US1423338A - Alloy and the method of producing same - Google Patents

Description

CLEMENS A. LAISE, F WEEHAVJKEN. NEXV JERSEY, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO GENERAL ELECTRIC COMPANY, OF SCI-IENECTADY, NEW YORK, A COR- PORATION OF NEW YORK.

ALLOY AND THE METHOD OF PRODUCING SAME.

11.4%23338. Specification of Letters Patent Patented July 118, 922.

1% Drawing. Application filed September 13, 1920. Serial No. 409,964.

To all whom itmay comer-n: same time it is very much cheaper than Be it known that l, tmmnxs A. lanai-z. a platinum or platinum-iridium. For the purcitizen of the United idtates. and a resident pose of producing a suitable product in acof VVeehawken. county of Hudson. State of cordance with this invention, I add to the a New Jersey. haie invented certain new and metal tungsten a small quantity of gold. useful Improvements in an Alloy and the This produces a mass that will not readily Method of Producing the Same, of which oxidize as the gold appears to provide a non- 6 the following is a specification. oxidizable surface film that effectively pro- This invention relates to a new and useful jects the tungsten particles from oxidation.

c alloy and to the method of producing the For the purpose of producin a product same. It relates more particularly to the still more advantageous than th e tungstenproduction of an alloy that shall possess degold mixture, I add a small amount of vanasirable properties which make it especially dium compound thereby obtaining an alloy suitable for uses as electrical contacts, magor mixture which has proven more satisfact neto points, targets and sheet metal for Wiretory in the manufacture of contact and magless equipment and wire for heating: and neto points than the materials heretofore lightingelements. used for this purpose. Such an alloy or One of the objects of my invention is to mixture does not readily oxidize, does not produce an alloy that will resist oxidation readily crystallize or become brittle, can be ac and will in fact be less readily oxidized than welded to steel, and possesses considerable the metal tungsten when used for the purmalleahility and ductility. The presence of" poses as above indicated. the gold and vanadium in the tungsten en- Another object of my invention is to pro ables the production of a weld with steel duce an alloy that will resist the tendency which is superior to that produced with sub- 35 to become pitted when used as an electrical stantially pure tungsten.

- contact point, etc. and will continue to pre- I have also found it advantageous to insent a smooth surface even after long use. troduce into the mixture a small quantity of Another object of 151) invention is to procompounds of other materials such as caL duce an alloy that may be readily welded to cium or thorium. The following specific exea steel and will be less apt than tungsten amples are given as being illustrative of the would be to become separated or detached invention, but it is to be understood that the from =1 S l. 1 Similar backing or holder. invention is not intended to be restricted to Another object of my Invention 18 t0 the exact materials or proportions glven: produce an alloy having the desirable prop- No L 35 erties enumerated above but which at the same time shall be cheaper to manufacture Calcium Vanathan platinum-iridium. I date 0.1% to 0.51% b ywe i ghtl 9Q Heretofore contact points have been made G ld 053% '60 5% of tungsten but these are unsatisfactory es- Tungsten--- 99.4% to 94 .5% cc pecially for magneto pfirposes because the 2 tungsten becomes oxidized and its surface becomes roughened or pitted when in use and Calcium Vana' 5 difliculties also arise because the tungsten date to by ig discs often come loose from the steel baclnng Gold to L 4 as or support to which they are attached as by Tungsten 7 t0 welding. Platinum points or co tacts 1alnd N 3 also those made of a platinum-iri ium a oy we have been found to be more satisfactory than g gggii g f 2g 77 ig tungsten in these respects, but such points G01 d 7; to 72 50 or contacts are very expensive. 99.0 mp4 By the present invention I am enabled to produce an alloy or mixture that fulfills the It has been found in practice that the gold ma requirements of a good contact and at the and vanadlum exert additional advantageous "high melting point.

effects in that the defective material produced during the manufacturing process is so much less than with substantially pure tungsten that the extra cost of the gold is more than conpensated for. Also the presenceof the gold and vanadium enables a sintered slug to be produced which is quite ductile and malleable before it is mechanically worked. The slugs may therefore be swaged. hammered or rolled and thus worked into sheets, plates or rods, the latter being subsequently drawn into wire. For convenience it is preferable to work the material' hot, as in the case of working metal of 4 Wire so produced is suitable for filaments for incandescent lamps. especially those known as daylight lamps or those which use a colored or nontransparent glass bulb in which the deposition or distillation of a small amount of gold out of the wire is not objectionable. The wire is also useful as heating units for electric furnace work. 4

Instead of using pure gold I may useualo metal or a gold-palladium mixture with certain advantageous results. Also, a goldplatinum mixture may be used instead of pure gold.

A' process of making the material will now be described in further illustration of this invention. I first prepare substantially pure tungsten trioxide, 1V0 This may be done by taking crude tungstic acid containing such impurities as alkaline earths, silica, iron, arsenic, etc., dissolving the same in a dilute ammonia or alkaline hydrate solution, and filtering. The filtrate consisting for the most part of ammonium tungstate, is then heated to a temperature of about degrees to 80 degrees C. and slowly introduced into a vessel containing a-boiling mixture of about 3 parts nitric acid, 6 parts hydrochloric acid and 4 parts water. A current of steam is injected into the mixture while the filtrate is being introduced and a precipitate of WVQ, is obtained which is removed and washed with hot distilled water.

The oxide of tungsten obtained as described may then be dissolved in ammonia by treating it with a mixture of NI-LOH and distilled water. The mixture should be heated for about an hour and then filtered, thereby obtaining a substantially pure filtrate of ammonium tungstate in solution from which it may be crystallized out by evaporation.

To one kilogram of the ammonium tungstate crystals I add 7 .5 to 10 grams of calcium vanadate and 20 to 25 gms. of gold chloride. The ingredients are thoroughly mixed. then dried, and ball-mi led for several hours.

Instead of introducing calcium vanadate into the ammonium tungstate I sometimes prefer to introduce a solution of calcium nitrate and ammonium vanadate in such amounts as to give approximately the same proportions of tungsten, calcium and vanadium as above mentioned. When the material is to be used for wire manufacture I prefer to use thorium nitrate instead of calcium nitrate. I

It is also practicable to introduce the calcium vanadate and the gold chloride into the tungsten trioxide instead of the ammonium tungstate, but I prefer the latter procedure.

The mixture produced as above specified containing the tungsten, gold, vanadium and calcium (or thorium) may be reduced in any convenient way as by means of hydrogen in a gas furnace or electric furnace. For this purpose a charge of the mixture may be placed in a nickel boat for example, which may be placed inside of a tube made of heat resisting material such as steel, porcelain, alundum or silica which is heated from 2 to 3 hours to a temperature of about 600 degrees to 650 degrees C. and then for about 5 or 6 hours to a temperature of 900 to 950 degrees C. while hydrogen is being simul taneously passed through the tube. This reduces the material and leaves it in a very fiufi'y, sticky state, having a weight of about 40 to 50 grams per cubic inch. The material may be reduced in other ways, as for example, by means of carbon, but I prefer to use hydrogen.

The above mixture possesses properties that render it adaptable for being pressed as the metallic powder is quite sticky. This powder is placed in a mold and pressed into ingots at a pressure of about 15 to 30 tons per square inch, the size and shape of the mold being determined by the purpose for which the ingots are to be used.

The ingots may then be sintered together by heating them in a chamber containing a reducing. atmosphere, such as hydrogen, or a mixture of hydrogen and nitrogen, at a temperature of 1200 degrees C. for half an hour, and then heating them to ahigh temperature about 90 per cent to 95 per cent of their melting point, which is to be previously determined, for another half hour. This high temperature may be produced by sending a current of electricity through the pressed up ingots or they may be placed upon a tungsten slab that may be heated to a temperature of about 2800 degrees C. by means of an electric current. In the latter case I prefer to use a tungsten slab that has a small percentage of silica, magnesia, thoria or lime incorporated therein to raise its melting point. The presence of the gold in the ingot to be sintered lowers its melting point so that it can be melted if desired onsuch a tungsten slab used as a resistor element.

When producing an alloy containing a high percentage of gold such as 15 per cent to 20 per cent, T first met the gold in a sand or carbon crucible, and then introduce into this molten gold enough or" the above described metal powder or discs to amount to to per cent by weight of the alloy. The gold alloys with the powder, and the final melt is either permitted to cool or first poured into a mold of any desired shape.

In either case the mixture or alloy produced as above described is ductile and may therefore be taken to a power hammer and mechanically worked while hot and may be rolled or drawn into the desired shapes using gradually decreasing temperatures as ordinarily employed in the art. Discs or sheets of small size may be punched out of the main or large sheet in the usual ways that are well known in this art, or the ingots may be swaged into rods and the discs cut off from the rod in the well known way.

It is to be understood that my invention is not limited by the exact figures mentionedabove as to weights and temperatures, etc., but may vary therefrom and therefore the scope of the invention is to be determined only by the claims appended hereto.

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

3. An alloy comprising tungsten, gold,

vanadium and a constituent to retard crystallization, the tungsten predominating.

t. An alloy comprising tungsten, gold, vanadium and calcium, the tungsten predomihating and the calcium constituting about 0.5 per cent of the weight of said alloy.

5. An alloy comprising tungsten, gold, vanadium an calcium, the tungsten being from approximately 9 to 150 times the weight of the other ingredients.

6. An alloy comprising tungsten, gold, vanadium and calcium, the tungsten predominating and the gold being approximately ten times the weight of the vanadium and calcium.

7. An alloy comprising tungsten, gold, vanadium and calcium, the gold being approximately ten times the weight of the vanadium and calcium, the tungsten being from approximately 9 to 150 times the weight of the other ingredients.

8. The herein described process which com prises mixing an oxide of tungsten with gold and vanadium salts and reducing the mixture at a high temperature.

9. The herein described process which comprises mixing an oxide of tungsten with gold and vanadium salts and reducing the mixture at a temperature between 600 degrees C. and 950 degrees C.

10. The herein described process which comprises mixing an oxide of tungsten with gold and vanadium salts and reducing the mixture at a temperature between 600 degrees C. and 950 degrees C. in the presence of hydrogen.

11. The herein described process which comprises mixing an oxide of tungsten with gold and vanadium salts and reducing the mixture at a high temperature, and then subjecting the mixture to a temperature of about 1200 degrees C.

12. The herein described process which comprises mixing an oxide of tungsten with gold and vanadium salts and reducing the mixture at a high temperature, and then subjecting the mixture to a temperature of about per cent of its melting point.

13. The herein described process which comprises mixing an oxide of tungsten with gold and vanadium salts and reducing the mixture at a temperature between 600 degrees C. and 950 degrees C., for about eight hours and subjecting said mixture to a temperature of about 1200 degrees C. for approximately half an hour.

14. The herein described process which comprises mixing an oxide of tungsten with gold and vanadium salts and reducing the mixture at a temperature between 600 degrees C. and 950 degrees C, pressing said mixture under a pressure from 15 to 30 tons per square inch and sintering the same.

15. The herein described process which comprises mixing an oxide of tungsten with gold and vanadium salts and reducing the mixture at a temperature between 600 degrees C. and 950 degrees C., pressing said mixture under a pressure from 15 to 30 tons per square inch and sintering the same at a temperature above 90 per cent of its melting point. v

16. The herein described process which comprises mixing an oxide of tungsten with gold and vanadium salts and reducing the mixture at a temperature between 600 degrees C. and 950 degrees (1., pressing said mixture under a pressure from 15 to 30 tons per square inch and sintering the same at a temperature of approximately 1200 derees C.

17. The herein described process which comprises mixing an oxide of tungsten, gold chloride and calcium vanadate and reducing said mixture.

18. The herein described process which comprises mixing an oxide of tungsten, gold. 1% chloride and calcium vanadate in substantially the proportions of 9 to 1 to 0.1 and reducing said mixture.

19. The herein described process which comprises mixing an oxide of tungsten, gold 1st chloride and calcium vanadate in substantially the proportions of 9 to 1 to 0.1 and reducing said mixture at a temperature between 600 degrees C. and 950 degrees C.

20. The herein described process which comprises mixing an oxide of tungsten, gold chloride and calcium vanadate in substantially the proportions of 9 to l to 0.1'and reducing said mixture, at a temperature between 600 degrees C. and 950 degrees 0., and pressing the resulting product at a pressure between 15 and 30 tons per square inch.

21. The herein described process which comprises mixing an oxide of tungsten, gold chloride and calcium vanadate in substantially the proportions of 9 to lto 0.1 and reducing said mixture, at a temperature between 600 degrees C. and 950 degrees (1, pressing the resulting product at a pressure between 15 and 30 tons per square inch, and 20 sintering the same.

22. A body consisting of tungsten and gold, and small admixtures of vanadium and calcium tungsten predominating.

23. A body of gold and tungsten, contain- 25 ing an admixture to retard crystallization tungsten predominating.

In witness whereof I have hereunto set my hand at the borough of Manhattan, city and State of New York, this 11th day of 30 September, 1920.

CLEMENS A. LAISE.

In presence of:

ISABEL R. FLETCHER.