close

Вход

Забыли?

вход по аккаунту

?

код для вставки
Patented Nov. 5, 1,945
2,410,717
vireo STATES. PATNT
2,410,717
-
oFFicEi '
'
METALLIC COMPOUNDS ADAPTED TO FORM
AN ELECTRICAL CONTACT
Irvin W. Cox, West Allis, Wis, assignor to-Cutler
Hammer, Inc., Milwaukee, Wis, a corporation
of Delaware.
WNo Drawing. Application October '10,. 1942,.
Serial No. 461,601
7: Claims.
1
(01. ‘75-05)
2
This invention relates to improvements in me
molybdenum and tungsten by the use of hydro
tallic compounds. The invention also relates to
gen‘, hydrocarbon, or carbonaceous gases; and-‘the
bodies- consisting of said metallic compounds.
invention also contemplates the controlled re
Although the compounds herein contemplated are
duction by such agents of mixture of the afore-»
adaptable for various uses, they are particularly 5 mentioned poly metallic salts.
advantageous for use in the formation of elec
An object of the invention is to provide. metaltrical switch contacts and the like.
110 compounds having most. of the desirable
Although, as will appear, my invention is use
characteristics of alloys.
‘
.
ful in- the formationof many different metallic
Another object is to provide for alloy char-~
compositions,-it is- particularly useful and ad
vantageous in the formation of metallic com
acteristics in metallic compounds the ingredients
of which are unalloyable in the ordinary sense. v
pounds,‘ having‘alloy characteristics, by the~use
Another and more speci?c object is to provide
of metals or elements which will not alloy in the
improved; metallic compounds adaptable for use
ordinary manner. For‘exam-ple, I refer to a com
in the production of electrical ‘switch contacts‘..
pound‘- of silver and molybdenum, from‘ which in 15
Another object is to provide electrical switch:
gredients' an alloy, in the ordinary sense, cannot‘
contacts and. the like of novel‘ composition.
be produced. In- accordance with my‘ invention,
however, such non-alloy-able- ingredients may be
Other objects and advantages of they invention
will hereinafter appear. ‘
compounded in'a manner to obtain substantially
all of the desirable characteristics of an alloy;
such as homogeneity of the mixture of the ingre
dients, proper proportionality thereof, required
hardness and electrical characteristics; etc.
Moreover, in accordance‘ with my invention the
aforementioned desirable results are attained by
treatment of the ingredients of the compound in
a relatively simple and inexpensive manner.
I will herein describe the method of‘ producing
-
One example of the method. herein contem
plated is as follows: To a hot saturated solution
of para ammonium molybdate is added. a hot. so‘
lution of dilute silver nitrate, with‘ resulting
> formation of a ?ne yellow precipitate. Such pre
25
cipitate is freed of ammonium nitrate in a Well
known manner, then dried, and then reduced in a.
current or flow of dry hydrogen in steps ;. say, for
about ?fteen minutes at 400 degrees EL, then. for
about ?fteen minutes at 800 degrees F., after
oneiof the desired compounds of silver and mo
which the temperature isgradually raised to about
lybdenum; but it is to- be understood that the 30 1600 degrees F., at which temperature the re
method or technique herein’ disclosed is likewise
duction appears to be complete. The product of
applicable to- the production of other similar
such reduction is an extremely fine grained sil-_
compounds of silver and molybdenum, and to a
very powder: of constant or homogeneous com
series of compounds of silver and tungsten, silver
position, in the sense that the‘ ?nest particles
and: cobalt; as well as to‘ a series of compounds of:v 35 thereof contain the same proportions of silver and
Nickel and tungsten, .
molybdenum as the coarsest.
Nickel and molybdenum,
Cobalt and tungsten,
in the manner just described showed a silver
Powder produced‘
content of 49.2 per cent by weight.
.
From the foregoing it‘. is obvious that the yel'40 low silver molybdate; (precipitate) was the para.
bide from cobalt tungsten cyanide),
salt corresponding to silver para ammonium
Cobalt, tungsten and chromium (stellite, from
molybdate, or AgsMoqO24(H2O)1X, and that the
‘cobalt chromate and cobalt tungsten. chro
reduced powder is the equivalent of silver molyb
mate),
'
dide, of the formula AgGMO'I.
Cobalt and molybdenum,
Cobalt,‘tungsten and carbon (cobalt tungsten car
Copper and tungsten,
Copper and molybdenum,
Iron and tungsten,
Iron and molybdenum,
45
‘When such reduced powder is molded or com-'
pressed into suitable form for use as electrical
contacts, a polished and etched specimen shows,
under a microscope, an extremely ?ne structure; in
Manganese andtungsten,
which silver and molybdenum are not distinguish
After the molded‘
contacts have been annealed: at a temperature of
and, in general,_ to suchv and other compounds
1200 degrees F. they have a hardness of- about 75:
containing atoms of. two or more metals in each.
Rockwell B., but by aging the same for several
molecule. The method comprises essentially the
hours at 600 degrees F. the hardness thereof: is
controlled reduction of well de?ned poly metallic 55 increased to about 97 R. B. This hardening is, to
salts, such as those of the acids of chromium,
a’ large. extent. atleast, a» strain hardening pro-w
Manganese and molybdenum.
'50 able as- separate components.
2,410,717
3
4
duced by the tendency toward precipitation of
der consisting of a homogeneous composition of
silver and molybdenum wherein the ?nest par
the silver from the silver molybdide of which the
contact is composed.
The fact that the material produced in accord
ticles thereof contain the same proportions of
silver and molybdenum as the coarsest, whereby
an inherently ?ne and substantially perfect dis
tribution of the molybdenum lattice is insured in
the molded contact, said powder having a com
ance with my invention is a new and different
constitution of matter has been demonstrated by
a comparison of a micro-photograph of such ma
terial with a similar micro-photograph of a sine "jposition which is the equivalent of silver molyb
dide of the formula AgsMow, said powder having
tered contact material made in the usual way
from substantially the same percentage content 10 a silver content of 49.2 per cent by weight.
3. As an article of manufacture, a pressure
of the ingredients silver and molybdenum (name
molded electrical contact consisting of a homo
ly, by ‘mixing silver powder with molybdenum
geneous powder composition of silver and molyb
powder, and pressing and sintering the mixture).
denum wherein the ?nest particles thereof con
The following is a partial list of the various sil
ver salts of molybdenum and tungsten acids--the 15 tain the same proportions of silver and molyb
denum as the coarsest, whereby an inherently
water of crystallization being omitted from the
?ne and substantially perfect distribution of the
formulae-—-and the ?nal column showing the re-V
molybdenum lattice in the contact is insured,
spective molybdides and tungstides:
said powder composition being the equivalent of
Silver molybdides
silver molybdide of the formula AgsMow.‘
Silver
Silver
Silver
Silver
Silver
molybdate, Ag2MOO4 ___________ __
dimolybdate, Ag2MO2O7 ________ __
trimolybdate, Ag2M03010 _______ __
tetramolybdate, AgzMoioia; ____ __
octamolybdate, AgzMOsOzs _____ __
AgzMo
AgzMoz
AgzMos
Ag2Mo4
AgzMOa
4. As an article of manufacture, a pressure
molded electrical contact consisting of a homo
geneous powder composition of silver and molyb- ‘
denum wherein the ?nest particles thereof con
tain the same proportions of silver and molyb
denum as the coarsest, whereby an inherently ?ne
and substantially perfect distribution of the mo
lybdenum lattice in the contact is insured, said
Silver paramolybdate, AgsM07024_______ AgsMOv
Silver
Silver
Silver
Silver
Silver
tungstate, AgzWOi ____________ __
Ag2W
ditungstate, Ag2W2O'z __________ _.AgzWz
tritungstate, AgzWaOm ________ __
AgzWs
tetratungstate, Ag2W4O13 ______ __
Ag2W4
paratungstate, Ag10W12041 _____ __ AgioWiz
The compounds of silver and molybdenum, silver
and tungsten, and silver and cobalt produced in
accordance with my invention are especially adapt
. ed for the production of electrica1 contacts or con
powder composition being the equivalent of sil
ver molybdide of the formula AgeMo'z, and the
silver content of said contact being 49.2 per cent
by weight.
5. As an article of manufacture, a pressure
molded electrical contact consisting of a. homo
35 geneous powder composition of silver and molyb
tact tips, inasmuch as the inherently ?ne and sub
stantially perfect (molecular) distribution of the
refractory metal lattice, molybdenum, tungsten or
denum wherein the ?nest particles thereof con
tain the same proportions of silver and molyb
crease in the contact resistance. Also, the afore
content of said contact being 49.2 per cent by
weight, and said contact when annealed at a
denum as the coarsest, whereby an inherently ?ne
and substantially perfect distribution of the mo
cobalt) enables its most efficient use; so that for
a given hardness and are resisting capactiy a 40 lybdenum lattice in the contact is insured, said
powder composition being the equivalent of sil
greater percentage of silver can be used than has
ver molybdide of the formula AgsMov, the silver
heretofore been possible, with a consequent de
mentioned precipitation hardening which pro;
duces a strain in the silver enhances the conduc
. temperature of 1200 degrees F. having a hard
ness of about 75 Rockwell B.
6. As an article of manufacture, a pressure
molded electrical contact consisting of a homo
tivity of the latter.
After producing any one of the powders (mo
lybdides, tungstides or chromides) in the man
ner herein disclosed I may add thereto and inti
mately mix therewith a powder of the particular
soft metal constituent thereof (such as silver,
copper, nickel, cobalt, iron or manganese) to in
crease the percentage quantity of such softer
metal in the ?nal molded article. ‘It is, of course,
preferable to employ a powder obtained by the
aforedescribed reducing operation which approXi-J
mates as closely as possible the desired percent
ages of the metallic ingredients in the final pres
sure molded and heat treated article.
"
I claim:
'
1. As an article of manufacture, a powder
adapted for molding under pressure into suitable
form for use as an electrical contact, said‘pow
der consisting of a homogeneous composition of
silver and molybdenum wherein the ?nest particles
thereof contain the same proportions of silver
and molybdenum as the coarsest, whereby an in
herently ?ne and substantially perfect distribw'
tion of the molybdenum lattice is insured in the
molded contact, said powder having a composi
tion which is the equivalent of silver molybdide of
the formula AgsMO'I.
geneous powder composition of silver and molyb
denum wherein the ?nest particles thereof con
tain the same proportions of silver and molyb
denum as the coarsest, whereby an inherently ?ne
and substantially perfect distribution of the mo
lybdenum lattice in the contact is insured, said
in in- powder composition being the equivalent of sil
ver molybdide of the formula AgeMov, the silver
content of said contact being 49.2 per cent by
weight, said contact when annealed at a tem
perature of 1200 degrees F. having a hardness of
about '75 Rockwell B., and said contact when
aged for several hours at 600 degrees F. having
a hardness of about 97 Rockwell B.
7. As an article of manufacture, a pressure
molded electrical contact consisting of a homo
geneous powder composition of silver and molyb
denum wherein the ?nest particles thereof. con
tain the same proportions of silver and molyb
denum as the coarsest, whereby an inherently ?ne
and substantially perfect distribution of the mo
70 lybdenum lattice in the contact is insured, so
‘
2. As an article of manufacture, a powder
adapted for molding under pressureinto suitable ' '
form for use as an electrical contact, said pow-> 75
that for a given hardness and are resisting ca
pacity an extremely high percentage of silver may
beutilized.
‘
'
'
'IRVIN w. ooxd
‘
Документ
Категория
Без категории
Просмотров
0
Размер файла
336 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа