US2138637A - Alloys - Google Patents

Description

Patented Nov. 29, 1938 PATENT OFFICE ALLOYS Robert H. Leach, Fairfield, Conn, assignor to Handy & Harman, New York, N. 1 a corporation of New York No Drawing. Application April 23, 1938, Serial No. 203,824

7 Claims.

This invention relates to alloys used for soldering purposes, and is concerned more particularly with a novel solder especially suited for use in connection with stainless steels.

In the fabrication of articles, for instance, hollow ware, of stainless steel, the use of ordinary solders is objectionable because such solders are different in color from the steel and joints made by their use are not only visible, but unsightly. Also, many solders heretofore employed for ordinary purposes are not suitable for use with stainless steel because the solders do not wet the steel and the joints produced are not strong.

The present invention is, accordingly, directed to the provision of a new solder alloy which is of a color closely matching that of stainless steel and may be used therewith to produce strongnon-porous joints which are highly resistant to certain types of corrosion.

The new solder comprises a substantial proportion of silver and less amount of other metals, the ranges of proportions of the ingredients being approximately as follows:

Percent 25 Silver to Copper to 15 Manganese to 15 Zinc to 30 Nickel to 7.5

2 Silicon 0.15 to 0.40

In the new alloy, the copper imparts malleability, ductility, and toughness, and it is cheaper than the silver, but it tends to give a yellow color. It is, therefore, desirable to keep the copper content low, and forsome purposes, it is satisfactory to use a form of the new alloy which contains as little as 1% of copper, or none whatever. The nickel counteracts the tendency of the copper to give a yellow color to the metal and, in addition, increases the resistance of the alloy to certain types of corrosion, as for example, chloride attack. The presence of the nickel also-appears to impart to the alloy the characteristic of wetting surfaces of stainless steel.

The presence of silicon within the range specified results in the production of sound joints free of porosity, but an increase in the silicon above the upper limit mentioned does not produce a further improvement in the alloy, and-in fact appears to be detrimental in some respects. The silicon also appears to be beneficial with respect to both the casting and rolling properties of the alloy, and, in some instances, lowers the flow point.

Specific examples of the new alloys, which have been found to give satisfactory results in connection with stainless steels, have the following approximate formulae:

Example No. 1

' Percent Silver 40 Copper Manganese 15 Zinc 25 Nickel 5 Silicon 0.25

The alloy of Example No. 1 has a melting point of 1275" F. and a flow point of 1295 F. In the preparation of this alloy, and other forms containing copper, the silicon is preferably added in the form of silicon-copper.

The alloy of Example No. 2 has a melting point of 1305 F. and a flow point of 1340 F.

Example N0. 3

Percent Silver 55 Copper 5 Manganese 15 Zinc 20 Nickel 5 Silicon 0.25

The alloy of Example No. 3 has a melting point of 1310 F. and a flow point of 1370" F.

Example No. 4

Percent Silver 60 Copper 5 I Manganese 10 Zinc 20 Nif'kP] 5 Silicon The alloy of Example No. 4 has a melting point of 1285 F. and a flow point of 1365" F.

Example N0. 5

Percent Silver 1 50 Copper 0 Manganese 15 Zinc 20 Nickel 5 Silicon 0.25

The alloy of Example No. 5 has a melting point of 1340" F. and a flow point of 1390 F.

Joints of stainless steel objects made with the new solder in the analyses given are of excellent strength, and the color of the solder approaches that of stainless steel much more closely than do the colors of any of the standard solders. Also, the joints are notably free of porosity, which has been one of the difllculties attendant upon the use of manganese solders.

As indicated above, I prefer to employ a substantial amount of copper in the new alloy, and ordinarily the copper content will run between and 15%, since this amount of copper imparts desirable characteristics, previously mentioned. Also, it reduces the cost of the alloy since, with its use, the quantity of silver may be proportionately reduced. However, for some purposes, it is satisfactory to use a form of the new solder containing no copper, as in the analysis given under Example No. 5.

I claim:

1. An alloy which consists of silver from about 40% to about 60%, copper from about 1% to about 15%, manganese from about 5% to about 15%, zinc from about to about 30%, nickel from about 2% to about 7.5%, and silicon from about 0.15% to about 0.40%.

2. An alloy which consists of silver from about 40% to about 60%, copper .from about 5% to about manganese from about 5% to about 15%, zinc from about 10% to about 30%, nickel from about 2% to about 7.5%, and silicon from about 0.15% to about 0.25%.

'3. An alloy which consists of silver from about 40% to about 60%, copper from about 5% to about 15%, manganese from about 5% to about 15%, zinc from about to about nickel from about 2% to about. 7.5%, and silicon from about 0.15% to about 0.25%

4. An alloy which consists of silver from about to about 60%, copper from about 5% to about 15%, manganese from about 10% to about 15%, zinc from about 20% to about 25%, about 5% of nickel, and about 0.25% of silicon.

5. An alloy which consists of about 40% to about of silver, about 10% to about 15% of copper, about 15% of manganese, about 20% to about 25% of zinc, about 5% of nickel, and

about 0.25% of silicon. 1

6. An alloy which consists of about to about of silver, about 5% of copper, about 10% to about 15% of manganese, about 20% of zinc, about 5% of nickel, and about 0.25% of silicon.

7. An alloy which consists of about 50% to about 55% of silver, copper from about 5% to about 10%, manganese from about 10% to about 15%, about 20% of zinc, about 5% of nickel, and

about 0.25% of silicon.

ROBERT E. LEACH.