US2317979A

US2317979A - Manganese-base alloy

Info

Publication number: US2317979A
Application number: US393371A
Authority: US
Inventors: Reginald S Dean; Clarence T Anderson
Original assignee: CHICAGO DEV CO
Current assignee: CHICAGO DEV CO; CHICAGO DEVELOPMENT Co
Priority date: 1941-05-14
Filing date: 1941-05-14
Publication date: 1943-05-04
Anticipated expiration: 1960-05-04

Description

Patented ay 4, 1943 2,317,979 I MANGANESE-BASE r Reginald S. Dean and Clarence T. Anderson, Salt Lake City, Utah, a'ssignors to Chicago Devel opment Company, Chicago, 111., a corporation' of Illinois No Drawing. Application May 14, 1941, Serial No. 393,371

present invention is from 50% to 85%, the nickel content from 2% to 30% and the remainder, not less than 10%, of the alloys comprises at least one of the elements zinc and copper.

We have also found that the coefficient 01 linear expansion may be increased and other desirable properties in the alloys enhanced by subjecting the said alloys to a suitable heat treatment. We have found that, for best results, the alloys should be cooled from a temperature around 900 degrees 0., the cooling being either slow or rapid. The preferable condition of the alloys is obtained by slow cooling. By slow cooling, as used herein, we mean the cooling of the alloys at a rate which would be obtained if they were allowed to cool in an ordinary heat-treating furnace. In general, the cooling rate ShOLllu be such that at least six hours is required for the alloys to reach room temperature after the heat is turned off. It will be understood, of course, that the length of time required to brin the temperature of the heated alloys down to room temperature during the slow cooling process will depend, in part, upon-the size and shape of the alloy elements being treated as well as upon the exact result desired by way of coefiicient of linear expansion, modulus of elasticity, fatigue, strength, and other properties sought. It will be understood, also, that the cooling may be carried out in air although, for best results, it should be carried. out in an inert atmosphere.

The following are examples of alloys falling within the scope of the present invention, all of which have a coefficient of linear expansion greats: than 20 x 10'- centimeters per centimeter per degree centigrade between and 100 degrees C. and many of them have substantially greater coefficients. Thus, for example, the alloy containing 72% manganese, 10% nickel, and 18% of either copper or zinc or substantially equal proportions of copper and zinc, has a coefilcient of linear expansion approximately centigrade, between 0 and degrees C. The electrical resistance of the alloys varies from about to 200 microhms per centimeter cubed. In general, cold working the alloys lowers the coeflicient of expansion and this lowering is more pronounced in proportion to the amount of zinc in the alloys. Those of the alloys which contain zinc to the exclusion of copper or which contain substantial proportions of zinc with respect to the amount/of the copper have the advantage of a lower specific gravity and are somewhat cheaper in cost.

We have indicated hereinabove that the high coefiicients of linear expansion, coupled with the various other properties of the alloys of our invention, make the said alloys highly useful for a wide variety of purposes, particularly, as bimetal strips for temperature control work. The alloys or the present invention may be utilized as the high expansion member in combination with any low expansion member such as various steels, Invar, and other low expansion members such as disclosed, for example, in Patents Nos. 1,947,065 and' 1,991,438. definitely preferred low expansion member of our bi-metal strips. Many of the lei-metallic strips made in accordance with our invention have about twice the movement per unit of temperature' change as compared with conventional strips such as those consisting of l'nvar with a 5 brass havin a relatively high temperature coefilcient of expansion. In producing the bimetal strips, they may be welded, fused, brazed or otherwise fabricated in accordance with knownpractices.

Another type of control unit for which the alloys of our invention are well adapted, is one where the expansion of the material, for example, a bar, is utilized for control purposes. Such control members may carry a current and may 28 x 210- centimeters per centimeter per degree be used in a circuit where rise of temperature Invar constitutes the produced through resistance of the member causes such linear expansion. of the control member as to open a set of contacts and interrupt the current. In such a system, the member is directly responsive to current input. Other specific installations of this general type may be used. 1 i

In order to produce the most satisfactory alloys for our purposes, wefprefer to employ a high purity manganese in the preparation of the alloys of our invention, that is, a manganese having a purity of at least about 99.0%. Electrolytic manganese having a purity of theorder of 99.9% is especially satisfactory and, therefore, its use represents a particularly preferred embodiment of our invention. The nickel, copper and zinc should also preferably be highly pure, for the best results, and We prefer to use the electrolytic metals.

While the alloys of our invention are particularly useful in those environments where high coefficients of linear expansion are desired, it will be understood that they are not so limited in their use but may also be employed for the fabrication of various other elements.

What we claim as new and desire to protect by Letters Patent of the United States is:

1. An alloy having a high coeflicient of linear expansion, said alloy consisting essentially of manganese, nickel and zinc, the manganese constituting from 50% to 85%, the nickel from 2% to 30%, balance substantially all zinc, the zinc constituting at least of the alloy.

2. An alloy having a high coemcient of linear expansion, said alloy having been slow-cooled from about 900 degrees C. and consisting essentially of high purity electrolytic manganese, nickel and zinc, the manganese constituting from 50% to 80%, the nickel from 2% to 30%, balance substantially all zinc, the zinc constituting at least 10% of the alloy.

3. An alloy having a high coefficient of linear expansion, said alloy consisting essentially of manganese, nickel and zinc, the manganese constituting at least 50%, the nickel at least 10%, balance substantially all zinc, the zinc constituting at least 10% of the alloy.

4. An alloy having a high coefficient of linear expansion, said alloy having been slow-cooled from about 900 degrees C. and consisting essentially of manganese, nickel and zinc, the manganese constituting approximately 72 the nickel approximately 10%, and the zinc approximately. 18%.

5. An alloy having a high coefllcient of linear expansion, said alloy containing from to manganese, from 10% to 30% nickel, balance substantially all at least one of the elements copper and zinc, the zinc constituting at least 4% of the alloy, the total of said elements adding up to substantially 6. An alloy having a high coeflicient of linear expansion, said alloy containing about 72% manganese, about 10% nickel, and the balance consisting substantially entirely of the elements copper and zinc, the zinc constituting not less than 4% of said alloy.

7. An alloy having a high coefficient of linear expansion, said alloy consisting essentially of manganese, nickel and zinc, the manganese constituting approximately 72%, the nickel approximately 10%, and the zinc approximately 18%.

8. A control member in the form of a strip which is adapted to expand and contract on heating and cooling, respectively, made of an' alloy consisting essentially of manganese, nickel and zinc, the manganese constituting approximately 72%, the nickel approximately 10%, and the zinc approximately 18% 9. A control member in the form of a strip which is adapted to expand and contract on heating and cooling, respectively, made of an alloy having a high coeflici nt of linear ;xpansion, said alloy containing about 72% manganese, about 10% nickel, and the balance consisting substantially entirely of the elements copper and zinc,

the zinc constituting not less than 4% of said alloy.

10. An alloy having a high coefficient of linear expansion, said alloy having been slow-cooled from about 900 degrees C. and containing about 72% manganese, about 10% nickel, and the balance consisting of at least one of the elements copper and zinc.

' REGINALD S. DEAN.

CLARENCE T. ANDERSON.