Improvements in the Manufacture of Alloys.
Year: 1894

page_text: Date of Application, 14th Nov., 1894
Complete Specification Left; 30th July, 1895-Accepted, 31st Aug., 1895
Improvements in the Manufacture of Alloys.
I, HENRI MOISSAN of 15 Rue des Halles, Paris, France, do hereby declare the
nature of this invention to be as follows:-
This invention relates to a process for introducing the refractory bodies:-such
as molybdenum, tungsten, uranium, zirconium, vanadium, cobalt, nickel, manganese,
chromium, titanium, silicon, and boron, into the various kinds of cast irons, steels,
bronzes, and other metals and alloys, by means of aluminium or of magnesium.
The simple bodies above mentioned which are for the most part infusible at the
highest temperature of our metallurgical furnaces, can be readily made to enter,
with the aid of the means I describe, into combination with aluminium, or in
solution in this metal, and thus produce alloys the melting point of which varies
with the proportion of the aluminium used but is always very considerably below
that of the refractory body contained in the alloys. These alloys when introduced
into a bath of cast iron, steel, or other metal, present phenomena with respect to
the refining action and to the prevention, of blowholes, which are identical with
the phenomena presented by, pure aluminium ;. moreover the said alloys leave
behind in the bath the hereinbefore mentioned' refractory bodies, viz. molybdenum,
tungsten, chromium, titanium, &c. in a liquid form. After this operation it is easy
10 get rid of the aluminium by causing it to pass off with the slag. I produce by
processes hereinafter described, and in a direct manner, alloys of aluminium which
are rich in refractory bodies and are entirely free from carbon, iron and silicon,
which result has not beeu effected heretofore.
In producing these alloys, I utilize the reducing property of aluminium, which
property is rendered manifest by the great evolution of heat produced by aluminium
in combining with oxygen.
These aluminium alloys may be produced either by the direct reduction of the
oxide of the refractory body by means of molten aluminium, which reduction is or
may be carried out in a crucible on a hearth furnace, or on a revolving furnace, at
a temperature which may vary from 700° to that of white heat; or by utilizing
the aluminium progressively as it is being produced in the apparatus employed at
present in industry for producing this metal.
Having produced the hereinbefore mentioned refractory metals by means of the
electric furnace which I have invented, I have tried, but without success, to alloy
them directly with aluminium by. direct fusion. Similarly, no combination is
produced by working with the blast furnace. Like attempts made with the
electric furnace have shown that the alloys may be produced in most cases, but
that these alloys contain an appreciable quantity of graphite and a crystallized
carbide of aluminium whose existence and properties I was the first to prove. These
two last mentioned substances prevent the alloy from passing into another metal, or
they saturate the latter with carbon.
These alloys might be produced by means of the electric furnace, by first
melting the refractory substance, then introducing the desired amount of aluminium,
and then running off at once. But this operation is very difficult because these
simple bodies remain liquid for a short time only, or they mix with difficulty
with aluminium, or they combine with the oxygen, or with the nitrogen of the
atmosphere.
With the object of solving these difficulties I have invented the herein described

page_text: method of production which enables me to produce alloys rich in refractory metals
and free from carbon. To this end I place the aluminium in a crucible which is
lined internally with magnesia or alumina. When a crucible of refractory earth is
employed, a small quantity of silicon from the crucible enters in the alloy.
The aluminium is heated to red heat, then the crucible is taken out of the
furnace and held firmly by tongs.
The metal is then stirred or puddled with a rod of refractory earth, or preferably
of alumina or magnesia, which is not capable of being reduced by aluminium, even
at a high temperature, and the oxide of the metal to be reduced is added in small
fractional quantities at a time. Immediately after this oxide has been introduced,
the metallic bath is agitated by rubbing on the circumference of the crucible, in
order to start the reaction, and even to cause a few particles of aluminium to ignite
on contact with the atmosphere. The reaction then sets in and manifests itself by
a considerable increase of temperature. The incandescence is sometimes so intense
that the eye is unable to bear its brightness.
The reaction is kept up by the introduction of fresh doses of oxide, these
successive additions being made with care, and the stirring or puddling being kept
up all the time.
The heat evolved during this reaction is of sufficient violence to produce
spurting. The alloy remains in a liquid state during the whole period of
reduction, and it can be run into moulds with ease at the termination of the
operation, without it being necessary to put the crucible back into the furnace.
The evolution of heat is such that it is possible by introducing into the crucible
an addition of certain metals in a powdered state, such as chromium, manganese,
nickel, cobalt, to cause said metals to become fused, and in this manner to enrich
the alloys in a direct manner with these metals. When, in this process, a portion
of the aluminium has been used, and has disappeared, it is easy to add a fresh
quantity of molten or liquid aluminium to the mass.
In cases in which the reduction is more difficult, as for instance in the case of
silica, there may be first prepared a mixture of the oxide to be reduced, with
aluminium, in a very fine powder which is thrown either on to a bath of aluminium
heated to redness, or into a strongly heated crucible.
When refractory bodies which are fusible with very great difficulty are
employed, it may be advisable to heat the oxide before throwing it in fractional
quantities on to the bath of aluminium. This reducing property of aluminium
with relation to the oxides of refractory bodies, may obviously be applied to
various salts, or combinations of said refractory bodies, and in particular to the
salts of the earthy alkalies.
The production of alloys according to my process is therefore based on the
utilization of the reducing power of aluminium and on the high temperature which
is generated by the combustion of this metal, which immediately causes the
aluminium to combine with the nascent metal and thus prevents the metal produced
from becoming re-oxidized.
During the entire duration of the operation, the liquid alloy of the aluminium
and the refractory body never come in contact with a salt or a mixture of fused
salts. This method of proceeding by the direct union of aluminium and of the
metal of the refractory oxide, differs entirely from all that has yet been
described.
At the termination of the operation, a dust composed of alumina and of small
grains of aluminium alloy, floats on top of the metal bath. This slag is placed
in suspension in a bath of fused chlorides or fluorides, and furnishes, by the union
of the small globules disseminated in the mass, a fused alloy of aluminium and of
the refractory body.
These alloys, produced in the manner just described, are introduced into the
selected metals in order to cause the refractory body contained in the alloy to
enter into said metals, the aluminium being subsequently eliminated.
Thus, in order to produce chrome copper, there is added to the molten copper a

page_text: determined quantity of chrome aluminium according to the percentage of chroni
it is desired to obtain.. The bath is stirred, and if the amount of aluminium is tob
great and is to be eliminated, the addition of a small quantity of copper oxide
burns the aluminium in excess and causes the alumina to pass into the slag.
Similarly in order to produce a titanium-steel, there is added to a bath of
molten steel, a determined quantity of titanium-aluminium: The aluminium in
excess is readily oxidized, either by the oxygen in solution in the metal in the form
of gas and oxide, or by a current of air, or by the addition of a determined
quantity of iron oxide (sesquioxide or forge scale oxide).
In general, the aluminium may be removed by the oxide of the metal on which
the operation is being carried out, or by an earthy salt of said metal.'
Similarly, tungsten-steel, molybdenum-steel, chrome-steel, may be produced
either in the Martin-Siemens furnace, or in the Bessemer converter.
For the purpose of producing alloys with the refractory bodies, the reducing
power of aluminium is exerted equally well on the metallic oxides at the moment
when this aluminium is being formed, (that is to say in the various furnaces or
apparatus in which that metal is produced).
Aluminium vapour may even be utilized progressively as it is being formed, by
passing an electric arc in the midst of a mixture of alumina, carbon, and the oxide
to be reduced.
I have ascertained by easily repeated experiments; that alumina is' reduted by:
carbon alone at the temperature of the electric arc, without 'electrolytic action.
But in this case, the aluminium alloys thus produced, may contain small quantities
of carbon and silicon.
Instead of aluminium I may sometimes use magnesium in carrying out my
invention.
I, HENRI MOISSAN, of 15, Rue des Halles; Paris, France, do hereby declare
the nature of this invention and in what manner the same is to be performed to be.
particularly described and ascertained in and by the following statement:―
.
This invention relates to a process for introducing the refractory elements'
molybdenum, tungsten, uranium; zirconium, vanadium, cobalt, nickel, manganese, *
chromium, titanium, silicon, and boron, into the various kinds of iron, steel, bronze
and other metals and alloys by means of aluminium or of magnesium.
The refractory elements above mentioned, which are for the most part infusible
at the highest temperature of ordinary metallurgical furnaces, can be readily made
to enter, by the means hereinafter described, into combination with aluminium,' or
into a state of solution in this metal, and thus produce alloys the melting points of
which vary with the proportion of the aluminium used but are always very con-
siderably below those of the refractory elements contained in the alloys. These
alloys when introduced into a bath of cast iron, steel, or other metal, présent
phenomena as regards refining action and the prevention of blow-holes, that are
identical with the phenomena presented by pure aluminium; moreover the said
alloys liberate in the bath the herein before-mentioned refractory elements viz.,
molybdenum, tungsten, chromium, titanium, etc.-in a liquid form. After this
operation it is easy to get rid of the aluminium by causing it to pass off with
the slag.
i

page_text: Having obtained the hercinbefore mentioned refractory metals by means of the
electric furnace that I have invented, I tried, but without success, to alloy them
directly with aluminium by direct fusion. Similarly, no combination is produced
by working with the blast-furnace. Like attempts made with the electric furnace
have shown that the alloys can, in most cases be produced, but that these alloys
contain an appreciable quantity of graphite and a crystallized carbide of aluminium
whose existence and properties I was the first to discover. These last-mentioned
two substances prevent the alloy from passing into another metal, or they saturate
the latter with carbon. The said aluminium-alloys might be produced by means
of the electric furnace, by first melting the refractory substance, then introducing
the desired amount of aluminium, and then running off the alloy at once. But this
operation is very difficult, because the refractory elements mentioned either remain
liquid for a short time only, or they mix with difficulty with aluminium, or they
combine with the oxygen or the nitrogen of the atmosphere.
With the object of solving these difficulties I have invented the method,
hereinafter described, which enables me to produce alloys rich in refractory metals
and free from carbon, which result, so far as I am aware, has not been heretofore
attained.
In making such aluminium alloys, I utilize the reducing property of aluminium,
which property is rendered manifest by the great evolution of heat produced by
aluminium in combining with oxygen. The said aluminium alloys may be produced
either by direct reduction of the oxide of the refractory element by means of molten
aluminium, which reduction is or may be carried out in a crucible, a stationary
hearth-furnace, or in a revolving furnace, at a temperature which may vary from
700° C. to that of white heat; or by utilizing the aluminium progressively as it is
being produced in any suitable apparatus-for example, that at present employed
in industry for producing this metal.
To this end conveniently, the said aluminium alloys are produced by placing
aluminium in a crucible which is lined with magnesia or alumina, because if a plain
crucible of refractory earth were employed, a small quantity of silicon from the
crucible would enter into the alloy. The aluminium is first raised to red heat,
whereupon the crucible is taken out of the furnace and held firmly by a pair of
tongs. The molten metal is then stirred or puddled with a rod of refractory earth,
preferably of alumina or maguesia, that is not capable of being reduced by
aluminium, even at a high temperature, and the oxide of the refractory metal to
be reduced is added in small fractional quantities at a time. Immediately after this
oxide has been introduced, the metallic bath is agitated, as by rubbing on the
circumference of the crucible, in order to start the reaction and even to cause a few
particles of aluminium to ignite on contact with the atmosphere. The reaction
then sets in and manifests itself by a considerable increase of temperature. The
incandescence is sometimes so intense that the eye is unable to bear its brightness.
The reaction is kept up by the introduction of fresh quantities of the refractory
oxide, these successive additions being made with care, and the stirring or puddling
being kept up all the time. The heat evolved during this reaction is of sufficient
violence to produce spurting. The alloy remains in a liquid state during the
whole period of reduction, and it can be run into moulds with ease at the
termination of the operation, without its being necessary to put the crucible back
into the furnace. The evolution of heat is so great that it is possible by intro-
ducing into the crucible an addition of certain metals-such as chromium,
manganese, nickel, and cobalt-in a powdered state, to cause the said metals to
become fused, and in this way to enrich the alloys in a direct manner with these
metals. When, in this process, a portion of the aluminium has been oxidised, it is
easy to add a fresh quantity of molten aluminium to the mass.
In cases in which the reduction is more difficult-as, for instance, in the case of
silica a mixture of aluminium and the oxide to be reduced may be first prepared
in the state of a very fine powder and then thrown either upon a bath of
aluminium heated to redness, or into a strongly heated crucible. When refractory

page_text: elements which are fusible only with very great difficulty are employed, it may be
advisable to heat the oxide before throwing it, in fractional quantities, upon the
bath of aluminium.
The reducing property of aluminium with relation to the oxides of refractory
bodies, may obviously be applied to various salts or combinations of the said
refractory bodies, and in particular to the salts of the earthy alkalies.
The production of alloys according to my process is therefore based on the
utilization of the reducing power of aluminium, and on the high temperature which
is generated by the combustion of this metal, which immediately causes the metallic.
aluminium present to combine with the nascent refractory metal and thus prevents
the latter from becoming re-oxidized. It will be seen that during the whole of
the operation, the liquid alloy of aluminium and the refractory metal produced,
is not brought in contact with any fused salt or mixture of salts acting as a flux.
This method of proceeding by the direct union of aluminium and the metal of the
refractory oxide, differs entirely, so far as I am aware, from anything that has
hitherto been proposed.
At the termination of the operation, a slag composed of alumina and containing
small globules of aluminium-alloy floats on the top of the metallic bath. This slag is
put into suspension in a bath of fused chlorides or fluorides, and furnishes, by the
union of the small globules disseminated in the mass, an additional quantity of the
alloy of aluminium and the refractory element.
Aluminium-alloys produced in the manner just described are introduced into
the selected metals or alloys in order to cause the refractory elements contained in
the aluminium alloys to become alloyed therewith, the aluminium being subsequently
eliminated.
Thus, in order to produce an alloy of chromium and copper, there is added to
molten copper a determined quantity of an alloy of aluminium and chromium
according to the percentage of chromium it is desired to alloy with the copper.
The bath is stirred to effect an intimate mixture of the copper and chromium, after
which the aluminium is eliminated by the addition of a small quantity of copper,
the resulting alumina passing into the slag.
Similarly in order to produce a titanium-steel, there is added to a bath of molten
steel, a determined quantity of titanium-aluminium. The aluminium is readily
oxidized to eliminate it, either by the oxygen contained in the metallic bath in the
forms of gas and oxide, or by a current of air, or by the addition of a determined
quantity of iron oxide (sesquioxide), for example iron scale obtained from a forge
or rolling mill. In general, the aluminium may be removed either by the oxide of
the metal on which the operation is being carried out or by an earthy salt of the
said metal.
Similarly, tungsten-steel, molybdenum-steel, and chromium-steel may be produced
either in a Siemen's-Martin furnace or in a Bessemer converter. I have found
that aluminium will exert its reducing power on the oxides of refractory elements
and thereby produce alloys with these substances equally well at the moment when
it has just been formed that is to say, in the various furnaces, or apparatus in which
it is produced.
Aluminium vapour may even be utilized as it is being formed, by producing an
electric arc in the midst of a mixture of alumina, carbon, and the oxide to he
reduced; I have ascertained by experiments, which can be easily repeated, that
alumina is reduced by carbon alone at the temperature of the electric arc, without
electrolytic action. But in this case, the aluminium-alloys produced may contain
small quantities of carbon and silicon. Instead of using aluminium I may sometimes
use magnesium in carrying out my invention.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The herein described method of producing an alloy of a refractory metal such

page_text: as herein specified with iron, steel, bronze, or other metal or alloy by adding to
the latter, an alloy of the refractory metal with aluminium or magnesium, this
alloy being produced by direct reduction of the oxide of the refractory metal by
aluminium or magnesium without the intervention of any fused salt or flux, as set
forth.
2. The manufacture of alloys of the refractory elements herein referred to and
aluminium or magnesium by bringing an oxide or other compound of the desired
refractory element into intimate contact with aluminium or magnesium, whereby
the said oxide or compound is reduced by and the resulting element caused to
become alloyed with the aluminium or magnesium, as set forth.
Dated this 30th day of July 1895.
Hor the A nnlicont
Hor the
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.