US1274250A - Alloy for resistance elements, &c. - Google Patents

Description

UNITED STATES WILBUB B. DRIVER, OF'EB'I ORANGE, NEW JERSEY.

ALLOY 1'03 RESISTANCE ELEMENTS, die.

1 374,25 Specification of Letters Patent. Patented July 30, 1918, I0 Drawing. Application filed January 2, 1914. Serial at. 810,012.

proved alloy for resis ncc elements, etc,

and has for its object to produce an alloy which has a high specific electrical resist ance together with a prolonged life under conditions of hi h temperature, so as to render it suitable or the making of resistance elements. a

My invention is based on the discovery that when titanium in substantial amounts is added to other metals, such as nickel, iron, copper, etc.-, or alloys of metals, it causes a marked increase in specifieelectrical resistance of the alloy so formed and produces an alloy which is extremely resistant to oxi dization, especially at high temperatures. From numerous experiments I have found that titanium is more powerful in these respects than chromium, and that titanium and chromium when simultaneously used as allo s with other metals, produce highly desira le results. I have also discovered that relatively large quantities of titanium can be used 1n alloys wlthout making them too hard or too brittle to' allow rolling and drawin For Sic purpose of illustration I give be-' low a list of alloys made according to m invention, together with the specific electrical resistance in microhms per cubic centimeter of sfiid alloys respectively.

The percentages in the above table, while not exact, are approximately correct. The

resence of titanium in each of these alloys increases the life at high temperatures of the metal or alloy to which it is added.

The qualities imparted by the addition of titanium are particularly valuable in connection with resistance elements used in electrical apparatus such as heaters, toasters and cooking appliances where the resistance elements are subjected to high temperatures b the passage of electric currents throng them. These electrical resistance elements may be of any ordinary form, such for instance as open helices or spirals. The 'form of the resistance element constitutes no part of my invention.

I have discovered that titanium hardens the metals or alloys to which it is added so that the quantity of titanium that can bl used is limited when it is necessary to re taih such malleability and ductility as will permit the rolling or drawing of the alloy.

he alloys above referred to are all sufficiently malleable and ductile so as to permit such rolling and drawing.

The melting to form the alloy can be carried on in any ap roved manner,- ecial care being exercise to prevent the introduction 0 carbon, either through the metals that are used or through contamination from the vessel in which the meltin Pure titanium is not commercia ly obtainable so far as I am aware. My experiments have been carried out with nickel-titanium and farm-titanium. Even if ure titanium were available its melting point is so high that it would not be desirable to form an alloy directly from it. ,An alloy of one of the metals which is to'form a substantial part of the final alloy should be used as a carrier for the titanium for the final meltis done.

so that it will be properly incorporated into the bath.

Quantities of titanium as low as one per cent. (1%) are eflective in increasing the 'electrical resistance of alloy containing it and in rotecting the alloy afi ainstoxidiaation at h temperatures. his efiect mcreases wi the percentage of titanium added. The only use of titanium in connectlon with melted eta-l baths of which I am aware, has been for the purpose of cleansm steel by removing impurities therefrom, an in this connection only small fractions of one per-cent. 1%) havebeen found necessaryordesirabe. Sofaraslamaware,the

uantity so used has been linuted to less llin one-half of one per cent, so that in the finished product there remains no substantial amount of tita 'um and no amount which afiects in any substantial degree the specific electrical resistance, life or hardness of theultiinate roduct.

As will be .ev1dent to those skilled in the art, the employment of my invention permits of considerable modification and variation without departing from the spirit of my invention or the scope of the appended me. What 1 claimis: V 1. A ductile .and malleable alloy of high electrical resistance containing as a constituent at least one per cent. of titanium and over twen per cent. of nickel, substantially as descri 2. A ductile and malleable alloy containing as a constituent at least one per cent. of titanium and over twenty per cent. ofnickel, substantially as described.

a .8. A ductile and malleable alloy-containing as constituents over tfienty per cent. of nickel and at least one per cent. of titanium, substantially as described.

4. An electrical resistance element consisting of a ductile and malleablealloy'containing as constituents nickel and at least one per cent. of titanium, substantially as described. a 5. A ductile and malleable alloy oi: high specific electrical resistance containing titanium as a constituent and over twen per cent of nickel, the titanium being cient in amount to produce high electrical resist ance and greatly retard oxidation at high temperatures.

6. An electrical resistance element comprising a ductile and malleable alloy conmining as constituents over twenty per cent. 0

f ni el and.at least one per cent. of titanium, substantially as dwcribed.

UR B. DRIVER. Witnesses:

H. B. Bnowsnnn, E. E. Mouse.