US1445253A - Resistance alloy - Google Patents

Description

Patented Feb. 13, 1923.

UNM STATES F F] E.

JOHN H. WHITE, OF CRANFORD, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

RESISTANCE ALLOY.

No Drawing.

To all whom it may concern:

Be it known that 1, JOHN H. WHITE, a

citizen of the United States, residing at, Cranford, in the county of Union, State of New Jersey, have invented certain new and useful Improvements in Resistance Alloys, of which the following is a full, clear, concise, and exact description.

This invention relates to resistance materials and has for its object an improved metallic alloy having a specific resistance many times that of copper, capable of withstanding high temperatures without deleterious oxidation and sufficiently ductile and otherwise workable to permit its formation into a filament or other forms suitable for use in the resistance elements for electric heating appliances and the like.

It has long been known that ferro-nickel alloys having more than nickel are capable of withstanding fairly high temperatures without excessive oxidation. Such alloys have not, however, proven entirely satisfactory for use in electric heating appliances for the reason that in order to ob tain the required electrical resistance it is necessary either to use a fine wire which is, therefore, not sufiiciently rugged to withstand the frequent jars to which such appliances are subjected, or to use a greater length of a larger wire, thereby producing an unduly large and cumbersome heating element. v

I have found that if a portion of the iron in such ferro-nickel alloys be replaced by tantalum, not only is the specific resistance of the alloy greatly increased but the resistance wires or filaments formed from it are much less subject to progressive oxidation and their life when subjected to high temperatures is greatly increased. The new alloys are furthermore easily worked and can be drawn into any desired filamentary form.

In place of tantalum, columbium (niobium) may be used, and in fact for com-' mercial production a combination of tan talum and columbium has been found preferable for the reason that such a combination may be more easily and more cheaply obtained than either the pure tantalum or pure columbium.

For example. the commercial ore known as tantalite when purified yields a mixture of the oxides of tantalum and columbium Application filed September 22, 1919. Serial No. 325,461.

which can easily be reduced to the metallic state.

Resistance elements suitable for use in electric heating appliances can be obtained by employing an alloy in which there is fromgrade for more than 900 consecutive hours without deleterious oxidation.

While the alloy above described is seen to have four ingredients when produced in a commercial form, that is, nickel, iron, tantalum and columbium, the alloy is essentially a ternary alloy containing nickel, iron and a metal having the properties of tantalum, columbium being a convenient substitute for the tantalum or; for a portion thereof.

The alloys described herein are also characterized by their resistance to chemical reagents and to mechanical working. It has been known heretofore that the resistance of nickel to acids is increased by the addi tion of tantalum. But alloys of nickel and tantalum or columbium are exceedingly hard to work and up to the present time have only been made by compressing the two metals in powdered form and then submitting the mixture to heat. It has been found that if iron is added to the binary alloy of nickel-tantalum or nickel-columbium or nickel-tantalum-columbium, a ternary or a quaternary alloy is obtained which may be readily formed and worked. The characteristics which are possessed by these ternary or quaternary alloys make them useful also in the construction of cutlery, chemical ware, machine tools. etc.

What is claimed is:

1. A ferro-nickel alloy containing more than 60% nickel in which a portion of the iron is replaced by a material having the properties of tantalum.

2. An electric resistance element consisting of a ferro-nickel alloy containing more than 60% nickel in which a portion of the iron is replaced by a material having the properties of tantalum.

than 60% nickel in which a. portion of the having the properties of tantalum, approxiiron has been replaced by tantalum and comately 10% of iron and the remainder of lumbium. nickel. s

4. A resistance element comprising an 6. A resistance element comprising an 5 alloy containing from 70 to 80% nickel, the alloy containing 75% nickel, 11% iron and 15 remainder being composed of substantially 14% tantalum-columbium, equal parts of iron and a metal having the In Witness whereof, I hereunto subscribe properties of tantalum. my name this 17th day of September A. D.,

5. A resistance element comprising an 1919. 10 alloy containing from 10 to 20% of a metal JOHN H. WHITE.