Special Metals Corporation

Kamal Asgar

Richard W Fountain

Steven H Reichman

David L Tremblay

A multi-component composition suitable for amalgamation with mercury to form a dental amalgam, an amalgam and a method for producing such a multi-component composition. The multi-component composition has: from 30 to 90% (by weight) of a first component containing at least 30% silver, at least 20% tin and at least 10% copper; from 10 to 70% (by weight) of a second component, or alternatively, from 5 to 65% (by weight) of a second component and from 5 to 65% (by weight) of a fourth component, the second and fourth components containing at least 30% silver, at least 20% tin and at least 10% copper; and up to 15% (by weight) of a third component containing silver and/or alloy powder containing at least 80% (by weight) silver. The first component is spherically shaped atomized alloy powder. The second component is mechanically worked atomized alloy powder. The surface area to volume ratio of the powder of the second component is greater than the surface area to volume ratio of the powder of the first component. The fourth component is irregularly shaped as atomized alloy powder.

Amalgamable composition and method of production

A multi-component composition suitable for amalgamation with mercury to form a dental amalgam, an amalgam and a method for producing such a multi-component composition. The multi-component composition has: from 30 to 90% (by weight) of a first component containing at least 30% silver, at least 20% tin and at least 10% copper; from 10 to 70% (by weight) of a second component containing at least 30% silver, at least 20% tin and at least 10% copper; and up to 15% (by weight) of a third component containing silver and/or alloy powder containing at least 80% (by weight) silver. The first component is spherically shaped atomized alloy powder. The second component is mechanically worked atomized alloy powder. The surface area to volume ratio of the powder of the second component is greater than the surface area to volume ratio of the powder of the first component.

A process for manufacturing an atomized amalgamable alloy having mold adaptation characteristics superior to other atomized alloys and comparable or better than those for ad-mixed type alloys (alloys which are mixtures of spherical and irregularly shaped particles), and physical properties comparable to ad-mixed alloys. The process includes the steps of: producing a melt of an amalgamable alloy; atomizing the alloy so as to form particles which are primarily irregular in shape; collecting the particles; drying the particles; mechanically working the particles so as to fracture and change their shape; classifying the particles to finer than 53 microns; heat treating the particles; and reducing oxides from the surface of the particles.

Method for producing amalgamable alloy

A silver-tin-copper-palladium alloy containing from 30 to 70% silver, 15 to 37% tin, at least 13% copper and from 0.05 to 0.95% palladium; and an amalgam thereof.

Silver-tin-copper-palladium alloy and amalgam thereof

An improved metal powder blend and improved dental amalgams produced therefrom comprising a mechanical mixture containing controlled proportions of an amalgamatable silver-base alloy powder and a substantially non-amalgamatable eutectic alloy powder containing a controlled quantity of tin which upon trituration with mercury forms a substantially continuous matrix having dispersed therethrough discrete phases of the non-amalgamatable powder particles which impart improved mechanical properties to the resultant dental restoration.

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Ann Arbor, MI, United States of America

Kamal Asgar