Process for Alloying the Surfaces of Metal Wires, Strips, Plates, . Sheets, and the like.
Year: 1892

page_text: Date of Application, 20th Aug., 1892-Accepted, 24th Sept., 1892
COMPLETE SPECIFICATION.
Process for Alloying the Surfaces of Metal Wires, Strips, Plates, .
Sheets, and the like.
I, EDOUARD MARTIN, of 13 Rue des Petits Ecuries, Paris, France, Metallurgist,
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 whereby ingots, wire, rods, plates, sheets and
bands composed of one or more metals have formed on their surfaces an alloy
that penetrates more or less into the metal and alters the same as regards its
outward appearance, colour and other properties, imparting thereto the appearance
or property of another metal or alloy.
Thus for example there may be produced in the above manner on the surface
of copper, and in particular of the so called "bimetal" (or steel core with copper
coating) a bronze or brass like formation which penetrates more or less into the
body and imparts to the outer surface of the metal the colour and properties of
bronze or brass.
The main principle of this process consists in coating the metal used (either by
electro deposit or by mechanical means) with a thin adhesive layer of another
metal, which is put, by heating, into a condition for forming an alloy with the
metal underneath it.
For producing this result, an ingot, wire, rod, plate, sheet or band of "bimetal "
or other metal is taken of any desired thickness or diameter, and is carefully
brushed and cleaned, and is then scaled. The object is then immersed completely
in a chloride of zinc solution, or other pickle, which facilitates the galvanizing
(zincing) process, after which it is placed in a bath of molten zinc in such manner
as to obtain a very uniform coating of zinc on the surface, the thickness of which
is regulated by the duration of immersion in the bath or by repeated immersion.
After the bath the prepared metal is slowly heated under exclusion of air in a
heating furnace, in order to produce the alloying of the zinc and copper.
A chemical reaction then sets up, and the zinc which was previously only a
coating combines with the copper which surrounds the steel, such combination
taking place to a greater or less depth according to the quantity of the metal
applied, and causing the surface to be converted into brass.
In the same way a bronze covering would be produced if in place of the zinc,
tin were employed in the above operations, or any other alloy according to the
different proportions of tin and zinc used.
After the metal object thus operated upon has been removed from the furnace, it
is again scaled and is brought to the desired thickness or diameter either:
or
1, By rolling in a heated condition, when ingots or sheet metal are being treated,
2, By drawing or fine-drawing in a cold state when wire is being treated.
According to the kind and proportions of metals used, the object will then have
the appearance of brass or bronze, and it will also have assumed both externally
and to a certain depth of its mass all the properties of such metals.
Up to the present time all alloys of bronze, brass and other kinds could only
be produced by direct combination of the component metals in a melting crucible,
for forming the entire mass of the object to be produced, while according to the
present invention there can be produced on the surface of the object, either entirely
or only in part, an alloy which imparts to the object a colour and external
properties which it does not naturally possess, and which do not interfere with its
economical and other properties as far as the internal part thereof is concerned.

page_text: Instead of immersing the ingot, wire, rod, plate, sheet, or band in a bath of
molten zinc, tin, or mixture of these metals, for forming a coating thereon which
will produce an alloy on the surface, the object can also be coated by the electro-
lytic process with a layer of greater or less thickness of such metals, the object
being then further treated as above described. .
In like manner the coating of brass or bronze on the surface can be produced
only on the one side or on one part of the surface in such manner that, after the
rolling or fine-drawing a product is obtained which has different colours and
.different properties on different sides or different parts of its surface.
With regard to the heating or reheating of the object after it has received the
coating of the metal for producing the alloy, the ingot, rod, or wire, can be drawn
slowly through a tube or muffle formed of fire brick, which is heated to the
requisite temperature for producing the alloy.
In the case of plates, sheet metal or bands, the object can be passed either
horizontally or vertically slowly through a furnace heated to the requisite degree
for producing the desired result.
Instead of immersing the ingot, rod, sheet, plate or band into a bath of tin or
zinc immediately after scaling, the object can be previously heated to a red heat
in such manner that the formation of the alloy to a greater or less depth is effected
at the time of immersing the object in the metal bath, such formation being
completed under the double influence of heat and of pressure by rolls while hot.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what 1
claim is :-
1. A process consisting in the production upon the surface of ingots, sheet metal,
plates, bands, rods, and wires composed of one or more metals, and in particular
on "bimetal" having a steel core and copper coating, an alloy, penetrating to a
greater or less depth, of brass or bronze which alters the metal object externally
both in its appearance and in its properties, and imparts thereto an appearance and
properties of another metal or alloy, the production of such alloy being effected
by coating the metal by mechanical or electrolytic means, upon the whole or upon
part of the surface or on one or more sides, with another metal in a thin adhering
layer, whereupon the two metals are subjected to the temperature necessary for
forming an alloy on the surface, the article being then brought to the required
thickness or diameter by rolling or drawing.
2. In the process referred to in the preceding claim, producing the said alloy on
the surface of the article by immersing the same in a bath of molten tin or zinc
or an alloy of these metals, after the article has been previously heated to a red
heat so that it will at once have formed on its surface an alloy penetrating more
or less deeply, whereupon the article is subjected to rolling in a heated condition
for completing the process.
Dated this 20th day of August 1892
ABEL & IMRAY,
Agents for the Applicant.