with Au substituting for Ag, and microprobe analysis demonstrates a segregation of small high Sn, high Au areas having a AuSn2 composition. When Hg is mixed with these spherical particles, gamma1, some gamma2, and Sn-Au phases (AuSn2 and AuSn4) form. The Au that combines with Sn seems to come from the beta or gamma phases rather than from the Sn-Au segregations in the alloy. The small amount of the gamma2 phase that is initially formed apparently disappears after a short period of time although there is some question as to whether a very small amount may still remain. The Ag-Hg hase (gamma1) is essentially the same as found in conventional amalgams as is the small amount of gamma2 initially formed. Furthermore, a nonequilibrium state seems to be necessary for the early and possibly complete elimination of gamma2. In the as-cast condition, after a period of time at 37 C, A Ag-Hg-Sn phase (beta1) is formed that is similar to that found in conventional amalgams that serve as restorations in the mouth for a period of time. However, in the 135-annealed amalgam, no beta1 appears.

UI MeSH Term Description Entries
D010316 Particle Size Relating to the size of solids. Particle Sizes,Size, Particle,Sizes, Particle
D003723 Dental Amalgam An alloy used in restorative dentistry that contains mercury, silver, tin, copper, and possibly zinc. Amalgam, Dental,Amalgams, Dental,Dental Amalgams
D004577 Electron Probe Microanalysis Identification and measurement of ELEMENTS and their location based on the fact that X-RAYS emitted by an element excited by an electron beam have a wavelength characteristic of that element and an intensity related to its concentration. It is performed with an electron microscope fitted with an x-ray spectrometer, in scanning or transmission mode. Microscopy, Electron, X-Ray Microanalysis,Spectrometry, X-Ray Emission, Electron Microscopic,Spectrometry, X-Ray Emission, Electron Probe,X-Ray Emission Spectrometry, Electron Microscopic,X-Ray Emission Spectrometry, Electron Probe,X-Ray Microanalysis, Electron Microscopic,X-Ray Microanalysis, Electron Probe,Microanalysis, Electron Probe,Spectrometry, X Ray Emission, Electron Microscopic,Spectrometry, X Ray Emission, Electron Probe,X Ray Emission Spectrometry, Electron Microscopic,X Ray Emission Spectrometry, Electron Probe,X-Ray Microanalysis,Electron Probe Microanalyses,Microanalyses, Electron Probe,Microanalysis, X-Ray,Probe Microanalyses, Electron,Probe Microanalysis, Electron,X Ray Microanalysis,X Ray Microanalysis, Electron Microscopic,X Ray Microanalysis, Electron Probe
D006046 Gold A yellow metallic element with the atomic symbol Au, atomic number 79, and atomic weight 197. It is used in jewelry, goldplating of other metals, as currency, and in dental restoration. Many of its clinical applications, such as ANTIRHEUMATIC AGENTS, are in the form of its salts.
D006047 Gold Alloys Alloys that contain a high percentage of gold. They are used in restorative or prosthetic dentistry. Gold Alloy,Alloy, Gold,Alloys, Gold
D012834 Silver An element with the atomic symbol Ag, atomic number 47, and atomic weight 107.87. It is a soft metal that is used medically in surgical instruments, dental prostheses, and alloys. Long-continued use of silver salts can lead to a form of poisoning known as ARGYRIA.
D013499 Surface Properties Characteristics or attributes of the outer boundaries of objects, including molecules. Properties, Surface,Property, Surface,Surface Property
D014001 Tin A trace element that is required in bone formation. It has the atomic symbol Sn, atomic number 50, and atomic weight 118.71. Stannum
D014961 X-Ray Diffraction The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) Xray Diffraction,Diffraction, X-Ray,Diffraction, Xray,Diffractions, X-Ray,Diffractions, Xray,X Ray Diffraction,X-Ray Diffractions,Xray Diffractions

Related Publications

D B Mahler, and J D Adey, and J van Eysden
November 1984, Journal of oral rehabilitation,
D B Mahler, and J D Adey, and J van Eysden
January 1976, Journal of dental research,
D B Mahler, and J D Adey, and J van Eysden
January 1973, Biomaterials, medical devices, and artificial organs,
D B Mahler, and J D Adey, and J van Eysden
January 1981, Acta odontologica Scandinavica,
D B Mahler, and J D Adey, and J van Eysden
January 1980, Acta odontologica Scandinavica,
D B Mahler, and J D Adey, and J van Eysden
May 1967, Journal of dentistry for children,
D B Mahler, and J D Adey, and J van Eysden
April 1984, Australian dental journal,
D B Mahler, and J D Adey, and J van Eysden
May 1987, Attualita dentale,
D B Mahler, and J D Adey, and J van Eysden
February 1988, Australian dental journal,
D B Mahler, and J D Adey, and J van Eysden
June 2007, Asian spine journal,
Copied contents to your clipboard!