US1377374A - Manganese-magnesium alloy and method of making same - Google Patents

Description

v the range can UNITED STATES PATENT. OFFICE.

WILLIAM R- VEAZEY, 0F CLEVELAND, OHIO, ASSIGNOR TO THE DOW CHEMICAL.

COMPANY,

OF MIDLAND, MICHIGAN,

A CORPORATION OF MICHIGAN.

MANGANESE-MAGNESIUM ALLOY AND METHOD OF MAKING SAME.

No Drawing.

To all whom it may concern:

Beit known that I, WILLIAM R. VEAZEY, a citizen of the-United States and a resident of Cleveland, county of (Juyahoga, and State of Ohio, have invented a new and useful Improvement in Man anese-Magnesium Alloys and Methods of Making Same, of which the following is a specification, the principle of the invention being herein explained and the best mode in which I have contemplated applying that principle, so as to distinguish it from other inventions.

The metals of magnesium and inaganese when heated together do not alloy to any appreciable extent, above the boiling point of magnesium. For this reason it has not been found possible to mix the nietals directly and even by indirect means the best results heretofore obtainable, so far as I am aware, were alloys in which the manganese was present in very minute amount (less than one per cent). By the present improved method, however, I have found it possible to produce alloys. of these two metals containing as high as eight per cent. of manganese, and undoubtedly be extended much further. The resulting product having a manganese content such that the spe cific gravity is less than two, shows an untimate strength of more than twenty thous-- and pounds per square inch when in the form of castings, without heat treatment or forging.

The invention, then, product consisting of an alloy of the metals in question with manganese in approximately the proportion stated, together with the steps involved in the making of such alloy hereafter fully described and particularly set forth in the claims. The following description, it will be understood, thus sets forth but several of various ways in which the invention may be carried out.

It has been known for some time in the practice of the familiar thermite process invented by Goldschmidt that a metallic oxid may be reduced by a metal or alloy, the ingredients being finely powdered and thoroughly intermixed so that when ignited at some point the reaction will continue until the reducing metal is entirely used up and the oxid converted into metal. Aluminum is the metal most frequently used as a reducing agent in this process, although Specification of Letters Patent.

except at temperatures consists of the new '(anhydrous) is then Patented May '10, 1921.

Application filed. July 24, 1918. Serial No. 246,614.

others, including magnesium, which is recognized as the most powerful of all,have been employed. I am also aware of the method for preparing metallic manganese from manganous chlorid using magnesium as reported by Glatzel in Ber. 22; pages 2$57-285 9 (1889), such report being reviewed in Jom'. Sec. Chem. Ind. for 1890,

page 74:. This process of Glatzel is practically the same as that of Goldschmidt, utilizing the chlorid of the metal to be reduced instead of its oxid.

I have found that if, instead of employing a limited quantity of the reducing metal, e. 9. magnesium, in order to convert the ox d or chlorid of manganese into the metalllc form, by in a sense reversing the process and using an excess of such magnesium with a limited quantity of the oxid or chlorid, an alloy of manganese with magnesium is obtained. The proportion of manganese will vary with the relative amounts of the manganese compound and metallic magnesium employed, butas previously stated, I have found it possible by the procedure outlined to obtain an alloy with as high as eight per nese.

lVhen manganous oxid is used, both such compound and the metallic magnesium must be finely divided and thoroughly mixed together, a considerable excess of magnesium being necessary in order to get an alloy. The charge is then placed in a suitable crucible and ignited, a suitable flux being introduced to prevent oxidation.

Much more satisfactory'results have been secured using manganous chlorid instead of the oxid. slightly different fashion from that described where the oxid is used; in other words. the magnesium is first melted in a suitable crucible, a flux, for example, of magnesium chlorid and sodium chlorid, being added to protect the metal from exposure to the ai. and consequent oxidation. The molten magnesium will float in the flux bath as a globule near the surface but remains covered by sufficient film of the flux to be protected. 'The manganous chlorid added, being placed directly on the floating mass of molten magnesium where it melts, and if left to itself 'runs over the surface of the mass and may cent. of manga-,

The process is carried out in mass. The molten alloy may then be conveniently removed from the crucible by means of an ordinary ladle, and is cast into bars or such other shapes asmay be desired. The amountv of manganese derived from any given quantity of the chlorid is about fortyfour per cent., but some of this apparently.- is lost in the reaction, at least less than the theoretical amount of manganese appears present in the final alloy. I have, however, by-properly calculating the amount of chlorid added, been able to obtain alloys containing from one-half of one per cent up to eight per cent. of manganese, and. anticipate that the range can be extended much further. As already stated, some of these alloys with specific gravity less than two, show an ultimate strength of more than twenty thousand pounds per square inch when in the form of castings.

The aforesaid oxid of just described for the chlorid;'c'. 6. instead of being intermixed before fusion with the metallic magnesium, such oxid may be added to a fused mass of magnesium in a bath'of molten flux as just described. The advantage in the use of the chlorid over the oxid lies in the fact that the magnesium chlorid that is produced dissolves in the flux, giving at once a clean product, whereas the magnesium oxid produced in the other case is insoluble in the flux and so has to be worked out of the alloy metal. It will then sink to the bottom heavier than the flux.

The use of-the flux, moreover, is not absolutely essential, for the chlorid or oxid of manganese may be added to the molten magnesium in an ordinary iron or graphite crucible. The magnesium will of course tend in such case to oxidize more-rapidly and so make the operation somewhat more difficult, as the oxid has to be scraped aside in order to add the manganese compound directly to the metal;

Other modes of applying the principle of my invention may be employed instead of of the bath as it is r the one explained, change being made as retinctly claim gards the composition and method herein disclosed, provided the ingredients or steps stated by any of the following claims or the equivalent of such stated ingredients or steps be employed.

I therefore particularly point out and dieas my invention 1. As a new product, an alloy of manganese with magnesium in which the magnesium largely predominates.

As a new product, an alloy of manganese with magnesium in the proportion varying from approximately one part of manmanganese may also be utilized in exactly the same way as ganese to two hundred of magnesium, to. eight parts to one hundred.

3. The method of making an alloy of manganese with magnesium, which consists in inter-fusing a limited amount of a suitable manganese compound with an excess of magnesium.

4. The method of making an alloy of manganese with magnesium, which consists of inter-fusing a limited amount of manganous chlorid with an excess of magnesium.

5. In a method of making an alloy of manganese with magnesium, the steps which consist in adding a limited amount of a suitable manganese compound to an excess of magnesium in molten state, whereby such compound is reduced and the desired pro portion of metallic manganese is incorporated in such magnesium. v

6.- In a method of making an alloy of manganese with magnesium, the steps which consist in adding a limited amount of manganese chlorid to an excess of magnesium in molten state, whereby such chlorid is reduced and the desired proportion of metallic manganese is'incorporated in such mag- 1188111111. I

7. In a method of making an alloy of manganese with magnesium, the steps which consist in maintaining a fused mass of magnesium floating in a suitable molten-flux, and then adding anhydrous manganous chlorid to such mass in relatively limited amount.

8. In a method of making an alloy of manganese with magnesium, the steps which consist in maintaining a fused mass of magnesium floating in a suitable molten flux, and then adding anhydrous manganous chlorid to such mass in amount sufficient to give a proportion varying from approximately one part of manganese to two hundred of magnesium to eight parts to one hundred in the finished product.

9. The method of making an alloy of another metal with magnesium, which consists in interfusing with an excess of magnesium a limited amount of a suitable compound of such other metal adapted to be reduced to metallic state by the magnesium.

10. In a method of making an alloy of' another metal with magnesium, the steps which consist in adding to an excess of magnesium in molten state a limited amount of a suitable compound of such other metal that is adapted to be reduced by the magneslum.

191Sgigned by me, this 19th day of July.