The Indianapolis times., 1933-09-02
-Dietz on Science
MORE ALLOYS,
CONSTANT CRY
OF INDUSTRY
More Than 5000 Mixtures
of Metals Now Are
in Use.
BY DAVID DIETZ
scripps-Howard Science Editor

from the fact that industry is con-
tinually crying for new alloys.
At the present time more than
5000 alloys. as mixtures Of metals
are known. are in use in industry.
If the layman is surprised that
5000 alloys are not enough, he will
be still more surprised when told
that variations in these 5000 alloys
are now possible which have the
result of really putting tens of thou
sands of kinds of materials at the
service of industry.
Has Many Properties
"An alloy may be so manufactured
and treated as to yield large num-
Der of properties" says DR.. Zay
Jeffries, consulting metallurgist of
the General Electric Company and
the Aluminium Company of Amer
ica. Suppose we consider a steel
with 0.2 per cent carbon as an ex-
ample. 1t may be melted and poured
into a mold and result in a steel
casting.
"The steel casting may be used as
cast or it may have its properties
changed in a number of ways by
heat treatment. Or the steel be
rolled hot and used for the struc-
tural members of buildings or
bridges, or for pipe.
"It may be rolled cold and used
for machinery parts such as Shaft
ing. It also may be drawn into
wire.
ANY of these operations is capa-
BILE of changing certain physical
properties throughout a consider
able range without changing the
chemical composition-that is, with
out changing the alloy.
Tens of Thousands available
So it is to a greater or lesser de-
gree with each of the 5000 different
alloys. Instead Of 5000 different
sets of properties, therefore. we have
tens of thousands"
1t is this richness of physical prop
critics of metals and alloys which
makes possible our modern indus
trial civilization, DR.. Jefries says.
1--WE need the low melting point
Of mercury or quicksilver, which is
40 degrees below zero, for thermom-
eterS, cages, etc, and the high melt
ing point of tungsten for lamp fila
ments,' he says.
1--WE need the softness of lead for
foil and the hardness of steel for
cutting tools. We need the mag
netism of iron and certain of it's
alloys, and we need other metallic
products which are nonmegnetic.
I'VE need aluminium and mag
neSium in part because they are
so light in weight
Conductor of Electricity
eve need copper because it is
such a fine conductor of electricity.
We need certain alloys because they
are poor conductors of electricity.
We need gold. platinum, nickel
and So-called noble" alloys because
they are so resistant to attack by
air, water and chemicals.
1--WE need tin because it makes
good bearing alloys. We need zinc
in part for galvanizing iron. And
so we could go indefinitely reciting
the outstanding characteristics of
the various metals and alloys.
I'm addition to great variation in
the main requirements of alloys, the
engineer desires different combina-
tions of properties for different uses.
These requirements conspire to pro-
mote the use of so many alloy COM
positions and treatments"
X-Ray Is Used
Scientists and research engineers
are pioneering in the search for
new alloys by the scientific study
of metals. FIighpowered micro
scopes and the X-ray are enabling
scientists to find out what is going
on within metals.
"The scientific study of metals
and alloys is most fascinating" DR..
Jeffries says. ITO the metallurigst
who examines metals with high
microscopes and even de-
termines the very positions of the
atoms by X-ray analysis, the in
terror of metal becomes an active
world, exhibiting Won
ders comparable to those which
we see about us.
"a piece of steel containing 0.9
per cent carbon is magnetic at
room temperature. When heated
above a red heat, say 1850 degrees
it becomes nonragnetic.
1.-THE carbon, which normally is in
the form of very hard compound
with iron at room temperature, is
completely dissolved in the iron at
the higher temperature, much like
salt dissolves in water, except the
iron is solid, not liquid"