Molded composite of silicon-impregnated reaction-coupled mixed ceramic material

Abstract

To provide a molded composite capable of being used as a bulletproof material against a tungsten carbide bullet.SOLUTION: A molded composite of a silicon-impregnated reaction-coupled mixed ceramic material has a microstructure defined by: primary grains (1) of crystalline boron carbide (B4C) having an average particle diameter of 500 μm>d50>100 μm and a composition of greater than 10 wt.% and less than 50 wt.%; and primary grains of fine silicon carbide having d50<70 μm and a composition of greater than 10 wt.% and less than 50 wt.%. The primary grains of crystalline boron carbide are bonded by silicon impregnation treatment (3) within a silicon carbide matrix having a free metallic silicon (2) in an amount greater than 1 wt.% and less than 20 wt.%, thereby forming a subsidiary silicon carbide as a component in an amount greater than 5 wt.% and less than 25 wt.%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to composites comprised of molten silicon infiltrated and reaction bonded mixed ceramics. [Background technology]

[0002] In the field of body armor (ballistic materials) for people, vehicles and aircraft, weight is a key issue. This is why composite ceramic solutions are being used, especially instead of steel solutions. Composite ceramics are able to stop the penetrating propulsion of a bullet with a lower overall weight than steel solutions, and are therefore more comfortable for the user.

[0003] In principle, aluminum oxide, silicon carbide, sintered boron carbide materials, and reaction-bonded materials containing metal components in the matrix (parent phase or substrate) are of interest. Examples of reaction-bonded materials are reaction-bonded (RB) silicon carbide (RB-SiC), reaction-bonded boron carbide (RB-B4C), and a combination of RB-SiC and RB-B4C (RB-SiC / B4C). Silicon carbide and boron carbide materials, especially boron carbide, offer the lightest protection but are also the most expensive. Due to their lightest weight, these materials are advantageously used in the fields of personnel protection as well as aircraft protection. In the field of personnel protection / personal protection, monolithic materials (integrated protective materials) are also used.

[0004] Among these products, sintered materials generally offer lighter armor than those made with reaction-bonded materials. However, in most cases, reaction-bonded materials offer a better price-performance ratio. For example, RB-B4C can be effectively combined with RB-SiC to provide protection against various threat types, such as NIJ4 standards, and hardened steel-core bullets. Reaction-bonded materials have dominated markets not only in Europe, but also in Asian countries such as Korea.

[0005] Patent Document 1 describes that the material exhibits excellent ballistic resistance against bullets made from cemented carbide alloys such as WC / Co (tungsten carbide-cobalt), particularly the excellent ballistic resistance required for "next-generation SAPI plates." The United States, the world's largest defense market, is of great interest in efficient protective materials. Until now, bullet tests using tungsten carbide cores have generally shown poor performance, not only with RB-B4C and RB-SiC, but also with sintered B4C. Therefore, sintered silicon carbide has been used in most cases, and reaction-bonded materials have rarely been used.

[0006] Sintered B4C is also inadequate for tungsten carbide-core bullets because the high hardness and high velocity of the penetrator material induce amorphization of the boron carbide material, as described, for example, in "Bronze carbide ballistics" (J. Am. Chem. Soc. 1999, 144:101-102, 1999). This amorphization reduces the performance of the ballistic material.

[0007] The frequent use of RB-B4C materials against non-tungsten carbide core threats, which are common in the US market, is described, for example, in US Patent No. 2,023,363, which shows that the suitability for so-called kinetic energy bullets made of tungsten carbide is lacking in the usual reactive bonding materials available on the US market.

[0008] Furthermore, most of the protective materials used have a fine particle size, as described in U.S. Patent No. 5,623,666. According to the prior art, fine particle size materials provide excellent ballistic performance. U.S. Patent No. 5,623,666 also describes a reaction-bonded boron carbide material, but the particle size of the boron carbide powder is less than 40 μm.

[0009] Furthermore, Patent Document 5 describes that the predominant coarse crystals reduce the bulletproof performance because the coarse microcrystals weaken the intercrystalline bonds.

[0010] Furthermore, Patent Document 6 describes silicon-impregnated boron carbide materials with particle sizes ranging from 600 grit to 120 grit. Therefore, particle sizes of less than 110 μm are generally used for silicon-impregnated boron carbide materials. Furthermore, the boron carbide (B4C) content described in Patent Document 6 is much greater than 50 wt. %. However, it has been found that a high boron carbide (B4C) content causes the boron carbide material to become amorphous, resulting in reduced performance against WC / Co bullets.

[0011] Finally, Patent Document 7 describes that particle sizes of 200 μm to 40 μm can be used in principle, and particles exceeding 90 μm are particularly used. Patent Document 7 further describes a material containing 50 to 60 wt % of boron carbide, which has traditionally been considered to be disadvantageous compared to tungsten carbide. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] U.S. Patent No. 8,128,861 [Patent Document 2] International Publication No. 2005 / 079202 Pamphlet [Patent Document 3] U.S. Patent No. 6,609,452 [Patent Document 4] Patent No. 5914026 [Patent Document 5] US Patent Application Publication No. 2013 / 0168905 [Patent Document 6] U.S. Patent No. 3,857,744 [Patent Document 7] US Patent Application Publication No. 2013 / 0168905 [Non-patent literature]

[0013] [Non-Patent Document 1] "High-Velocity Ballistic Impact with Boron Carbide Produces Localized Amorphization," MRS Bulletin, Vol. 28, No. 5, May 2011, p. 333. Summary of the Invention [Problem to be solved by the invention]

[0014] It is therefore an object of the present invention to provide an improved molded composite made of reaction-bonded SiC / B₄C material that can be used for critical ballistic protection against tungsten carbide bullets, at an optimum price / performance ratio. [Means for solving the problem]

[0015] This object is achieved by the features of claim 1.

[0016] Thus, ceramic bodies are provided that are particularly suitable for use in ballistic armor applications, based on metal ceramic composites containing silicon (Si), silicon carbide (SiC), and coarse-grained boron carbide (B4C). The material's properties are determined by the raw material composition, molding process, and siliconization process. The molded composites produced in this way typically have optimized density and high hardness, and their special microstructure makes them particularly suitable for ballistic armor applications.

[0017] Microstructure is influenced by the by-production of silicon carbide in reaction-bonded silicon-infiltrated composite ceramic materials. The nature and amount of optional carbon addition is crucial for the formation of by-product silicon carbide and the formation of bonding bridges that determine the strength of the material. The siliconization procedure, in which molten silicon is infiltrated into a porous compact, is significantly influenced by the pore structure.

[0018] Surprisingly, ballistic tests using molded composites of the present invention have shown that relatively good properties can be achieved by embedding primarily reaction-bonded (RB) crystalline boron carbide particles larger than 100 μm and containing less than 50 wt. % boron carbide (B4C) in a finely grained silicon carbide matrix composed primarily of silicon carbide (SiC) and secondary silicon carbide (SiC) particles. Surprisingly, the combination of large boron carbide particles and a boron carbide composition that is not excessively large prevents amorphization as the silicon carbide matrix (matrix / substrate) stabilizes. The selected boron carbide primary grain size also has the effect of stabilizing the silicon carbide matrix. These are material properties not previously noted in the prior art.

[0019] Finally, controlling the amount of carbon added in the present invention can affect the formation of by-product silicon carbide and the resulting bond bridges. In the present invention, it is preferable to have a lower amount of silicon carbide (SiC) formed during impregnation, for example, greater than 5 wt.% and less than 25 wt.%, and it is preferable to have a silicon (Si) composition of less than 20 wt.%. Therefore, the material of the present invention appears to produce a kind of functional deformation at the level of boron carbide (B4C) in ceramics that are otherwise largely undeformable.

[0020] Not only a high silicon carbide (SiC) content, but also a low silicon (Si) content can be advantageous. Of particular advantage is a residual silicon content of less than 15 wt%. Particularly preferred is a material having a boron carbide (B4C) content of between 30 and 40 wt%, a by-product silicon carbide (SiC) content of 15 to 25 wt%, a silicon content of less than 15 wt%, and a primary boron carbide particle size of greater than 100 μm.

[0021] All conventional processes can be used for the forming operation. For example, in the case of limited size and simple geometric shapes, such as for bulletproof plates for human bodies, casting, especially pressure slip casting, is the most efficient manufacturing technique. It should be noted that the coarse crystallites of boron carbide (B4C) tend to settle. However, regardless of the tendency of the crystallites to settle, it is possible to produce slips that are stable with respect to settling.

[0022] Slip casting is limited to a wall thickness of 10 mm, especially as wall thicknesses exceed 10 mm and very large geometries become more prone to cracking and extensive deformation. The 10 mm wall thickness limit also applies to isostatically pressed materials, as density gradients increase with size and volume during isostatic pressing.

[0023] Surprisingly, powder bed fusion (powder bed) based 3D printing has emerged as a suitable manufacturing technique for very large components. In particular, for the material of the present invention - coarse boron carbide (B4C) combined with fine silicon carbide (SiC) - powder bed fusion printing technology is a very efficient manufacturing method. Large geometries are particularly required in the aerospace industry, for example, for protective parts such as seats and larger-than-seat plates. [Effects of the Invention]

[0024] On the one hand, coarse boron carbide (B4C) crystallites have the obvious advantage of increasing printing efficiency. On the other hand, surprisingly, large components produced by powder bed fusion 3D printing using coarse boron carbide crystallites were found to be much more homogeneous than those produced by casting, die casting (stamping), or isostatic pressing. Compared to isostatic pressing and subsequent green machining, powder bed fusion printing offers significant cost advantages, as it does not require machining (milling of the green material) and uses very little material.

[0025] For example, powder bed fusion 3D printing makes it possible to manufacture large components, such as seat shells and backrests, from molded composites according to the invention. The near-net-shape approach allows these components to be manufactured using only the amount of material actually required for the application, thus saving material as well as reducing weight.

[0026] The bulletproof plate manufactured in this way is 1m 2 These dimensions can be easily envisioned, allowing the entire protective material, such as vehicle or aircraft doors, rear doors (tailgates), floor components, and other structural parts, to be constructed as a single structure. The larger size of the protective material components promotes the integration of the protective material, avoiding joints that could become weak points in artillery fire. It is known that triple points (where the three corners of a bulletproof tile meet) can reduce ballistic performance by up to 30%. However, due to the high homogeneity of the material achieved by 3D printing, it is possible to reduce the volume of the outer shell (envelope) to 200 x 200 x 200 mm. 3 Larger than 500 x 500 mm 2 Very large components with areas larger than 1000 mm can also be realized without any problems. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 shows a schematic cross section of the microstructure. DETAILED DESCRIPTION OF THE INVENTION

[0028] Further details of the present invention can be found in the following description and claims that follow.

[0029] The invention will now be explained in more detail with reference to exemplary embodiments.

[0030] The present invention relates to a molded composite of silicon-impregnated, reaction-bonded mixed ceramic materials. The microstructure of the molded composite is defined by primary grains of crystalline boron carbide (B4C) with an average grain size d50 of greater than 100 μm and less than 500 μm, and a content of greater than 10% but less than 50% by weight. The microstructure of the molded composite of the present invention is further defined by primary grains of silicon carbide with a d50<70 μm and a content of greater than 10% but less than 50% by weight. The silicon-bonded primary grains of crystalline boron carbide produce secondary silicon carbide in a silicon carbide matrix (matrix or substrate) with a content of greater than 5% but less than 25% by weight. The silicon carbide matrix contains greater than 1% but less than 20% by weight of free metallic silicon (unreacted metallic silicon). Figure 1 shows an example of a microstructure according to the present invention. The weight percent values ​​indicate weight ratios as percentages. The content (composition) means the rate or ratio of grains (crystal grains) contained, or both.

[0031] Thus, the present invention relates to reaction-bonded SiC / B4C having a boron carbide (B4C) content of less than 50 wt. %, a mean particle size (d50) of the boron carbide material greater than 100 μm, a by-product silicon carbide (SiC) content of less than 25 wt. %, and a silicon metal content of less than 20 wt. %.

[0032] The content of by-produced silicon carbide (SiC) is preferably between 15% and 25% by weight, which provides a stable support matrix for the predominant crystalline boron carbide (B4C) and silicon (Si), thereby increasing projectile (bullet) resistance, for example.

[0033] Particularly preferred are shaped composites having a boron carbide (B4C) content of between 30 and 40% by weight, a silicon content of less than 15% by weight, and a boron carbide primary grain size (primary particle size) of greater than 200 μm.

[0034] Furthermore, it is particularly preferred that the primary grains are silicon carbide with d50<40 μm, especially <10 μm. The density gradient may be less than 2 wt.%. The molded composite may further contain boron (B) dissolved in the metallic silicon in an amount greater than 0.05 wt.% and less than 5 wt.%.

[0035] The microstructure in Figure 1 shows a structure composed of primary grains of crystalline boron carbide (B4C) 1, free metallic silicon (Si) 2, and an infiltrated complex of finely divided primary silicon carbide (SiC) and secondary silicon carbide 3.

[0036] Molded composites can be produced by pressure slip casting, which involves the production of a slip containing silicon carbide (SiC) / boron carbide (B4C) particles as well as colloidal carbon and organic auxiliary materials. The green body produced by pressure slip casting is then contacted with liquid silicon at temperatures between 1500°C and 1700°C for impregnation. During the contact and impregnation process, silicon reacts with carbon to produce silicon carbide (SiC) by-product.

[0037] In another embodiment of the invention, the molding operation is performed by 3D printing, allowing the fabrication of complex products such as seat shells and backrests for aerospace applications. The ceramics thus produced, in combination with carbon fiber, glass fiber and / or metals as well as polymers (PE, aramid, etc.), provide particularly efficient protection against WC / Co bullets, especially against armor-piercing bullet types such as M993 and M995.

[0038] A further object of the present invention is to use the molded composite as a ballistic armor. To this end, the molded composite is advantageously surface-treated with one or more layers of a backing material. For example, at least one layer of the backing material can be pressed with the mixed ceramic of the present invention. Furthermore, the backing material is preferably formed from several layers of one or more plastics, such as polyethylene or aramid, carbon fiber, glass fiber, or metal, such as aluminum or steel, or a combination of these materials, or a bonding material, such as an adhesive foil. Furthermore, the backing material is preferably formed from several layers of both plastic, carbon fiber, glass fiber, metal, a combination of these materials, and a bonding material.

[0039] Next, various application examples will be described.

[0040] (First embodiment) The use of pressurized slip casting to produce a bulletproof plate for human bodies from the molded composite of the present invention is described. An aqueous suspension is prepared containing 10% by weight of colloidal carbon with an average particle size of less than 1 μm, 50% by weight of finely divided silicon carbide with an average particle size of 5-10 μm, and 40% by weight of coarsely divided boron carbide (B4C) with an average particle size of 120 μm. For this purpose, 18% by weight of water and 1% by weight of organic auxiliary substances (wetting agent, fluidization aid, binder) are used relative to 100% by weight of solids. The slip is cast in a die-casting (stamping) machine using a porous plastic mold based on polymethyl methacrylate at a slip pressure of 0.4 kPa to form a multi-curved plate with dimensions of 350 x 275 x 9 mm.

[0041] The cast shards are dried in a circulating air drying chamber and converted by reactive firing into ceramic plates based on a reaction-bonded composite material consisting essentially of silicon carbide (SiC) and boron carbide (B4C) as well as free silicon. The composite thus produced forms a body armor plate that can be used as a monolithic insert in a bulletproof vest. For this purpose, the molded composite is composed of a material containing, for example, 31% by weight of coarse-grained boron carbide (B4C), 41% by weight of fine-grained primary silicon carbide (SiC), 17% by weight of fine-grained by-product silicon carbide (SiC), and 11% by weight of free metallic silicon.

[0042] (Second embodiment) The following describes the use of uniaxial press molding to manufacture vehicle bulletproof armor plates from the molded composite of the present invention. First, an aqueous suspension is prepared according to the composition described in the first embodiment, and then further processed into pressed granules by a spray drying process. All that is required is to adjust the composition of organic additives and add a press support step.

[0043] The granules are then packed into a rectangular cemented carbide die and pressed at a pressure of 17 kPa. The blank thus obtained is then subjected to reaction sintering to produce a ceramic plate based on a reaction-bonded composite material consisting essentially of silicon carbide (SiC) and boron carbide (B4C) as well as free silicon. The ceramic plate has an edge length of 50 mm and a wall thickness of 9 mm. The molded composite thus obtained forms a polygonal ballistic plate that can be used as an efficient backing for large areas in vehicle ballistic armor.

[0044] (Third embodiment) A 3D printing process is used to manufacture a helmet from the molded composite of the present invention. The helmet shape is created layer by layer from amorphous granules of silicon carbide (SiC) and boron carbide (B4C) in a mixture ratio of 70% SiC and 30% B4C by weight. The boron carbide (B4C) powder has a particle size distribution similar to that used in industrial refractory ceramics, e.g., classified as 100 / F, with characteristic values ​​of d10 = 75 μm, d50 = 115 μm, and d90 = 160 μm. Further refined silicon carbide (SiC) powder has a particle size distribution similar to that used in industrial abrasives, e.g., classified as F180, with an average particle size of d50 = 65 μm.

[0045] The particles are selectively solidified via an inkjet printhead by the dropwise introduction of an organic binder, preferably a furan (or furfural) resin, at locations specified by the underlying CAD model. The CAD model used for selective solidification corresponds to the geometric shape of the final component, allowing for the creation of complex structures.

[0046] Following the two sub-steps of solidification and molding, the thickness of the resulting plane is reduced by a predetermined thickness, e.g., 300 μm in the third embodiment. This series of steps is repeated until the layer-by-layer structure of the CAD model is determined. The resulting complex-shaped pre-body has a porosity of 45% by volume. It is then impregnated with an aqueous dispersion containing 30% by weight of colloidal carbon, along with a dispersing aid and a wetting agent.

[0047] After the first impregnation process, a complex-shaped ceramic preform is thus produced. The preform contains 87% by weight of a silicon carbide (SiC)-boron carbide (B4C) powder mixture as raw materials and 13% by weight of colloidal carbon. After the drying process and an optional second impregnation step, this ratio changes to 79 / 21% by weight, and after an optional third impregnation step, it changes to 76 / 24% by weight.

[0048] Based on a reaction-bonded composite material essentially composed of silicon carbide (SiC) and boron carbide (B4C) with free silicon addition, the complex-shaped preform thus produced, after a final drying process, is converted into a ceramic substrate by reactive sintering. The resulting material, for example, consists of 15% by weight of coarse-grained boron carbide (B4C), 45% by weight of fine-grained primary silicon carbide (SiC), 24% by weight of fine-grained secondary silicon carbide (SiC), and 15% by weight of free metallic silicon. The complex-shaped preform thus obtained can be used as the basic element of a ballistic helmet for head protection. Manufacturing using the 3D printing process described in the third embodiment allows for the provision of ergonomically tailored helmet geometries.

[0049] (Fourth embodiment) The fourth embodiment describes the production of a seat shell by 3D printing using a molded composite according to the present invention. As described in the third embodiment, the mixing ratio in the powder bed fusion-based 3D printing process is 60% by weight of silicon carbide (SiC) and 40% by weight of boron carbide (B4C). This reduces the density of the fired component, making the production of this material composition particularly suitable for the aerospace industry. The material thus obtained consists, for example, of 21% by weight of coarse-grained boron carbide (B4C), 40% by weight of fine-grained primary silicon carbide (SiC), 24% by weight of fine-grained by-product silicon carbide (SiC), and 15% by weight of free metallic silicon.

[0050] Thus, in the fourth embodiment, using an appropriate CAD model, a weight-optimized seat shell can be realized for use in various air vehicles, such as helicopters. The seat shell thus manufactured measures approximately 300 x 300 mm, has a wall thickness of 9 mm, is 200 mm high, and is ergonomically shaped. The associated backrest measures 500 mm long, 300 mm wide, and 100 mm high, and is also ergonomically shaped. Even such large components can be manufactured without cracks. Subtractive machining, such as milling, is no longer necessary.

[0051] (Fifth embodiment) The fifth embodiment describes the use of 3D printing to produce an aerospace bulletproof armor plate using a molded composite according to the present invention. As in the fourth embodiment, a powder bed fusion-based 3D printing process is used to produce the molded composite according to the present invention. The mixing ratio in the powder bed fusion-based 3D printing process is 50% by weight of silicon carbide (SiC) and 50% by weight of boron carbide (B4C). The material thus obtained consists, for example, of 26% by weight of coarse-grained boron carbide (B4C), 35% by weight of fine-grained primary silicon carbide (SiC), 24% by weight of fine-grained by-product silicon carbide (SiC), and 15% by weight of free metallic silicon. These contents further reduce the density of the component upon sintering. Therefore, the production of a molded composite with the material composition described in the fifth embodiment is particularly suitable for the aerospace field, especially for large components such as aerospace bulletproof armor plates. The side element manufactured in this manner has dimensions of, for example, 1200 mm x 800 mm x 9 mm.

[0052] (Sixth embodiment) The sixth embodiment will be described with respect to the case where a bulletproof armor is manufactured using the molded composite of the present invention. In particular, the sixth embodiment relates to the case where a bulletproof armor for a tungsten carbide core ammunition system is manufactured using the molded composite. For example, the weight per unit area is 2075 g / 700 cm. 2= 33.5 kg / m 2 The sixth embodiment is a bulletproof armored equipment. The bulletproof armored equipment according to the sixth embodiment comprises a silicon-impregnated mixed ceramic having a shape (configuration) of 240 mm x 305 mm x 9.1 mm and weighing 1790 g. The lining material of the bulletproof armored equipment according to the sixth embodiment preferably has, for example, 27 polyethylene layers and further preferably has 8 carbon fiber layers. The weight per unit area of ​​the bulletproof armored equipment according to the sixth embodiment is, for example, 385 g.

[0053] The mixed ceramic material and the backing material may be compressed together by applying heat and pressure. Preferably, the mixed ceramic material and the backing material are compressed together in an autoclave (heated pressure cooker). As a result, the ballistic armor according to the sixth embodiment achieves ballistic protection against a single shot of a 5.56x45 M995 bullet with a tungsten carbide core. In tests, the protection against a single shot of a 5.56x45 M995 bullet means that the bullet only deformed the back surface by 39 mm without penetrating. Generally, the backing material can be composed of an aramid fiber lining, polyethylene (PE), a carbon fiber lining, a glass fiber lining, or a mixture thereof, or all of these. Furthermore, a layer of backing material is preferably attached to one or both sides of the mixed ceramic material layer. Therefore, generally speaking, a single shot of a tungsten carbide-core M995 bullet with a force of 32 kg / m is sufficient. 2 Preferably, it can be stopped at a basis weight below.

[0054] (Seventh embodiment) The seventh embodiment will be described with respect to the manufacture of a bulletproof armor from the molded composite of the present invention. In particular, the seventh embodiment will be described with respect to a bulletproof armor for a tungsten carbide core ammunition system. The bulletproof armor according to the seventh embodiment has a weight per unit area of ​​2342 g / 700 cm. 2 = 33.5 kg / m 2The bulletproof armor according to the seventh embodiment includes a silicon-impregnated mixed ceramic having a size (configuration) of 240 mm x 305 mm x 9.1 mm and weighing 1792 g, and the backing material preferably has 39 polyethylene layers and 8 carbon fiber layers. The bulletproof armor according to the seventh embodiment has a weight per unit area of ​​385 g, for example.

[0055] The mixed ceramic material and the backing material may be compressed by heating and pressure. Preferably, the mixed ceramic material and the backing material can be compressed together in an autoclave (heated pressure cooker). As a result, the ballistic armor according to the seventh embodiment achieves ballistic protection against two shots of a 5.56x45 M995 bullet with a tungsten carbide core. In tests, the protection provided by the ballistic armor according to the seventh embodiment was demonstrated by a deformation of only 29 mm for the first shot and 37 mm for the second shot, without penetration. Generally, the backing material can be composed of an aramid fiber lining, polyethylene (PE), a carbon fiber lining, or a glass fiber lining, or a mixture thereof, or all of these. Furthermore, a layer of backing material can be suitably attached to one or both sides of the layer of mixed ceramic material. Generally, therefore, two shots of a tungsten carbide-core M995 bullet with a force of 40 kg / m², preferably at a distance of 100 mm, are resistant. 2 It can be suitably stopped at a basis weight below. [Explanation of symbols]

[0056] 1...Primary grains of crystalline boron carbide (B4C), 2...Free metallic silicon (Si), 3...Infiltrated complex of primary silicon carbide (SiC) and secondary silicon carbide.

Claims

1. Crystalline boron carbide (B) with an average particle size d50>100 μm and a composition of 30-40 wt% 4 C) a molded composite of silicon-impregnated reaction-bonded mixed ceramic material having a microstructure defined by the primary grains of the microstructure is defined by fine primary grains of silicon carbide; the primary grains are siliconized and bonded by by-produced silicon carbide of 15-25 wt. % composition, and the microstructure has free metallic silicon of less than 15 wt. % composition, formed with controlled carbon additions to influence the siliconization procedure to form a silicon carbide matrix comprising a predominant silicon carbide component and a by-produced silicon carbide component; The crystalline boron carbide (B 4 C) the primary grain components are embedded in the silicon carbide matrix.

2. 2. The molded composite of claim 1, wherein the primary grains of the silicon carbide have a d50<40 μm or a d50<10 μm.

3. 3. The composite compact according to claim 1, wherein said composite compact can be formed by slip casting, pressure casting, uniaxial pressing, isostatic pressing, stamping or manual powder compaction.

4. The molded composite of any one of claims 1 to 3, wherein molding of the composite compact can be performed via a powder bed fusion 3D printing process.

5. The silicon carbide (SiC) and boron carbide (B 4 5. The composite molding according to claim 4, wherein the powder mixture of C) is printed by powder bed fusion with a binder to form a three-dimensional component, which is then siliconized.

6. 6. The molded composite according to claim 1, wherein the composite molded body is formed in the form of a plate.

7. 7. The composite compact according to claim 1, wherein the composite compact is molded so that the volume of the outer shell of the composite compact is greater than 200×200×200 mm.

8. and a backing material comprising one or more layers, the backing material comprising one or more layers being compressed with the mixed ceramic material to a basis weight of 32 kg / m. 2 Less than or equal to 40 kg / m 2 8. A method for using the molded composite of claim 1 in a bulletproof armor system, characterized in that the molded composite is configured to be larger than the conventional one, thereby selectively providing protection against one or two shot ammunition systems.

9. 9. The use of a composite compact in a ballistic armor system according to claim 8, wherein said backing material is designed to protect against tungsten or tungsten carbide containing bullets.

10. 10. The use of a molded composite as claimed in claim 8 or 9 in a ballistic armor system, wherein the backing material is comprised of one or more of plastic, carbon fiber, fiberglass, metal, or a combination thereof, or a bonding material.

11. the plastic is polyethylene or aramid and the backing material is an adhesive foil, or 11. The use of a molded composite in a ballistic armor system according to claim 10, wherein the plastic is polyethylene or aramid, or the backing material is an adhesive foil.

12. 11. A method for using a composite molding according to claim 8 or 10 in bulletproof armor equipment, characterized in that the molding of the composite molding is used to provide a bulletproof plate for a human body, a seat shell, a backrest, a combination thereof, or an aerospace bulletproof armor plate.

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