US1829903A - Alloy - Google Patents

Description

- Patented Nov. .3, 1931 sential constituents.

UNITED STATES PYATENT- OFFICE nonnn'r n. LEAGH, or rmrmm,'co1vmc'ncu'r, ASSIGNOB "r0 nanny a Human, or

NEW YORK, N.

Y., CORPORATION OF NEW YORK ALLOY Io Drawing. Application filed This invention relates to alloys and is concerned more particularly with 'a novel alloy for soldering and brazing purposes which includes silver and copper as its main'and es- The new alloy is of especial utility for uniting objects of copper and copper alloys, but it may also be employed to good advantage in brass and nickel silver wor and even with steel in some cases.

The new alloy includes silver in an amount varying approximately from 10% to 25%, copper varying approximately from 67% to 88%, and phosphorous varying approximately from 2% to 8%. Examples of specific compositions of the alloy which have been found particularly satisfactory include:

, when itis hot.

- Percent 1. Silver 15 Copper 80 Phosphorus 5 2. Silver 10 Copper 82 Phosphorus 8 3. Silver 20 Copper 73.6

Phosphorus 6.4

These and other alloys within the ranges set forth have the advantage of having melting points which are lower than those of the alloys generally known as silver solders, and they are cheaper than silver solders, and, due to the presence of the phosphorus, may be. employed with little or no flux.

I am aware that the Jones Patent No. 1,651,7 .09 discloses an alloy consisting of copper and phosphorus, the latter running up to 9%. It has been my experience, however, that such alloys tend to be brittle if there is an appreciable amount ofphosphorus present,-

so that the alloys can be fabricated only to a limited extent and by working the metal It is well-known that phosphorus lowers the melting point when alloyed with copper and also acts as a deoxidizer, so the alloy may be used as a solder substantially without a flux. Also, such an alloy is fairly cheap due to the absence of precious metals. But the difiiculty of working the alloy offers is raised much above 25%,

pie N0. 2 has a melting 188.14, 1981. Serial No. 537,485.

a considerable handicap to its use and the melting point from 1292 F. to 1652 F. is inconveniently high for many purposes.

My new alloy offers advantages over both the copper phosphorus alloys and the silver solders above mentioned, is malleable and readily worked due to the presence of the silver, and the later when used within the range stated also lowers the melting point. While some variation from the range of 10% to 25% is permissible, I find that if the silver content of the new alloy drops much below 10%, the desired malleability and low melting point are not obtained. If the silver content the melting point is not lowered 'but on the contrary has a tendency to rise. Also, an increase in the amount of silver beyond 25% increases the cost of the new alloy without commensurate benefit.

The phosphorus in my new alloy may run up to 8% or 9% but while the melting point falls as the phosphorus content increases, an increase in phosphorus much beyond 5% adds to the brittleness of the alloy and this disadvantage may overbalance the reduction in melting point resulting from using larger amounts of phosphorus.

My new alloy has different melting depending on its composition, but in general the melting points are lower than those of standard silver solders and below the range of those of the copper-phosphorus alloys mentioned. The range of melting points of my alloy is approximately 1130 F. to about 1340" F. For example, the alloy of Exampoint of about 1250 and that of Example N0. 3 has a melting point of about 1130 F. The silver solder consisting of silver, copper, and zinc which has the lowest melt point with which I am familiar, melts at about 1300 F.

My tests also indicate that my new alloy is superior to the alloys which have heretofore been used for the same general purposes, in that it produces stronger joints and provides much lower flow points. It has been used to considerable advantage in the manufacture of electrical machinery, for example in the soldering of transformer leads, and since little or no flux is required, it may be used in operations involving resistance heating with excellent results.

What 1 claim is: 1. An alloy which consists of silver varying from about 10% to about 25%, copper varying from ebout 67% to about 88%, and phosphorus varying from about 2% to about 2. An alloy which consists of about 15% silver, shout copper and about 5% phosphorus.

3 An alloy which consists of about 10% silvpl', about 82% copper, and about 8% phosphorus.

An alloy which consists of about 520% silver, about 73.6% copper, and about 6.4%

of about 15% copper, and from v phosphorus.

5. An alloy which consists of silver, about 77% to 80% 5% to 8% phosphorus.

In testimony whereof I afiix my si nature. ROBERT g H. LEACH.