Improvements in the Manufacture of Aluminium Alloys.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Aluminium Alloys.
We WILLIAM PEARSON of 189 Vauxhall Road Birmingham Engineer and
JULIA ANN BOTT, of Wynstay Road Colwyn Bay North Wales Married Woman
do hereby declare the nature of this invention to be as follows:-
Our invention consists of an improved method of alloying together the metal
aluminium with the metal cobalt, or its oxide, in the proportion of from one tenth
of one per cent. up to five per cent. of cobalt, according to the increase in hardness
and tenacity required in the resultant aluminium-alloy.
Owing to the great difference between the melting points of aluminium and
cobalt, and their tendency to combine with silica and iron when melted together
in an ordinary refractory crucible, it has hitherto been exceedingly difficult to
produce an alloy of aluminium with other metals such as cobalt, nickel, manganese,
chrome, etc., without the alloy being contaminated with silicious impurities.
In our invention, however, we overcome this difficulty by making a primary alloy
rich in cobalt, preferably 50% cobalt and 50% aluminium, which we melt in a
plumbago crucible,-melting the cobalt first, with a flux consisting of chloride of
potassium, then, when the cobalt is melted, we add the aluminium, the resultant
molten alloy is then of sufficient specific gravity to allow all of the slag or other
impurities being skimmed off, and the resultant cobalt-aluminium alloy may be used to
alloy with aluminium, either when it is molten, or it may be run into ingots to be
remelted when required.
In addition to our said primary alloy of cobalt and aluminium being of the
requisite specific gravity to render practicable the removal of any slag or other
impurities, we also obtain another important object, and that is, our cobalt-
aluminium primary alloy has a lower fusing point than cobalt per se, and, taking
advantage of this essential feature in our invention, we are thereby enabled to
produce our aluminium alloy in a crucible made of nickel, or such other metal
crucible in which aluminium may be safely melted without fear of injurious
contamination.
Having described the production of our primary alloy of cobalt and aluminium,
we now set forth the manner in which we make our final aluminium alloy,
namely:-
We melt the required quantity of metallic aluminium in a crucible (preferably
constructed of nickel) using any suitable flux containing chlorine, and when the
aluminium is melted, we add sufficient of the primary cobalt-aluminium alloy
herein before described, as will, when alloyed, produce a final aluminium alloy
containing from one tenth of one per cent. up to five per cent. of cobalt, according
to the increase in hardness and tenacity required in the resultant aluminium
alloy.
The primary cobalt-aluminium alloy may be added to the molten aluminium in
the nickel (or other metal) crucible, in a molten condition, or in ingot form, we
prefer however to add it in its molten condition, in either case, however, its melting
point being much lower than that of cobalt or nickel per se, no injury can take

page_text: place to the nickel (or other metal) crucible, whilst the resultant alloy will be free
from any impurities.
1 1000
WILLIAM PEARSON.
JULIA ANN BOTT.
We, WILLIAM PEARSON, of 189 Vauxhall Road, Birmingham, Engineer, and
JULIA ANN BOTT of Wynstay Road, Colwyn Bay, North Wales, Married Woman,
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:-
Our invention relates to the manufacture of alloys of aluminium with cobalt in
proportions which may vary from one tenth of a part to five parts of cobalt, to
one hundred parts of aluminium, according as the less or greater hardness required
in the alloy.
Owing to the melting points of aluminium and cobalt being very different, and
the tendency to form slag with silica and iron, it has been found very difficult to
produce a good alloy by melting the metals in ordinary refractory or graphite
crucibles or in any furnace.
According to our invention we overcome these difficulties in the following
manner.
We first melt the aluminium in a closed crucible made of nickel, and when it
is quite liquid, we add as flux a little mercury chloride to clear the metal from
dross, we then run off the melted aluminium from the bottom of the crucible, thus
obtaining it quite pure, into a crucible in which the required quantity of cobalt is
already melted.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
. The manufacture of an alloy of aluminium and cobalt by the use of a nickel
crucible, substantially as herein described.
ABEL & IMRAY,
Agents for the Applicants.