Evening star., 1952-06-20
New Alloy Is Developed
For Permanent Magnets
Naval Ordnance Scientists
Find New Coercive Force
By Thomos R. Henry

BY Thomos r. Henry
A new metallic alloy from which the
worlds most-permanent magnets can be
made has been developed by scientists Of
the Naval Ordnance Laboratory here.
This material, q mixture of bismuth
and manganese. has been found to have
the highest coercive force, or resistance
to demagnetization. of any known sub
stance-a force of 5000 oersteds COM
pared with $500 oersteds for its closest
rival.
It Is formed as q powder which can
be nodded into any shape desired. Its
properties are such that no particular
geometric form Is required-Such as a
bar or horseshoe, essential for most
other materials. Bits of the metal about
q centimeter square are being produced
for use in complex apparatus.
Permanent magnets are being used
more and more in present-day civiliza-
ton. They are necessary parts of loud
speakers. head phones. hearing aids and
radio detecting and measuring devices.
They also are essential for thermostats
and, in industry. for magnetic separa-
tors, magnetic chucks. and q host Of
other devices.
The new alloy, bismanol, was prepared
as part of search for magnetic
material not containing nickel or cobalt
and which could be compacted in the
form of fine particles to form permanent
magnets. It was selected because Of its
peculiar crystal structure.
Difficult Problem.
The material was the work Of
Edmond Adams and his co-workers.
William M. Hubbard and Albert M.
Syeles. A particularly difficult problem
was that of grinding it into fine powder
without changing its magnetic proper
ties through oxidation, and then COM
pacting it into the desired shapes.
Both bismuth and manganese are nom
magnetic, when alone. In preparation Of
the magnetic alloy powdered manganese
and powdered bismuth are mixed and
heated to about TOO degrees c. Then the
mixture is cooled to 400 degrees c and
aged at that temperature from to Is
hours. At this point the first crystals Of
the bimetallic compound begin to form.
The crystalline substance is known as
bitSmuthide. The whole Is ground to
powder again and the magnetic portions
separated from the non-magnetlc metals
by magnetic separator. The magnetic
portion then is hot-pressed at tempera-
ture of 300 degrees c in strong mag
netic field. The latter Is used to align
the particles along the direction Of easy
magnetism.
The new magnets have q powerful
pull, equal to that of the best materials
known in the past. The pull is approxi-
mately 100000 gauss-oersteds.
A rather grim picture Of some Of the
country's future health problems is
painted by Public Health Service Statis-
ticians.
1t is based on projection into the
future of the statistics from the last
comprehensive national health survey.
taking into account the increasing popu-
lation and the raising Of the average age
level
Here are some of the conclusions Of
DR.. G. st. J. Perrott, chief of the Divi-
sion of Public Health Methods, and his
associates:
The number Of disabling illnesses in
the United States lasting seven consecu-
tive days or longer will be Is to 80 per
cent higher in 1850 and 40 to so per cent
higher in 1875.
The number of cases Of heart-blood-
vessel-kidney diseases - the So-called
cardiovascular-renal complex, in the
population IS years old and above may
reach 100000 by 1875 compared to
100000 at present. OF the total about
100000 are expected to be disabled for
seven or more consecutive days in 1875,
about 2.5 times the present number.
Estimates on Disabilities.
This disease complex in the old-age
group alone by 1875 may result in an
annual total of $4,000 years of dis
ability, including 214,000 years in bed
and 1000 years in hospitals. An esti-
mated total of 100000 physicians calls
were made on older persons suffering
from this complex in 1885. The total may
reach 18,50O,00O by 1875.
On the basis of hospital beds used for
cardiovascular- renal conditions in 1885.
it is estimated that more than $4,000
such beds will be required by 1875.
Admittedly there may be scientific
advances which may profoundly alter
these figures. But, says DR.. Perrott, it
seems inescapable that the health status
of older people will require expanded
resources and an increasing proportion
of all medical, hospital and nursing
services will be concentrated on the
chronic diseases as result of the aging
Of the population.
BY 1875 the group 65 or over will
represent tenth or more of the total
population.
From the last statistics available the
period of disability from chronic illnesses
during the year was more than four
times as long for the old-age group as
for the average.
Disability from acute Illness accord
ing to the report, tends to level of at
about 20 years in frequency. prevalence
and average number of days of dis
ability per person. It rises sharply at
about so in the number Of days of dis
ability per case.