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.

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    It is very malleable and ductile, and may be easily rolled out into thin plate or drawn into wire; it is also very tenacious, in which quality it is only exceeded by steel. It is magnetic like iron, but possesses this quality to a much smaller degree, and loses its magnetism by heating to 250^ C. (481^ F.), recovering the quality again, however, upon cooling. It requires a very high temperature to fuse it, the melting-point of nickel being 1600' C. (2912 ^ F.), and it may be welded at a red heat. Use in the Dental Laboratory.—Oast and sheet nickel muffles are now extensively employed for dental furnace work; the metal appears to have been first introduced for this ])urpose in 1886. Alloys of Nickel.—The chief alloys of nickel are those in combination with copper and zinc in varying proportions, producing a series of alloys of much value, and to denote which different manufacturers employ fanciful names. German Silver, or nickel silver, consists of nickel, copper, and zinc in proportions varying with the uses to which it is applied, the best qualities containing a larger proportion of nickel than the inferior qualities. German silver, as made by good makers, consists usually of one part of nickel, one part of zinc, with two or three parts of copper. Prepakation.—Various methods are pursued for the manufacture of German silver, but that generally adopted at the present time consists in first alloying the zinc with one-half of the copper, the brass so formed lieing cast into thin plates, so that it can be easily broken up, while the nickel is melted with the re- maining portion of the copper in another crucible, to