An Improvement in the Electro Deposition of Metals and Alloys.
Year: 1897

page_text: Date of Application, 21st Jan., 1897-Accepted, 13th Mar., 1897
COMPLETE SPECIFICATION.
An Improvement in the Electro Deposition of Metals and Alloys.
GEORGE ARTHUR WEBB Electrical Engineer 108 St. John's Street Road
London, E.C. and WILLIAM ARTHUR THOMS, Electro Plater, 108 St. John's
Street Road London, E.C. 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 process or method is based upon the employment of electro metallurgy
applied to covering, plating, or coating articles of metal, metallic alloys or any
suitable substance with an electro deposit of a material that to the best of our
knowledge has not hitherto been used for commercial purposes though we know
that in the laboratory it has been tried but with indifferent success.
This process of deposition has for its object the coating or plating of metals or
metallic alloys or other suitable material with a metal or metallic alloy containing
phosphorus such agent phosphorus being associated with a metal or metallic alloy
to form the anode electrode, or as electrolyte associated with metallic salts to form
the electrolytic bath.
By our said invention we are enabled to produce a homogeneous, adhesive
plating or coating of great hardness, fine colour, and capable of receiving a
brilliant polish or finish and is suitable for plating or coating articles of iron, steel,
copper, brass, bronze, lead, zinc, aluminium &c. or alloys of same as a protection
against oxidation, against the action of sea water, and to act as a general protective
coating against all outside influences that tend to destroy all coatings or platings
upon metals.
By this process of electro depositing metals containing phosphorus we can make
our electrolytic bath to contain one or more metallic salts to form the required
electro deposit, as for instance the bath may be composed of salts of phosphor tin,
the result being a hard white deposit, or the bath may contain a salt of phosphor
metallic copper, a bright, copper coloured deposit being the result, or again we can
use a bath containing the salts of both the phosphor metallic tin and the phosphor
metallic copper in suitable proportions to form a phosphor tin and copper alloy
(better known as phosphor bronze) deposit, in fact all metals or alloys of metals
that are or can be associated with phosphorus of whatever percentage can be
electro deposited by this process.
Metals associated artificially with phosphorus have for years been known and are
at the present time very extensively used, more particularly an alloy of phosphor
copper and phosphor tin and known generally as phosphor bronzc, these metals or
alloys on account of their toughness, tensile strength, colour and hardness are
extensively used by engineers and metal workers generally, taking advantage of
the beneficial influence exerted by phosphorus when associated with metals we
purpose using phosphorus as an auxiliary in our process of electro deposition.
We do not bind ourselves to any particular percentage of phosphorus either for
making our anode electrodes or for forming our electrolyte as with molten metal
associated with phosphorus so with this process, for many excellent phosphor
bronzes contain but a very small quantity of phosphorus which exerts no essential
influence upon the qualities of the alloy, the phosphorus having exerted its
influence during the preparation of the alloy.
The ordinary bronzes consist of mixtures in which the copper actually forms the

page_text: only crystallized constituent the tin crystallizing with great difficulty and the
alloy in consequence of this dissimular condition of the two metals is not as solid as
it would be if both constituents were crystallized, the presence of the phosphorus
is usful and effective in giving the tin a crystallized character which enables it to
alloy itself more completely and strongly with the copper the result being a more
homogeneous mixture.
We make no special claim to any one particular process of making our
electrolytic bath for the reduction of the phosphor metal or metals as most
existing processes of electro depositing for the particular metal or metals will
answer, either alkaline, acid, or neutral, but the electrolytes hereinafter mentioned
.will give satisfactory results yet the materials used may be altered or modified in
various ways.
The metals that can be deposited by this process may be platinum, iridium,
palladium, ruthenium and the like heavy metals, copper, tin, gold, silver, zinc,
cadmium, nickel cobalt, iron, lead, bismuth, antimony either separately or alloyed
with one another.
The formation of the anodes forms an essential feature of this invention, the
anodes should consist of a metal or metals associated with phosphorus of a nature
corresponding with the metal or metals to be deposited, thus an anode of phosphor
metallic copper and phosphor metallic tin would be used for depositing phosphor
bronze, or an anode of silver associated with phosphorus for a deposit of
phosphor silver, but anodes of an insoluable nature such as platinum, carbon &c.
may be employed but in this case the electrolytic bath soon becomes impoverished
of metal and requires replenishing by the addition of a concentrated solution of the
required phosphor metallic salts.
As an example of our process, an electrolyte compounded as follows has given
good results for a deposition of phosphor bronze i.e. an alloy of phosphor metallic
copper (7 parts) and of phosphor metallic tin (1 part). We take
1 oz. phosphor metallic tin, this metal is first brought to the state of chloride by
known chemical processes, the chloride after having been dried at a moderate
temperature preferably by steam is dissolved in distilled or other soft water, to this
solution is added another solution containing 8 ozs. soda hydrate to this we add
8 ozs. of phosphate of soda dissolved in water, and lastly a solution containing
8 oze. of cyanide of potassium of good quality say 90% to 95%. Water is then
added to make the solution half a gallon. We then take
7 ozs. phosphor metallic copper and convert it into a cyanide by known means
this must be added to water, the solution with its added water must contain
7 gallons, the two solutions, tbe one of tin and the other of copper, are then mixed
well stirring all the while. The bath is worked at a temperature of about 150°
to 180° Fahrenheit. During the deposition this being what we consider a
convenient working temperature, the anode used would be as before described an
alloy of phosphor metallic tin and phosphor metallic copper i.e. an anode corre-
sponding to the metals that compose the electrolyte. The electrical current required
must in this case be of a high electro motive force dynamo power well regulated
being the most suitable. This solution deposits a hard reguline adhesive metal of
good colour and capable of receiving and retaining a high polish or finish, it
deposits its metal without any intermediate coating of anothor metal, upon iron,
steel, lead, zinc &c.
.
With this example as with those that follow we do not bind ourselves to the
exact proportions given, either in the formation of the electrode or the electrolyte
as the compounds forming same can be modified to suit requirements as for instance
in the example just given a larger percentage of phosphor metallic copper could
be used, the result being a deeper or redder. deposit or again a larger percentage
of phosphor metallic tin could be used the result being a paler or lighter deposit.
So it would be impossible to demonstrate every modification to which these
phosphor metals could be subjected to, or again an electrolytic bath for the deposition
of the heavy metals associated with phosphorus, such metals can be platinum,

page_text: iridium, palladium, ruthenium, and the like, one example will suffice to show the
process of depositing same metals, as the same quantities of material used and same
conditions will answer for each particular metal.
For a phosphor platinum deposit we take
1 oz. phosphor metallic platinum converted into chloride by known means.
20 fluid ozs. of water is then added, we then add a solution containing 4 ozs. of
ammonia phosphate, the two solutions viz. the phosphor platinum chloride and the
ammonia phosphate are added to a solution of 20 ozs. of phosphate of soda, and
water added to make up 1 gallon. The whole is then allowed to boil for
3 or 4 hours water being added from time to time to take the place of that last by
evaporation, it is then allowed to cool down to a temperature of about 80° to 90° F.
which we have found to give satisfactory results.
Anodes of phosphor platinum, phosphor iridium, phosphor palladium or phosphor
ruthenium, or any of the heavy metals of that group associated with phosphorus
answer well for use in their respective electrolytes, i.e. phosphor platinum anodes
for a phosphor platinum deposit and so on.
The electric current required must in this case be of a high electro motive force
on account of the low conductivity of the electrolyte. Or again
A depositing bath for plating or coating with phosphor gold can be compounded
as follows
1 oz. phosphor metallic gold is converted into chloride by known means,
40 fluid ozs. of water are then added. To this added
1 oz. of hyposulphite of soda dissolved in 10 fluid ozs. of water after which a
solution of cyanide of potassium of good quality say 90% to 95% is added until
a clear solution is formed water is then added to make up 1 gallon of solution to
be used at a temperature of about 90° to 100° F.
Phosphor gold anode. To be worked with mild electric current or again
phosphor silver can be deposited by forming an electrolyte as follows
1 oz. phosphor metallic silver converted into chloride by known means, cyanide
of potassium of good quality say 90% to 95% with water is added until the
phosphor chloride is dissolved and a clear fluid the result Water is then added to
make up gallon.
This solution can be used either warm or cold, by cold we mean a temperature
of about 60° to 68° F.
A phosphor metallic silver anode with a mild form of electric current, or again
a depositing bath for plating or coating with phosphor cobalt, we can proceed
as follows
I oz. phosphor metallic cobalt is converted into chloride by known means to this
we add 2 fluid ozs. of liquid ammonia of specific gravity 880. Then we associate
2 ozs. of chloride of ammonium dissolved in 20 fluid ozs. of water, water is then
added to make up 1 gallon of solution, this solution is preferably used cold.
A phosphor metallic cobalt anode being used, and good electric current.
Or again for a depositing bath for plating or coating with phosphor nickel we
can proceed as follows
1 oz. phosphor metallic nickel is converted into chloride by known means to this
we add 20 fluid ozs. of water, we then have dissolved 8 ozs. of chloride of
ammonium in 100 fluid cz. of water which we add to the above solution of phosphor
chloride of nickel and water, and water added to make up 1 gallon of solution.
This solution is used cold.
An anode of phosphor metallic nickel being used and good electric current.
again
Or
A depositing bath for plating or coating with phosphor zinc we can proceed as
follows.
1 oz. phosphor metallic zinc is converted into chloride by known means and water
added to make up 1 gallon, this solution is preferbly used cold.
An anode of phosphor metallic zinc being used and mild electric curreыi. Or
again

page_text: A depositing bath for plating or coating with phosphor cadmium we can compound
a solution as follows
1 oz. phosphor metallic cadmium is converted by known means into chloride to
this is added a solution of cyanide of potassium of good quality say 90% to 95%
until a clear fluid is formed, this solution can be worked either hot or cold.
An anode of phosphor metallic cadmium, with mild electric current. Or again
A depositing bath for plating or coating with phosphor antimony we can proceed
as follows
1 oz. phosphor metallic antimony is converted into chloride by known means to
this we add 8 ozs. of ammonium chloride dissolved in 1 gallon of water, this solution
is preferably used cold an anode of phosphor metallic antimony being used and a
mild electric current. Or again
A depositing bath for plating or coating with phosphor bismuth we can proceed
as follows
1 oz. phosphor metallic bismuth is converted into chloride by known means to
this we add 8 ozs. of ammonium chloride dissolved in 1 gallon of water, this solution
is preferably used cold.
An anode of phosphor metallic bismuth being used, and a mild electric current.
Or again
A depositing bath for plating or coating with phosphor tin we can proceed as
follows
1 oz. phosphor metallic tin is converted into chloride by known means to this we
add 4 ozs. of soda hydrate dissolved in 40 fluid ozs. of water, afterwards we add
8 ozs. of pyro phosphate of soda dissolved in 40 fluid ozs. of water, when water is
added to make 1 gallon of solution this solution with mild electric current can be
used either hot or cold..
An anode of phosphor metallic tin being used.
Or we may use baths prepared electrolytically by passing the electric current
through any suitable solution from a phosphor metal or alloy anode to form the
working electrolyte. As an example we can make an electrolyte of cyanide of
potassium and water and force into the said electrolyte phosphor gold from an anode.
formed of phosphor metallic gold, or again we can make an electrolyte of acidulated
sulphate of copper and water and force into said electrolyte phosphor metallic
copper from an anode formed of phosphor metallic copper. Or again
We can make an electrolyte of chloride of ammonium and water and force into
said electrolyte phosphor iron from an anode formed of phosphor metallic iron. Or
again
We can make an electrolyte formed by adding finely pulverized litharge dissolved
in soda hydrate and water, and force into said electrolyte phosphor metallic lead
from an anode formed of phosphor metallic lead.
Thus showing that the electrolytes may be prepared wholly or in part by
electrolysis. Or again
We
e may form our electrolyte by the following process or processes, an electrolyte
may be formed of the salts of one or more metals and the anode electrode consist of
another metal or metals.
Thus forming an electrolytic bath suitable for depositing alloy metals, as an
example.
By using a suitable phosphor metallic copper electrolyte we may employ a
phosphor tin anode.
Or we may use a suitable phosphor metallic tin electrolyte using a phosphor
copper electrode, the result being in both cases the deposit of a phosphor bronze.
Or again
A suitable electrolyte may be formed with salts of phosphor metallic platinum
and by our using a phosphor metallic tin anode we obtain a phosphor tin platinum
alloy deposit. Or again
We may only employ phosphorus in forming our electrolytic or depositing bath,

page_text: using ordinary metal anodes i.e. metal anodes having no percentage of phosphorus
in their composition. Or again
We may only empley phosphorus in forming our anode electrodes using a salt or
salts of ordinary metal or metals i.e. metallic salts having no percentage of
phosphorus in their composition.
And from the above typical examples it will be readily seen that we may use
any one of our electrolytes or our anodes in the above described form.
We wish it understood that we do not limit ourselves to any specific proportions
of the metals or chemicals used, as such proportions may be varied according to the
purpose for which the metallic deposit is required without departing from the
nature of our invention.
Having now particularly described and ascertained the nature of our said inveu-
tion and in what manner the same is to be performed we declare that what we
claim is
The method of depositing by electrolysis metals or alloy of metals such as
platinum, iridium, palladium, ruthenium, and the like heavy metals, copper, tin,
gold, silver, zinc, cadmim, nickel, cobalt, iron, lead, bismuth, antimony either
separatly or alloyed associated with phosphorus upon metals or alloy of metals or
other suitable materials substantially as described.
GEORGE ARTHUR WEBB.
WILLIAM ARTHUR THOMS