US853716A - Process of producing compound metal bodies. - Google Patents

Description

'PATENTED MAY 14, 1907.

J. F. MONNOT. PROCESS OF PRODUCING COMPOUND METAL BODIES.

APPLICATION FILED QILPT. 6. 1906.

UNITED STA S PATENT OFFICE.

JOHN FERREOL MONNOT, OF, NEW YORK, N. Y.

PROCESS OF PRODUCING COMPOUND METAL BODIES.

Specification of Letters Patent.

. Yatented May 14, 1907.

Applicatie ii filed September 6,1906. serial no. 333.570.

scription of the same, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to processes of producing compound metal bodies and consists in a method of uniting layers or strata of unlike metals,i. e., metals or,alloys of unlike chemical nature, whereby such metals and alloys are united asfirmly and permanently as weld-united layers of iron or steel, for example. The union between metals which are unlike in the above-sense, produced according to the method herein described is in all respects equivalent to the most perfect weld possible, insofar as the subsequent behavior of the united bodies of metal is concerned; for which reason, and because the term weld is the one which would most naturally be ap lied to such a union, by those skilled in t e art, I term such union hereinafter a weld, Without intending thereby to limit or confine myself to any particular.

theory as to the actual nature of the union between the unlike metals.

By the method herein described it is possi ble to produce com ound metal ingots, and also manufacture articles of compound metal, such as plates, sheets, rods, tube, wire and the like. In most cases the union between the unlike metals may be, and prefer-.

ably is, an autogenous one; but in certain cases, as where one of the metals or an ingredient thereof is subject to excessive volatilization or oxidation at the temperatures required in carrying out certain stages of the process, there may be an intermediate film or.

coating of another metal, as hereinafter described. I

. It is well known thatit is very difiicult to.

unite,

permanently, unlike metals; and 'particular y to wrou meta s like nickel and cobalt, with metals of a non-ferrous nature, such as copper, silver, old, aluminium, cupnferous alloys, (such as ronze, brass etc.,)- aluminium alloystsuch as aluminium bronzehamanganese bronze,

etc. I have found, and it is a matter of comand State of New York,

' metal metals of relatively after fusion, but stea unite a ferrous metal, such as ht iron and the various steels, .or'

mon knowledge and experience, that iron and copper, iron and silver, iron and aluminium,

and similar-pairs of unlike metals, cannot be weld-united or e uivalently. united bycastin or 'nary casting temperatures of such metals, against the surface of an iron or steel object to becoated.

The fundamental discovery u on which my new rocess rests is, that w e unlike metals 0 high fusing temperatures, such as those named above, do not weld readily or at the copper, si ver, aluminium, etc. at theall under ordinary conditions of metal working, nor by casting one of the metals at ordinary casting temperature against an unlike likewise of high casting'tem' rature; yet if the metal so cast be heated, be orecasting, far above its melting point casting temperature, and be cast at such abnormally high temperature, the lack of afiin-' ity between the metals observed atlower temperatures disappears, and the unlike metals contacted at such high temperature unite readily to form a union of an autogenous, permanent character equivalent to a true weld. Metals such as copper, silver and aluminium, at such a high temperature, which for the sake of a name may becalled a supermolten temperature, display, extraordinary chemical il uniting with gases and other bodies, and also with wholly unlike metals, such as iron and the various grades of steel ;'and I believe that the same is true generally of other h melting tem era ture, such as gold, nicke cobalt, etc. 'le the fact is as stated, I am unable to give a and ordinary.

and physical activity, readdefinite explanation of the phenomenon.

Possibl it is due to dissociation of proximate molecules of the metals which still persist at and near the melting point. It is commonly believed by ph sicists that ultimate moleculesof most su stances in the'solid state are associated to form larger complexmolecules-- anassociation which ersists to some. extent ily diminishes with increase of heat; and that the influence of heat upon chemical reactivity is due partly to this p enomenon. This peculiar increase of chemicalreactivit of certain'molten metals and concomitant eightening of their afiini- {ties for'certain other metals, whether these jafiinities be molecular, atomic' or physicochemical, which occurs on raising their temerature much above the point where they ecome molten, if heretofore observed, has

ICO

not to-my knowledge been applied to the uniting of unlike metals of the classes herein contemplated; the sole attempt of experimenters in the field of uniting unlike metals by casting'one such metal against the other -'-having been .to heat the metal to be cast to a between the contacting surfacsof the metals forming no union with it to be treme y high temperature utilized in the hereinafterdescribed method. 7

Copper and steel may be taken as a pair of unlike metals affording a typical example. casting temperature,

displ unlike metal, steel, hardly wetting it and which will withstand tools or heat changes, even if it be cast at such ordinary casting temperature against solidification. The best union the surface of the steel and'held there during that can-be formedin this manner, so far as known, is a mere adhesion or sticking together of the two metals,,and not a true cohesion. The metals so united will separate subse uently during working or by the action of cat or shock, or can be separated readily by means of a tool. Ina wa it may be said that the two metals, behave as if their surfaces were merel fitted together and not really united. copper at the so-called supermolten temperature above referred to. be contacted with the steel and held against the surface thereof during solidification, the temperature of the molten metal being allowed to fall as soon 'as true wetting is effected, a union is formed which is absolutely permanent and as strong as a true weld, the metals so joined beried out' changes in the joined metals, if

mg inseparableby change of temperature or y shock;,and a cold chisel or like tool, app ied alo'n the line of juncture of the two metals, wi I not follow said line readily, as it would if the metals were merely stuck together, but tends to dig into the one metal or the. other. Nor will reheating the joined metals to a red heat and quenching in water result in'jseparation of the metals. The union'thus produced is equivalent to what, in

- the case of,united bodies of steeLand iron, is

called 'a-weld. As to-tlie nature of the union thus produced, uncertainty exists; but it is known'that when the process is pr'operly carany an excessively thin film be are confined to proximate surfaces, the-main portween; the

' tionsof the bodies of joined metals possessing the union sult of thorough wetting of the steel by theirprdinary'properties. It may be that between the metals is a mere rethe'copper'; a molecular joined at the instant of casting the exmaintenance to thin In the case of copper, the supermolten temcontact and coherence between adjacent molecules of copper and steel similar to that which unites the molecules of copper and the molecules of steel each among themselves; 01', again, it may be that the uniting layer is of a difierent composition from the joined metals and is an alloy-of such metals, chemically or physically combined, as combination, mixture or solution. The existence of such an alloy film seems probable, because in the carrying out of the process certain evidences of slight solution of the iron in the copper, such as might naturally accompany an alloying inter-action, have been observed; but whether or not an alloy film is formed, and without restricting myself tothe theory that any true alloy is formed, it is convenient to term the uniting layer between the joined metals, for,

the sake of a name, an alloy film, and I use said term in this sense hereinafter.

It is not essential, for the uniting of the supermolten copper to the iron or steel, that the copper be confined in contact with the steel while solidifying. If a cleaned piece of steel be immersed momentarily in a bath of supermolten copper and then withdrawn therefrom, underconditions precluding oxidation, and'allowed to cool, llIWlll be ound to be covered ,with a thin coating of copper or, possibly, copper-iron alloy, s0 firmly united to the steel as to be welded. thereto in the same sense as the cop or coating of substantial thickness formed y confining a considerable body of supermolten co per in contact with a steel surface and then allowing the same to cool, as above described; and since this thin coating is substantially the same as the layer uniting'the two layers of unlike metal joined in the manner above described, I commonly a ply' to it also, for the sake of convenience, t e term alloy film, sometimes, however, film film coating or Asaboveexplained, I do not intend by the use of the term alloy in these terms to com it /and confine myself to the existence qf what in common parlance is termed an alloy, but merely use the terms mentioned as convenient distinguishing terms.

Whatever the nature of the alloy film or unlting film, it is capable of indefinite extenalloy coating.

thereby may be tent, even to the thinnest sheets or wire, Without the union failing, without the separation of the two metals, and without the de-' velopment of flaws, pores or seams thereinor therebetween, and even with substantial of the original relative proportions of the two metals; all of which shows terming it the weld-- ICO slon since an ingot of two metals joined extended to any desired exthat the original union between the two I metals still persists in the coextended ware produced by working the ingot, even down sheets and wrre.

rature appears to be from 2500 to 2800 Ehrenlieit or higher. The super-molten temperature of silver is about the same; that of aluminium is somewhat lower. The tempera tures named have not been determined with absolute accuracy, it bein well known that it is difficult, if notimpossib e, to measure temperatures in the neighborhood of or exceeding 2000 F. with even approximate certainty the figures given In practice, it is not necessary to coated,

so dipped a coating which, when cold, possesses the qualities of the alloy film or weldbut even then it is metal somewhat .hotter still, in order that ing film above recited, it is known that the supermolten temperature has been reached; desirable to heat the there may be a margin of temperature available. In practice, the workmen en agedin carrying out the process become ab e to tell by e appearance of the molten metal when the (proper supermolten temperature has been'reached, without the necessity of test-' ingrcontinually.

his property of combining with unlike metals at supermolten temperatures appears to be generic with all the metals of high melting points, and renders possible the procurance of many pairs of. well-united metals which cannot be obtained at all by common methods of working.

In some cases, the coating formed by contacting a solid body of one metal with a supermolten body of an unlike metal and then permitting the adhering coating formed by the action of the supermolten metal to solidify, is suflicient; but in gelneral I contemplate applyingrelatively t coatm to ingots, coresor bases of considerable .t 'ckness, and then coextendin the metals of the compoundingot thus pro need,

by rolling, hammerin pressing, drawing, or other suitable metho of-working the metals, thereby producing compound metal plates, sheets, rods, tubes, wire, and the like. The

compound metal articles thus produced may sheets composed of metal, such as iron or steel, covered with an be used to great advantage in a variety of arts and for many different purposes, as combining the specific advantages of the component metals. For example, plates or a readily oxidizable impervious coherent coating of. copper or other less oxidizable metal, may be used to ck layers or' great advantage place of ordinary iron or steel plates or sheets wherever such plates are exposed to the weather, air, or other oxidizing influences or to the action of corrodin liqui s, gases or vapors which readily attac iron or steel but do not attack at all, or at least to so serious an extent, the coating metal em loyed. Plates, sheets and other articles 0 copper, silver, gold, aluminium, brass, bronzes, etc., backed with iron or steel may be used with great advanta e where con siderable strength or stiffness 0 metal is desired, coupled with the chemical, physical, electrical or other properties or color or aparance of the non-ferrous metals mentioned.

or electrical conductors, it-is desirable to combine the high electrical conductivity of copper, aluminium, etc, with the great strengt of steel.

For the uses mentioned, and for a greatvariety of other uses'w-hich might be mentioned, it is a prime requisite that the unlike metals shall be so inse arately united in the first instance that t e compound ingot, sheet, rod etc. be capable of great extensionor working, as by rolling, or ham.- mering, to thin sheets, rods, a les, tubes, etc., drawing, pressing in dies, spinning etc., without separation of the component la ers, without; develo ment of seams, pores, aws, 5 etc; and it'is in ibct desirable that during such working the strata of the component metals shall maintain substantially their original relative proportions, even down to the I thinnest sheets or wire. It is further highly non important that the layer of coating metal shall be in such a condition as to be absolutely impervious to liquids and gases. Electroplat'ng or other methods of deposition of metals donot produce a coating possessing these qualities. On the contrary, electric ally-deposited and like coatings are porous,

'the metal being thrown down in granular or crystalline form, with dividing lines and interstices between so that liquids and gases penetrate the coating and attack the metal beneath; neither is the adhesion of coatings so deposited good, such coatings being merely adherent to the base and not coherent thereto, and for this r15 reason and also because of lack of cohesion. of the coating itself, it is impracticable to roll or draw electro-plated metals without destro ing the continuity of the coating. For 'simi ar reasons, tinning and galvanizing do not produce as satisfactory results as is desirable, and it is not practicable by these processes to produce large coated surfaces which are everywhere free from defects and ermanently united with the base; moreover r 25 ibr many purposes tinned and galvanized surfaces are altogether unsuitable, because not possessing the desired superficial appearance and other qualities; and a'tinned or galvanized-coating will not stand extension by 0 the crystals or granules, no'

dering and similar drawing, rolling, pressing between dies, etc., to any great extent. It is in fact impossible that tinning or alvanizing shall produce a union between t e metals in any way analogous to that produced by the method herein described, since it is impossible to heat tin or zinc or lead to temperatures such that an permanent union is produced by contact with the metals of high melting point, tin, zinc and lead all oxidizing orvolatilizingatrelatively low temperatures. Neither do brazing, solprocesses satisfactorily unite unlike metals for all purposes, the metals being merely stuck together, the articles produced by such processes being incapable of extension by drawing, rollin etc. to as great an extent as desired, beingli ely to separate by heating, etc. The ideal union between unlike metals must be autogenous, i. e., must be formed by a complete direct uniting of the metals, such as may for the reasons above stated, be termed welding.

By my process I am enabled for the first time in the history of the art, as I believe, to actually and inseparably weld coherent, dense, impervious and poreless coatings of the less oxidizable and more ductile and malleable metals upon surfaces of unlike stronger and more oxidizable metals, which mg relative to the thic has been able,-so far as I amaware,

coatings may vary from any desired thickness to a tenuity comparable to that of ordinary electrocoatings. When the unlike metals are absolutely welded together, as by my process, no difliculties are experienced such as are encountered in the use of electroplated articles and in the use and working of tinned, soldered and galvanized articles, as, for instance weak lines ofunion permittin peeling and other separation, or flawed an porous coatin s, but on the contrary coatings produced y my process are absolutely impervious and continuous, and cohere to themselves and to the metal to which they are joined, so that a compound plate, ingot, rod, wire or the like is produced which is capable of being rolled, drawn or otherwise extended parallel to the weld to any desired extent without interruption of the continuity of the coating, without its separation from the base and with substantial maintenance of the ori 'nal'thickness of coatness of base. Moreover, the coatings in articles so extended are in a dense, hard condition, much more so than coatin s obtained by electroplating, tinnin'g or ga vanizing, and thus are far more durable.

In the many unsuccessful attempts in the prior art to produce articles similar to or equivalent to those produced by me, tno one 0 produce a coating such as described, as for exam le a coating of cop on steel, which 0 uId not be se arate from its base by means of a cold 0 isel or equivalent tool, or

prevent destruction; in copper-steel wire,

for instance, the copper has had to be'suflicient in amount to furnish a tube of substantial strength, inclosing the steel core. I am not aware that in such prior articles a coatmg of much less than 30 per cent has ever been found practicable, whereas in ingots to be extended greatly, 'I may provide a thickness'of coating equivalent to on] 5 per cent; and when the articles to be ma e ingot are not to be greatly reduced in crosssection (as in structural steel shapes) the coating applied to the ingot may be as thin as 3 per cent.

In the heavy coated articles of'the prior art just referred to, because of the lack of the mtimate and perfect union, such as secured by me, there is always to be found, in the in got for example, a large roportion of the compound metal in which t ere are flaws,-defects and places of no union of the joined metals which must be cut out and rejected, thereby entailing an undue wastage, both of material and of the skilledlabor required in such prior processes. In the article produced by my process the union is so intimate and'thorough between all meeting surfaces that there is no need of loss by wastage or in labor. Theprocess is conducted in such manner that there is no possibility of scale spots and similar defects developlng. The operation is .so simple that comparatively unskilledlabor is sufficient, thereby materiall cheapening the finished product.

11 my new method, by affixing coatings of copper, silver, gold and the like to an ingot or other large body of metal and then co-extending the joined metals, I am able to secure coated 'artices much more cheaply that if said articles had first been produced in the base metal and then coated, as is the common practice, 1 t

Of course it may be understood that I can, when desired, a ply the coating to the finished, or half iiilished, article and in such cases, if the article be large, the copper or other coating metal may not be more than fractional per cent of the total.

large area, like sheets and- Wire, my process has the advantage, as compared with the prior art, that whereas by such former proceases the entire surface to be coated must re ceive the careful attention of the operator to avoid flaws and the like, and such surface is substantially the same as that of thefinjshed article, according to-my process the surface from such For the-production of coated surfacesof Y .on each side of it, even to the thinnest arti cles, so that by the relatively small amount of care necessary to secure perfect union in the ingot or the like, the production of perfect sheets, wires rods, etc., therefrom is substantially assured.

A It is not always convenient, practicable or desirable to apply the entire-coating in one operation, or to form the entire coating from a bath of supermolten metal. I have found that if one of two unlike metals such as referred to above have .formed on it a mere film-coating of 'the other by 'the action of a supermolten body of that other, a further body of said second or coating metal can be cast against such film-coating at substantially ordinary casting temperature and will unite therewith so intimately as to be inseparable and indistinguishable therefrom. For instance, if a steel ingot be film-coated by the action of supermolten copper or silver, and a further body of copper or silver be cast against and caused to solidify against said film-coating, the metal so cast being at substantially the ordinary casting temperature,

a perfect union of the cast metal with the film-coating may be obtained, and so a perfect union with the steel base. And I further find that the metal so cast is not necessarily the same as the metal which forms the filmy coating. These two facts render practicable many convenient and extremely important embodiments of my process. For instance, there are many alloys containing readily fusible or oxidizable or volatilizable metals, such as the various brasses, tin bronzes, etc. which do not well withstand heating to a supermolten temperature. In the case of brass, the zinc tends to volatilize below the supermolten temperature of the copper, and in tin bronzes the tin tends to oxidize or volatilize below the supermolten:temperature of the copper, and hence the superm-olten tempoi'ature cannot be obtained at. all, or without serious loss of zinc or tin such as will vary 'matcrially the quality of the alloy'. In such cases 1 film coat the base metal, with a metal with wh ch the metal of themam coating Will combine readily at convenient casting -,tempiratures, and .then cast the main coating metal against such film coating. For example, when coating steel with brass or tin bron'ze, I film-coatthe steel with supermolten against the co per film so produced and cause it to solidifythereagainst. The molten brass or bronze combines readily with such copper film at ordinary casting temperatures. The said double treatment, 'i. a, film coating and then forming a further coating of substantial thickness against the film coating, is also convenient in many cases in using pure metal or in obtaining therefrom coat-' ings of pure metal or metal of definite characteristics. perature many metals are very. sensitive to flame gases and other bodies, readily becoming impure; and there is reason to believe that at such temperature such metals have a solvent action on other solid metals placed in them. By ppl U only admin in -'coating by the action r if supermolten metal, and then applying the main coating by means of metal nearer its oint of solidification, there is less probabihty of reduction of quality of the coating metal. However,

the main coating may be, and frequently is,

formed entirely from the supermolten metal, this method having the important advantages of requiring less manipulation and fewer baths of molten metal. I

The metals which I have found to have a supermolten condition at which they unite with iron and steel by a union analo ous to a weld, are all metals having a me ting point above 900 F. I am not aware that metals melting below this point reach a similar supermolten condition before volatilization or oxidation, and it is in fact substantiall impracticable to 1 weld-coat iron or stee with a view to subsequent extension,

with metal melting below 900 F., as iron and steel require to be heated to 900 F. and above for the extension desired-of compound metals. It is not only the ferrous metals (iron and the various steels) which can be coated wi unlike metals (such as copper, silver, gold, aluminium, brass, bronze, including aluminium and manganese bronzes, etc.) by the method herein described. I ma coat coper with silver or vice versa; an in general I may combine by the method herein described any two of the metals of high melting point which it is difficult or im ossible to combine by ordinar methods.- y process makes it particular y easy to weld or braze together pieces of aluminium, which, as is well known, cannot be united satisfactorily by ordinary methods; for it is easy to coat the aluminium surfaces to be umted with copper, silver or'other suitable metal which brazes or welds readily, applying the coating by the process herein described, and then to braze the coatings of copper, silver or' other metal. My process also makes easy the hot working of metals, such as nickel, high-carbon steel, etc., which are subject to excessive oxidation or other deterioration whenworked copper, and then cast the brass or bronze hot in the presence of air; itbeing easy by 1 0 my process to coat objects of such metals with a metal less subject to oxidation or deteriorationj In an application for Letters Patent, filed March 2,1906, Sr. No. 303,917, I have described and claimed such process of hot working metals.

As an illustration of'my'process, I will describe the uniting of copper to steel. The

difficulty, or even "impossibility, of uniting steel and copper by a joint equivalent to a weld between two pieces of steel, by methods heretofore known, is well recognized. And I will suppose that it is a steel ingot which 18 to be coated with copper, and that all surfaces of the ingot are to be coated with a substantial thickness of copper, and then the coated ingot extended by rolling,'hanimering, or the like, to form sheets, rods, or other extended ware.

The surface of the steel ingot is first brought to an absolutely clean metallic surface by sandblasting or other suitable mechanical method of removing'scale, oxid and the like, and then customarily is pickled.

In pickling I preferably use hydrochloric or' hydrofluoric acid, as these acids form on the steel surface anon-oxygenated closely'ad-. hering protective coating of chlorid or fluorid, which volatilize s readily at alater stage in the clperation, ex osing an absolutely clean an fresh metal ic surface to the supermolten metal. In pickling the steel may form an anode of an electric couple, when desired.

After pickling, it'is best to heat the ingot preliminarily before contacting the same with the supermolten metal, to avoid abstraction of undue amounts of heat from the supermolten metal. One method of con.- ducting this preliminary heatingwill be described hereafter, but others *may be used.- Customarily, I do not heat the ingot preliminarily above a red or low yellow heat. The heated ingot is then transferred to and immersed in a bath of supermolteneopper,

being protected from oxldation as hereinafter described, during the transfer. A few seconds contact of the supermolten metal with the heated ingot usually suffices for the copper to unite with the steel-the exact time depending somewhat upon how hot the steel was heated preliminarily; experience soon teaches the workmen how long the contact of the steel with the supermolten metal should continue. The surface of the steel ingot probably at once assumes the high temperature of the supermolten copper.

When the entire coating is to be formed from the metal of the supermolten bath, I then segregate from the main body of the supermolten metal a layer thereof, in contact with the surface of the ingot, of sufficient thickness to form the desired coating, according to the method described in my application for Letters Patent filed June 16,

4 of the ingot.

1905, Sr. No. 265,508, and withdraw the ingot and segregated layer of molten metal and cause the latter to solidify on the surface But when only a film coating is to be formed by the action of the supermolten metal, I withdraw the ingot fromthe supermolten bath'as soon as sufficient time has elapsed for the formation of the film coating (a few seconds usually suffices), and then either place the film-coated ingot in a suit- .able mold and cast around or against its filmed surface-[the metal to form the main coating, or immerse the film-cbated ingot in a second bath of molten metal maintained at substantially ordinary casting temperature, and then segregate a proper layer of such molten metal according to the method of my said'application No. 265,508, and

cause the same to solidify against the filmcoat-ed surface. During the solidification of the substantial layer of copper produced by any of these three methods it is desirable to use some pressure to maintain contact of the copper with the surface against which it solidifies; but if the segregated or cast-011 copper layer forms an annulus surrounding the ingot, the self-compression of the copper due to its contraction during solidification and cooling, is ordinarily 'sufhclent. And III an application for Letters Patent filed May 23, 1905, Sr. No. 261,739, I have illustrated and described means for applying positive pressure from an external source during solidification and cooling. In any of thesemethods the excessively high temperature of the abutting layers between copper and steel exists only temporarily as the heat of such layers soaks into the steel core while the heat of the copper is transferred outwardly by the cooling of the mold walls, and no opportunity is afforded for detrimental 'action upon either the main body of the steel or thatof the copper. Such changes as take place, or may take place, in either metal, are .only in the excessively thin joining layer between; and since, as already explained, I do not limit myself to any theory of how the union between the unlike metals takes place, therefore I do not assert positively, that when the operation is properly performed, any change of the two metals, or

"either of them, at the point of juncture, actuother-coating metal used, while such copper or other coating'metal remains in the supermolten condition, is very brief. for long eontact of the two metals with the copper or other coating metal in the very highly reactive condition afforded by the supermolten temperature. would of course be detrimental to both. By limiting to a few seconds the period of contact of the metals IQO while one of them is in the supermolten condition, I limit to extreme thinness the joining layer of alloyed, mixed, intcrpenetrating, or tlierwise-united metals.

ln transferring the .lilm-coatml ingot preparatory to either casting or segregating a further coating around or against the filmcoated surfaces it is highly important to guard. against oxidation of the film-coating. 'lhis l'do preferably by surrounding the film-coating with a neutral or inditl'erent gas, such for example as producer gas made from coke, charcoal or anthracite, and containing no decomposable hydrocarbons. A method of and means for so inc-losing the iilm-coating are hereinafterdescribed.

In carrying out the process by any of the above methods, as soon as the coating formed by the action of the pickling bath on the ingot encounters the super'moltcn metal it is volatilized, leaving an absolutely clean and fresh metallic surface for attack by the sup ermolten metal.

The coated ingot produced in any of the ways above described is usually worked, as by rolling, (either at once, or after submission to a soaking heating to bring all the parts to a uniform temperature), to condense the metal of the coating and also to extend the ingot to marketable shapes, such as bars, rods, plates, or structural shapes. In such extension the joined metals extend together without rupture of the union between them aml the linal article usually contains the same relative proportions of coating and base as the finished ingot. In rolling, drawing, and pressing the compound copper-steel metal, it has been observed that the metal works better than steel of corresponding grade alone, the coating of unlike metal seeming to facilitate the working of the steel.

In the accompanying drawings I illustrate, rather diagrammatically, apparatus such as may be used in carrying out my process.

In the said drawingsz Figure 1 represents a sectional view of one form of apparatus for carrying out the said process. Fig. 2 shows in detail section the construction of bottom plate and lower portion of easing preferably employed. Fig. 3 shows a sectional view of another form of easing which may be employed.

In Fig. 1, 1 is a preliminary heating chamber for the ingot or core; 2 is a furnace for heating a crucible 3 to maintain in the latter a body of surermolten coating metal; and 4 is a second similar crucible, whichin this instance may be supposed to contain molten coating metal maintained at substantially ordinary casting temperature. 5 designates a power hoist, here shown as an electrical hoist,

mounted on a suitable track so that it can be moved from place to place; and from said hoist is suspended. by means of a porter bar 6, the ingot 7, which is the object to be coated. Said ingot is shown surrounded by a casing 8 having an internal diameter slightly larger than the external diameter of the ingot, and. to said casing is connected a pipe 9, a portion of which is flexible, said pipe provided with a three-way valve 10. This pipe and the valve 10 are provided for supplyingto the casing, when desired, an atmosphere of indifferent or neutral gas. such as producer gas. has a weighted head 11 which insures that when the casing is lowered into the, molten metal it shall sink therein to the desired depth. 1.2 designates a bottom plate for the casing arranged to be secured to the ingot 7 itself, by means of a screw 13. Said bottom plate is provided with a raised rib or ring 14 matching a corresponding groove 15, in the loweredge of the casing, and adapted to coact with said groove to make a'tight joint. For raising and lowering the casing 8 with respect to the ingot 7, a special hoist 16, suspended like porter bar 6 from hoist 5, is provided. It has, in the form shown, two winding drums 17 upon which are wound two cables 18 connected to opposite sides of the casing, so that said casing may be raised and lowered truly vertically. I customarily provide each crucible with a loose removable cover 19, one only of which is shown in Fig. 1,

which cover is designed to exclude airfrom the molten metal so far as possible, and is removed only when and so long as necessary to lower an ingot and easing into the crucible, or to inspect the molten metal, or for similar reason. To further exclude air from the surface of the molten metal, I cover so much of its surface as possible with a layer of charcoal, a ring 20 of refractory material which floats on the surface of the molten metal serving to maintain a clear space in the center for the passage of the ingot and casing. To assist in forming a tight joint between the bottom plate and casing, I provide in the groove 15 at the bottom of the casing a packing of asbestos cord 21 covered with graphite paste 22.

The casing and associated parts shown in Fig. 3 are substantially the same as above described; but the casing 8 is provided in addition with inlets 23 near its upper end, said inlets arranged to be closed at will by a sliding. shield or valve 24.

The casing 8 I customarily use, not only as a means for surrounding the ingot with a neutral or indifferent atmosphere and so pro-- tecting it form oxidation, but as a means either for segregating the necessary amount of molten metal to form the desired coating, or as a mold into which the molten metal to form said coating is poured as hereinafter described with particular reference to Fig. 3.

In carrying out the process, a core or ingot 7, previously prepared by sandblasting and pickling as above described, or in any other suitable way, is placed within the heating chamber 1, which I customarily heat by circulating around it hot producer gas or prod- Casing 8 nets of combustion. When the core has been heated to the proper'degree',the hoist with the casing S. suspended therefrom is moved over chamber 1, the porter bar6 is lowered and attached to the ingot, and then said ingot israised into casing 8. I sometimes fill the casing with a neutral or indiflerent atmosphere, such as producer gas,

before raising the ingot 7' into it, so as to prevent possible oxidation of the surface of the ingot while in transit to the supermolten bath; but this is hardly necessary, as the coating on the surface of theingot formed by the pickling fluids mentioned is itself an effective protection when the preliminary heating is not too great. The casing and ingot are then moved over' the crucible 3 containing-the supermolten coating metal, the lid 19 ofsaid crucible removed, and the casing with the ingot within it is dropped to the surface of the molten metal, after which the ingot is lowered from'the casing 8 into the supermolten metal, by means of the hoist 5, the casing being meanwhile kept stationary by means of hoist 16, and after suflicient time for'the action of the supermolten metal on the ingot has elapsed, said ingot is raised into the casing 8 again (said casing having previously been filled with theprotective gas, by means of pipe 9 and valve 10) and the .casing with the ingot Within it is raised-from crucible 1, the bottom plate 12 is applied to the ingot, the casing with the ingot withinv it is movedover the 'secondbath of molten metal, in crucible 4 and is lowered to the'surface of the molten metal, and then the ingot with the bottom plate attached is lowered from the casing into the molten metal and immediately thereafter the casing 8 is lowered through the molten metal until it rests upon and is closed at the bottom by bottom plate 1.2; a layer of the molten metal of thickness required to form the desired coating is thereby segregated from the main body of molten metal. The casing, tightly closed at the lower end by the bottom plate, is then raised, and the segregated layer of molten metal within it permitted'to solidify against the film coating on the surface of the ingot; said layer of molten metal combining with said film coating before or during solidification, so that when solidification is complete and the coated ingot is removed from the mold or casing 8, the coating is permanently weld-united to the core. The coated ingot thus produced is thenworked as above described.

In carrying out the process, as just described, the protection of the film coating formed in the supermolten bath, against oxidation, by the protective atmosphere Within casing 8, is an important feature. The film coating formed by the supermolten metal on the surface of the ingot, is at a very high temperature at first, and at least in the case of a metal such as copper, would oxidize instantly if exposed to the air. -By the described method of procedure, involving the passage of this film coating direct'from the molten metal into a neutral or indifferent atmosphere, all oxidation of the coating is avoided. As above stated, the preferred gas is producer gas formedfrom coke, charcoal or anthracite; such gas containing no constituents which will dccompose'npon contact with the'highly heated surfaces and de osit carbon or other undesirable substance 't iereon. Such gas, though of about the same specific gravity as air of corresponding temperature, does not escape from the bottom of the casing except. as an excess of the gas is supplied to the casing, because it is highly heated by contact with the bot ingot and so made much lighter than the air surrounding the casing. In practice, to provide for leakage around,the porter bar, and for the tendency of gases to diffuse notwithstanding differences in specific gravity, I provide-a steady flow of gas into the casing through pipe 9, until the bottom of the casing has been immersed in the metal of bath 4, the excess of gas escaping at the bottom of the casing and burning there .harmlessly.

Instead of carrying out the process as above described, by segregating a layer of metal of bath 4 to form the main portion of the coating, I sometimes use the form of casing shown in Fig. 3, provided with filling openings 23 and a closure 24 therefor. Up to the point of dipping into bath 4 this casing .is used the same as that shown in Fig. 1,

openings 23 being kept closed during transfer 0 the ingot from prelimina heating chamber 1 to the supermolten bat 3,.and the easing, filled with a rotective atmos here, serving to protect t e film coating om oxidation upon withdrawal of the ingot'from the supermolten bath. But with this form of casing shown in Fi 3, the bottom late 12 is caused to close t e bottom of t ceasing tightly before the casing, with the ingot with in it, is immersed in the metal of bath 4; and when said casing is immersed in the metal of said bath 4, it is lowered therein until the filling openings 23 have passed beneath the surface of the molten metal and beneath the layer of bad metal which is usually at the surface into the body of good metal beneath the surface, the closure 24 being raised just as it nears the surface of the molten metal. The molten metal then flows in through openings 23, filling the casing, and as soon as the easing is filled, it is raised, the molten metal within it permitted to solidify against the film-coated surface of the ingot and to combine with such film coating, and then the ingot is removed through the bottom of the casing and treated to such working as desired or required, as already explained. In carrying out the process in this manner, the proexample by coverin tective atmosphere already within the casing When the filling holes 23 are opened protects the film coating and the molten metal which enters the casing against oxidation; and in fact no air can enter. the casing, because the holes 23 are submerged by the molten metal almost instantly after the closure 24 is raised, and during the possible brief instant while said openin s are open but not completely submerged t e outrush of gas from the casing will prevent entrance of air.

To hasten the filling,of the casing with molten metal, and to prevent trapping of as in the molten metal as it solidifies, I re erably apply suction to the outlet 25 o valve 10, having first set said valve so as to cut off the entrance of gas and to place outlet 25 in communication with the interior of the casing. This is done, however, only after the molten metal has commenced to flow in. And when necessary or expedient, I reduce the fluid pressure upon the joint between. the bottom plate and easing, while raising either the casing shown in Fig. 1 or the casing shown in Fig. 3, by applying suction to the outlet 25 of valve 10.

Instead of carrying out the process in. two steps, as above described, I may form the entire coati'r. g from the metal of the supermolten bath 3, either by segregating the metal to form the desired coating by means of the form of easing shown in Fi 1, or bylowering a casing such as shown in g. 3, with the preliminarily heated ingot within it, into the metal in bath 3, and withdrawing the casin as soon as the latter is filled. In this way avoid the use of more than one bath of molten metal. However, as above explained, when the main portion of the coating is to be formed of a metal or alloy which cannot be heated safely or with advantage to the super molten temperature, I conduct the process in two stages, film-coating the ingot with a supermolten metal with which the metal of the main coating will readily unite, and then applying such second coating as above described.

To improve and condense the molten metal, I may apply pressureto the interior of the casing, after the same has been removed from the molten metal and the joint at its bottom has been sealed thorou hly by solidification (which will take'place t ere while the Y greater portion of the metal is still fluid.) The pressure may be applied through valve 10, or in any other suitable manner.

Obviously, itwill often be desirable to apply the coating merely to one or more, but not all, of the sides or surface of an ingot or other object; in which case those portions which are not to be coated will be protected from contact with the molten metal, asfor 0 such portions with a. protective shield, or by causing the casing to fit such. portions so tightly as to exclude .with a graphite wash.

molten metal, or by contacting the molten metal only with such portions of the surface as are to be coated. To protect the casin and bottom late from the action of the mo ten. metal, I cover the surfaces of the same The complete protecting of the heated surfaces against oxidation afforded by the film produced by the ickling liquor, by the described meth reliminarily heating the ingots, and especia y by the chamber 8 containing a neutral or indifferent or non-oxidizmg atmosphere, enables me to use as coating metals such readily oxidizable metals as nickel and cobalt, or to coat rods or in ots of metals such as oxidize very readily or example, nickel, cobalt, or very pure iron or steel, high-carbon steel,.etc.) with unlike metals. i

The core or base'need not be iron or steel,

but for most purposes an iron or steel base or core will be preferred. Hence in certain of the following claims I specify steel as the metal of such core or base; and this term steel I employ generically to designate all forms of iron, including not merely ordinary carbon steel, both low-carbon or In='d and high-carbon or hard, but also wrought iron (the properties of which are nearly identical with those of mild steel) andvarious compound steels, such as tungsten steel, titan- 1um steel, vanadium steel, chrome steel, nickel steel, manganese steel, cobaltsteel; also substantially pure iron i. 0., the chemical element Fe, substantially-free from carbon and other metalloids-or impurities and modifying ingredients.

The process herein described is an improvement'upon and modification of the'process described in my application for Letters Patent filed Oct. 6, 1905, Sr. No. 281,680; however I have elected to claim the process generically in this ap lication rather in said application 281,680, t e claims of which will be limited to those features of the process s ecifically different from thosespecifically c aimed herein.

In an application for Letters Patent filed June 16, 1905, Sr. No. 265,508, I have illustrated, described and claimed a process for forming coatings by segregation from molten metal, and in an application filed Dec. 26, 1905, Sr. No. 293,411, I have illustrated, described and claimed segregation apparatus such as referred to. In an application filed April 10, 1906, Sr. No. 310,910," I have claimed the process of protecting the heated surfaces from oxidation by means of an in different or protective atmosphere; and in an application filed July 31,1906, Sr. No. 328,606, I have illustrated, described and claimed the metal coating ap aratus herein illustrated and described. herefore I do .not claim any of said inventions herein.

The thorough protection against oxidation IIO' provided in my process makes it possible to work according to it, any of the sensitive metals, such as nickel, cobalt, manganese, chromium, tungsten, etc. Likewise steels containing such metals, also vanadium, phosphorus, etc., and high carbon steel may be worked. It is very difficult to maintain the same'grade in steel during working, when its surface is exposed while hot to the air. But in my process the surface of the steel is never exposed to the air after the pickling.

What I claim is:

1. The 'process of producing compound- ,-bodies of unlike metals welded together iss which consists in contacting a surface of one such metal with a supermolten mass of an unlike metal and confining a body of molten metal of substantial thickness in contact with such surface and causing it to solidify thereon. v

2. The process of producing compound bodies of unlike metals welded together which consists in weld-filming a surface of one such metal by contacting therewith a supermolten mass of an unlike metal and then confining a second body of molten metal of substantial thickness in contact with such film-coated surface and causing it to solidify thereagainst and combine therewith.

3. The process of roducing compound bodies of ferrous and welded together which consists in'weld-filming the surface of a metal of one such group by contacting therewith momentarily a molten-mass of ametal of another such grou having a melting point above 900 F. sue second metal maintained at a temperature much above its melting temperature, and thereafter welding 'a substantial coating of metal of such second group on such film. v

' 4. The process of producing compound bodies of ferrous and non-ferrous metals welded together which consists in weld-filming the surface of a ferrous metal by conta ct-.

ing therewithmomentarily a molten mass of a non-ferrous metal having a melting point above 900 F. such second metal maintained at a temperature much'above its melting temperature, and thereafter welding a substan tial coating of non-ferrous. metal onf-such film. 1 I

5. The proce'sszof producing compound bodies of unlike metals Zwelded together autogenously, which consits in weld-filming a surface of one such metal by contacting therewith a supermolten massof an unlike metal and thereby coating the surface so coated with awelded-on film of metal derived from the molten mass.

6. The process of producing a film-coating of non-ferrous metal on a surface of a ferrous metal which consists in exposing such surface momentarily to contact with a body of supermolten non-ferrous metal havmg a melting non-ferrous metals temperature above 900 F., and then Withdrawing from such contact.

7. The process of producing a film-coating of substantial thickness in contact with such surface and causing it to solidify thereon.

9. The process ofproducing compound bodies of unlike metals welded together which consists in contacting 'a surface of a steel base with a supermolten mass of copper,

and confining a body of molten metal of substantial thickness in contact with such surface and causing it to solldify thereon.

10. The process of producing compound bodies of unlike metals welded together which consists in contacting a surface of a steel base with a supermolten mass of copper, and confining a body of molten copper in contact with such surface and causing it to solidify thereon.

11. 'The process of producing compound bodies of unlike metals welded together which consists in weld-filming the surface. of

one such metal by contacting therewith another unlike metal at a temperature much above its melting temperature and thereafter welding a substantial coating of unlike metal on the film coating so formed.

12. The process of producing compound bodies of unlike metals-welded together which consists in weld-filming a surface of a.

steel base by contacting therewith an unlike a metal having a melting point above 900 F) and which is at a temperature much above its melting point and thereafter welding to such surface a substantial coating of metal having a melting pointabove 900 F. and of a nature unlike steel.

. 13. The process of producing compoundv bodies of metals welded together which consists in weld-coating a surface of a ferrous metal base by contacting. momentarily a molten mass of a non-ferrous metal having a melting point above 900 F.,' such second metal maintained 'at a'temperature much above its melting temperature, and there- .after welding to such surface a substantial coating of a cupriferous metal.

14. The process, of producing compound bodies of metal welded together which consists in weld-coating a surface of aferrousmetal base by contacting therewith momentarily a molten mass of a non-ferrous metal;

having a meltingpoint above 900 R, such metal.

second metal maintained at a temperature much above its melting temperature, and thereafter welding to such surface a substantial coating of copper.

15. The process of bodies of metals welde together whic consists in weld-coating a surface of a ferrousmetal base by contacting therewith momentarily a molten mass of copper maintained at a temperature much above its meltin temrature-and thereafter welding to sue surace a substantial coating of copper.

16. The process of roducing com ound bodies of metals welder together whic consists in weld-coating a surface of a ferrousmetal base by contacting therewith momentarily out of contact with the air a molten mass of copper maintained ata temperature much above its melting temperature, excluding air from contact with such filmed surface, and thereafter welding to such surface a substantial coating of copper.

17. The rocess of producing compound bodies of unlike metals welded together which consists in weld-filming the surface of a body of one metal by contacting with such'surface a su ermolten mass of an unlike coatin meta and causing a bod of coating meta to solidify against such lm coating under conditions affording pressure between it and said coating.

, i 18. The process ofproducing compound bodies of ferrous and nonferrousmetals welded together which consists in exposing a body of metal of one 'such class first and moinentarily to a bath of molten metal of the other class having a melting point above 900 F., such second metal maintained at a temperature much above its melting'temperamic, and then to a lower-tern of molten metal of such other e ass;

19. The rocess of producing compound bodies of errous and non-ferrous metals welded together which consists in exposing a lvody'of ferrous metal first and momentarily to a bath of non-ferrous metal having a/melting point above 900 R, such second metal maintained at a temperature much above its .melting-temperature, and then to a lowertemperature bath of moltennon-ferrous 20. The rocess of producing compound bodies of errous and non-ferrous rnetals welded together which consists in exposinga body of ferrous metal first and momentarily I to a bath ofnon-ferrous metal having a melt,- ing pointabove 900 F.;such second metal. maintained at a temperature mucli ahove'its melting tem erature, and then to a lowertempcrature ath of molten copper,

21. The process of producing compound bodies of .ferrous and nonferrous .metals welded together which consists in exposing a body of ferrous metal first and momentarily to'a bath of molten copper maintained at is producing com und rature bath temperature much above its 'melting temperature, and then to a lower-temperature bath of molten copper.-

22.The rocess of producing compound bodies of un ike metals welded together which consists in weld-filming the surface of a steel lrasc'ty contacting therewith a supermolten mass of an unlike metal, and causing a body of coating metal to solidify against such film coating under conditions affording pressure between it and said coating.

23. The process of producing compound bodies of unlike metals welded together which consists in producing an absolute metallic surface on a body of one metal, weldfilming such surface by contacting therewith a su ermolten mass of an unlike coating meta and causin a body of coating metal to solidify on such fi m coating under conditions affording pressure between it and said-coatmg.

24. The process of producing compound bodies of unlike metals welded to other which consists in producing an ahsolu e metallic surface on a steel base, weld-filming such surface by contacting therewith a su permolten mass of an unlike metal, and causing abody of coating metal to solidify on 2 such film coating under conditions affording pressure between it and said coating.

25. The processof producing compound metal bodies com rising steel and a cuprif= erous metal welde together, which consists in producing an absolute metallic surface on a steel base, weld-filming said surface by contacting therewith a supermolten mass of another metal,'and causing a bed of cupriferone metal to solidify on such lm coating, under conditions affording pressure between it and said coating. v 1

26.'The process of producing compound metal bodies comprising steel and copper welded together, w ich consists in producing an absolute metallic surface on a steel base,

weld-filming such surface by contacting therewith a supermolten mass of vco 'per, and

causing a body of copper to solidi film coating, under conditions affording pressure between it and said coating.

-27. The process of producing compound bodies of unlike metals welded together which consists in film-coating a surface of a body of one metal by contacting therewith a body of molten metal of. unlike nature at a temperature much aboveits melting temperature, and then contactinga second body of molten metal likewise unlike said first on such metal with said film coating and causing a bodies of unlike metals wel ed together 'Whichconsists in film-coating a surface of a body of steel by contacting therewith a body 28f The process of producin compound,

of molten metal of unlike nature at a temperature much above its me tm temperature, and then contacting a 'seco d body of tacting a second body of molten copper with said film-coating and causing a substantial layer of it to combine with and solidify against said filmscoating.

30. The process of producing compound bodies of unlike metals welded together, which consists in exposing asurface of a body of one metal to the action, first ofa' bath of molten metal of unlike nature at a temperature much above its melting temperature andthen to.a lower-temperature bath of coating metal, likewise unlike said first metal, and by pressure completing the weld, there by forming onsa'id surface a coating of an unlike metal. J

311' The process of roducing compound bodies comprising stee and an unlikemetal welded together which consists in ex osin a surface of a' steel base to the action, t of a bath of molten metal of unlike nature at a'temperature much above its melting temperature and then to a lower-temperature bath of metal, likewise unlike said steel, and by pressure comlpleting the weld, thereby forming on said stee surface a coating of an unlike metal.

32. The process of bodies comprising stee welded together, which consists in exposing a surface of a steel-base to the action, first of a bath of molten metal of unlike nature at a temperature much above its melting tem- .perature' andthen to a lower-temperature ath of copper, and by pressure completing the weld, thereby forming on said steel 'surautogenou s face a coating of copper.

33. The process ofproducing compound bodies comprisin stee and an unlike metal -y we. ded I together, which con-' sists in exposing asurface of a steel base to the action, first of a bath of molten metal ,of unlike nature at a temperature much above its melting temperature and then to a lowertemperature bath of said metal, and by pres sure'completing the weld, thereby forming tion, first of a ba th of molten copper at a} on'saidsteelsurface a coating of an} unlike metal.

34. The process of producing compound bodies com isin'g; steel and copper autogenously we ded together,-..-whichconsists in exposing asurface of a steelbase to the acbodies of metal welde sists'in immersing a'metallic object in a bath lproducing compound and an unlike metal I bodies of metal .welde seams atuLre and then to a lower-temperature bath of 'cop er, and by pressure completing a sists incontacting a metallic surface with a body of molten metal at a tem erature much above 1ts melting point, wit drawing, said surface from such contact into a protective temperature much above'its melting temperatmosphere, and contacting said surface with a furt er body of molten metal .and causin a substantial layer thereof to combine with and solidify on such surface.

36. The process of roducing com ound 'bodies oimetal welds to ether whic consists in contacting a meta lic surface with a body of molten metal of unlike nature maintained at a uniting temperature much above its melting point, withdrawing said surface from such contact into a' protective atmosphere, and contacting said surface with a further body of molten, metal and causing a substantial layer thereof tocombine with and solidify on such surface.

37. The process of dproducingcom ound of supermolten metal of unlike nature, withdrawing said object therefrom into :1. protect ive atmosphere,- and then contacting with said object a further body of molten metal of together whic conunlike nature and causing a layer thereof to solidify upon such object.

38. The process of roducing com ound bodies of metal welde to ether 'whic consists in film-coating a meta lic object by contactin with it a body of supermolten metal of unl e nature, protecting the film coatin from oxidation by enveloping the same with .a noneoxidizing atmosphere, and contacting with said film coating a body of molten metal and causing a layer thereof to combine "with and solidify against said film coating.

' 39. The process of dproducing compound together. which consists in forming a chlorid coatin on a surface of a metal object, exposingsai surface to a supermolten body of unlike metal and thereby volatilizing said coating andfilming over the surface of the metal, and causing a substantial coating of molten-metal to solidify I on such filmed surface.

40. The process of producing ,com ound v bodies of metal-welded together whic consists in forminga volatilizable coating on a surface of .a metal object, exposin said sur-" face. to .a supermolten body of u ike metal and thereby volatilizingisaid coating and filming over the surface ofthe metal, and causing a substantial coatin of molten' :metal to solidify'on s'uch filme surface.

41. The process of producing compound bodies of metal welded together which consists in forming a volatilizable coating on a surface of-a metal object, exposing said surface to a body of unlike molten metal at a temperature much above its melting point and thereby volatilizing said coating and film-coating the surface of the metal object, withdrawing the film-coated object from contact with said molten metal into a protective atmosphere to revent impairment of the film-coating, and causing a substantial coating of molten metal to solidify on such filmed surface.

42. The process of roducing com ound bodies of metal welded together whic consists in forming a volatilizable coating on a surface of a metal object by chemical attack of such surface, exposing said surface to a body of unlike molten metal at atemperature much above its melting point and thereby volatilizing said coating and film-coating the surface of the metal object, withdrawing the film-coated object from contact with said molten metal into a protective atmosphere to prevent impairment of the film-coating, and causing a substantial coating ofmolten metal to solidify on such filmed surface.

43. The process of roducing compound bodies of metal welded together which consists in pickling a surface of a metal object and thereby forming on such surface a volatilizable coating, exposing suchsurface to a body of unlike molten metal at a temperature much above its melting point and thereby volatilizing said coating and film-coating the surface of the metal object, withdrawing the film-coated object from contact with said molten metal into a protective atmosphere to prevent impairment of the film-coating, and causing a substantial coating of molten metal to solidify on such filmed surface."

44. The process .of applying cast-on coatings which consists in inclosing a heated object to be coated in a closed casing containing a protective atmosphere, introducing molten metal into such casing-and exhausting therefrom such protective atmosphere, and applyingpressure to the interior of the casing and causing the molten metal therein to solidify on the surface of said object.

'45. The process of producing compound bodies of ferrous and non-ferrous metals inseparably united, which consists in contacting a surface of one such metal with a supermolten mass of the other metal, limiting the uniting layer thereby formed by limiting the time of contact between the two metals while one of them remains in the supermolten condition, and causing a layer of molten metal to solidify on such surface.

46. The process of producing compound bodies of ferrous and non-ferrous metals inseparably united, whichconsists in contact ing a surface of one such metal with a supermolten mass of the other such metal, limiting to infinitesimal thickness the uniting layer thereby formed by limiting to a brief period the time of contact between the two metals while one of them remains in the supermolten condition, and causing a layer of molten metal to solidify on such surface. I

47. The process of producing compoun bodies of ferrous and nonferrous metals inseparably united, which consists in thoroughly cleansing and protecting the surface of a ferrous metal body ofsuitable shape and thickness, heating such a body to a tem erature between a red heat and a yellow eat, melting an adequate mass of non-ferrous metal and superheating such massto the described supermolten condition, and bringing the cleansed, heated and protected surface of the ferrous-metal object into momentary contact with the supermolten metal, maintaining the contact for substantially only that time which is required for union of the two metals, and then causing cooling .below the supermolten temperature of the metal immediately surrounding'said ferrous object and causing a layer of moltenmetal, to solidify thereon.

48. The process of producing" compound bodies of steel and copper inseparably united, which consists in thoroughly cleansing and protecting the surface of a steel body of suit able shape and thickness and heating such body to a temperature between a red heat and a yellow heat, melting an adequate mass of cop er and su erheating such mass to the desired supermol ten condition, and bringing the cleansed, heated and protected surface of the steel body into momentary contact with the supermolten metal, maintaining the eon tact for substantially only that time which is required for union of the two metals, and then causing cooling below the supermolten temperature of the metal immediately surrounding said steel object and causing a layer of the molten metal to solidify thereon.

In testimony whereof I allix my signature, in the presence of two witnesses.

JOHN FERREOL MONNOT.

Witnesses:

MAY I. TRIMBLE, H. M. MARBLE.

Images