US1777192A - Manufacture of copper alloys - Google Patents

Description

Sept. 30, 1930. u. DE BERKER ET AL 1,777,192

' MANUFACTURE OF cOPPER ALLOY Fi led March 5, 1930 2 Sheets-Sheet -1 mv v-raes Sept. 30, 1930.: 7 u. DE BERKER Er AL 1,777,192

MANUFACTURE OF COPPER ALLOYS Filed March 5, 1930' 2 Sheets-Sheet 2' Lil ELONGAT|ON% ELONGATION 7 b TENSILE. STRENGTH TON- PER n W- 6-0 acme/mg ovve/v we:

Patented Sept. 30, 1930 UNITED STATES UDO DE BER/KER, WALTER MACHIN, AND WILLIAM BOUCH OBRIDN GOUDIELOCK, OF

PATENT OFFICE LONDON, ENGLAND, ASSIGNORS TO P-M-G METAL TRUST LIMITED, LONDON, ENG- LAND I MANUFACTURE OF COPPER ALLOYS Application filed March 5,1930, Serial No. 433,420, and in Great Britain December 12, 1929.

This invention relates to copper alloys and their production and provides an improved method of manufacture whereby alloys are produced having good casting properties, capable of withstanding high pressures, and which can be readily forged, rolled, extruded, drawn, stamped or otherwise worked.

' This invention forms a further improvement of the co-pending application Serial N0. 377,338, filed July 10, 1929.

It is known (see Ruer and Goerens: Ferrum, 1917, volume 14, page 49, and Ruer and Kuschmann, Zeit f. Anorg. Chem. 1927,

volume 164, pages 366-376) that iron and copper do not alloy readily with one another, and only about 5 per cent of iron can be alloyed with copper at or about the melting point of copper, and about 20 per cent of copper with iron at or about the melting point of iron, and that if these limits be exceeded some of the iron (or copper, according to which metal predominates) remains. unalloyed when the metals are melted together. In the above-mentioned application, Serial No. 377,338, homogeneous alloys of iron and copper are described containing up to 30 per cent of iron, silicon also being included in the alloy. lVe have now found that by the addition to a molten mixture of iron and copper of a suflicient quantity of silicon a homogeneous alloy of iron and copper in all proportions of the two metals may be ensured.

For example, two parts of iron have been alloyed with one part of copper by an amount of silicon equal to 10 per cent of the inixture. Equal parts of copper and iron are not completely alloyed by thev admixture of 12 per cent=of silicon, but are completely alloyed by incorporating an amount of silicon equal to 18 per cent. Two parts of copper and one part of iron re- I quire an amount of silicon more than 10 per cent, but not more than 20 per cent of the total mixture to alloy them completely.- An amount of silicon equal tov about 20 per cent or more of the mixture is suflicient to complete the alloying of iron and copper 111 'any proportions. But uniformmixtures are obtained when the amount of silicon greatly exceeds 20 per cent, for example, as much as per cent, may be incorporated without separation of the iron from the copper.

We have further. discovered that alloys produced as above described in which homogeneousadmixture or alloying of iron and copper 111 Various proportions isattai'ned can be used with great advantage in the production of high grade copper alloys, wherein the homogeneous alloy is an cfli'ective' substitute for tin and other metals as a hardener.

It has been found that by this procedure great savings are effected in cost owing to the cheapness of the hardener alloy; at the same time, bronze substitute alloys made by this invention possess better casting propertles, and fewer foundry waste'rs are produced, while it has been found that in service they are more dependable and their performance is superior to that of the tin V to secure the complete alloying of the iron and copper, and it has also been ascertained that for such purposes the addition of phosphorus to these alloys is advantageous in that it lowers the melting point of the hardener, increases fluidity and in other ways improves the casting properties of the final alloy with which the hardener is incorporated, and that high grade castings can be made direct from the alloy as first prepared without it being necessary first to cast the alloy into ingots and remelt, as is commonly necessary with the high grade alloys.

The invention accordingly consists firstly in the production of alloys of copper and iron in any desired proportion by the use of an appropriate amount of silicon and secondly in the use of such alloys with or without the addition of phosphorus as hardeners in the formation of high grade copper alloys having properties similar to bronzes, phosphor bronzes, gunmetal and the like.

The composition of the hardener may be varied in accordance with the particular characteristic which it is desired to give to the final copper alloy, but usually it is made with its composition maintained within about the following limits Per cent Iron About 30 to70 Copper About to 60 Silicon About 10 to 50 Phosphorus i 0.1 to 10 copper alloys.

In applying the hardener to copper or a copper alloy, the final alloy may conveniently be prepared in a similar manner to that usually employed in the manufacture of copper alloys, such as bronzes, the hardener being melted with the copper, or added when the copper is melted. a

The hardener above described can be'applied in varying percentages to the production of copper alloys. For example, in one method of applying the hardener, the tin content of admiralty bronze of the approximate. composition 88 per cent copper, 10 per cent tin and 2 per cent zinc, is replaced by a hardener alloy constituted as above described.

It may also be convenient to vary the composition of the hardener according to the qualities desired in the final alloy.

When it is desired to use the hardener for the manufacture or improvement of a copper alloy containing in addition elements, other than those present in the hardener-,as .described above, these additional elements may be introduced into the final alloyindepend ently, or incorporated in the hardener. For example, in the admiralty bronze substitute alloy, describedabove, the zinc (or a portion thereof) may be incorporated as a constituent of thehardener.

By our invention it is possible to manufacture alloys consisting predominantly of copper, but incorporating the ingredients iron and silicon in Widely varying proportions according to the amount and composition of A the hardener used. We have ascertained that possess valuable properties similar to those associated with bronzes and other high grade copper alloys, and that these properties are maintained substantially constant, even though the composition of the alloys may be varied over a Wide range.

Reference will now be made to the accomremainder being copper. Alloys represented by points Within the shaded area bounded by the continuous line A B C D F form a series whose properties have not hitherto been determined, but which are now found to be remarkably constant. These alloys have good casting properties and possess, in the cast state, very regular and good mechanical properties which are approximately as follows Yield point, 811 tons per sq. in. (12.8 to

17.6 kg. mm a Tensile strength, 20-22 tons per sq. in. (32 to 35.2 kg./mm

Elongation on 2", 40-20 per cent (50 min.)

The properties of alloys of copper containing iron and silicon change rather suddenly at or near the compositions indicated by the line A B C D E F, in Figure 1, for example 1. When silicon and iron are increased beyond the compositions indicated by the position 0 D E of this line, the elongation drops to a low value, usually with a simultaneous decrease in tensile strength. Figures 2, 3 and 4 represent the elongations and tensile strengths of alloys vcontaining 2.0 per cent iron, 6.0 per cent iron, and 3.0 per cent silicon respectively, the silicon or iron being varied continuously-as indicated; in each series of alloys it is shown that the elongation becomes small at or near the composition indicated by the line C D E and the tensile strength falls simultaneously.

2. When the iron content is high and the silicon content low, i. e. with compositions indicated by points outside the shaded area in the neighbourhood of the point E on the diagram, the iron and copper do not mix readily, homogeneous alloys are not obtained and satisfactory castings cannot be made.

3. When the iron content is high, but the silicon content low,.i. e. in alloys indicated by points outside the shaded area between the line E F and the near edge of the diagram, the casting properties are poor, useful castings are difiicult to make, and the alloys have inferior mechanical properties.

4. When the silicon content is high, but.

the iron content is low, i. e. in alloys indicated by points falling outside the shaded area between the line B C and the near edge of the diagram, the casting properties are poor, useful castings are diflicult to make, and the alloys have inferior mechanical properties. i

5. When both iron and silicon contents are low, i. e. in alloys indicated by points out. side the shaded area between the line B A F and the neighbouring edges of the diagram, the alloys possess lower yield points and tensile strengths, but may nevertheless have a commercial usefulness, particularly as alloys for forging, rolling, drawing or otherwise working, as in the manufacture of rods, tubes,

wires, sections and the like.

.the alloy containing The existence of an extensive series of commercially useful high grade alloys as defined by the area A B C D E F in Figure 1 having nearly constant mechanical properties could not be foreseen from the known properties of either silicon-copper or ironcopper alloys, nor from the properties of previously known copper alloys containing iron and silicon. These new alloys are easier to cast than either copper-silicon or copper-iron alloys, especiallyby the preferred 'method described in this specification; on

account of their good casting properties, and their mechanical roperites, they can be used with advantage or a large variety of purposes, for which other copper alloys such as brasses and bronzes have previously been used. The alloys can also be worked by ordinary commercial processes.

For some purposes it is advantageous to incorporate a small amount of phosphorus, not exceeding 1 per cent, in the above alloys, whereby the casting properties are somewhat improved. For example. a small amount of phosphorus. say about 0.1 per cent, may usefully be added to alloys for castings such as valves. pumps and the like, the mechanical properties being thereby little aflec ted; or a greater amount may be added, as in castings to be used for bearings, the hardness and strength thereby being increased. I

As one instance of the commercial usetulness of the alloys, the case may be cited of 2.0 per cent of iron; 3.0 per cent of silicon; 0.1 per cent of phosphorus and the remainder copper. This alloy has excellent casting properties, and can be used for such purposes as the manufacture of strong copper alloy castings; castings to withstand high fluid pressures, such as valves, pumps and bearings. The properties of the alloy are well maintained and it does not oxidize readily at high temperatures, as in superheating 1 services and the like; it possesses good resistance to corroslon and to attack by acids, and is suitable for service under marme condithe like; die castings; high duty tions. It can also be readily forged, rolled, extruded, drawn, stamped or otherwise worked, whereby its properties are further improved, and in the Worked condition can be used for a large variety of purposes, such as strong copper alloy rods, bolts and nuts, stays, wire, sections, tubes, sheets, drop forgings and stampings, turbine blading and the like wrought forms. It can also be readily welded, as by electric or oxy-acetylene Weldmg.

The proportions given in all the preceding examples are by Weight.

Having now described our invention, what we claim as new and desire to secure by Letters Patent is 1. A hardener 01' pre-alloy for use in the manufacture of alloys consisging principally of copper, this hardener or p e-alloy containing 30 to 70 per cent of iron,20 to per cent of copper and 10 to 50 per cent of silicon.

2. A hardener or pre-alloy for use in the manufacture of alloys consisting principally of copper, this hardener or pre-alloy containing 30 to 7 0 per cent of iron, 20 to 60 per cent of copper, 10 to 50 per cent of silicon and 0.1 to 10 per cent of phosphorus.

3. The process for the manufacture of copper alloys which consists in adding to copper a hardener or pre-alloy containing 30 to per cent of iron, 20 to 60 per cent of copper and 10 to 50 per cent of silicon.

4. The process for the manufacture of copper alloys which consists in adding to copper a hardener or pre-alloy containing 30 to 70 per cent of iron, 20 to 60 per cent of copper, 10 to 50 per cent of silicon and 0.1 to 1.0 per cent of phosphorus.

5. The process for the manufacture of copper alloys which consists in adding to a copper alloy a hardener orpre-alloy containing 30 to 7 0 per cent of iron, 20 to 60 per cent of copper and 10 to 50 per cent of silicon.

6. The process for the manufacture of copper alloys which consists in adding to a copper alloy at hardener or pre-alloy containing 30 to 70 per cent of iron, 20 to 60 per cent of copper, 10 to 50 per cent of silicon and 0.1 to 10 per cent of phosphorus.

7 Alloys consisting of more than 1.5 per cent and less than 5 per cent of silicon, "from 0.2 to 11 per cent of iron, the remainder being copper.

8. Alloys consisting predominantly of copper and containing also silicon in appreciable amounts up to 5 per cent; iron in appreciable amounts up to 11 per cent; and phosphorus in appreciable amounts up to 1 per cent.

In testimony whereof we have signed our names to this specification. I

UDO DE BERKER.

W. MACHIN. W. B. GOUDIELOCK.

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