Improvements in the Manufacture of Alloys of Aluminium and Magnesium and Process for Hardening the same.
Year: 1899

page_text: Date of Application, 9th Mar., 1899
Complete Specification Left, 25th July, 1899-Accepted, 10th Feb., 1900
Improvements in the Manufacture of Alloys of Aluminium and
Magnesium and Process for Hardening the same.
A communication from abroad by Dr. LUDWIG MACH, of Villa Brueninghaus,
Kalaische Strasse, Jena, Germany.
I, ALFRED GEORGE BROOKES, of 55 and 56, Chancery Lane, in the County of
London, Chartered Patent Agent, do hereby declare the nature of this invention
to be as follows:-
It is a well known fact that aluminium gains nothing in hardness by being
sent through the rolling mill, and that, consequently, the process of rolling does
not enhance the capacity of that metal for being "worked" with cutting tools.
Indeed, this peculiarity of aluminium is in no way affected by small additions
of other metals, including such as possess-like copper, for example-a high
degree of ductility. Now my correspondent has found that an alloy of aluminium
and magnesium-containing from 2 to 10 parts of magnesium to every 100 parts
of aluminium-which, in regard to its mechanical properties, and, in particular,
its susceptibility to the action of tools, scarcely differs from pure aluminium to
any material extent, will harden very considerably when rolled, drawn or pressed;
and this influence of the magnesium asserts itself even in those cases where
more or less appreciable quantities of other metals, such as antimony, zinc
etcetera are superadded to the alloy.
In carrying out the rolling process in practice, the course to be adopted is as
follows:
The pieces of material are first drawn once, or any requisite number
of times, through the rolling mill in the cold condition; they are then heated
to from 400° to 500° Centigrade;" then again rolled cold, once or several times,
and so on; this treatment, by alternately heating and rolling the blanks,"
being repeated over and over again until the material has gathered a sufficient
degree of hardness. The expediency of heating the alloy is accounted for by
the fact that the material, if rolled unremittingly, without being thus heated
at intervals, will eventually become cracked (or flawy); whereas each inter-
vening heating operation restores its original tenacity; and yet there will be
observed, in this connection, the striking phenomenon that, unlike other metals,
and alloys of metals, such as iron, brass, zinc etcetera, the aluminium-and-
magnesium alloy, through being heated, loses none of the hardness which has
been imparted to it by the previous rolling process.
It may further be here stated that alloys containing from 3 to 5 parts of
magnesium to every hundred parts of aluminium, give the most favourable results
in the process of rolling, as this material, both as regards its cohesion and its
workability may be said to be, at the very least, equivalent to brass, while in
regard to certain other properties-such as tenacity, for example-it is even
superior to the last-mentioned alloy.

page_text: An aluminium-and-magnesium alloy containing less than 2 per cent. of
magnesium cannot be hardened by rolling and conversely, where the proportion
of magnesium is upwards of 9 per cent, the material obtained will be somewhat
brittle and, as such, not so well suited for rolling.
The alloy of aluminium and magnesium herein described retains its cohesive-
ness or hardening capacity owing to its increasing (molecular) density even
though other metals should be incorporated with it while, in certain cases,
owing to additions of this kind, the material will acquire properties which may
prove valuable in other respects; in this connection I refer mainly, as mixtures,
to antimony and arsenic.
Dated the 9th day of March 1809
Improvements in the Manufacture of Alloys of Aluminium and
Magnesium and Process for Hardening the same.
A communication from abroad by Dr. LUDWIG MACH, of Villa Brueninghaus,
Kalaische Strasse, Jena, Germany.
I, ALFRED GEORGE BROOKES, of 55 and 50, Chancery Lane, in the County of
London, Chartered Patent Agent, 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 an improvement in aluminium-magnesium alloys
such as have been described in the Specification of an application for Letters
Patent dated November 25 1898 No. 24878. In this specification I have described
in what manner magnesium exerts its influence on aluminium as to its suscepti-
bility to the action of cutting tools. It had been stated that magnesium added
in 10 to 30 parts to 100 parts of aluminium improves the susceptibility of the
latter to the action of cutting tools. By such an addition aluminium obtains all
those qualities which pure aluminium does not possess, and this without increasing
its specific gravity, but rather reducing it according to the smaller specific gravity
of magnesium.
Furthermore it results from the tests mentioned that the aluminium-magnesium
alloy becomes more brittle with an increasing proportion of magnesium and
that on the other side less than 10 parts of magnesium to 100 parts aluminium
are not allowed to be employed if those properties should not be destroyed.
This invention relates to further means by which it had been stated that the
susceptibility of aluminium to the action of cutting tools is increased even if
the lowest limit of magnesium will not be reached. This invention intends to
render aluminium workable without being restrained to the proportions of at
least 10 parts of magnesium to 100 parts of aluminium and without reducing
the ductility of pure aluminium at a considerable degree. For this purpose the
components of the alloy are melted together in such proportions that 100 parts
of aluminium contain 2 to 10 parts of magnesium. From this an alloy of
aluminium and magnesium results which, in regard to its mechanical properties,
and, in particular, to its workability, scarcely differs from pure aluminium and
which like this, allows to be rolled and drawn, but has the same inconvenience
as pure aluminium, for it is not capable of being worked by cutting tools and

page_text: for example stops up the files &c. If, however, this alloy of 2 to 10 parts
magnesium and 100 parts of aluminium is subjected to a compressing process
by rolling, drawing, pressing &c., the properties of the material become quite
different. As contrasted with pure aluminium treated in the same manner that
compressed material possesses the same qualities which can be obtained only by
essentially higher additions of magnesium, i.e. the alloy with the smaller addi-
tions of magnesium can be excellently worked by cutting tools.
In carrying out the rolling process in practice the course to be adopted is
as follows:-
-
The pieces of material are first drawn once, or any requisite number of
times, through the rolling mill in the cold condition; they are then heated to
from 4000 to 500° Centigrade; then again rolled cold, once or several times,
and so on; this treatment, by alternately heating and rolling the blanks, being
repeated over and over again until the material has gathered the thickness desired.
The expediency of heating the alloy is accounted for by the fact that the material,
if rolled unremittingly, without being thus heated at intervals,-will become
eventually cracked (or flawy); whereas each intervening heating operation
restores its original tenacity.
It may further be here stated that alloys, containing from 3 to 5 parts of
magnesium to 100 parts of aluminium give the most favourable results in the
process of rolling, as this material, both as regards its cohesion and its work-
ability may be said, at the very least, to be equivalent to brass, while in regard
to certain other properties such as tenacity, for example-it is even superior
to the last-mentioned alloy.
An aluminium and magnesium alloy, containing less than 2 parts of magnesium
to 100 parts of aluminium cannot be hardened by rolling; and conversely, where
the proportion of magnesium is upwards of 9 parts to 100 parts of aluminium
the material obtained will be somewhat brittle, and, as such, not so well suited
for rolling.
The alloys of aluminium and magnesium berein described retain their cohesive-
ness or hardening capacity owing to its increasing (molecular) density (com-
pression, condensation) even though other metals should be incorporated there-
with, such as antimony, arsenic, and the like.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is: :-
1. Alloys of aluminium and magnesium containing for every 100 parts of
aluminium from about 2 to 10 parts of magnesium, for the purpose of producing
a light metal capable of being rendered workable by cutting tools by rolling,
drawing or condensing the same, substantially as described.
2. Increasing the hardness and tenacity of aluminium-magnesium alloys by
subjecting them to a condensing process, substantially as described.
3. Increasing the hardness and tenacity of aluminium-magnesium alloys by
subjecting them alternately to a condensing and a heating process substantially
as and for the purpose described.
4. The manufacture of alloys, of magnesium and aluminium admixed in the
herein before prescribed proportions and hardened by a process of compression,
all substantially as and for the purpose herein before set forth.
1 the 24th day of July 1.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.