The Carbon County news., 1931-08-13
Hard Copper is
NeU Product of
State Scientists

Considerable interest in this and
other countries has been stirred
by experiments that have been
conducted at the Montana School
of Mines. A new hardenable var
iety of copper has been produced
that will add to the versatility of
copper as an industrial metal and
increase its consumption.
The metallurgieal phenomenon
was announced by DR.. Curtis L.
Wilson, professor of metallurgy at
the School of Mines. Its pro-
duction, he says, unlike many
secret processes alleged to be
rediscoveries of the so-ealled lost
art of tempering copper. is based
upon sound scientific principles.
1t was observed by NJ. G. Gorson
in 1926, and the results of our in
vestigations were first presented
before the Montana section of the
American Institute of Mining and
Metallurgical Engineers in May
DR.. Wilson, in an article written
for the Mining Journal of July 15,
describes some of the physical
properties of the metal:
Its tensile strength in the solid
solution state, Immediately after
quenching, is around 10000 pounds
per So. in, while after annealing
and the precipitation of the nickel
silicide it is increased to $4,000
pounds per SO. in., almost twice
as strong as structural steel.
The ease with which the new
alloy may be worked in its solid
solution state, together with tie
possibility of hardening and
strengthening it after it has been
properly shaped, makes copper an
even more useful metal than it
now is. In transmission lines, in
the engraving industry, in pipe
and in castings, the property of
improvability is a valuable one.
pure copper is the best con-
ductor of electricity known, with
the one exception of silver which
conducts just a little better than
copper but is too scarce and ex-
pensive to serve the purpose. For
trolley wires and other transmits
sion lines another property besides
electrical conductivity is neces-
sary; namely, strength, for the
wire must support the weight of
considerable lengths of itself and
must likewise withstand wind
pressure and the weight of ice
and snow which may cling to it.
Some conducting power must
therefore be sacrificed for addi-
tional strength.
"The new hardenable copper in
its solid solution state, has, like
all solid solutions, low conduc-
tivity. The annealing process in
creases this conductivity by caus-
ing the nickel silicide to precipi-
tate. and at the same time in
creases its strength considerably
over that of any material now
used for transmission lines. The
maximum conductivity attained in
our Investigations was 70 percent
of that of pure copper, and it is
expected that more nearly COM
plete precipitation Of the nickel
silicide from solution will raise
this to higher figure.
"Another possibility is in the
manufacture of castings. Pure
copper does not cast as we'll as
brass or bronze. The addition of
small amount of nickel silicide
to it makes the molten copper
copper quite fluid, so that it fills
the entire space of even the most
intricate molds. On solidification
the resulting castings are sharp
and beautiful in outline. Further
more, by simple heat treatment
they can be made hard and strong
without becoming brittle. This
means that the castings need no
longer be made thick and clumsy.
THE new metal machines we'll,
too, great deal better than ordin-
ary copper and as we'll if not better
than the finest brass. Corrosion
tests have not been made, but from
casual laboratory observations
throughout the year, it is believed
that the new hardened copper
withstands corrosion as we'll as
copper and its alloys.
DIR. Francis A. Thompson, pres
ident of the Montana School OF
Mines, to whose encouragement
the results of these Investigations
are in large measure due, has
given the assurance that facilities
will be provided for further study
of the precipitation hardening of
copper. The field is new one
in the metallurgy of copper, and
its development will do much to
augment the process of engineer
ing"