MATIERES REACTIVES A HAUTE DENSITE

HIGH DENSITY REACTIVE MATERIALS

Abrégé français

L'invention se rapporte à des matériaux réactifs à haute densité, de préférence des matériaux à haute densité et dotés d'une sortie exothermique. L'invention se rapporte à un matériau réactif à haute densité comprenant A) au moins deux des métaux du groupe 4 distincts, présents dans la plage de 40 à 90 % en poids B) au moins un oxydant ou un métal d'alliage, présent dans la plage allant de 5 à 55 % en poids C) un liant présent dans la plage de 1 à 10 % en poids, lesdits réactifs et auxiliaires de pressage éventuels étant présents dans sensiblement 100 % en poids.

Abrégé anglais

The invention relates to high density reactive materials, preferably materials with a high density and exothermic output There is provided a high density reactive material comprising, A) at least two separate group 4 metals, present in the range of from 40 to 90%wt B) at least one oxidiser or alloying metal, present in the range of from 5 to 55%wt C) a binder present in the range of 1 -10%wt. wherein said reagents and optional pressing aids are present in substantially 100%wt.

Revendications

6
CLAIMS
1. A high density reactive material composition comprising,
A) at least two separate group 4 metals, present in the range of from 40
to 90%wt
B) at least one oxidiser or alloying element, present in the range of from
to 55%wt
C) a binder present in the range of 1-10%wt.
wherein said reagents and optional pressing aids are present in
substantially 100%wt.
2. A composition according to claim 1, wherein B) is at least one oxidiser.
3. A composition according to claim 1 or 2, wherein the at least one
oxidiser
is a metal salt.
4. A composition according to any one of the preceding claims, wherein the
at least one oxidiser is present in the range of from 35 to 55%.
5. A composition according to any one of the preceding claims, wherein at
least one of the group 4 metals is hafnium.
6. A composition according to claim 5, wherein the hafnium is present in
the
range of from 15 to 30%wt
7. A composition according to any one of the preceding claims, wherein
said binder is a fluoroelastomer binder.
8. A composition according to claim 7, wherein said fluoroelastomer binder
is present in the in the range of from 3 to 7%wt.
9. A composition wherein according to any one of the preceding claims
wherein the at least two group 4 metals are encapsulated.
10. A munition comprising a portion of the consolidated composition
according to any one of the preceding claims.
11. A munition where the portion comprises all, substantially all or part
of a
projectile, shell, casing, shaped charge liner, natural, forced or preformed
fragments or a mortar.

7
12. A high density reactive material composition comprising,
at least one group 4 metal, present in the range of from 45 to 90%wt
at least one oxidiser or alloying element, present in the range of from 5 to
55%wt
a binder present in the range of 1-10%wt.
wherein said reagents and optional pressing aids are present in
substantially 100%wt, wherein said consolidated composition provides
an effective density by weight fraction of greater than 5.40.
13. A device substantially as described herein with reference to the
accompanying drawings.

Description

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Reactive materials
The invention relates to high density reactive materials, preferably
materials with a high density and exothermic output.
High Density reactive materials (HDRM) are a new emerging class of
materials http://en.wikipedia.org/wiki/Reactive_materials, which have higher
densities than conventional reactive materials such that they may provide
enhanced performance with mechanical properties suitable for application in a
broad range of weapon systems. This includes potential for effective transfer
of
Kinetic Energy in impact penetrators, fragments and other systems, whilst
offering an additional advantage of providing a further exothermic output
under
explosive loading or following High Velocity impact.
According to a first aspect of the invention there is provided a high
density reactive material composition comprising,
A) at least two separate group 4 metals, present in the range of from 40 to
90%wt
B) at least one oxidiser or alloying element, present in the range of from 5
to
55%wt
C) a binder present in the range of 1-10%wt.
wherein said reagents A), B), C) and optional pressing aids are present in
substantially 100%wt.
Preferably B) is at least one oxidiser. The at least one oxidiser may
preferably present in the range of from 35 to 55%wt.
The at least one oxidiser may be a metal salt, such as, for example,
oxides, nitrates, perchlorates, permanganates, peroxides, chlorates.
Preferably
a high density metal salt, such as for example, metal oxides, for example CuO.
The reagent B) when selected from an alloying element may be selected
from any non-group 4 metal, metalloid, that undergoes an exothermic alloying

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reaction with group 4 metals, preferably carbon or boron. The boron may be
present in an amount 5 to 20%wt, preferably 10%wt.
The reagent A) group 4 metals are group 4, d-block (transition metals)
such as titanium, zirconium, and hafnium. These metals offer high densities,
and the specific selection of two different group 4 options offers a chance to
target specific density ranges for the final composition whilst retaining
similar
reactivity.
In a preferred arrangement at least one of the group 4 metals is hafnium.
Preferably the hafnium is present in the range of from 15 to 30%wt. The
specific
inclusion of Hafnium, in the range of from 15 to 30%wt, or more preferably in
the range of 20 to 25%wt,which provides a significant increase to the overall
effective density of the consolidated composition, for a relatively minor
volumetric inclusion.
The group 4 metals may offer a range of morphologies - comprising
nano, sub micron, or micron sized particulates. The at least two group 4
metals
may be selected to maximise mixing capability to promote uniformity of
distribution (these may be substantially the same size, or targeted different
size
ranges to achieve a specific multimodal distribution, such as a bimodal
distribution.
The reagent B may be selected from nano, sub micron, or micron sized
particulates, such that upon intimate mixing with group 4 metals, may
support/provide a homogenous mixture. The particulate size of the group 4
metals and reagent B materials may be selected to provide multimodal
distributions.
The reagent C) binder may be selected from at least one fluoroelastomer
binder. The fluoroelastomer binder may be selected from a range of materials
such as for example hexafluoropropylene, vinylidene fluoride, terpolymers of
tetrafluoroethylene, vinylidene fluoride and hexafluoropropylene (HFP),
perfluoromethylvinylether, THV 220, and PTFE, preferably a Viton, more
preferably Viton A.
The reagent C) binder may preferably be present in the in the range of
from 3 to 7%wt, preferably 5%wt.

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According to a further aspect there is provided a munition comprising a
portion of the consolidated composition as defined herein. The portion of the
munition may comprise all, substantially all or part of a munition. The
munition
may such as for example be a direct fire or indirect fire munition. The
munition
may be kinetic energy or chemical energy munition or a combination thereof,
such as, for example a projectile, shell, casing, shaped charge liner,
preformed
fragments or mortar.
The munition may be a kinetic energy projectile such as for example,
such as a round, from a small calibre ordnance, a medium calibre projectile
such as, for example calibres of 30- 40mm and above, penetrator rods or
flechettes. The projectile may comprise or contain only a monolithic
projectile of
consolidated composition as defined herein. Certain medium calibre projectiles
typically comprise a high explosive, the use of a projectile (small or medium
calibre) comprising or containing only a consolidated composition according to
the invention may provide an insensitive munition.
The munition may be a gun launched shell, such as for example, 105mm
or 155mm, wherein part, substantially all or all of the shell casing is a
composition as defined herein. The composition may be prepared to form pre
formed fragments which are further consolidated to form a shell casing. In a
munition subjected to a high set back force, such as a gun launched munition,
preferably there is a higher percentage weight of fluorelastomer binder.
The munition may comprise at least one layer deposed thereon of the
composition as defined herein.
The casing of the munition may be subjected to prompt break up, ignition
and burn to enhance blast effectiveness.
The particulates of the composition may not be consolidated and may be
available as agglomerates/clumps, and may be ignited as such, and undergo
ignition and continue to burn in flight. This may offer enhancement to blast
and
after burn or Kinetic Energy transfer to targets at range.
The composition either solid or agglomerates may be ejected, or
projected , in such a manner to retain physical form/mass and associated

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Kinetic Energy allowing reaction on impact with targets at a specific thresh-
hold
impact velocity causing shock reaction and ignition of the material on the
surface or within the target structure.
According to a yet further aspect of the invention there is provided a
method of preparing a high density reactive material as defined herein, such
as
for example, dead load pressing, isostatic pressing, hot sintering, to provide
a
composition which may be consolidated to form a structural casing or
projectile.
Ingredient 1 Ingredient 2 Ingredient 3 Ingredient 4
Overall
Effective
Ref Name Wt % Name Wt % Name Wt % Name Wt
% Density by
Wt fraction
la Zirconium 25% CuO 50% Viton A 5% Hafnium
20% 6.27
21a Titanium 35% Boron 10% Viton A 5%
Hafnium 50% 5.46
23a Hafnium 51% Boron 10% Viton A 5%
Zirconium 34% 6.28
25a Titanium 25% CuO 45% Viton A 5% Hafnium
25% 5.79
26a Hafnium 20% CuO 45% Viton A 5% Zirconium
30% 6.28
28a Zirconium 45% THV220
10% Tungsten 45% 5.71
29a Hafnium 79% THV220 10% Zirconium
11% 6.29
U1 Zirconium 45% Zinc 40%
Tungsten 15% 7.53
Table 1
Table 1 provides a number of examples where the composition
comprises a group 4 metal present in the range of from 45 to 95%wt. the
materials are sintered, preferably using both elevated temperatures and
pressure with the a binder and optional pressing aids to facilitate
consolidation.

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Reagent A Reagent B Reagent C Reagent A Overall
Effective
Ref Name Wt % Name Wt % Name Wt %
Name Wt % Density by
Wt fraction
la Zirconium 25% CuO 50% Viton A 5%
Hafnium 20% 6.27
21a Titanum 35% Boron 10% Viton A 5% Hafnium 50%
5.46
23a Hafnium 51% Boron 10% Viton A 5% Zirconium
34% 6.28
25a Titanium 25% CuO 45% Viton A 5% Hafnium
25% 5.79
26a Hafnium 20% CuO 45% Viton A 5% Zirconium
30% 6.28
Table 2
Table 2 above, provides preferred examples of compositions, wherein at least
two different group 4 metals are selected.
The group 4 metals may be encapsulated or a passivation layer, or
sacrificial layer to prevent reaction with air, moisture or unwanted reactions
with
the other reagents, until activated in the designed mode of use. The group 4
metals may be encapsulated with at least one inert material, to prevent
reaction
with moisture or air. Preferably by premixing the group 4 metal with reagent
C)
a binder, preferably a fluoroelastomer. The coating/microencapsulation of the
group 4 metal may prevent combustion in air during the sintering process.
According to a further aspect of the invention there is provided a high
density reactive material composition comprising,
at least one group 4 metal, present in the range of from 45 to 90%wt
at least one oxidiser or alloying element, present in the range of from 5 to
55%wt
a binder present in the range of 1-10%wt.
wherein said reagents and optional pressing aids are present in substantially
100%wt, wherein said consolidated composition provides an effective density
by weight fraction of greater than 5.40.