Ellsworth American. [volume] (Ellsworth, Me.) 1855-current, 1916-04-05
SUBSTITUTE FOR rLArINrr
successful Experiments with Mo,u.
denun and Tungsten ALLOW.

where the worlds greatest deposi,
molybdenum is located. Is soon d..,;.-,
to come into it's own. Rece Mt succs..,.,
experiments with MOL bdepum -.
tungsten alloy as q substitute for MA.
mum, have directed the eyes OF mat,
lurgists to the GATHERINGS hill denosi,.
and prospectors are hungrily looking tor
larger deposits OF tungsten.
A discovery that is vastly more ir,ro,,
ant than it seems on the surface, saws ~.
New York Worlds Magazine, was an
nouced at the meeting of the Amsrlc.,
Institute Of Mining Engineers in No,,
York recently by DIR. Frank Alfred Fab.
renwaid, of the Case School of Applied
Science. Cleveland, Ohio. This w..
nothing less that substitute for Mat
mum.
To appreciate fully how far-reacbino q.
this discovery one has but to copsids.
that platinum Is now more than ,o,,
times as costly as gold. 1t was ouotsa
early in March at fSs an ounce. but i, VIM
tried to buy an ounce you would probsblv
have to pay more. Platinum is so indi..
pensabie that the British ministry n,
munition recently ordered return of all
stocks OF it, its ores and residues. and
forbade any trading in these.
Large quantities OF platinum are used in
jewelry, though It 10 not nearly so sui,sble
as gold or silver for this purpose. uutD
recently in incandescent lamps the wire
passing through the thick glass neck Of
he bulb was almost universally platinum.
for the reason that NO other known mental
expanded and contracted as did glass.
But more than one-third OF ali the plat.
mum IL used by dentists and, in the nature
Of the case, irrevocably lost. Platinum is
also used in spark plugs and in many
other kinds OF electrical apparatus. In
metallurRy and chemistry 1t Is invaluable
for crucibies, because its melting point is
1850 degrees centigrade, almost 100 degree.
higher than gold. It Is unaffected by mos,
acids, and 10 easily drawn into fine wire or
thin foil.
A substitute for platinum has now been
found in alloys OF tungsten and molybce-
h0Ihs AbSr9 as0t8As hotu VI COuEse long
been known and used. But 4, has not
hitherto been known how they could b.
made resistant to oxidation.
In the department Of mining and met.
allurgy 1t the Case School OF Applied
Science and In the department OF chemical
engineering 1t the University OF Michigan,
DR.. Fahrsnwald conducted the expert
ments that led to the solution OF this
problem. Tungsten and molly bdenum
possess many characteristics in common.
The former melts at about 3,oD degrees
e., the latter At $500 degrees c. They are
practically insoluble in any OF the COM
mon acids, their tensile strength exceeds
that OF steel, they can be drawn to finer
threads than any other metals, and their
specific gravity 10 70 per cent. greater than
lead. In recent years tungsten has been
replacing platinum in the automobile in
dustry. Their co-efiicient OF expansion
is 50 per cent. lower than that OF pis,i-
mum.
The serious objections to them were that
they oxidizcd easily ct red heat and that
they would not readily solder with gold
and its alloys. Moreover, the larger wires
were quite brittle.
DIR. Fshrcnwaid discovered that lungs
ten and molly bdenum emerged from .
bath OF molten gold with q beautiful i'm.
pervious coating. This removed the OBJ
lection about corroding. but the metal
was still q brittle ~ glass. so he set to
work to discover how TO overcome this.
DIR. Fahr~nwaid tested at various tenn
rerstures and under various high pres
sures many combinations OF tungsten,
gold, molly bdenum and palladium. He
devised an electric furnace that gave him
5000 degrees Z. Temperature. He made
tiny briquets OF these blends by submit
ting finely divided powder to q pressure
OF moro than 30, 900 pounds to the square
inch while heated by an electric current.
He placed thess 10 the furnace and treated
them to temperatures ranging from 500 to
!, 800 degrees C.-the highest Temperature
ever used in treating . metai-for periods
OF from one minute to one hour, and ham
mered them while hot.
DR.. Fahrenwald summedlthe results OF
these experiments by saying: Except Id
two respects, pure ductile tungsten and,
to Lesser degree, molly bdenum, meet all
of the specifications Of . practical sub
stitute for platinum and its alloys. These
two defects are its ease Of oxidation and
the difficulty with which it can DO
Aoldered, and they have been overcome by
coating with . precious metal or alloy
the resulting material being in many ways
far superior to platinum or its alloys"
Tungsten and molly bdenum are not
nearly 50 expensive as platinum. Inc
former was quoted in December at s3,uo
a ton for 90 per cent. ore. 1t is now even
higher. Molly bdenum ore, which was
f750 ton before the war, was quoted IN
February at $500. These metals are
necessary to the maxim. OF high speed
tool steel, as they prevent it from losing
its temper even when red hot. They arc
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