US2229463A

US2229463A - Alloy

Info

Publication number: US2229463A
Application number: US300579A
Authority: US
Inventors: Robert H Leach
Original assignee: Handy and Harman
Current assignee: Handy and Harman
Priority date: 1939-10-21
Filing date: 1939-10-21
Publication date: 1941-01-21
Anticipated expiration: 1958-01-21

Description

Patented Jan. 21, 1941 UNITED STATES PATENT OFFICE ALLOY tion of New York No Drawing.

Application October 21, 1939,

Serial No. 300,579

5 Claims.

This invention relates to alloys and is concerned more particularly with a novel gold alloy which is suitable for use in'the manufacture of jewelry and is characterized by having a fine grain structure. The new alloy has greater hardness and resistance to Wear than standard compositions heretofore used for similar purposes and also has increased corrosion'resistance. In addition, the new alloy is capable of being hardened by appropriate heating and cooling treatments as well as by cold working, and by variation in the amounts of the constituents employed, it may be given different colors as well as different physical properties which vary in accordance with the 1d nature of the articles into which it is to be manufactured.

The new alloys may be made with varying amounts of gold, depending on the karat desired. In general, it contains substantial amounts of gold, copper, and silver, and ordinarily a less amount of zinc. In addition, it contains a small quantity of iron. The proportions of these constituents will, of course, vary in accordance with the purposes for which the alloy is to be used, but ordinarily the proportions will fall within the ranges given in the following analysis in which the range limitations given are approximate.

Per cent Gold 35 to 75 Silver 5 to Copper 12 to Zinc 0.1 to 12 Iron 1 to 5 it) A specific example of the new alloy, which is a ten karat gold, is of the following approximate analysis:

' Example No. 1

Per cent a Silver 25 Copper 32 Zinc 0.3 Iron l Another alloy embodying the principles of the invention and of fourteen karat is of the following approximate analysis:

v Example No. 2 Per cent Gold 58.3 Silver 24.28 Copper 16.28 Zinc 0.14 Iron 1 Other alloys embodying the principles of the invention and of fourteen karat are given in the following examples:

As an indication of the efiect of appropriate heat treatments on such alloys, the following data are given. An alloy of Example No. 2, after 39 having been annealed at 1200" F. for one-half hour and then quenched, shows a Rockwell B hardness of and a scleroscope value of 30. On reheating this alloy for one hour at 600 F., the Rockwell "13 hardness increases to 102 and the 35 scleroscope to 52.

The new alloy exhibits excellent physical properties and the addition of iron does not materially change the color. Also, although the presence of iron increases the hardness and wear 40 resistance of the alloy, the iron does not make it more difficult to fabricate. In general, an increase in the iron content reduces the ductility and the quantity of iron used will, therefore, depend on the purposes for which the alloy is to be 45 employed. The grain size of that form of the new alloy containing from 2% to 5% iron is much smaller than that of those forms of the alloy containing only 1% iron. Above 2% iron, however, there is no marked grain size reduction 50 imparted by the higher iron content. It, therefore, appears that a form of the new alloy containing between 1% and 2% iron would exhibit the optimum composition of grain refinement, hardness, and ductility. as

In making up the new alloy, the constituents, other than iron and a part of the gold, are: melted and the iron introduced into the melt in the form of a master alloy containing 80% gold and 20% iron.

In addition to the physical properties previously mentioned, the new alloy is characterized by having a considerable resilience or springiness, particularly when employed in the form of thin sections. Accordingly, it may he used to advantage in the production of articles, such as watch cases and vanity cases, in which the springiness of the alloy'causes it to resist deformation. Also, these characteristics make it desirable for use in the production of pen points.

I claim:

1. An alloy which consists of gold in an amount ranging from about 35% to about'75%, silver in an amount ranging from about 5% to about copper in an amount rangingfrom about 12% to about zinc in an amount ranging from about 0.1% to about 12 and iron in an amount ranging from about 1% to about 5%.

2. An alloy which consists of at least 35% of gold, silver in an amount ranging from about 5% to about 25%, copper in an amount ranging from about 12% to about 35%, zinc in an amount ranging from about 0.1% to about 12%, and iron in an amount ranging from about 1% to about 5%.

3. An alloy which consists of about 41.7% gold, about 25% silver, about 32% copper, about 0.3% zinc, and about 1% iron.

4. An alloy which consists of at least 58.3% gold, silver ranging from about 22.28% to about 24.28%, copper ranging fromabout 14.28% to about 16.28%, about 0.14% zinc, and iron ranging from about 1% to about 5%.

5. An alloy which consists of about 58.3% gold, about 24.28% silver, about 16.28% copper, about 0.14% zinc, and about 1% iron.

ROBERT H. LEACH.