IMPROVEMENTS IN THE MANU- FACTURE OF CERTAIN ALLOYS OF GOLD
Year: 1882

page_text: LETTERS PATENT to Auguste Guye of St. Bride Street in the City of London
Watch Manufacturer for an Invention of IMPROVEMENTS IN THE MANU-
FACTURE OF CERTAIN ALLOYS OF GOLD A communication to him from abroad
by Philippe Auguste Guye of Geneva Switzerland
PROVISIONAL SPECIFICATION left by the said Auguste Guye at the Office
of the Commissioners of Patents on the 15th September 1882.
AUGUSTE GUYE of St Bride Street in the City of London, Watch Manufacturer,
"IMPROVEMENTS IN THE MANUFACTURE OF CERTAIN ALLOYS OF GOLD." [A com-
munication to him from abroad by Philippe Auguste Guye of Geneva Switzerland.]
This Invention relates to the manufacture of a series of alloys of gold with
aluminium bronze, and with other alloys of aluminium and copper, and an
important feature of the invention is the method of preparing the alloys whereby
the contamination of the aluminium by the silicon of the crucible is prevented.
By alloying pure gold with aluminium and copper in proportions varying
according to the desired standard of the ingot, a series of alloys of gold are
obtained varying from the highest to the lowest standard, of a fine gold color,
malleable, ductile, sufficiently hard and resisting, inoxidisable in the air, less
oxidisable at a red heat than the alloys of gold now employed, and of a lower
density or in other words, having a greater specific volume than the latter for
corresponding standards.
The preparation of these alloys may be made in any suitable kind of crucible,
avoiding however those containing too high a proportion of silica, which renders
the alloy brittle, a consequence which may probably be attributed to the formation
of aluminic silicates.
Equally good results are obtained by alloying the gold with aluminium bronze
or. with a mixture in corresponding proportions of copper and aluminium, or
successively with these two metals. In the latter case it is preferable to alloy the
gold first with the copper and after with the aluminium. Aluminium bronze
.”

page_text: should contain about 10 parts aluminium and 90 parts copper, but the proportion
of aluminium may be increased or diminished according to the degree of ductility
and malleability and the color it is desired the alloy should have. Thus to obtain
alloys of a pale gold color, the proportion of aluminium contained in the aluminium
bronze may be increased to 11 or 11.5 per cent or more the alloy of gold becoming
paler and harder as the proportion of aluminium is increased. On the other hand
if a redder and more malleable alloy is required, the proportion of aluminium
contained in the aluminium bronze may be diminished to 4 or 5 per cent. A lower
proportion may even be taken but the alloys are then easily oxidised at a red heat.
The chief practical difficulties to be overcome are due to the fact, 1st. that the
aluminium becomes easily contaminated by contact with the ordinary crucibles,
and 2nd, that if heated for too long a time it tends to become oxidised. The first
objection is obviated by employing iron crucibles, and both objections are avoided
at once by taking care to add the aluminium (whether it be in fusion or not) only
to metals which are themselves already in fusion. It is upon this latter principle
that the following methods of manufacture are based.
1st In an ordinary crucible containing gold in fusion, I add the alloy of
aluminium and copper in calculated proportions, mix, and cast in ingot.
2nd To a mixture of gold and copper in fusion I add the proper proportion of
aluminium mix, and cast in ingot.
3rd I first cast the gold in the form of a crucible which is then placed within an
ordinary crucible and the whole heated. Before the gold begins to melt, I place in
this gold lined crucible the proper quantity of aluminium copper alloy or of a
mixture not yet melted together, of copper and aluminium complete the fusion of
the whole, mix, and cast in ingots. This method may be followed in preparing the
aluminium copper alloy.
4th In an ordinary crucible I place gold and copper in calculated proportions,
and as soon as these metals begin to melt, I place above this crucible another
crucible of iron containing the proper proportion of aluminium and having a hole
in the bottom so that as the aluminium melts it will fall into the molten mixture
of gold and copper. This method may also be followed in preparing the aluminium
copper alloy.
5th. The gold and copper are melted together in proper proportions in an
ordinary crucible, and the aluminium in proper proportion is melted separately in
an iron crucible. When all the metals are brought to a state of fusion, the contents
of the first crucible, that is to say, the mixture of gold and copper are poured into
the iron crucible, mixed and cast in ingots.
By this method an alloy of gold perfectly free, from silicates is obtained. This
method may also be followed in preparing the aluminium copper alloy.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Auguste Guye in the Great Seal Patent Office on the 14th March
1883.
.
"
AUGUSTE GUYE of St. Bride Street in the City of London Watch Manufacturer
"IMPROVEMENTS IN THE MANUFACTURE OF CERTAIN ALLOYS OF GOLD
A com-
munication to me from abroad by Philippe Auguste Guye of Geneva, Switzerland
This Invention relates to the manufacture of a series of alloys of gold with
aluminium bronze, and with other alloys of aluminium and copper and an important
feature of the Invention is the method of preparing the alloys whereby the con-
tamination of the aluminium by the silica of the crucible is prevented and whereby
the alloys are endowed with qualities of malleability and ductility which fit them
admirably for general use in the arts in substitution of the gold silver and copper
and gold copper alloys now generally employed. No such alloy has I believe
ever yet been produced sufficiently malleable and ductile to enable it to be used in
the goldsmith's art.
By alloying pure gold with aluminium and copper in any of the ways hereafter
described and in proportions varying according to the desired standard of the
ingot, a series of alloys of gold are obtained varying from the highest to the lowest
standard, of a fine gold color, malleable, ductile hard and elastic, and much less
oxidisable in the air at ordinary temperatures or at a red heat than the alloys of
gold now generally employed and of a lower density (or in other words, having a
greater specific volume) than the latter, the comparison in each case being made of
course between corresponding standards.
The preparation of these alloys may be made in any earthenware crucible whose
composition does not contain such a high proportion of silica as would render the
alloy brittle, a consequence which may probably be attributed to the formation of
aluminic silicates or a silicide of aluminium.
Equally good results are obtained by alloying the gold with aluminium bronze,
or with a mixture in corresponding proportions of copper and aluminium, or
successively with these two metals. In the latter case it is essential to alloy the
gold first with the copper and afterwards with the aluminium. The aluminium
bronze used for the purposes of this Invention should contain about 10 parts
aluminium and 90 parts copper, but the proportion of aluminium may be increased
or diminished according to the degree of ductility and malleability and the color it
is desired the alloy should have. Thus to obtain alloys of a pale gold color the
proportion of aluminium contained in the aluminium bronze may be increased to
about 15 per cent, the alloy of gold becoming paler and harder as the proportion of
aluminium is increased. On the other hand if a redder and more malleable alloy is
required, the proportion of aluminium contained in the aluminium bronze may be
diminished to 4 or 5 per cent or even to 1 per cent but if a lower proportion of
aluminium than 4 per cent be taken the alloys will be more liable to be oxidised
at a red heat.
The chief practical difficulties to be overcome are due to the fact 1st that the
aluminium becomes easily contaminated by contact with the ordinary earthen
crucibles, and 2nd that if heated for too long a time it tends to become oxidised.
Both these objections are avoided at once by taking care to add the aluminium
(whether it be in fusion or not) only to metals which are themselves already in
fusion. It is upon this latter principle that the following methods of manufacture
are based.
1 In an ordinary earthen crucible, containing gold in fusion, I add the alloy of
aluminium and copper in calculated proportions, mix, and cast in ingot.

page_text: 2nd To a mixture of gold and copper in fusion I add the proper proportion of
aluminium mix and cast in ingot.
3rd I first cast the gold in the form of a crucible which is then placed within an
ordinary earthen crucible and the whole heated. Before the gold begins to melt, I
place in this gold lined crucible the proper quantity of aluminium copper alloy or
of a mixture not yet melted together, of copper and aluminium. I complete the
fusion of the whole mix, and cast in ingots.
This method should be followed in preparing the aluminium copper alloy, or
equivalent precautions should be taken to avoid any chemical change in the
aluminium in making said alloy.
4th In an ordinary earthen crucible I place gold and copper in calculated
proportions, and as soon as these metals begin to melt, I place above this crucible
another crucible of iron containing the proper proportion of aluminium and having
a hole in the bottom so that as the aluminium melts it will fall into the molten
mixture of gold and copper. This method may also be followed in preparing the
aluminium copper alloy.
5th The gold and copper are melted together in proper proportions in an ordinary
earthen crucible, and the aluminium in proper proportion is melted separately in
an iron or earthen crucible and when all the metals are brought to a state of
fusion, the aluminium is poured into the first crucible mixed and cast in ingots.
This method may also be followed in preparing the aluminium copper alloy.
Having described the nature of the said Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is :-
The manufacture of malleable and ductile alloys of gold with aluminium bronze
or other alloy of aluminium and copper substantially in any of the various ways
herein specified.
In Witness whereof I the said Auguste Guye have hereunto set my hand and
seal this tenth day of March in the year of Our Lord One thousand eight
hundred and eighty three.