U.S. patent application number 12/673424 was filed with the patent office on 2011-07-21 for method and device for producing a tubular solid body from a refractory tungsten heavy metal alloy, particularly as a semi-finished product for the production of a penetrator for a kinetic energy projectile with fragmentation effect.
This patent application is currently assigned to RHEINMETALL WAFFE MUNITION GMBH. Invention is credited to Klaus-Dieter Beister, Rene Oudelhoven, Michael Vagedes.
Application Number | 20110176951 12/673424 |
Document ID | / |
Family ID | 39800561 |
Filed Date | 2011-07-21 |
United States Patent
Application |
20110176951 |
Kind Code |
A1 |
Beister; Klaus-Dieter ; et
al. |
July 21, 2011 |
METHOD AND DEVICE FOR PRODUCING A TUBULAR SOLID BODY FROM A
REFRACTORY TUNGSTEN HEAVY METAL ALLOY, PARTICULARLY AS A
SEMI-FINISHED PRODUCT FOR THE PRODUCTION OF A PENETRATOR FOR A
KINETIC ENERGY PROJECTILE WITH FRAGMENTATION EFFECT
Abstract
The invention relates to a filler device (1) comprising an
exterior tube (2) having an extrusion die (3) located therein and a
filler piece (4) that is filled with a metal powder mixture in the
intermediate space (8) formed between the filler piece (4) and the
extrusion die (3), whereupon the intermediate space is closed. In
order to compact the metal powder, the filler device (1) is placed
in a hydrostatic pressing system and the metal powder mixture is
pressed into a green preform. The pressed tubes are subsequently
sintered in one or more passes through a furnace, for which purpose
the pressed tubes are subjected to a preselected time/temperature
progression so as to ensure that a melt of tungsten (W) forms and
contracts evenly in all directions so that a geometrically desired
solid body results after sintering.
Inventors: |
Beister; Klaus-Dieter;
(Eschede, DE) ; Oudelhoven; Rene; (Vaals, NL)
; Vagedes; Michael; (Hermannsburg, DE) |
Assignee: |
RHEINMETALL WAFFE MUNITION
GMBH
Unterluss
DE
|
Family ID: |
39800561 |
Appl. No.: |
12/673424 |
Filed: |
July 16, 2008 |
PCT Filed: |
July 16, 2008 |
PCT NO: |
PCT/EP2008/005800 |
371 Date: |
March 4, 2011 |
Current U.S.
Class: |
419/28 ; 141/390;
419/29; 419/41 |
Current CPC
Class: |
B22F 2999/00 20130101;
F42B 12/22 20130101; F42B 33/0242 20130101; C22C 1/045 20130101;
B22F 3/1035 20130101; B22F 2999/00 20130101; B22F 5/106 20130101;
B22F 3/24 20130101; B22F 2998/00 20130101; B22F 3/17 20130101; B22F
2003/248 20130101; B22F 3/24 20130101; B22F 3/004 20130101; B22F
2998/00 20130101 |
Class at
Publication: |
419/28 ; 419/41;
419/29; 141/390 |
International
Class: |
B22F 3/12 20060101
B22F003/12; B22F 1/00 20060101 B22F001/00; B22F 3/24 20060101
B22F003/24; B65B 1/04 20060101 B65B001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 9, 2007 |
DE |
10 2007 037 702.0 |
Claims
1. A method for producing a tubular solid body, particularly for
producing a penetrator for a kinetic energy projectile with
fragmentation effect, wherein the method includes the steps of: (a)
filling a filler device, wherein the filler device comprises an
outer tube provided with an extrusion die situated therein as well
as a filler piece, with a metal powder mixture in an intermediate
space formed between the filler piece and the extrusion die, and
then closing the extrusion die; (b) in order to compact the metal
powder mixture, placing the filler device (1) in a hydrostatic
pressing system and pressing the metal powder to produce a green
perform; and (c) subsequently sintering the pressed tubes in one or
more passes through a furnace, for which purpose the pressed tubes
are subjected to a preselected time/temperature progression so as
to ensure that a melt forms and contracts evenly in all directions,
so that after sintering a geometrically desired solid body
results.
2. A method according to claim 1, wherein, after sintering, the
solid body is subjected to a heat treatment, through which tensile
strength and elongation at break are adjusted.
3. A method according to claim 2, wherein, after the heat
treatment, the solid body is subjected to a forging process,
through which flow point and tensile strength increase.
4. A method according to claim 1, wherein the filler device is
filled with the metal powder mixture via a filler tube that is
placed on the filler piece and enables a filling between the filler
piece and the extrusion die.
5. A method according to claim 1, wherein the filler tube is
removed after filling of the filler device.
6. A method according to claim 1, wherein the intermediate space is
closed by a plug.
7. A method according to claim 1, wherein the metal powder mixture
comprises a tungsten heavy metal alloy with 80-98%, by weight,
tungsten and at least one second component selected from the group
consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Mo, and any combination
thereof.
8. A filler device for the production of a tubular solid body, in
particular, a penetrator for a kinetic energy projectile with
fragmentation effect, wherein the filler device comprises: (a) an
outer tube in which an extrusion die and a filler piece are
attached concentrically; and (b) a filler tube placed on the filler
piece for filling an intermediate space, formed between the
extrusion die and the filler piece, with a metal powder
mixture.
9. A filler device according to claim 8, wherein the outer tube is
a steel tube and the extrusion die is a polyurethane tube.
10. A method according to claim 2, wherein the filler device is
filled with the metal powder mixture via a filler tube that is
placed on the filler piece and enables a filling between the filler
piece and the extrusion die.
11. A method according to claim 3, wherein the filler device is
filled with the metal powder mixture via a filler tube that is
placed on the filler piece and enables a filling between the filler
piece and the extrusion die.
12. A method according to claim 2, wherein the filler tube is
removed after filling of the filler device.
13. A method according to claim 3, wherein the filler tube is
removed after filling of the filler device.
14. A method according to claim 4, wherein the filler tube is
removed after filling of the filler device.
15. A method according to claim 10, wherein the filler tube is
removed after filling of the filler device.
16. A method according to claim 11, wherein the filler tube is
removed after filling of the filler device.
Description
[0001] This is a National Phase Application in the United States of
International Patent Application No. PCT/EP2008/005800 filed Jul.
16, 2008, which claims priority on German Patent Application No. DE
10 2007 037 702.0, filed Aug. 9, 2007. The entire disclosures of
the above patent applications are hereby incorporated by
reference.
FIELD OF THE INVENTION
[0002] The invention relates to a method and a device for producing
a tubular solid body from a refractory tungsten heavy metal alloy,
particularly, as a semi-finished product for the production of a
penetrator for a kinetic energy projectile with fragmentation
effect.
BACKGROUND OF THE INVENTION
[0003] Kinetic energy projectiles with a solid penetrator of WSM
(tungsten heavy metal) are known. These so-called kinetic energy
penetrators are optimized to a maximum penetration depth in armored
targets and serve to combat enemy battle tanks.
[0004] For specific munitions such as, for example, Penetrator with
Enhanced Lateral Effect (PELE), Active Lateral Penetrator (ALP), or
Winchester Short Magnum (WSM) explosive projectiles, tubular
penetrators are used due to the new requirements for these
munitions. These should avoid possible collateral damage of a
penetrator, for example, when penetrating a wall, or the like. Such
penetrators have previously been produced from solid bars that are
subsequently processed by deep-hole boring in order, thus, to be
hollowed out or bored through. This method is technically very
laborious and not economical.
[0005] A method for producing a full penetrator of this type is
known, for example, from DE 10 2005 049 748 A1. For the
cost-effective production of such a penetrator, a double-funnel
filler device matched to the dimension of the penetrator core is
inserted concentrically at the outside dimensions of the
penetrator, as a result of which an intermediate space is created.
While a first tungsten-like powder mixture with a high proportion
of tungsten is filled in the inner tube to produce the penetrator
core, a second tungsten-containing powder mixture is inserted into
the ring-shaped intermediate space, which second powder mixture has
a smaller proportion of tungsten than the other powder mixture.
[0006] Here, the object of the present invention is to show a more
cost-effective method, and a device for carrying out this method,
for the production of WSM tubes, as a semi-finished product for the
production of, e.g., penetrators for kinetic energy projectiles
with fragmentation effect.
SUMMARY OF THE PRESENT INVENTION
[0007] The object of the invention is achieved by the features of a
first embodiment of the invention or of an eighth embodiment of the
invention. Additional advantageous embodiments of the invention are
described with respect to the subordinate embodiments. More
specifically, in accordance with the first embodiment of the
invention, a method for producing a tubular solid body,
particularly for producing a penetrator for a kinetic energy
projectile with fragmentation effect, is provided and characterized
in that (a) a filler device, comprising an outer tube (2) with an
extrusion die (3) situated therein as well as a filler piece (4),
is filled with a metal powder mixture in the intermediate space (8)
forming between the filler piece (4) and the extrusion die (3), and
the extrusion die (3) is then closed, (b) in order to compact the
metal powder, the filler device (1) is placed in a hydrostatic
pressing system and the metal powder mixture is pressed to produce
a green preform, and (c) the pressed tubes are subsequently
sintered in one or more passes through a furnace, for which purpose
the pressed tubes are subjected to a preselected time/temperature
progression so that it is ensured that a melt forms and contracts
evenly in all directions, so that after the sintering a
geometrically desired solid body results.
[0008] In accordance with a second embodiment of the invention, the
first embodiment is modified so that, after the sintering, the
solid body is subjected to a heat treatment, through which tensile
strength and elongation at break can be adjusted. In accordance
with a third embodiment of the invention, the second embodiment is
further modified so that, after the heat treatment, the solid body
is subjected to a forging process, through which the flow point and
tensile strength increase. In accordance with a fourth embodiment
of the invention, the first embodiment, the second embodiment, and
the third embodiment are further modified so that the filler device
is filled with the metal powder via a filler tube (5) that is
placed on the filler piece (4) and enables a filling between filler
piece (4) and extrusion die (3). In accordance with a fifth
embodiment of the present invention, the first embodiment, the
second embodiment, the third embodiment and the fourth embodiment
are further modified so that the filler tube (5) is removed after
the filling of the filler device. In accordance with a sixth
embodiment of the present invention, the first embodiment, the
second embodiment, the third embodiment, the fourth embodiment, and
the fifth embodiment are further modified so that the intermediate
space (8) is closed by a plug (9). In accordance with a seventh
embodiment of the present invention, the first embodiment, the
second embodiment, the third embodiment, the fourth embodiment, the
fifth embodiment and the sixth embodiment are further modified so
that the metal powder mixture comprises a tungsten heavy metal
alloy with 80-98% by weight tungsten and at least one second
component from the group Ti, V, Cr, Mn, Fe, Co, Ni, Mo, or any
combination thereof.
[0009] In accordance with an eighth embodiment of the present
invention, a filler device is provided for the production of a
tubular solid body, in particular, a penetrator for a kinetic
energy projectile with fragmentation effect, wherein the filler
device includes: (a) an outer tube (2) in which an extrusion die
(3) and a filler piece (4) are attached concentrically; and (b) a
filler tube (5) is placed on the filler piece (4) for filling the
intermediate space (8), forming between extrusion die (3) and
filler piece (4), with a metal powder mixture. In accordance with a
ninth embodiment of the present invention, the eighth embodiment is
modified so that the outer tube (2) is a steel tube and the
extrusion die (3) is a polyurethane tube.
[0010] The invention is based on the concept of producing such
tubes or tubular penetrators, both of whose ends can be open or
else one can be closed, in a sintering process without reworking
the inner contour. The sintering is carried out with an internal
medium in the unworked piece that can easily be removed after the
sintering. A uniform contraction is achieved by appropriate
pressing methods and temperature progressions during the sintering,
as is known for solid bars. The material properties are adjusted by
the alloy composition and are made more pronounced by heat
treatment, as well as optionally by mechanical shaping.
[0011] The method can be used for small bars for medium-caliber
munitions (e.g., outer diameter 22 mm, inner diameter 15 mm), as
sub-caliber large-caliber munitions, and for large bars for
full-caliber 120 mm munitions (e.g., outer diameter 120 mm, inner
diameter 110 mm). The material is a tungsten heavy metal alloy.
[0012] The length and diameter are variable and are currently
limited not by the method itself, but rather by the conventional
manufacturing plants. However, this has the advantage that
available manufacturing plants can be used.
[0013] To produce such a tubular solid body, a filler device
comprising an outer tube with concentrically arranged extrusion
die, as well as a filler piece with a filler tube and centering
part placed thereon, is filled with a metal powder mixture. The
length and diameter of the outer tube and extrusion die determine
the outer contour, and the geometry of the filler piece determines
the inner contour of the tubular solid body.
[0014] To center the filler piece in the extrusion die, a centering
disk of plastic is fixed at one end, and at the other end, the
centering takes place via a centering part placed thereon with a
filler tube permanently connected thereto. The filler tube enables
the cavity between the extrusion die and the filler piece to be
filled with a metal powder mixture. After the filler device has
been filled up to the upper edge of the filler piece, the centering
part is removed from the filler piece together with the filler
tube. To produce tubular solid bodies with one closed end, after
the removal of the centering part and filler tube, the metal powder
mixture is filled by hand up to the desired height above the filler
piece. After the filling, the extrusion die is closed with a
plug.
[0015] To compact the metal powder, the filler device is placed in
a pressing system and pressed to form a green preform. Depending on
the construction of the filler device, after the green preform has
been taken out of the device, the preform has the shape of a tube
closed on one side or open on both sides.
[0016] After the pressing, the green preform is sintered in one or
more passes, as a result of which workpieces with solid body
properties are produced from the compact through known measures.
For example, tubes for the production of penetrators with very good
fragmentation effect are created, which effect can be adjusted via
the ratio of inner to outer diameter and the corresponding material
or the material composition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention is to be explained in more detail based on an
exemplary embodiment with drawings. The drawings show:
[0018] FIG. 1a, which shows a filler device in the filling
state,
[0019] FIG. 1b, which shows the filler device in the filled
(closed) state, and
[0020] FIG. 2, which shows a tubular solid body produced according
to the method with an end closed on one side.
DETAILED DESCRIPTION OF THE INVENTION
[0021] FIGS. 1a, b show a filler device or filler mold 1 for the
production of a tubular solid body 10, here closed on one side
(c.f., FIG. 2). The filler device, as shown in FIG. 1a, comprises
an outer tube 2 (preferably made of steel), in which bores are
situated on the jacket- and base surface at regular intervals. In
this outer tube 2, an extrusion die 3 (preferably made of
polyurethane), a filler piece 4 (preferably made of metal), and a
filler tube 5 are attached concentrically. The concentricity of the
filler piece 4 is ensured by a centering disk 6 (preferably made of
polyurethane) at the bottom end, and the centering part 7 of the
filler tube 5 placed on the filler piece at the top end. The
centering part 7 and the filler tube 5 are permanently connected to
one another. An intermediate space 8 forming between the extrusion
die 3 and filler piece 4 is filled thereby. After the filler device
of FIG. 1a has been filled with the metal powder mixture up to the
upper end of the filler piece 4, the centering part 7, together
with the filler tube 5, is removed from the filler piece 4 and
subsequently metal powder mixture is further filled by hand and the
extrusion die is closed with a plug 9 (FIG. 1b).
[0022] In order to compact the metal powder, the filler device as
shown in FIG. 1b is placed in a hydrostatic pressing system (not
shown in more detail, since known) and the metal powder mixture is
pressed into a green preform at a pressure of approx. 1500 bar.
After removal from the filler device shown in FIG. 1b, the green
preform has the shape of a tube closed on one side and can be
handled without breaking.
[0023] The pressed tubes are subsequently sintered in one or more
passes through a furnace (pre-sintering at a temperature between
1400.degree. C. and 1490.degree. C., post-sintering at a
temperature between 1495.degree. C. and 1570.degree. C.), so that
workpieces with solid body properties are produced from the green
preform. For this purpose, the pressed tubes are subjected to a
preselected time/temperature progression (i.e., a progression of
temperature over time) during the pre- and post-sintering, wherein
it is ensured that a melt of tungsten and the remaining binder
elements forms in a stable tungsten skeleton, and contracts evenly
in all directions, so that after the post-sintering a geometrically
desired solid body results, as shown, for example, in FIG. 2.
[0024] In order to obtain a material with the desired material
properties, after the post-sintering, the solid body is subjected
to a heat treatment. E.g., tensile strength, elongation at break,
and contraction can be adjusted thereby, depending on the heat
treatment. This takes place preferably in an annealing process, in
which annealing under high vacuum below the melt temperature of the
binder leads to a phase change that, with a subsequent quenching,
e.g., in N.sub.2, leads to the fixing of the material state and
thus of the material properties.
[0025] FIG. 2 shows a tubular solid body for the production of a
munition not shown in more detail (for example a kinetic energy
projectile with fragmentation effect), which munition has been
produced according to the method previously described and has
adjusted solid body properties. The munition has, with L.sub.g, a
predeterminable total length and, with L.sub.v, a length of the
solid body, and has an inner diameter d.sub.i and an outer diameter
d.sub.a.
* * * * *