USRE13961E - Fritz zimmermann - Google Patents

Description

To all whom it may concern l n u with iridium in various percentages.

- scientific rmtzrmueamann, 'or NEWARK, New Jersey, assmnon. 'ro BAKER a co.,

INCORPORATED, A CORPORATION OF NEW JERSEY.

ALLOYS or rna'rmuia AND OSMIUM.

August 14, 1913. Serial No. 784,812.

Be it known that I, 'Fnrrz ZIMMERMANN, a citizen of the German Empire, residing in Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Alloys of Platinum and Osmium, of which the followin is a specification. I

his invention relates, to alloys of platinum and osmium'which combine in a high degree the property of great hardness with tensile stren h and are a plicablefor use in the arts, 0 iefly for jewel electrical and urposes. V Hereto ore platinum has been allo ypld e higher the percentage of iridium which is added to the platinum, the greater is the resulting hardness. The highest ercentage of iridium alloyed with platinum is about The alloy of platinum and iridium is known in the trade as iridio platinum, 'orin short hard platinum.

The steadily increasing platinumflohe limited supply of iridium and its high price, have created a demand for another hard alloy of platinum with a precious metal which can be supplied at less cost than the iridio platinum.

I have found by a series of practical tests that the addition of ismium to platinum greatly increases the hardness of the platinum. The percentage of osmium which has been alloyed by me with platinum varies from less than i of 1% to 10% or more. Alloys of platinum and osmium containing more than '10%'of osmium are only workable with difiiculty, while alloys containing a percentage of osmium are brittle and hardly workable. It was further found that by alloying platinum with osmium, as far. as. hardness is concerned, one part of-o'smium is the equivalent of 2% parts of iridium, and thatthe tensile strength of the alloy is very high, so that a fine wire of platinum-osmium is more easily produced than a fine wire of iridiumlatinum of the same hardness. It was urther found that an alloy of platinum demand for hard .ture,

higher than 30% and osmium containing 2% of osmium and 98% of platinum can be advantageously used, for jewelry work, it being hard tough, while alloys containing 90% to 9 L% of latinuniand 10% to 6% of osmium will rep ace iridium latinum containing from 15% to 25% of iridium for contact-pointsin electrical apparatus. As there is very little demand for osmium, the same can be obtained at a much lower cost than the more while it is in every other when alloyed with platinum, as regards hardness and tensile strength, theequal of iridium-platinum; The osmiumplatinum alloy is also more resistant to the action of acids than platinum.

For melting platinum and osmium together, it is necessaryto refine the platinum and osmium of commerce to a high degree of purity so as to remove from the platinum the small quantities of metals of the platinum group and other impurities, and the impurities contained in the osmium. It is well known that platinum, as found in nacontains osmium as well as other metals of the platinum group; also copper and iron, but it islimpossible to make use of this natural product as an alloy, as the expensive iridium, respect good properties of the osmium-platinum alloy.

The new .alloy herein described, which is obtained by melting together refined platinum and refined osmium, combines great tensile stren h with hardness and ductility, and is there y adapted in a high degree for application in the arts.

Witnessesi C. P. Gonrm A. Bum.

and

FRITZ ZIMMERMANN.

UNITED STATES PATENT OFFICE.

Specification oi Reissued Letters latent. Reissfld Aug. 10, 1915. 1T0 Drawing. original No. 1,055,119, dated larch 4, 1913, Serial No. 715,266. Application for reissue flied I presence of the other metals impairs the