US3147113A - Aluminum bronze alloy containing vanadium and manganese and having improved wear resistance - Google Patents

Description

United States Patent ALUMINUM BRONZE ALLOY CONTAINING VA- NADIUM AND MANGANESE AND HAVING IM- PROVED WEAR RESESTANCE John F. Klement, Milwaukee, Wis., assignor to Ampco Metal, Inc., Milwaukee, Wis., a corporation of Wisconsin No Drawing. Filed Oct. 27, 1961, Ser. No. 148,038

6 Claims. (Cl. 75-462) This invention relates to an aluminum bronze alloy and more particularly to an aluminum bronze alloy containing a small addition of vanadium and manganese and having improved wear resistance.

In drawing operations for sheet and plate alloys such as stainless steel, aluminum, nickel, titanium, mild steel and some copper base alloys, the dies are often fabricated from aluminum-bronze alloys. The aluminum bronze alloys used in die applications have good corrosion resistance, Wear resistance and are non-galling against many wrought materials.

The aluminum bronze alloys which in the past have shown the optimum properties for deep drawing dies are those which contain approximately 14% aluminum, a small amount of iron and the balance copper. Alloys of this type have good corrosion resistance and nongalling properties. However, under heavy use in die applications, an alloy of this type wears undesirably fast so that close dimensional tolerances cannot be maintained because of the wear that occurs in the die surface.

The present invention is directed to an aluminum bronze alloy which has the corrosion resistance and the non-galling properties characteristic of aluminum bronze alloys, but has improved wear resistance, toughness and hardness. These increased physical properties are brought about by the addition of a small amount of vanadium and manganese. The combination of vanadium and manganese tends to make the alloy more homogeneous in the distribution of the metallurgical phases and compounds during solidification and heat treatment and also promotes uniform, controlled grain size. The alloy has improved machinability and is less susceptible to eutectoid transformation and its embrittling structure.

The alloy of the invention has the following general composition by Weight:

Percent Aluminum 13.0-18.0 Iron 2.06.0 Vanadium 0.012.5 Manganese 0.5 06.0 Copper Balance The alloy falling within the above range of composition has a tensile strength in the range of 70,000 to 100,- 000 p.s.i., a yield strength of 50,000 to 80,000 p.s.i., an elongation in two inches up to 3% and a Rockwell C hardness in the range of 25 to 55.

A specific illustration of the composition of the alloy falling within the above range is as follows in weight percent:

Percent Aluminum 14.50 Iron 4.25 Vanadium 1.00 Manganese 3.00 Copper 77.25

In addition to the above elements, small amounts of impurities can be present in the alloy up to an amount of about 0.50% without alfecting the basic properties of the alloy.

This alloy can be cast either statically or centrifugaL ly and in the centrifugally cast state the alloy has a tensile strength of 90,000 p.s.i., a yield strength of 72,000 p.s.i., an elongaton in two inches of 0.5% and a Rockwell C hardness of 40.

The alloy of the invention has greatly improved wear resistance over the conventional aluminum-ironcopper alloy due to the addition of vanadium and manganese. The wear resistance of the alloy is determined on a rolling-slip friction device such as an Amsler wear test machine. In the test procedure, a cylindrical aluminum bronze alloy test specimen is subjected to rolling and sliding motions against an 18-8 stainless steel cylinder of identical dimensions with a 15 kilogram load applied on the specimens. The wear rate is determined copper had a wear rate of 0.00200 gram per 1000 revolulutions in the testing procedure.

With a wear test procedure such as this, a standard aluminum bronze die alloy containing 14.5% aluminum, 4.5% iron and 81.0% copper had a wear rate or weight loss of 0.00256 gram per 1000 revolutions and a Rockwell C hardness of 39. In comparison with this, the alloy of the invention containing 14.70% aluminum, 4.60% iron, 0.75% vanadium, 1.0% manganese and 78.95% copper had a Wear rate of 0.00200 gram per 1000 revolutions and a Rockwell C hardness of 40. From these test results it can be seen that the wear resistance of the alloy was increased about 22% by the addition of vanadium and manganese, while the hardness of the alloy was not increased to any appreciable extent.

Generally, the wear rate of the alloy of the invention containing the vanadium and manganese additions is in the range of 0.00160 to 0.00210 gram per 1000 revolutions per 15 kilogram load, as measured by an Amsler wear testing machine against 18-8 stainless steel. In addition, the alloy has a hardness in the range of 25 Rockwell C to 55 Rockwell C, depending on the specific aluminum, iron, vanadium and manganese contents in the alloy.

The alloy of the invention has greatly improved wear resistance over that of an ordinary aluminum bronze alloy and this increase in wear resistance is most significant since the hardness of the alloy is not appreciably changed over the aluminum bronze alloy having similar proportions of aluminum and iron, but not containing the vanadium and manganese. This unexpected increase in wear resistance without an increase in hardness is believed to be due to the formation of an intermetallic compound formed predominately of iron, vanadium and manganese and containing aluminum and copper. This intermetallic compound in the form of small particles is extremely hard and resistant to wear.

The metallographic structure of the alloy consists essentially of a gamma two phase which is uniformly distributed in a matrix of beta. The intermetallic compound composed of iron, vanadium, manganese, aluminum and copper exists in small particles of uniform size and shape which are distributed throughout the phases.

If the vanadium content of the alloy is increased over 2.5%, additional quantities of vanadium will come out of solution as intermetallic particles, which will make the particles extremely rich in vanadium and cause pickup or galling of the workpiece. If the vanadium content is reduced below the lower limit of the aforementioned range, there is no appreciable efiect shown in the increase in wear resistance.

The manganese serves to retard eutectoid development and its embrittling structure. If the manganese content is increased over 6.0%, the manganese tends to take up excessive quantities of the aluminum and other additives and makes the melt diificult to control. Moreover, if the manganese is increased beyond 6%, the

thermal conductivity of the alloy will be decreased to a value making the alloy unsuitable for die applications where rapid heat transfer from the die surface is important.

In order to obtain optimum properties, the metal used for the alloy should be of high quality. Electrolytic or wrought fire-refined copper, high purity aluminum, low carbon iron, and high purity vanadium and manganese are preferred to be used. It has been found that the best method of obtaining the desired uniformity in the alloy is by using a double melting procedure whereby a pre-alloy is made. The pre-alloy is one that has approximately 60% aluminum, 20% iron, vanadium and copper. In the melting procedure this prealloy is melted in the crucible with an additional quantity of a copper-manganese alloy. Alternately, the vanadium and manganese can be employed in the pre-alloy which, if containing vanadium and manganese, will generally consist of 50% aluminum, 16% iron, 22% copper, 4% vanadium and 8% manganese.

It is not necessary to heat treat the alloy of the invention. However, in some applications, a conventional stress relieving treatment can be employed and, because of the manganese, the alloy can be stress relieved without embrittlement due to excessive eutectoid formation.

The alloy of this invention can be used to produce articles for wear resistant application in drawing and forming operations. The articles may take the form of deep drawing dies, hold down dies, wear guides, forming rolls, skids, slides and the like.

The alloy can also be extruded into Weld rods and weld wire. The alloy in the form of coated or uncoated weld rod can be overlaid on a metal base by metal spraying or other welding methods such as heliarc, carbon are, metal are and the like to obtain a corrosion resistant wear surface.

It has been found that the addition of vanadium and manganese to the copper-aluminum-iron alloys to be used as die materials greatly improves the toughness and wear resistance of the alloy and makes it less susceptible to eutectoid embrittlement.

In addition, the alloy of the invention has not only increased toughness, strength, and wear resistance but also has improved machinability by controlling the distribution of the various component phases. The improved machinability permits die sinking of more intricate designs on die surfaces than was previously possible on ordinary aluminum bronze die alloys.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.

I claim:

1. An aluminum bronze alloy, consisting essentially by weight of 13.0 to 18.0% aluminum, 2.0 to 6.0% iron, 0.01 to 2.5% vanadium, 0.50 to 6.0% manganese and the balance being substantially copper, said alloy being characterized by having excellent corrosion resistance and improved toughness and wear resistance.

2. An aluminum bronze alloy, consisting essentially by weight of 13.0 to 18.0% aluminum, 2.0 to 6.0% iron, 0.01 to 2.5% vanadium, 0.50 to 6.0% manganese and the balance being substantially copper, said alloy being characterized by a tensile strength in the range of 70,000 to 100,000 p.s.i., a yield strength in the range of 50,000 to 80,000 p.s.i., an elongation in two inches of up to 3%, and hardness in the range of 25 to Rockwell C.

3. An aluminum bronze alloy, consisting essentially by weight of 13.0 to 18.0% aluminum, 2.0 to 6.0% iron, 0.01 to 2.5% vanadium, 0.50 to 6.0% manganese and the balance being substantially copper, said alloy having a wear rate in the range of 0.00160 to 0.00210 gram per 1000 revolutions per 15 kilogram load of frictional work as measured on a rolling-slip wear testing machine against 18-8 stainless steel.

4. A deep drawing die characterized by having excellent corrosion resistance, a hardness in the range of 25 to 55 Rockwell C and improved wear resistance, said die being fabricated from an aluminum bronze alloy consisting essentially by weight of 13.0 to 18.0% aluminum, 2.0 to 6.0% iron, 0.01 to 2.5% vanadium, 0.50 to 6.0% manganese and the balance being substantially copper.

5. An aluminum bronze alloy, consisting essentially of 14.5% aluminum, 4.25% iron, 0.75% vanadium, 3.0% manganese and 77.25% copper, said alloy being characterized by having excellent corrosion resistance and improved toughness and wear resistance.

6. An aluminum bronze welding electrode, consisting essentially by weight of 13.0 to 18.0% aluminum, 2.0 to 6.0% iron, 0.01 to 2.5% vanadium, 0.50 to 6.0% manganese and the balance being substantially copper.

References Cited in the file of this patent UNITED STATES PATENTS 1,074,285 Nolan Sept. 30, 1913 1,811,682 Binney June 23, 1931 2,778,733 Frejacques Jan. 22, 1957 2,874,042 Klement Feb. 17, 1959 2,937,941 Klement May 24, 1960 3,025,158 Klement Mar. 13, 1962 FOREIGN PATENTS 703,304 Germany Mar. 6, 1941 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,147,113 I September 1, 1964 John F, Klement It is hereby certified that error appears inthe above numbered patent reqliri ng correction and that the said Letters Patent should read as' corrected below.

Column 2, line 15, for "copper had a wear rate of 0.00200 gram per" read by the weight loss of the test speoi-men in Signed and sealed this 29th day of December 1964.

(SEAL) Attest:

ERNEST w; SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents

Claims (1)

1. AN ALUMINUM BRONZE ALLOY, CONSISTING ESSENTIALLY BY WEIGHT OF 13.0 TO 18.0% ALUMINUM, 2.0 TO 6.0% IRON, 0.01 TO 2.5% VANADIUM, 0.50 TO 6.0% MANGANESE AND THE BALANCE BEING SUBSTANTIALLY COPPER, SAID ALLOY BEING CHARACTERIZED BY HAVING EXCELLENT CORROSION RESISTANCE AND IMPROVED TOUGHNESS AND WEAR RESISTANCE.