US1816961A - Alloy and method of preparing same - Google Patents

Description

Patented Aug. 4, 1931 UNITED STATES.

PATENT OFFICE HUGH S. COOPER, OF CLEVELAND, OHIO, ASSIGNOR TO BERYLLIUM CORPORATION OF AMERICA, 01? NEW YORK, N. Y.,

A CORPORATION. OF NEW YORK ALLOY AND METHOD OF PREPARING SAME No Drawing. Application filed December This invention relates to alloys which have as their chief components silver an beryllium. The main object of the invention is to provide an alloy having special resistance to the action of sulfur compounds. A further object is to reduce the specific gravity of silver in order that it shall possess greater spreading properties. These properties are manifested in alloys containing silver and beryllium and when ductility is also an important consideration, I find that it is desirable to use only rather small amounts. /of either constituent.

Silver is characterized by its for sulfur, and the yellow or great aifinity long been desired.

Utilizing beryllium prepared according to my; copending application Serial No. 7 54,446 I .have prepared beryllium-silver alloys in nearly all possible compositions. Beryllium is an element which has very little aflinity for sulfur, and I have found that even when small percentages of this metal are added to silver or silver alloys, the resistance to tarnishing is increased to an astonishing degree. With only about 3% of beryllium present, the alloys are seemingly immune to vapors of sulfur compounds. Alloys containing about 3% to 5% of beryllium are somewhat brittle in the chill -cast condition, but by rolling or otherwise workg d and with afinal annealing, the various silver-containing, at elevated temperatures,

ing compositions within this range are almost as ductile as pure silver.

' The great diflerence in specific gravity of the two metals makes the preparation of uniform alloys somewhat difficult, but I have found that one way of overcoming this difficulty is to first prepare a basic alloy of beryllium and silver, the beryllium content being from 30% to Such an alloy is very brittle and easily broken into small pieces which can be uniformly mixed. To make the alloy, the silver is first brought into a molten condition under a thin coating of alkali fluoride or chloride flux. Small brownish color which this element quickly assumes in air is t 2, 1925. Serial No. 72,817.

beryllium salt with or without an added salt 0 or salts of more electropositive metals and with or without the addition of beryllium oxide, using molten silver as the cathode.

The following will serve as an example:

200 grams of sodium-beryllium.fluoride approximating the formula QNaFBeF were melted in a graphite crucible externally heated from 1100 to 1200 C. A carbon anode of an inch in diameter was immersed to the extent of about 2 inches into the bath. A pool of molten silver at the bottom of the graphite crucible acted as cathode. At intervals additions of beryllium oxide and beryllium fluoride were made. The voltage varied from 5 to 10 volts, the current varying from 15 to 95 amperes.

My invention consists not only in the preparation of silvereryllium alloys but also in the addition of beryllium to tGCl'lIllcally known silver alloys such as alloys silver with, for example, aluminum, magnesium, copper, nickel, zinc, 'cadm'ium or Alloys having less than about 10% of either silver or beryllium seem at this time preferable because of their better phys cal properties, but I do not wish to be llm ted to any specific compositions or proportions except as to those claims which have been purposely and di tinctly restricted in this respect.

I claim:

" 1. An alloy containing substantial amounts up to 10% each of beryllium andsilver;

2. An alloy containing silver and from 3% to 5% of beryllium. 4

. In testimony whereof, I aifix my signature.

HUGH S. COOPER.

having the desired"