A manual on dental metallurgy / by Ernest A. Smith.

  • Smith, Ernest A. (Ernest Alfred)
Date:
1903
Catalogue details

Licence: In copyright

Credit: A manual on dental metallurgy / by Ernest A. Smith. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

    237/334 (page 217)
    Tin and Copper,—Tin unites readly with co]>per, the most important alloys being the various bronzes, &c., described under Copper Alloys, p. 222. Tin and Mercury.—Tin readily combines with mercury. (See Tin.Amalgam, p. 138.) Tin and Antimony.—These metals unite when melted together, the effect of antimony being to harden the tin and generally to impair the malleability and ductility, making it more or less brittle. The brittle- ness increases with the proportion of antimony. An alloy of 4 parts of tin and I part of antimony is suffi- ciently malleable to be hammered and rolled cold. Britannia Metal.—This is an alloy of tin and anti- mony in very variable proportions, to which small quantities of other metals are also frequently added. It is a hard, very malleable and ductile alloy, and can be rolled out and stamped into various shapes. It takes a high polish and is largely employed for the manufacture of impression trays and other articles used by dentists. An inferior kind of Britannia metal known as Queen's Metal consists on an average of 75 per cent, of tin, 8.5 per cent, of antimony, with 8.5 per cent, of lead, and 8 per cent, of bismuth. Meter ilfe/a/.^This is composed of tin, antimony, and lead; it is used in the dental laboratory for making matrix and polishing plates. It possesses certain valu- able properties that enable it to be worked up in a steam swager, a thin diaphragm of the alloy being- made to give accurate copies and adapt itself to the surface of the model with ease. Owing to its fusibility it may be melted over a good Bunsen burner. Detection of Tin in Alloys.—To detect the presence of tin in an alloy advantage is taken of the fact