Glassy Metal Body Armor

A stab resistant body armor and method of forming such component, wherein the component includes plurality of iron based glassy metal sheets, wherein the iron based glassy metal sheets comprise an iron based glass metal alloy including iron present in the range of 45 atomic percent to 71 atomic percent, nickel present in the range of 4 atomic percent to 17.5 atomic percent, boron present in the range of 11 atomic percent to 16 atomic percent, silicon present in the range of 0.3 atomic percent to 4.0 atomic percent and optionally chromium present in the range of 0.1 atomic percent to 19 atomic percent, and the alloy includes spinodal glass matrix microconstituent structures including one or both of a) semicrystalline phases and b) crystalline phases in a glass matrix.

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Description
CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of the filing date of U.S. Provisional Application No. 61/530,582, filed Sep. 2, 2011, the teachings of which are incorporated herein by reference.

FIELD OF INVENTION

The present disclosure is directed to body armor systems and, in particular, armor systems that provide stab resistance and ballistic protection, wherein the armor systems include iron based glass metals combined with ballistic materials.

BACKGROUND

Stab resistant vests are generally understood as reinforced pieces of body armor designed to resist both “spike” and “edged blade” attacks. Stab vests are typically different from many ballistic vests and do not provide considerable ballistic protection. Ballistic vests are designed to resist threats caused by, for example, projectiles and shrapnel, and may also be modified to offer protection against stab threats by adding inserts.

Products used in body armor components to defeat stab threats have generally been found to be relatively heavy and/or rigid, reducing comfort and tolerability for the wearer. Accordingly, the relatively heavy and relatively stiff products that have been introduced to the body armor industry to defeat stab threats have generally not been adopted by the industry as they restrict movement and cause fatigue. Thus, lighter weight solutions are desired. In addition, since many body armor components are worn in a covert manner, such as under shirts or jackets, relatively highly flexible and thin solutions are desired.

SUMMARY

An aspect of the present disclosure relates to a stab resistant body armor component. The component includes a plurality of iron based glassy metal sheets, wherein the iron based glassy metal sheets comprise an iron based glassy metal alloy including iron present in the range of 45 atomic percent to 71 atomic percent, nickel present in the range of 4 atomic percent to 17.5 atomic percent, boron present in the range of 11 atomic percent to 16 atomic percent, silicon present in the range of 0.3 atomic percent to 4.0 atomic percent and optionally chromium present in the range of 0.1 atomic percent to 19 atomic percent, and the alloy includes spinodal glass matrix microconstituent structures including one or both of a) semicrystalline phases and b) crystalline phases in a glass matrix.

Another aspect of the present disclosure relates to a method of forming a stab resistant body armor component. The method includes forming a plurality of iron based glassy metal sheets and arranging said plurality of iron based glassy metal sheets into a stack. The iron based glassy metal sheets comprise iron based glass metal alloys including iron present in the range of 45 atomic percent to 71 atomic percent, nickel present in the range of 4 atomic percent to 17.5 atomic percent, boron present in the range of 11 atomic percent to 16 atomic percent, silicon present in the range of 0.3 atomic percent to 4.0 atomic percent and optionally chromium present in the range of 0.1 atomic percent to 19 atomic percent, and the alloy includes spinodal glass matrix microconstituent structures including one or both of a) semicrystalline phases and b) crystalline phases in a glass matrix.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features of this disclosure, and the manner of attaining them, may become more apparent and better understood by reference to the following description of embodiments described herein taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic of an embodiment of a woven glassy metal fabric;

FIG. 2 is a schematic of an embodiment of a woven glassy metal and non-metallic polymer material fabric;

FIG. 3 is a schematic of an embodiment of a woven glassy metal and non-metallic polymer material fabric;

FIG. 4 is a schematic of an embodiment of a stack of glassy metal layers;

FIG. 5 is a schematic of an embodiment of a combination of a stack of glassy metal layers and a flexible or rigid ballistic material backer;

FIG. 6 is a schematic of an embodiment of a stack of alternating glassy metal foils and non-metallic polymeric material layers;

FIG. 7 is a schematic of an embodiment of a stack of alternating glassy metal layers and non-metallic polymeric material layers and a flexible or rigid ballistic material backer;

FIGS. 8a through 8c are schematics of mechanisms provided by a stack of glassy metal foils to defeat a stab instrument for testing stab resistance;

FIG. 9 is an illustration of a defeated and bent NH 0155.00 spike which occurred upon impact with a stack of iron based glassy metal foils that weight 1.0 pound per square foot; and

FIG. 10 is an illustration of a defeated NH 0155.00 double edge blade which bounced upon impact with a stack of iron based glass metal foils that weighted 1.25 pounds per square foot.

 DETAILED DESCRIPTION

The present disclosure is directed personal body armor which exhibits stab resistance while decreasing the weight and thickness of the armor systems, and in most conditions, provides relative improvements in flexibility. Iron based glassy metals are incorporated into body armor components such as vests and insert plates. In such a manner, the body armor described herein, incorporating iron based glassy metals, is able to defeat high energy level attacks, i.e., up to level 3 NIJ standard 0115.00 attacks, with a stab instrument such as a single or double edged bladed or a spike. When the iron based glassy metals are combined with ballistic materials multi-threat protection against ballistics and stabs is enabled at relatively low weight and relatively reduced thickness while offering relatively high flexibility.

Iron based glassy metals are defined as iron based glasses and glass matrix structures containing nanoscale precipitates. The body armor takes advantage of the iron based glassy metal's properties such as relatively high strength (0.4-3.9 GPa), elasticity (1.5-2.0%), and hardness (900-950 HV) and, in some cases, also a relative increase tensile ductility (>2.0%) over conventional, iron based non-glassy metals. Mechanistically, iron based glassy metals have reduced grain sizes (1 to 200 nm) which result in relative increases in strength and hardness over conventional, iron based non-glassy metals.

The iron based glassy metals are formed utilizing glass forming chemistries that lead to the development of Spinodal Glass Matrix Microconstituents (SGMM) structures, which may exhibit relatively significant ductility and high tensile strength. Spinodal glass matrix microconstituents may be understood as microconstituents (i.e., crystalline or glass phases) that are formed by a transformation mechanism that is not nucleation controlled. More basically, spinodal decomposition may be understood as a mechanism by which a solution of two or more components (e.g., metal compositions) of the alloy can separate into distinct regions (or phases) with distinctly different chemical compositions and physical properties. This mechanism differs from classical nucleation in that phase separation occurs uniformly throughout the material and not just at discrete nucleation sites. The phases may include one or more semicrystalline clusters or crystalline phases, which may form through a successive diffusion of atoms on a local level until the chemistry fluctuations lead to at least one distinct crystalline phase. Semi-crystalline clusters may be understood herein as exhibiting a largest linear dimension of 2 nm or less, where as crystalline clusters may exhibit a largest linear dimension of greater than 2 nm and up to 200 nm, including all values and ranges therein. Note that during the early stages of spinodal decomposition, the clusters which are formed may be relatively small and while their chemistry differs from a surrounding glass matrix, they are not yet fully crystalline and have not yet achieved well ordered crystalline periodicity. Additional crystalline phases may exhibit the same crystal structure or distinct structures. Furthermore, as noted the phases may include or be present in a glass matrix. The glass matrix may be understood to include microstructures that may exhibit associations of structural units in the solid phase that may be randomly packed together. The level of refinement, or the size, of the structural units in the glass phase may be in the angstrom scale range, i.e., 5 Å to 100 Å.

Spinodal glass matrix microconstituent formation is quite different than the devitrification of a metallic glass. Metallic glasses may exhibit characteristics which are both metal like, (since they may contain non-directional metallic bonds, metallic luster, and relatively significant electrical and thermal conductivity), and ceramic like (since relatively high hardness may often be exhibited coupled with brittleness and the lack of tensile ductility). Metallic glasses may be understood to include supercooled liquids that exist in solid form at room temperature but which may have structures that are similar to what is found in the liquid with only short range order present. Metallic glasses may generally have free electrons, exhibit metallic luster, and exhibit metallic bonding similar to what is found in conventional metals. Metallic glasses may be understood to be metastable materials and when heated up, they may transform into a crystalline state through crystallization or devitrification. Since diffusion may be limited at room temperature, enough heat (i.e. Boltzman's Energy) may be applied to overcome the nucleation barrier to cause a solid-solid state transformation which is caused by glass devitrification.

The devitrification temperature of metallic glasses can vary widely and may be, for example, in the range of 300° C. to 800° C. with enthalpies of crystallization commonly from −25 J/g to −250 J/g. The devitrification process can occur in one or multiple stages. When occurring in multiple stages, a crystalline phase may be formed and then depending on the specific partition coefficient, atoms may either be attracted to the new crystallites or rejected into the remaining volume of the glass. This may result in more stable glass chemistry which may necessitate additional heat input to cause partial or full devitrification. Thus, partially devitrified structures may result in crystalline precipitates in a glass matrix. Commonly, these precipitates may be in the size range of 30 nm to 125 nm. Full devitrification to a completely crystalline state may result from heat treating above the highest temperature glass peak which can be revealed through thermal analysis such as differential scanning calorimetry or differential thermal analysis.

The relatively fine length scale of the structural order, (i.e. molecular associations), and near defect free nature of the material, (i.e. no 1-d dislocation or 2-d grain/phase boundary defects), may provide relatively high strength, (and corresponding hardness), which may be on the order of 33% to 45% of theoretical. However, due to the lack of crystallinity, dislocations may not be found and a mechanism for relatively significant (i.e. >1%) tensile elongation may not be apparent. Metallic glasses may exhibit limited fracture toughness associated with the relatively rapid propagation of shear bands and/or cracks which may be a concern for the technological utilization of these materials. While these materials may show adequate ductility when tested in compression, when tested in tension they exhibit elongation very close to zero and fracture in the brittle manner. The inherent inability of these classes of materials to deform in tension at room temperature may be a limiting factor for all potential structural applications where intrinsic ductility is needed to avoid catastrophic failure. Owing to strain softening and/or thermal softening, plastic deformation of metallic glasses may be relatively highly localized into shear bands, resulting in a limited plastic strain (exhibiting less than 1% elongation) and catastrophic failure at room temperature.

As opposed to the above described metallic glasses, the alloys leading to the Spinodal Glass Matrix Microconstituent structures may exhibit induced Shear Band Blunting (ISBB) and Shear Band Arresting Interactions (SBAI) which may be enabled by the spinodal glass matrix microconstituent (SGMM). ISBB may be understood as the ability to blunt and stop propagating shear bands through interactions with the SGMM structure. SBAI may be understood as the arresting of shear bands through shear band/shear band interactions and may occur after the initial or primary shear bands are blunted through ISBB.

While conventional materials may deform through dislocations moving on specific slip systems in crystalline metals, ISBB and SBAI deformation mechanisms may involve moving shear bands (i.e., discontinuities where localized deformation occurs) in a spinodal glass matrix microconstituent, which are blunted by localized deformation induced changes (LDIC) described further herein. With increasing levels of stress, once a shear band is blunted, new shear bands may be nucleated and then interact with existing shear bands creating relatively high shear band densities in tension and the development of relatively significant levels of global plasticity. Thus, the alloys with favorable SGMM structures may prevent or mitigate shear band propagation in tension, which may result in relatively significant tensile ductility (>2%) and lead to strain hardening during tensile testing. The alloys contemplated herein may include or consist of chemistries capable of forming a spinodal glass matrix microconstituent, wherein the spinodal glass matrix microconstituents may be present in the range of 5.0% to 95% by volume, including glassy, semi-crystalline, and/or crystalline phases.

Glass forming chemistries that may be used to form compositions including the spinodal glass matrix microconstituent structures may include certain iron based glass forming alloys, which are then processed to provide the SGMM structures noted herein. The iron based alloys may include iron present at levels of greater than or equal to 45 atomic %. In addition, the alloys may include the elements nickel, boron, silicon and optionally chromium. In some embodiments, the alloys may consist essentially of or may be limited only to iron, nickel, boron, silicon and optionally chromium. In further embodiments, the alloys do not include cobalt, which would otherwise increase the relative cost of the alloy compositions.

In some embodiments, the alloys may include iron present in the range of 45 atomic percent to 71 atomic percent, nickel present in the range of 4 atomic percent to 17.5 atomic percent, boron present in the range of 11 atomic percent to 16 atomic percent, silicon present in the range of 0.3 atomic percent to 4.0 atomic percent and optionally chromium present in the range of 0.1 atomic percent to 19 atomic percent. The compositions of the alloys may vary at all values and increments in the above described ranges.

Therefore, iron may be selected from the following values of 45.0 atomic percent (at. %), 45.1 at. %, 45.2 at. %, 45.3 at. %, 45.4 at. %, 45.6 at. %, 45.7 at. %, 45.8 at. %, 45.9 at. %, 46.0 at. %, 46.1 at. %, 46.2 at. %, 46.3 at. %, 46.4 at. %, 46.5 at. %, 46.7 at. %, 46.8 at. %, 46.9 at. %, 47.0 at. %, 47.1 at. %, 47.2 at. %, 47.3 at. %, 47.4 at. %, 47.5 at. %, 47.6 at. %, 47.7 at. %, 47.8 at. %, 47.9 at. %, 48 at. %, 48.1 at. %, 48.2 at. %, 48.3 at. %, 48.4 at. %, 48.5 at. %, 48.6 at. %, 48.7 at. %, 48.8 at. %, 48.9 at. %, 49 at. %, 49.1 at. %, 49.2 at. %, 49.3 at. %, 49.4 at. %, 49.5 at. %, 49.6 at. %, 49.7 at. %, 49.8 at. %, 49.9 at. %, 50 at. %, 50.1 at. %, 50.2 at. %, 50.3 at. %, 50.4 at. %, 50.5 at. %, 50.6 at. %, 50.7 at. %, 50.8 at. %, 50.9 at. %, 51 at. %, 51.1 at. %, 51.2 at. %, 51.3 at. %, 51.4 at. %, 51.5 at. %, 51.6 at. %, 51.7 at. %, 51.8 at. %, 51.9 at. %, 52 at. %, 52.1 at. %, 52.2 at. %, 52.3 at. %, 52.4 at. %, 52.5 at. %, 52.6 at. %, 52.7 at. %, 52.8 at. %, 52.9 at. %, 53 at. %, 53.1 at. %, 53.2 at. %, 53.3 at. %, 53.4 at. %, 53.5 at. %, 53.6 at. %, 53.7 at. %, 53.8 at. %, 53.9 at. %, 54 at. %, 54.1 at. %, 54.2 at. %, 54.3 at. %, 54.4 at. %, 54.5 at. %, 54.6 at. %, 54.7 at. %, 54.8 at. %, 54.9 at. %, 55 at. %, 55.1 at. %, 55.2 at. %, 55.3 at. %, 55.4 at. %, 55.5 at. %, 55.6 at. %, 55.7 at. %, 55.8 at. %, 55.9 at. %, 56 at. %, 56.1 at. %, 56.2 at. %, 56.3 at. %, 56.4 at. %, 56.5 at. %, 56.6 at. %, 56.7 at. %, 56.8 at. %, 56.9 at. %, 57 at. %, 57.1 at. %, 57.2 at. %, 57.3 at. %, 57.4 at. %, 57.5 at. %, 57.6 at. %, 57.7 at. %, 57.8 at. %, 57.9 at. %, 58 at. %, 58.1 at. %, 58.2 at. %, 58.3 at. %, 58.4 at. %, 58.5 at. %, 58.6 at. %, 58.7 at. %, 58.8 at. %, 58.9 at. %, 59 at. %, 59.1 at. %, 59.2 at. %, 59.3 at. %, 59.4 at. %, 59.5 at. %, 59.6 at. %, 59.7 at. %, 59.8 at. %, 59.9 at. %, 60 at. %, 60.1 at. %, 60.2 at. %, 60.3 at. %, 60.4 at. %, 60.5 at. %, 60.6 at. %, 60.7 at. %, 60.8 at. %, 60.9 at. %, 61 at. %, 61.1 at. %, 61.2 at. %, 61.3 at. %, 61.4 at. %, 61.5 at. %, 61.6 at. %, 61.7 at. %, 61.8 at. %, 61.9 at. %, 62 at. %, 62.1 at. %, 62.2 at. %, 62.3 at. %, 62.4 at. %, 62.5 at. %, 62.6 at. %, 62.7 at. %, 62.8 at. %, 62.9 at. %, 63 at. %, 63.1 at. %, 63.2 at. %, 63.3 at. %, 63.4 at. %, 63.5 at. %, 63.6 at. %, 63.7 at. %, 63.8 at. %, 63.9 at. %, 64 at. %, 64.1 at. %, 64.2 at. %, 64.3 at. %, 64.4 at. %, 64.5 at. %, 64.6 at. %, 64.7 at. %, 64.8 at. %, 64.9 at. %, 65 at. %, 65.1 at. %, 65.2 at. %, 65.3 at. %, 65.4 at. %, 65.5 at. %, 65.6 at. %, 65.7 at. %, 65.8 at. %, 65.9 at. %, 66 at. %, 66.1 at. %, 66.2 at. %, 66.3 at. %, 66.4 at. %, 66.5 at. %, 66.6 at. %, 66.7 at. %, 66.8 at. %, 66.9 at. %, 67 at. %, 67.1 at. %, 67.2 at. %, 67.3 at. %, 67.4 at. %, 67.5 at. %, 67.6 at. %, 67.7 at. %, 67.8 at. %, 67.9 at. %, 68 at. %, 68.1 at. %, 68.2 at. %, 68.3 at. %, 68.4 at. %, 68.5 at. %, 68.6 at. %, 68.7 at. %, 68.8 at. %, 68.9 at. %, 69 at. %, 69.1 at. %, 69.2 at. %, 69.3 at. %, 69.4 at. %, 69.5 at. %, 69.6 at. %, 69.7 at. %, 69.8 at. %, 69.9 at. %, 70 at. %, 70.1 at. %, 70.2 at. %, 70.3 at. %, 70.4 at. %, 70.5 at. %, 70.6 at. %, 70.7 at. %, 70.8 at. %, 70.9 at. %, and/or 71 at. %.

Nickel may be selected from the following values of 4.0 at. %, 4.1 at. %, 4.2 at. %, 4.3 at. %, 4.4 at. %, 4.5 at. %, 4.6 at. %, 4.7 at. %, 4.8 at. %, 4.9 at. %, 5 at. %, 5.1 at. %, 5.2 at. %, 5.3 at. %, 5.4 at. %, 5.5 at. %, 5.6 at. %, 5.7 at. %, 5.8 at. %, 5.9 at. %, 6 at. %, 6.1 at. %, 6.2 at. %, 6.3 at. %, 6.4 at. %, 6.5 at. %, 6.6 at. %, 6.7 at. %, 6.8 at. %, 6.9 at. %, 7 at. %, 7.1 at. %, 7.2 at. %, 7.3 at. %, 7.4 at. %, 7.5 at. %, 7.6 at. %, 7.7 at. %, 7.8 at. %, 7.9 at. %, 8 at. %, 8.1 at. %, 8.2 at. %, 8.3 at. %, 8.4 at. %, 8.5 at. %, 8.6 at. %, 8.7 at. %, 8.8 at. %, 8.9 at. %, 9 at. %, 9.1 at. %, 9.2 at. %, 9.3 at. %, 9.4 at. %, 9.5 at. %, 9.6 at. %, 9.7 at. %, 9.8 at. %, 9.9 at. %, 10 at. %, 10.1 at. %, 10.2 at. %, 10.3 at. %, 10.4 at. %, 10.5 at. %, 10.6 at. %, 10.7 at. %, 10.8 at. %, 10.9 at. %, 11 at. %, 11.1 at. %, 11.2 at. %, 11.3 at. %, 11.4 at. %, 11.5 at. %, 11.6 at. %, 11.7 at. %, 11.8 at. %, 11.9 at. %, 12 at. %, 12.1 at. %, 12.2 at. %, 12.3 at. %, 12.4 at. %, 12.5 at. %, 12.6 at. %, 12.7 at. %, 12.8 at. %, 12.9 at. %, 13 at. %, 13.1 at. %, 13.2 at. %, 13.3 at. %, 13.4 at. %, 13.5 at. %, 13.6 at. %, 13.7 at. %, 13.8 at. %, 13.9 at. %, 14 at. %, 14.1 at. %, 14.2 at. %, 14.3 at. %, 14.4 at. %, 14.5 at. %, 14.6 at. %, 14.7 at. %, 14.8 at. %, 14.9 at. %, 15 at. %, 15.1 at. %, 15.2 at. %, 15.3 at. %, 15.4 at. %, 15.5 at. %, 15.6 at. %, 15.7 at. %, 15.8 at. %, 15.9 at. %, 16.0 at. %, 16.1 at. %, 16.2 at. %, 16.3 at. %, 16.4 at. %, 16.5. at. %, 16.6 at. %, 16.7. at. %, 16.8 at. %, 16.9 at. %, 17.0 at. %, 17.1 at. %, 17.2 at. %, 17.3 at. %, 17.4 at. %, 17.5 at. %.

Boron may be selected from the following values of 11.0 at. %, 11.1 at. %, 11.2 at. %, 11.3 at. %, 11.4 at. %, 11.5 at. %, 11.6 at. %, 11.7 at. %, 11.8 at. %, 11.9 at. %, 12 at. %, 12.1 at. %, 12.2 at. %, 12.3 at. %, 12.4 at. %, 12.5 at. %, 12.6 at. %, 12.7 at. %, 12.8 at. %, 12.9 at. %, 13 at. %, 13.1 at. %, 13.2 at. %, 13.3 at. %, 13.4 at. %, 13.5 at. %, 13.6 at. %, 13.7 at. %, 13.8 at. %, 13.9 at. %, 14 at. %, 14.1 at. %, 14.2 at. %, 14.3 at. %, 14.4 at. %, 14.5 at. %, 14.6 at. %, 14.7 at. %, 14.8 at. %, 14.9 at. %, 15 at. %, 15.1 at. %, 15.2 at. %, 15.3 at. %, 15.4 at. %, 15.5 at. %, 15.6 at. %, 15.7 at. %, 15.8 at. %, 15.9 at. %, 16 at. %.

Silicon may be selected from the following values of 0.3 at. %, 0.4 at. %, 0.5 at. %, 0.6 at. %, 0.7 at. %, 0.8 at. %, 0.9 at. %, 1.0 at. %, 1.1 at. %, 1.2 at. %, 1.3 at. %, 1.4 at. %, 1.5 at. %, 1.6 at. 5, 1.7 at. %, 1.8 at. %, 1.9 at. %, 2.0 at. %, 2.1 at. %, 2.2 at. %, 2.3 at. %, 2.4 at. %, 2.5 at. %, 2.6 at. %, 2.7 at. %, 2.8 at. %, 2.9 at. % 3.0 at. %, 3.1 at. %, 3.2 at. %, 3.3 at. %, 3.4 at. %, 3.5 at. %, 3.6 at. %, 3.7 at. %, 3.8 at. %, 3.9 at. % 4.0 at. %.

Chromium may be selected from the following values of 0 at. %, 0.1 at. %, 0.2 at. %, 0.3 at. %, 0.4 at. %, 0.5 at. %, 0.6 at. %, 0.7 at. %, 0.8 at. %, 0.9 at. %, 1 at. %, 1.1 at. %, 1.2 at. %, 1.3 at. %, 1.4 at. %, 1.5 at. %, 1.6 at. %, 1.7 at. %, 1.8 at. %, 1.9 at. %, 2 at. %, 2.1 at. %, 2.2 at. %, 2.3 at. %, 2.4 at. %, 2.5 at. %, 2.6 at. %, 2.7 at. %, 2.8 at. %, 2.9 at. %, 3 at. %, 3.1 at. %, 3.2 at. %, 3.3 at. %, 3.4 at. %, 3.5 at. %, 3.6 at. %, 3.7 at. %, 3.8 at. %, 3.9 at. %, 4 at. %, 4.1 at. %, 4.2 at. %, 4.3 at. %, 4.4 at. %, 4.5 at. %, 4.6 at. %, 4.7 at. %, 4.8 at. %, 4.9 at. %, 5 at. %, 5.1 at. %, 5.2 at. %, 5.3 at. %, 5.4 at. %, 5.5 at. %, 5.6 at. %, 5.7 at. %, 5.8 at. %, 5.9 at. %, 6 at. %, 6.1 at. %, 6.2 at. %, 6.3 at. %, 6.4 at. %, 6.5 at. %, 6.6 at. %, 6.7 at. %, 6.8 at. %, 6.9 at. %, 7 at. %, 7.1 at. %, 7.2 at. %, 7.3 at. %, 7.4 at. %, 7.5 at. %, 7.6 at. %, 7.7 at. %, 7.8 at. %, 7.9 at. %, 8 at. %, 8.1 at. %, 8.2 at. %, 8.3 at. %, 8.4 at. %, 8.5 at. %, 8.6 at. %, 8.7 at. %, 8.8 at. %, 8.9 at. %, 9 at. %, 9.1 at. %, 9.2 at. %, 9.3 at. %, 9.4 at. %, 9.5 at. %, 9.6 at. %, 9.7 at. %, 9.8 at. %, 9.9 at. %, 10 at. %, 10.1 at. %, 10.2 at. %, 10.3 at. %, 10.4 at. %, 10.5 at. %, 10.6 at. %, 10.7 at. %, 10.8 at. %, 10.9 at. %, 11 at. %, 11.1 at. %, 11.2 at. %, 11.3 at. %, 11.4 at. %, 11.5 at. %, 11.6 at. %, 11.7 at. %, 11.8 at. %, 11.9 at. %, 12 at. %, 12.1 at. %, 12.2 at. %, 12.3 at. %, 12.4 at. %, 12.5 at. %, 12.6 at. %, 12.7 at. %, 12.8 at. %, 12.9 at. %, 13 at. %, 13.1 at. %, 13.2 at. %, 13.3 at. %, 13.4 at. %, 13.5 at. %, 13.6 at. %, 13.7 at. %, 13.8 at. %, 13.9 at. %, 14 at. %, 14.1 at. %, 14.2 at. %, 14.3 at. %, 14.4 at. %, 14.5 at. %, 14.6 at. %, 14.7 at. %, 14.8 at. %, 14.9 at. %, 15 at. %, 15.1 at. %, 15.2 at. %, 15.3 at. %, 15.4 at. %, 15.5 at. %, 15.6 at. %, 15.7 at. %, 15.8 at. %, 15.9 at. %, 16 at. %, 16.1 at. %, 16.2 at. %, 16.3 at. %, 16.4 at. %, 16.5 at. %, 16.6 at. %, 16.7 at. %, 16.8 at. %, 16.9 at. %, 17 at. %, 17.1 at. %, 17.2 at. %, 17.3 at. %, 17.4 at. %, 17.5 at. %, 17.6 at. %, 17.7 at. %, 17.8 at. %, 17.9 at. %, 18 at. %, 18.1 at. %, 18.2 at. %, 18.3 at. %, 18.4 at. %, 18.5 at. %, 18.6 at. %, 18.7 at. %, 18.8 at. %, 18.9 at. %, and/or 19 at. %.

In addition, due to, for example, the purity of the feedstocks and introduction of impurities during processing, the alloys may include up to 10 atomic percent of impurities. Therefore, the above described iron based alloy composition may be present in the range of 90 to 100 atomic percent of a given composition, including all values and increments therein, such as in the range of 90 to 99 atomic percent, etc.

While not intended to be limiting, an analysis of the mechanisms of deformation appear to show that that the operating mechanisms for ISBB and SBAI are orders of magnitude smaller than the system size. The operable system size may be understood as the volume of material containing the SGMM structure, which again may be in the range of 5% to 95% by volume. Additionally, for a liquid melt cooling on a chill surface such as a wheel or roller (which can be as wide as engineering will allow) 2-dimensional cooling may be a predominant factor in spinodal glass matrix microconstituent formation, thus the thickness may be a limiting factor on structure formation and resulting operable system size. At thicknesses above a reasonable system size compared to the mechanism size, the ductility mechanism may be unaffected. For example, the shear band widths may be relatively small (10 to 100 nm) and even with the LDIC interactions with the structure the interaction size may be from 20 to 200 nm. Thus, for example, achievement of relatively significant ductility (≧2%) at a 100 micron thickness means that the system thickness is already 500 to 10,000 times greater than ductility mechanism sizes.

It is contemplated that the operable system size, which when exceeded would allow for ISBB and SBAI interactions, may be in the range of ˜10 nm to 1 micron in thickness or 1000 nm3 to 1 μm3 in volume. Achieving thicknesses greater ˜1 micron or operable volumes greater 1 μm3 may not be expected to significantly affect the operable mechanisms or achievement of significant levels of plasticity since the operable ductility mechanistic size is below this limit. Thus, greater thickness or greater volume samples or products would be contemplated to achieve an operable ductility with ISBB and SBAI mechanisms in a similar fashion as identified as long as the SGMM structure is formed.

The iron based glassy metals can be produced in a relatively wide foil form or a variety of relatively narrow forms including narrow foil, fiber, or ribbon or in a wire form. The iron based glassy metals may be formed using techniques for producing foils, ribbons, wires or fibers, that may result in cooling rates sufficient to provide SGMM structure, which may be in the range of 103 to 106 K/s. Examples of such processing techniques suitable for forming the metallic foil sheets herein, or the fiber-based sheets herein, may include melt-spinning/jet casting, planar flow casting.

Melt spinning may be understood to include a liquid melt ejected using gas pressure onto a rapidly moving metallic wheel which may be made of copper. Continuous or broken up lengths of ribbon may be produced. The width and thickness may depend on the melt spun materials viscosity and surface tension and the wheel tangential velocity. Typical cooling rates in the melt-spinning process may be from ˜104 to ˜106 K/s, including all values and increments therein. Ribbons may generally be produced in a continuous fashion up to 25 m long using a laboratory scale system.

Jet casters may be used to melt-spin alloys on a commercial scale. Process parameters in one embodiment of melt spinning may include providing the liquid melt in a chamber, which is in an environment including air or an inert gas, such as helium, carbon dioxide, carbon dioxide and carbon monoxide mixtures, or carbon dioxide and argon mixtures. The chamber pressure may be in the range of 0.25 atm to 1 atm, including all values and increments therein. Further, the casting wheel tangential velocity may be in the range of 15 meters per second (m/s) to 30 m/s, including all values and increments therein. Resulting ejection pressures may be in the range of 100 to 300 mbar and resulting ejection temperatures may be in the range of 1000° C. to 1300° C., including all values and increments therein.

Planar flow casting may be understood as a relatively low cost and relatively high volume technique to produce wide ribbon in the form of continuous sheet. The process may include flowing a liquid melt at a close distance over a chill surface. Widths of thin foil/sheet up to 18.4″ (215 mm), including all values and increments in the range of 10 mm to 215 mm, may be produced on a commercial scale. Cooling rates in the range of ˜104 to ˜106 K/s, including all values and increments therein may be provided. After production of sheets, the individual sheets (from 5 to 50) may be warm pressed to roll bond the compacts into sheets.

The solidified iron based glass metal alloys may have a density in the range of 7.40 g/cm3 to 7.80 g/cm3, including all values and increments therein. In addition, the iron based alloys glass metal alloys may exhibit a glass to crystalline transformation temperature in the range of approximately 396° C. to 713° C., including all values and ranges therein, when measured by differential thermal analysis (DTA) or differential scanning calorimetry (DSC) at a heating rate of 10° C./minute. The enthalpy of transformation may be in the range of −16 J/gram to −167 J/gram, including all values and increments therein, when measured by differential thermal analysis (DTA) or differential scanning calorimetry (DSC) at a heating rate of 10° C./minute.

The iron based alloys may exhibit 180 degree bending, where ribbons having a thickness in the range of 0.020 mm to 0.060 mm may be bent over completely flat. The iron based alloys may also exhibit an ultimate tensile strength in the range of 0.4 GPa to 3.90 GPa, including all values and ranges therein, such as 1.00 GPa to 3.26 GPa, when tested at a strain rate of 0.001 s−1. In addition, the iron based alloys may exhibit a total elongation in the range of 0.4% to 5.5%, including all values and ranges therein, such as 1.0% to 5.5%, when tested at a strain rate of 0.001 s−1. The alloys may exhibit a Vickers hardness in the range of 900 to 950, including all values and ranges therein, when tested with a diamond pyramid indenter using a 50 g load. The alloys may also exhibit a shear band density of at least 90×103/meter to 300×103/meter, including all values and ranges therein. The presence of the ductility and the relatively high shear band density indicate that SGMM structures have formed in the alloys.

The iron based glass metals are provided as sheets that are either woven from fibers or metal foils produced using the iron based glass metal alloys described above. Fiber based sheets may include metal and non-metal components, or also be all metal. The iron based glassy metal sheets can be incorporated into body armor components in a number of different manners to protect against different attack threats. The iron based glassy metal sheets can be used in an all-metal form for stab threats, or they could be combined with non-metallic polymeric material based fibers or sheets to produce a multi-threat protection system capable of defeating both stab and ballistic threats. The iron based glassy metal will provide some level of ballistic performance as well. In other words, one can have metal sheets alone that are stacked, or metal sheets alone that are stacked with non-metallic sheets, or fiber-based sheets that include glassy metal alloys and non-metallic fibers, which also may be stacked on their own, or with metal sheets in between.

For example, weaving, knitting, or crocheting of the glassy metal narrow forms, i.e., ribbon, fibers, threads, can be used to produce glassy metal fabrics Glassy metal fabrics 100 can be produced using only glassy metal elements 102 such as fibers or ribbons, as illustrated in FIG. 1. The fabrics may exhibit both a warp W and a fill F (or weft) direction. Hybrid fabrics combine glassy metal elements with other non-glassy metal fiber materials. Other non-glassy metal fiber materials may include inorganic fibers, natural fibers, polymeric fibers and combinations thereof. Examples of inorganic fibers include carbon fibers, glass fibers, ceramic fibers, etc. Examples of natural fibers include cellulosic fibers such as cotton, jute, flax, sisal or hemp as well as naturally derived fibers such as rayon, actetate, triacetate, etc. Polymeric fibers may include para-aramids, ultra-high molecular weight polyethylene, or other oriented fibers including polyester fibers and liquid-crystal polymers.

The hybrid fabrics can be produced with a balanced or unbalanced design. Balanced hybrid fabric 200 contain the same volume percentage of glassy metal 202 and non-glassy metal fibers 204 in both the warp and fill directions, such as the fabric illustrated in FIG. 2. Unbalanced hybrid fabric 300 contains a different volume percentage of glassy metal fibers 302 and/or other non-glassy metal fibers 304 in the warp and fill directions as illustrated in FIG. 3. Hybrid fabrics can also be produced with independent strands of glassy metal and polymeric fibers, or the glassy metal and other fibers can be comingled to produce a hybrid yarn, such as by interwining of glassy metal and polymeric fibers, which could then be used to produce a hybrid fabric. The non-glassy metal fibers may be present in the range of 5 to 95% by weight, including all values and increments therein, such as 5 to 10% by weight, 20 to 80% by weight, 25 to 75% by weight, or 40 to 50% by weight of the total fabric.

FIGS. 4 through 7 depict other preferred embodiments of using iron based glassy metal foils or iron based glassy metal woven fabrics in body armor components. FIG. 4 illustrates a cross sectional view of a body armor component 400 which comprises stacked sheets of iron based glassy metal foil or woven glass metal fabric 402 partially or completely encased in an outer cover 404.

Depending on how the sheets were formed, the sheets may exhibit a machine direction and a cross-machine or transverse direction. Properties may vary relative to these directions. Thus, the sheets may be oriented relative to one another at various angles relative to the machine direction or the transverse direction, such as at angles in the range of 5° to 355°, including all values and increments therein, such as 30°, 45°, 60°, 90°, etc.

The cover may include ripstop or ballistic nylon, fabric formed of para-aramid fibers, or fabrics formed of other relatively high tenacity fibers such as ultra high molecular weight polyethylene. A preferred outer cover may include 210 denier reinforced ripstop nylon fabric. In addition to fabrics, the sheets may be encased in films or other composite materials. While the sheets are illustrated as being encased in an outer cover, in other embodiments, the sheets may be secured together at the edges of the sheets, such as at one or more points along one edge, more than one edge or all of the edges, or secured along on entire edge, more than one edge or around all of the edges. In certain embodiments, the sheets are secured around less than all edges or not secured around the edges at all. The sheets may be secured together via an adhesive, such as by a pressure sensitive tape, or by an adhesive applied to the surfaces of the sheets or by mechanical means, such as crimping, clamping or via fasteners provided through openings in the sheets.

The number of alloy sheets that are stacked herein will depend upon the final construction of the body armor system at issue and the testing requirements that may be satisfied. For example, when the sheets are used on their own, a plurality of sheets may be stacked (i.e. more than one sheet) starting preferably with 10 sheets (e.g. glassy metal foil or metal fiber based sheets), which may then indicate sufficient protection from an attack imposed at a 90 degree orientation. Such sheets may have a thickness of 0.0005 inches to 0.0020 inches.

On the other hand, when the sheets herein are used with other non-metallic layers, such as outer layers of para-aramid fibers, the core structure may also contain a plurality of sheets, again at thicknesses of 0.0005 inches to 0.0020 inches, and such system may then be capable of defeating the highest energy level stab threats (NIJ0115.00 Level 3, Energy 2) and can be incorporated into body armor components such as vests and insert plates at low weights such as 0.5 to 2.0 lb/ft2, including all values and increments therein, such as 0.5 lb/ft2 to 0.7 lb/ft2, 0.5 lb/ft2 to 1.0 lb/ft2, 0.75 lb/ft2 to 1.25 lb/ft2, etc. while retaining a relatively high degree of flexibility. In this situation, the plurality of sheets forming the core may include between 4-50 sheets. It is contemplated that the flexibility will be better than the existing technology due to the thickness of the existing technology using conventional metals, which are 10-15× thicker than the iron based glassy metals utilized herein.

The stack of iron based glassy metals can be used independently as shown in FIG. 4, or can be combined with a ballistic material backer as is shown in the cross sectional view in FIG. 5 for multi-threat protection. Specifically, FIG. 5 illustrates a composite 500 including a stack of iron based glassy metal sheets 502 arranged over or disposed adjacent to a flexible or rigid ballistic material backer 504. Ballistic material may be understood as material that exhibits resistance to the penetration of projectiles and/or shrapnel into and through the material. Flexible ballistic materials may include layers of ballistic fabric of like-type or combinations of a variety of ballistic fabrics such as para-aramids or ultra high molecular weight polyethylene. Rigid ballistic materials may include pressed polyethylene or polycarbonate. Other non polymeric materials may also be incorporated into the ballistic materials, such as ceramics and inorganic materials, including glass fibers.

In some embodiments, the ballistic material may be adhered to at least one of the iron based glassy metal sheets. Relatively high adhesion of the glassy steel foil to the ballistic material may be achieved through the use of surface treatments applied to the metal such as silane surface treatment. The surface treatments are reactive with both organic and inorganic materials and act as a coupling agent to join the glass steel foil to the ballistic material. One example of a silane is a 3-glycidoxypropyltrimethoxysilane which can be applied to the glassy steel foil as a dilute aqueous solution.

The combined system is optionally partially or completely encased in an outer cover 506 disposed around a portion of or around the entire composite 500 such as 210 denier reinforced ripstop nylon or the other covers noted above. Such a body armor system may be incorporated into various body armor components such as vests and insert plates at low areal weights such as 0.5 lb/ft2 to 2.0 lb/ft2, including all values and increments therein, such as 0.5 to 0.75 lb/ft2, 0.75 to 1.25 lb/ft2 etc., while retaining a moderate degree of flexibility with the flexible ballistic materials systems. However, rigid systems may provide little to no flexibility. The iron based glassy metal sheets may be provided on the exterior surface of the composite, facing outward from the body and the ballistic material backer may be provided facing toward the body.

FIG. 6 illustrates a cross sectional view of a body armor component 600 which comprises stacked sheets of iron based glassy metal foils or woven fabrics described above 602 alternating with non-metallic polymeric layers 604 such as para-aramids or ultra high molecular weight polyethylene fabrics or polymeric composites incorporating glass fiber composites, carbon fiber composites, ceramics or combinations thereof in the polymeric layers. The layers may be alternated at a ratio in the range of 10:1, 5:1, 1:1, 1:2, to 1:10 of iron based glassy metal foils or woven fabrics to the non-metallic polymeric layers. The stack of sheets may be encased in an outer cover such those noted above. Again, the preferred number of sheets of iron based glassy metal is between 3 and 50 wherein each metallic sheet has a thickness in the range of 0.0005 in. to 0.0020 in., including all values and increments therein, and the non-metallic polymer fiber layer has a thickness in the range of 0.005 in. to 0.020 in., including all values and increments therein. This body armor system can be incorporated into body armor components such as vests and insert plates at relatively low weights such as in the range of 0.5 lb/ft2 to 2.0 lb/ft2, including all values and increments therein, such as 0.5 to 0.75 lb/ft2, 0.75 to 1.25 lb/ft2 etc., while retaining a relatively high degree of flexibility. Again, it is contemplated that the flexibility will be significantly better than the existing technology due to the thickness of the existing technology which is generally thicker than the iron based glassy metal solution.

The stack of iron based glassy metal foils or woven fabrics alternating with non-metallic polymeric fabrics can be used independently for multi-threat protection as shown in FIG. 6, or for a higher level ballistic resistance the alternating material stack can be combined with a flexible or rigid ballistic material backer as is shown in the cross sectional view in FIG. 7. As illustrated in FIG. 7 a composite 700 is provided including, consisting of or consisting essentially of a stack of alternating layers of iron based glassy metal foils 702 or woven fabrics and polymeric layers 704 are arranged over or disposed adjacent to a ballistic material 706. Again, flexible ballistic materials may include layers of ballistic fabric of like-type or combinations of a variety of ballistic fabrics such as para-aramids or ultra high molecular weight polyethylene. Rigid ballistic materials may include pressed polyethylene or polycarbonate. Other non polymeric materials may also be incorporated into the ballistic materials, such as ceramics and inorganic materials, including glass fibers. The combined system is optionally encased in an outer cover 708 such as those described above.

Similar to above, the ballistic material may be adhered to at least one of the iron based glassy metal sheets. Relatively high adhesion of the glassy steel foil to the ballistic material may be achieved through the use of surface treatments applied to the metal such as silane surface treatment. The surface treatments are reactive with both organic and inorganic materials and act as a coupling agent to join the glass steel foil to the ballistic material. One example of a silane is a 3-glycidoxypropyltrimethoxysilane which can be applied to the glassy steel foil as a dilute aqueous solution.

This body armor system can be incorporated into body armor components such as vests and insert plates relatively low weights such as in the range of 0.5 lb/ft2 to 2.0 lb/ft2, including all values and increments therein, such as 0.5 to 0.75 lb/ft2, 0.75 to 1.25 lb/ft2 etc., while retaining a relatively high degree of flexibility. Again, it is contemplated that the flexibility will be significantly better than the existing technology due to the thickness of the existing technology which is generally thicker than the iron based glassy metal solution. In addition, the iron based glass metal/polymeric layers may be provided on the exterior surface of the composite.

These figures are not meant to be all inclusive in the manner in which the materials can be arranged, but rather to provide a few examples of how they could be used. However, it is also contemplated that the above embodiments consist of, or consist essentially of the above components to achieve a desired stab resistance or ballistics performance as measured by NIJ Standard 0115.00 set forth in September 2000 and NIJ Standard 0101.06 set forth in July 2008, respectively.

Without being bound to any particular theory, the stab instrument is defeated by the iron based glassy metals through the action of multiple mechanisms, schematically illustrated in FIGS. 8a through 8c. FIG. 8a illustrates the sheets 802 and the instrument 804 immediately prior to impact. At the point of impact, the relatively high hardness of the iron based glassy metal sheets 802 may act to dull the stab instrument 804 reducing the cutting and piercing potential of the stab instrument, while the stack of high strength sheets 802 compresses due to the force of the instrument and acts in a bulk manner directly below the point of impact to resist puncture of the material as illustrated in FIG. 8b. The relatively large surface area around the point of impact provided by a number of stacked thin sheets 802 (4″×4″ or larger for each sheet) combined with the relatively high elasticity (>1.0%) of the iron based glassy metal sheets 802, iron based glassy metal sheets 802 deflect and act together to create a spring, in a manner similar to a leaf spring as illustrated in FIG. 8c. The spring action returns the energy of the stab instrument back to the stab instrument (attacker) instead of into the body armor, thereby reducing the effective stab energy. The combination of the three mechanisms has been shown to effectively defeat stab threats of single and double edged blades as well as spikes such as the California ice pick to NH 0115.00 Level 3, Energy 2 standard test at pack weights below 1.0 lb/ft2.

Thus, the iron based glassy sheets including the iron based glassy foils or woven fabrics may be utilized in various forms to provide a stab resistant component for body armor. The iron based glassy sheets alone, or incorporated into a composite (such as described in FIGS. 5 and 7), may be formed into or incorporated into a vest, armor plates for surrounding the torso, arms, legs, or helmets to create suitable body armor.

For example, the iron based glassy sheets including the iron based glassy foils or woven fabrics may be utilized in various forms to provide a stab threat vest, such as those typically used by correctional officers, where a ballistic threat doesn't exist. Stab threat inserts including the iron based glassy sheets described above may be provided as add-on components to body armor ballistic vests or plates to provide local stab threat protection, as used by military and law enforcement personnel. Ballistic blunt force trauma (BFT) reduction systems may also incorporate the iron based glassy metal foil described herein and have demonstrated the ability to reduce blunt force trauma in a relatively lower weight, thinner, and more flexible material system than the conventional technology. BFT insert plates are used in combination with ballistic body armor to enhance the protection level of the armor in critical areas such as over the sternum.

EXAMPLES Example 1

A stack of iron based glassy sheets were mounted in a testing fixture according to the NIJ 0115.00 procedure. 20 foils were provided in the stack, each having a thickness of 0.030 mm. The stack weighed 1.0 pounds per square foot. A 0° stab test was performed at a strike energy of 65+/−0.80 Joules. The spike impacted the stack of foils with the highest NIJ 0115.00 energy level (Level 3, Energy 2). FIG. 9 illustrates the bending of a stab instrument 902 upon impact with the glassy metal sheets 904. As can be seen in the figure, the glassy metal sheets were dented, but not penetrated.

Example 2

A stack of iron based glassy sheets were mounted in a testing fixture according to the NIJ 0115.00 procedure. 24 foils were provided in the stack, each having a thickness of 0.030 mm. The stack of foils weight 1.25 pounds per square feet. A 0° double edge test was performed at a strike energy of 65+/−0.80 Joules. FIG. 10 illustrates that the double edge test instrument 1002 bounced off of the body armor 1004. The double edged blade impacted the stack of foils with the highest NIJ 0115.00 energy level (Level 3, Energy 2). The double edged blade bounced upon impact with the stack of iron based glassy metal foils.

Example 3

Level 3 edged-blade and spike stab resistance, per NIJ 0115.00, has been achieved in a 1.5 lb/ft2 soft and flexible material system consisting of 27 layers of iron based glassy metal foil and 3 layers of thermoplastic coated woven para-aramid fabric. The system is structured such that 1 layer of the para-aramid fabric is on the strike face, followed by 27 layers of foil, then 2 layers of para-aramid fabric on the back face (body-side). The material system effectively defeated the most severe stab attack testing (Level 3) per NIJ 0115.00 against single-edge (P1) and double-edged (S1) blades as well as the engineered spike at attack angles of 90° and 45° to the material system strike face. The soft body armor material system achieving the combined (edged-blade and spike) level of stab protection has an areal density of 1.65 lb/ft2.

Example 4

Iron based glassy metal soft ballistic blunt force trauma (BFT) plates consisting of 4 layers of iron-based glassy metal foil sandwiched between 2 layers of a 3D structured para-aramid fabric were constructed and tested using the NIJ 0101.06 standard ballistic test procedure. Ballistic testing of the iron based glassy metal hybrid soft BFT material system, in combination with a NIJ 0101.06 certified Level II ballistic vest, showed 31% weight reduction and equivalent trauma reduction when compared to conventional trauma plates as is shown in Table 2. The average bullet velocity in the ballistic tests was 1430 ft/sec for the 0.357 Mag and 1300 ft/sec for the 9 mm rounds. The trauma reduction is a measure of the reduction beyond what the ballistic vest without the BFT plate would provide. In addition to reduced weight provided by the iron based glassy metal hybrid soft BFT, it was observed that the material system was relatively more flexible and thinner than conventional trauma plates and provided resistance to electroshock weapons since it provides a low resistance current path between the weapon's electrodes.

TABLE 2 Blunt force trauma reduction using convention and iron based glassy metal BFT plates Trauma Reduction .357 Trauma Plate Areal Density Mag 9 mm Conventional  1.0 lb/ft2 18% 40% Iron based glassy 0.69 lb/ft2 16% 40% metal hybrid

While particular embodiments have been described, it should be understood that various changes, adaptations and modifications can be made therein without departing from the spirit of the invention and the scope of the appended claims. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents. Furthermore, it should be understood that the appended claims do not necessarily comprise the broadest scope of the invention which the Applicant is entitled to claim, or the only manner(s) in which the invention may be claimed, or that all recited features are necessary.

Claims

1. A stab resistant body armor component, comprising:

a plurality of iron based glassy metal sheets, wherein said iron based glassy metal sheets comprise an iron based glassy metal alloy including iron present in the range of 45 atomic percent to 71 atomic percent, nickel present in the range of 4 atomic percent to 17.5 atomic percent, boron present in the range of 11 atomic percent to 16 atomic percent, silicon present in the range of 0.3 atomic percent to 4.0 atomic percent and optionally chromium present in the range of 0.1 atomic percent to 19 atomic percent, and said alloy includes spinodal glass matrix microconstituent structures including one or both of a) semicrystalline phases and b) crystalline phases in a glass matrix.

2. The component of claim 1, wherein said plurality of iron based glassy metal sheets, in combination with a polymeric material outer layer, exhibit resistance to Level 3 NIJ standard 0115.00 spike, single edge and double edge attacks.

3. The component of claim 1, wherein said component exhibits an areal weight of 0.5 lb/ft2 to 2.0 lb/ft2.

4. The component of claim 1, wherein said spinodal glass matrix microconstituent structures are present in the range of 5% to 95% by volume.

5. The component of claim 1, wherein said semicrystalline or crystalline phases are in the range of 1 to 200 nm in size.

6. The component of claim 1, wherein said iron based glass metal alloy has a density in the range of 7.40 g/cm3 to 7.80 g/cm3.

7. The component of claim 1, wherein said iron based glass metal alloy exhibits a glass to crystalline transformation temperature in the range of approximately 396° C. to 713° C., including all values and ranges therein, when measured by differential thermal analysis (DTA) or differential scanning calorimetry (DSC) at a heating rate of 10° C./minute.

8. The component of claim 1, wherein said iron based glass metal alloy exhibits an ultimate tensile strength in the range of 0.4 GPa to 3.90 GPa and a total elongation in the range of 0.4% to 5.5%, when tested at a strain rate of 0.001 s−1.

9. The component claim 1, wherein said iron based glass metal alloy exhibits a Vickers hardness of 900 to 950 using a diamond pyramid indenter with a 50 gram load.

10. The component of claim 1, wherein said iron based glassy alloy sheets comprises foils each having a thickness in the range of 0.0005 inches to 0.0020 inches.

11. The component of claim 1, wherein said iron based glassy alloy sheets comprise fibers of said iron based glass metal alloy woven into a fabric.

12. The component of claim 11, further comprising one or more non-glassy metal fibers selected from the group consisting of: polymeric fibers, natural fibers and inorganic fibers, wherein said non-glassy metal fibers are interwoven with said iron based glass metal alloy fibers.

13. The component of claim 12, wherein said non-glassy metal fibers are present in the range of 5% by weight to 95% by weight.

14. The component of claim 1, further comprising one or more polymeric layers.

15. The component of claim 14, wherein said polymer layers are alternated with said iron based glassy metal sheets at a ratio of in the range of 10:1 to 1:10.

16. The component of claim 1, further comprising a ballistic material disposed adjacent to said iron based glassy metal sheets.

17. The component of claim 1, further comprising a cover disposed around at least a portion of said iron based glassy metal sheets.

18. A method of forming a stab resistant body armor component, comprising:

forming a plurality of iron based glassy metal sheets, wherein said iron based glassy metal sheets comprise iron based glass metal alloys including iron present in the range of 45 atomic percent to 71 atomic percent, nickel present in the range of 4 atomic percent to 17.5 atomic percent, boron present in the range of 11 atomic percent to 16 atomic percent, silicon present in the range of 0.3 atomic percent to 4.0 atomic percent and optionally chromium present in the range of 0.1 atomic percent to 19 atomic percent, and said alloy includes spinodal glass matrix microconstituent structures including one or both of a) semicrystalline phases and b) crystalline phases in a glass matrix; and
arranging said plurality of iron based glassy metal sheets into a stack.

19. The method of claim 18, wherein forming said plurality of iron based glass metal sheets comprises forming foils.

20. The method of claim 18, wherein forming said plurality of iron based glass metal sheets comprises forming said iron based glass metal alloys into fibers and forming said fibers into a fabric.

21. The method of claim 20, wherein said fabric further comprises non-glassy metal fibers.

22. The method of claim 18, further comprising alternating said iron based glassy metal sheets with one or more polymeric layers.

23. The method of claim 18, further comprising disposing said stack of iron based glassy metal sheets adjacent to a ballistic material.

Patent History
Publication number: 20140082807
Type: Application
Filed: Sep 4, 2012
Publication Date: Mar 27, 2014
Inventors: Charles D. TUFFILE (Dighton, MA), John Vincent COSTA (Somerset, MA), Daniel James BRANAGAN (Idaho Falls, ID)
Application Number: 13/603,198
Classifications
Current U.S. Class: Penetration Resistant (2/2.5)
International Classification: F41H 1/02 (20060101);