US1663963A - Magnesium alloy and method of making same - Google Patents

Description

Patented Mar. 21, 1928.

UNITED STATES PATENT OFFICE. v

WILLIAM R. VEAZEY, OF CLEVELAND HEIGHTS, OHIO, ASSIGNOR TO THE DOW CHEMI- CAL- COMPANY, OF MIDLAND, MICHIGAN, A CORI'ORATION OF MICHIGAN.

MAGNESIUM ALLOY AND METHOD OF MAKING SAME.

No Drawing.

The present improved alloy is one in which magnesium is the predominant element, the object being to develop an alloy that will possess the characteristic lightness which is obtained by the use of magnesium in excess of eighty per cent, while such alloy will be characterized by high strength and toughness as well as possess a suflicient degree ofhardness. More particularly such alloy consists of magnesium and from several hundredths to several tenths per cent of vanadium.

It has not been found feasible to heat the metals in ngestion together for the purpose of alloying the same, since this will involve the use of a temperature above the boiling point of magnesium, the melting point of vanadium being approximately 1715 degrees centi-\ grade. By the present improved method, however, it has been foundpossible to produce alloys of these two metals containing substantial amounts of vanadium corresponding with theamount for instance employed in so-called vanadium steels and exercising a marked influence in the resultant product. Such product having a vanadium content of less than one percent is for all practical purposes no heavier than pure magnesium, which of course is very much lighter than aluminum and the connnercial aluminum alloys; at the same time if properly cast such alloy is of considerably greater tensile strength and impact-toughness without being unduly hard.

The invention then consists of anew product containing magnesium and vanadium in approximately the proportions stated, to-

gether with the steps involved in the making of such alloys hereinafter fully described and particularly set forth in the claims. The following description it will be under-' stood thus sets forth but several of various ways in which the invention may be carried out.

Briefly stated, the improved method of making the alloy in hand consists in inter- .fusing a limited amount of a suitable vanadium compound'with an excess of magnesium whereby such compound is reducedto the metal and thereupon forms an alloy with the residuum of'magnesium still largely exceeding the amount of the vanadium thus; reduced, from the compound -employed.

Application filed December a, 1924. sent; it). 754,484.

Preferably vanadium pentoxide (V,O,) is' employed, which compound may be prepared most conveniently from ammonium vanadate (NH,"VO,-). Such preparation is accomplished by igniting the vanadate and then fusing the resulting red-yellow powder in a suitable crucible, the resulting product ,being a red li uor which on solidifying becomes a dense ark red crystalline substance, melting at about 680 degrees centrigrade. (Thorpe).

mass of molten magnesium is then prepared preferably using a flux of slightly greater specific gravity than the molten metal and having sufiicient surface tension to cause it to form a film thereover and thus 4 prevent exposure of the metal to the .atmosphere; The vanadium pentoxide is then added to such molten magnesium being pushed under the surface thereof since it exhibits a tendency to float and if necessary 1 a thorough inter-mixture of the oxide may be insured by stirring. However, the react1on-of the magnesium with the oxide occurs almost immediately, the latter being reduced to metallic form and incorporated in the mass of molten magnesium to form the desired alloy.

The molten alloy may then be conveniently removed from the crucible or melting pot by means of an ordinary ladle and is cast into bars or such other shapesas may be desired. .The amount of vanadium derived from any given quantity ofthe oxide is 56 per cent but some of this apparently is lost in the reaction, at least less than the theoretical amount of vanadium appears in the final alloy. However, the amount of oxide that requires to be added to give an alloy containing the desired number of hundredths per cent of vanadium may be readily calculated, as need not be explained in detail. The amount of such alloying ingredient actually introduced may be checked by analysis using the method ordinarily employed in the analysis of chrome-vanadium steels. From three (3) one-hundredths'per cent to fifteen (15) one-hundredths per cent of vanadium have been found to give most satisfactory results.

Other modes-of a plying the principleof my invention may a e employed instead of the one explained, change being made as regards 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 distinctly claim as my invention 1. As a new product, an alloy containing magnesium as the predominant component and vanadium as a relatively small modifying-component.

2. As a new product, an alloy containing magnesium and Vanadium, wherein the magnesiuni is the predominant component and the vanadium is present in substantial amount but less than one per cent.

3. As a new product, an alloy consisting Ofq magnesium and from several hundre'dths to several tenths per cent of vanadium; K

4:. As a new product, an alloy consisting of magnesium and approximately fifteen (l5) hundredths per cent of vanadium.

5. The method of making an alloy of vanadium with magnesium, which consists in interfusing with an excess of magnesium an amount of a vanadium compound adaptmetallic vanadium is ed to be reduced to metallic alloy state in the magnesium.

"6. The method of making an alloy of vanadium with magnesium, which consists in interfusing with an excess of magnesium an amount of vanadium pentoxide to be reduced to metallic'state in the magnesium.

7. The method of making an alloy of vanadium with magnesium, which consists in adding to a body of magnesium in molten state an amount of vanadium compound in excess of that required to reduce such compound, whereby the desired proportion of metallic vanadium is alloyed in such magnesium.

8. The method of making an alloy of vanadium with magnesium, which consists in adding to a body of magnesium in molten state an amount of vanadium pentoxide in excess of that required'to reduce such compound, whereby the desired proportion of alloyed in such' magnesium. I

Signed by-me, this 4th dayof.December, 1924.

WILLIAM R. VEAZEY.