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Patented Sept. 24, 1946
2,407,995
UNITED ' STATES PATENT“ OFFICE
2,407,995
, METHOD OF PRODUCING FILLETS‘
Harris r. Moyer, ‘Toledo, Ohio, assignor' to ‘The '
' Aviation Corporation, New York, N. Y., a ‘cor
poration of Delaware
No Drawing. ‘Application July 30, 1943,
Serial No. 496,779
5 Claims.
' The invention relates to alloys for producing
?llets and producing ?llets therewith.
Desiderata in ?llets produced in structures,
such as hollow‘ steel propeller blades, are: A
smooth or good meniscus on the ?llet and one
which will form slightly above the quench tem
perature of the propeller blade to prevent warp
age during the ?lleting operation; a tenacious or
efficient‘ bond‘ between the ?llet material and the
.
'
(Cl. 117-22)
2
the surfaces to be ?lleted are treatedwith a flux
composed of sodium borate and silicon dioxide.
The alloy in powder form or in the form of a wire
is placed in the corners to be ?lleted in any suit
able manner as well understood in the art. This
copper manganese alloy has a melting point rang
ing from 1760° to 1780° F.
The blade is then
heated to a temperature su?icient to‘ melt the
?llet material and form the ?llet in the corners
blade which will not rupture or loosen when the 10 where the alloy has been placed. During the
blade is subjected to working stresses; avoidance
melting of the ?llet material, the chamber in the
of an interface action between the ?llet material
and the steel after aging; avoidance of any ap
blade which contains the alloy is subjected to a
preciable affect upon the ?llet’ material during
subsequent heat treating operations or processing
of the blade, and the avoidance of brittleness in
‘the ?llet which, so far as is known tome, have
not been completely achieved with ?lleting mate
approximately 10% H2, 10% CO, and 801% N2.
This reducing atmosphere is maintained in the
rials heretofore used.
.
reducing atmosphere, such as a gas composed of
chamber in the blade during the formation of the
?llet, usually by means of a tube or conduit which
extends through the open shank and terminates
adjacent the tip of the blade. A constant ?ow
One object of the invention is to provide an 20 of this gas is maintained in said chamber so that
alloy for use in producing ?llets which results in
a very slight increased pressure of the reducing
a smooth or good meniscus on the ?llet; which
gas is maintained. A gas pilot flame is‘ main
produces a tenacious bond with the steel which
tained adjacent the end of the tube, to burn the
will not rupture or become loose when the blade
reducing gas escaping from the chamber in the
is subjected to working stresses; which‘ will not . blade and prevent the entrance of oxygen into
produce interface reaction with the steel when
the inside of the blade while the ?llet is being
the ?llet material is aged; and which has a melt
ing temperature suf?-ciently higher than that used
In producing the ?llet, it is highly desirable
in heat treating or quenching" the blade after it
that a good reducing atmosphere should be main
‘has been ?lleted so that the ?llet will not be
tained to prevent contamination of the alloy by
appreciably affected by heating and quenching
oxidation‘. The extreme activity 'of the manga
the blade.
nese in the alloy makes it necessary to prevent
A ?lleting alloy of substantially 85% copper
any oxygen from coming in contact‘ with the ma
and 15% manganese has been found to achieve
terial, which would result in oxidation and de
the desired results in a steel propeller and the
terioration cf the elfectiveness of the material.
?llet has been found to achieve unexpected re
This alloy does not develop any brittleness in the
sults, after the blade ‘has been heat treated or
?llet.
quenched and cooled,‘by maintaining its bond
In processing hollow steel propeller blades after
with the steel without rupture in destructive tests
the blade has been ?lleted, the blades are heat
in which the steel was subjected to rupture.
40 treated and quenched and drawn to harden the
Another object of the invention is to provide
steel to increase its resistance to fatigue and
an improved method of producing ?llets with the
abrasion. The quenching is done while the blade
alloy.
is approximately at 1550° F. and the blades are
Other objects of the invention will appear from
drawn at approximately 1000° F., and as a result
the detailed description.
45 the temperatures to which the blade is subjected
The invention consists in the several novel fea
after ?lleting do not melt or unfavorably affect
tures which are hereinafter set forth and more
the previously formed ?llet. For that purpose,
particularly de?ned by claims at the conclusion
the melting point of the alloy should be from 100°
hereof.
to 150° F. above the quenching temperature.
The preferred ?lleting material of the inven
This alloy and the temperature to which it is
tion consists of an alloy of substantially 85%
subjected during ?lleting result in a smooth and
copper and 15% manganese. In producing ?llets
good meniscus on the ?llet. This alloy, with its
in a, structure, for example, the inside corners of
suitable melting point, produces high tensile
the leading and. trailing edges of a hollow steel
strength in the ?llet with a minimum of distor
propeller blade of airfoil contour, with this alloy, 55 tion of the blade. This alloy also results in a
formed.
'
.
2,407,995
tenacious bond between the ?llet and the steel.
' The use of a flux containing sodium borate and
silicon dioxide has been found to be important
in achieving these desired results with the cop
per-manganese alloy.
The use of common so
dium borate and boric acid flux has been found
to yieldporous and inferior melts. The alloy has
a good capillary'action and does not become brit
tle during the formation of the ?llet or the proc
essing of the blade. There is no harmful inter
face action between the ?llet metal and the steel
after aging. Unexpected results from destructive
tests have indicated that the ?llet retains its bond
to the steel and will not rupture when the steel
4
claim as new and desire to secure by letters Pat
ent is:
1. That improvement in forming a ?llet in an
element of ferrous metal, which comprises: ap
GI plying a suitable ?ux and an alloy containing
from 82 to 90% copper, 10 to 18% manganese and
having a melting point substantially over 1550° F.
to the surface to be ?lleted, and melting the alloy
on said surface in a constantly maintained re
10 ducing atmosphere to prevent oxidation and in
such manner that said alloy will become alloyed
with the ferrous metal and form the ?llet.
2. That improvement in forming a ?llet in an
element of ferrous metal, which comprises: ap
15 plying a flux containing sodium borate and sili-v
> is subjected to rupture.
con dioxide and an alloy containing from 82 to
The alloy composed of 15% manganese and
V 85% copper has been found to achieve the afore- _ 90% copper and‘ 10 to 18% manganese and hav
- ing a melting point substantially over 1550° F. to
said desired characteristics. The alloy, if the
the'surface to be ?lleted, and melting the alloy
manganese content is increased substantially
above 15%, has a binary or two-phase character 20 on said surfaces in a constantly maintained re
ducing atmosphere to prevent oxidation and in '
istic which it is believed should be avoided. A
such manner that said alloy will become alloyed
substantial increase of the copper content over
with the ferrous metal and form the ?llet.
85% raises the melting temperature and lowers
3. That improvement in forming a ?llet in an
the tensile strength of the ?llet. The alloy of
-85% copper and 15% manganese has been found 25 element of ferrous metal, which comprises: ap
plying a ?ux containing sodium borate and sili
to be the optimum and to produce the most e?i
con dioxide and an alloy containing substantial
cient and desirable results. These results can, to
ly 85% copper and 15% manganese and having a.
some degree, be attained by an alloy consisting
melting point substantially over 1550° vF‘. to the
of 82 to 90% copper and 18 to 10% manganese.
It has also been found that the addition of 5% 30 surface to be ?lleted, and melting the alloy on
said surface in a constantly maintained reducing
nickel to the copper-manganese alloy may be
atmosphere to prevent oxidation and in such
bene?cial in some instances, but on account of
manner that said alloy wil1 become alloyed with
being a critical metal, it is not deemed prefer
the ferrous metal and form the ?llet.
able.
4. That improvement in forming a ?llet in an
The invention exempli?es an alloy: for pro 35
element of ferrous metal, which comprises: ap
ducing ?llets with a flux composed of sodium bo
plying a flux and an alloy containing from 82 to
rate and silicon oxide; and which has a suitable
90% copper and 10 to 18% manganese and hav
melting range and capillary action; which has no
ing a melting point substantially over 1550° F.’ to
appreciable per cent of silicon which results in
the surface to be ?lleted, melting the, alloy on said
brittleness; which produces good menisci; which
surface in a'constantly maintained reducing at
forms a tenacious bond with the steel; which has
mosphere to prevent oxidation and in such man
a high tensile strength, and has no interfacere
nel‘ that said alloy will become alloyed with the
action with the steel from aging or produced by
ferrous metal and form the ?llet, and quenching
subsequent heating operations on the blade at a
temperature lower than the melting point of the 45 the ?lleted element without melting the ?llet.
5. That improvement in forming a ?llet in an
alloy. These characteristics are particularly ad
element of ferrous metal, which comprises: ap
vantageous in ?lleting hollow steel propeller
plying a suitable ?ux and an alloy containing
blades. While the alloy is adapted for ?lleting
from 82 to 90% copper, 10 to 18% manganese,
in propeller blades, it is to be understood that it
may also be used for ?llets used for joining parts 50 and not over 5% of nickel, and having a melting
point substantially over 1550° F. tothe surface to
together on account of its great tensile strength
be ?lleted, and melting the alloy on said surface
and its tenacious bonding properties.
'
in a constantly maintained reducing atmosphere
The invention is not to be understood as re
to prevent oxidation and in such manner that
stricted to the details set forth, since these may
be modi?ed within the scope of the appended 55 said alloy will become alloyed with the ferrous
metal and form the ?llet.
claims without departing from the spirit and
scope of the invention.
Having thus described the invention, what I
HARRIS P. MOYER. _
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