US1572744A - Nickel alloy and method of making the same - Google Patents

Description

Patented Feb. 9, 1926.

UNITED, STATES PATENT OFFICE.

PAUL D. MERICA, OF NEW YORK, N. Y., ASSIGNOR TO THE INTERNATIONAL NICKEL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

NICKEL ALLOY AND METHOD OF MAKING THE SAME.

No Drawing.

This invention relates to nickel alloys and method of making the same, and particularly t0 alloys of aluminum and nickel or of aluminum and Monel metal, which is a trade name for a natural nickel and copper alloy made by The International Nickel Companv.

I have found that the addition of aluminum to nickel or nickel-bearing metals, such as Monel metal, has a great effect on the physical properties thereof. The resulting alloy 'has a high tensile strength and is highly resistant'to erosion and corrosion. It is therefore particularly valuable for use in steam turbine blading or in other applica-- tions where these properties are desirable.

In the manufacture of this alloy, I take molten nickel or Monel metal and deoxidize it, preferably with magnesium. The deoxidized metal is then mixed with molten aluminum in the proper proportions. To facilitate a thorough mixing, I pour the principal melt, that is, the nickel or nickelbearing metal, onto the aluminum. This pouring of the heavier metal onto the lighter insures thorough mixing and uniform composition. i

The mixing of the metals produces a marked evolution of heat which raises the temperature of the ladle considerably. I utilize this extra heat by allowing the molten alloy to stand for a period of three to five minutes, thus giving the impurities an opportunity to rise-to the surface and separate from the metal. The amount of heat evolved is roughly proportional to the percentage of aluminum added.

The clean metal is then poured into ingots which are reduced to shapes by the processes usual in nickel and Monel metal practice.

The surface of the ingots must be removed;

prior to rolling, and with an aluminum content of under 3% or 4% the surface may be chipped or planed olf. When the aluminum content is higher, it is necessary to grind the ingots Application filed June 26, 1923. Serial No. 647,911.

After heating and rolling, aluminum Monel alloys containing as much as 5% aluminum can be machined with ordinary tools.

. The addition of aluminum increases both the hardness and tensile strength of the metal. The best mechanical properties are obtained with aluminum between 3% and 5%, although amounts above 1% are effective. The upper limit of the aluminum content depends largely on the properties desired. Good results may be had up to 10%, although there is great difficulty in grinding and reducing ingots containing so much aluminum. If the aluminum content is increased above 17%, the alloy is very brittle.

lVith an aluminum content between 3% and 5%, hot rolled rods may be produced with a true proportional limit of as high as 80,000 pounds per square inch, which Would be reduced by dead annealing at 1650 F. to not less than 60,000 pounds per square inch. High temperature tests show that the alloy retains its strength very satisfactorily at 750 F., and in fact the percentage reduction in the proportional limit at this temperature 'as compared with ordinary temperatures is less than in the case of Monel metal. The resistance .to corrosion is as great as, or greater than, in Monel metal.

The addition of carbon to the alloy between 0.1% and 0.5% exercises a marked effect in increasing the hardness and tensile strength.

While I prefer to use Monel metal, which is the natural alloy consisting of 68% to 70% nickel, a small percentage of iron and the remainder copper, I may use nickel and copper in other proportions, as, for example, 50% to 80% nickel and 20% to 40% copper, together with aluminum in the desired amount. The addition of 25% to 2.5% manganese is also desirable. Thealloy apparently is not greatly affected by the presence of other metals in small amounts as may occur on account if impurities in the metals used.

\Vhile I have described the preferred e1nbodiment of my invention. it will be understood that it is not limited thereto but may be otherwise embodied within the scope of the following claims.

I claim:

1. The method of making nickel alloys. which includes deoxidizing the principal melt and then mixing it with molten aluminum.

2. The method of making nickel alloys, which includes deoxidizing the principal melt with magnesium and then mixing it with molten aluminum.

3. The method of making nickel alloys,

which includes mixing the principal melt With aluminum and utilizing the evolved heat to maintain the alloy at or above a pouring temperature over a settling period, thereby giving impurities in the alloy time to separate therefrom.

4. The method of making nickel alloys, which includes deoxidizing the principal melt, mixing the principal melt with aluminum. and utilizing the evolved heat to maintain the alloy at or above a pouring temperature over a settling period, thereby giving impurities in the alloy time to separate therefrom.

5. The method of making nickel aluminum alloys, which includes pouring the nickel melt onto the aluminum.

6. An alloy containing the elements which go to make up Monel metal and aluminum, containing from 1% to 10% of aluminum.

7. An alloy containing the elements which I go to make up Monel metal and aluminum, containing from 1% to 10% of aluminum and containing carbon from .1% to .5%.

8. An alloy containing -80% nickel, 2040% copper, 110% aluminum, and 0.252.5% manganese.

9. An alloy containing 50-80% nickel,

.2040% copper, 110% aluminum, 0.252.5%

manganese, and 01-05% carbon.

10. An alloy of nickel, copper and aluminum, wherein the content of nickel is in excess of 50% and the content of aluminum is not less than about 3% and not more than 17 the predominant metal of the remaining content being copper.

less than the content of copper is not less than 18%, and the content of aluminum is not less than about 3%, the three metals tent of aluminum is about 4% to 5%, the.

predominant metal of the remaining content being copper.

13. An alloy of nickel, copper and aluminum, wherein. the content of nickel is to 70% and the content of aluminum is 10% to 3%, the predominant metal of the remaining content being copper.

14. An alloy of nickel, copper and aluminum, wherein the content of nickel is in excess of 50% and the content of aluminum is not less than about 3% but is insufiicient to destroy the malleability of the alloy for mechanical working, the predominant metal of the remaining content being copper,

15. An alloy of nickel, copper and aluminum, wherein the content of nickel is not less than 50% and the content of aluminum is between 1% and 17%, the remaining content consisting essentially of copper.

16. An alloy containing. 1%-17% of aluminum, the remainder consisting essentially ofnickel and copper with the nickel in excess of the copper, the copper being not less than 18%.

17. An alloy consisting essentially of 50%80% nickel, 20%10% copper, and 1%10% aluminum.

18. An alloy consisting essentially of 50% 80% nickel, 20%40% copper, and 1%- 10% aluminum, together with carbon not in excess of .5%.

19.An alloy containing the elements which go to make up Monel metal and aluminum containing from 1% to 10% of aluminum, together with carbon not in ex- I cess of .5%. 11. An alloy of nickel, copper and aluminum, wherein the content of nickel is not- In testimony whereof I have hereunto set my hand.

PAUL D. MERTOA.