US1757507A - Alloy - Google Patents

Description

Patented May 6, 1930 UNITED STATES PATENT OFFICE MAURICE E. BARKER, OF THE UNITED STATES ARMY, CAMBRIDGE, MASSACHUSETTS, ASSIGNOR 0F ONE-FIFTH TO HARRY H. SEMMES, OF WASHINGTON, DISTRICT OF GOLUMBIA ALLOY No Drawing.

Application filed September 5, 1928. Serial No. 304,160.

(GRANTED UNDER THE ACT OF MARCH 8, 1883, AS AMENDED APRIL 30, 1928; 370 O. G. 757) This invention described herein may be manufactured and used by or for the Government for government purposes, wlthout the payment to me of any royalty thereon.

My invention relates to the art of metallurgy and more particularly to alloys containing silver together with other less expensive metals.

Silver is today one of the most wldely used metals for ornamental, and other purposes, where a substantially inert metal is necessary. Although pure silver is substantially inert to ordinary materials and is not sub ect to corrosion, as are iron and steel, yet its use in articles wherein durability and hardness are essential is not practical. Many attempts have been made to avoid this undesirable property, such as by silverplating metals l1ke iron and steel, and alloying silver with other metals.

Silver is also a relatively expensive metal, and in many instances its use has been restricted because of its cost.

Silverplating, although employed to a large extent, is not entirely satisfactory as in the course of time, especially if the article is subjected to much wear or erosion, the coating of silver plate will vanish, leaving the metal of which the article is formed exposed. Articles from which the silver plate is worn are, besides being unsightly, subject to corrosion to the same extent as if they had never been plated.

The alloys heretofore perfected have not been entirely satisfactory as they have been costly, and have not had the properties desired to meet the conditions which such sub stances should be capable of withstanding.

Nickel has in many instances been substituted for silver but despite its hard and durable properties, it has not been successfully employed because it lacks the attractiveness and inertness of silver.

An object of this invention is to produce a substitute for metallic silver having as many of the desirable properties of silver and as few of the undesirable properties of silver as is possible.

Another object of my invention is to produce alloys of silver having the inert and ornamental properties of silver together with the durable characteristics of other metals.

Still another object of my invention is to produce a durable silver-like metal suitable for use in constructing articles for the household such as cfitlery and other Ware and as a general substitute for silver.

l/Vith these and other objects in view, the invention consists in the process and product herein set forth, with the understanding that the several necessary elements entering Into the-composition of the alloys may be varied in proportion, without departing from the nature or scope of the invention.

- It is particularly desirable in the manufacture of metallic articles, such as cutlery, tableware or other metallic products which may possibly be subjected to the corrosive efi'ects of food, that some metal be available that will resist corrosion and yet will be durable and capable of undergoing changes in physical shape without detrimentally affecting the physical or chemical structure of the material. Also, the metal of which cutlery is made should be somewhat hard so as to be capable of holding a sharp cutting edge.

My invention contemplates the production of alloys containing relatively small amounts of silver which have some properties similar to silver and which are especially desirable for use in the manufacture of tableware and other articles that must be durable and yet resist corrosion.

The alloys constituting this invention contain nickel, copper and silver in amounts requisite for producing alloys having the properties desired.

Any of the standard methods for preparing alloys may be employed in the production of the metal constituting my invention. One particular method is to form alloys of one metal with each of the others and then fuse the two preliminary alloys into the final product. Such a procedure or a similar one is essential as it is absolutely necessary that all of the metals entering into the alloy be completely fused and thoroughly dissolved in each other.

If the metals entering into the alloy are not completely fused and the solution formed is not homo eneous, the resulting mixture will not exhi it the properties of a properly made alloy containing the same ingredients.

It is also essential in the production of alloys according to my invention, that the materials used in the preparation thereof be of substantial purity. The highest purity of commercial grade of the metals should be used in preparing these alloys to produce a m satisfactorysubstitute for silver. Of course silver substitutes for certain purposes not so exacting in requirements can be prepared from less pure metals.

Although the composition of the alloy constituting my invention may be varied within rather Wide limits without sacrificing any of the desirable properties, it is preferable to form the silver substitute alloy of a composition within the limits given below.

Nickel "55% to 65% Copper 27% to 37% Silver 3% to 131% Nickel 60% Copper 32% Silver A 8% This alloy containing only 8% of silver is a very valuable substitute for silver, in that it can be fairly cheaply produced and yet sufiiciently meets all demands of resistance to corrosion and beauty for which silver is used, together with the durability of iron and other similar metals. One essential property of a metal entering into the manufacture of variously shaped articles is that of ease of working. This particular property is characteristic of my alloy, thus making it also desirable from the actual construction point of view.

Thus my invention accomplishes the production of alloys having all the desirable ualities of silver for ornamental use and at t e same time possessing greater tensile strength, ease of working, and resistance to corrosion in the ordinary air and in contact with ordinary foods. These alloys can be used especially for the production of cutlery, flat pieces and other articles used on the table, though of course there are other uses to 65 which they can be put. Alloys such as described do not require silver plating in order to resent all the pleasing appearance of ster ing silver, but enable articles of solid were of silver appearance to be made at a price which can compete most favorably with the best of plated ware.

As the com osition can be varied within a wide range it is possible to produce a variet of alloys suitable to meet all demands of t e trade, dependin on the use. to which the material is to be su jected.

Although I have described a preferred embodiment of my invention, that is alloys of definite composition, I wish it to be un- \derstood that the composition of the alloys may be varied within rather wide limits and yet be within the scope of my invention.

I claim:

1. An alloy containing 55% to 65% nickel,

- 27 g; to 37% copper and 3% to 13% silver.

Analloy containing 60% nickel, 32% copper and 8% silver.

3. An alloy containing 57 to 63% nickel, 29 to 35% copper, and 5 to 11% silver.

4. An alloy containing 58 to 62% nickel, 3.0 to 34% copper, and 6 to 10% silver.

In testimony whereof I affix my signature.

MAURICE E. BARKER.