Since the density of ceramic armor is substantially lower than the density of steel, by substituting steel with ceramic armor, areal weight can be reduced by approximately half. Boron carbide b4c properties and information about. Its strong chemical bonds and hard surface minimize wear in rigorous environments. Screening of silicon precursors for incorporation into. Paxis develops and manufactures specialty solutions for high end ballistic armor employing state of the art metal ceramic materials. Lowtemperature synthesis of boron carbide ceramics. Investigation of a combination of mechanical properties of the nanostructural ceramics showed its advantage over a material obtained using the. Each product is made of nextgeneration materials, shapes, and sizes for use in body, ground vehicle, aircraft, and marine applications to protect the soldiers of today and tomorrow. Originally discovered in mid 19 th century as a byproduct in the production of metal borides, boron carbide was only studied in detail since 1930 boron carbide powder see figure 1 is mainly produced by.
May 23, 2008 a nanodimensional powder of doped boron carbide has been obtained by means of mechanoactivation in a planetary centrifugal mill and used to produce a nanostructural ceramic material by hot pressing at a temperature of 1900c and a pressure of 30 mpa. Boron carbide chemical formula approximately b 4 c is an extremely hard boroncarbon ceramic and covalent material used in tank armor, bulletproof vests, engine sabotage powders, as well as numerous industrial applications. Boron carbide is used in refractory applications due to its high melting point and thermal stability. Boron carbide b 4 c is one of the hardest materials known, ranking third behind diamond and cubic boron nitride. Reactionbonded boron carbide for lightweight armor. Gnp ceramics boron carbide microgrits can be used in a variety of applications such as. The experimental results for manufacturing ceramics from industrial boron carbide powder with 10 wt% of ultradispersed fraction of a powder of the same composition by spark plasma sintering have been presented. It is the third hardest materials known, after diamond and cubic boron nitride. Boron carbide powder is produced when carbon reacts with boron trioxide b 2 o 3. Boron carbide b 4 c has a complex crystal structure, and is an extremely hard ceramic with vickers hardness 30 mpa and a high cross section for absorbing neutrons. Over time the geometries have become more complex, and as a result, precut ceramic panels in 3m boron carbide and 3m sintered silicon carbide are playing a more and more important role in todays designs. In support of improved personal armour development, depth of penetration tests. However, the sintering process that is required to fully densify the material causes the boron carbide body to shrink approximately 20%.
Us3702593a removal of surface from boron carbide composite. In addition, boron carbide is a high temperature semiconductor that can potentially be used for novel electronic applications. Boron carbide tends to contain secondphase graphite and it is this property which has a major influence on the strength of the material. Paxis is the only local active company in this field, alongside a handful of major global companies.
Influence of ultradispersed fraction of boron carbide. The effect of carbon on the sintering of boron doped sic was studied. Boron carbide b 4 c is one of a number of boroncarbon compounds, but is the one most frequently used as a ceramic material. Processing techniques and available classes of armor. Boron carbide ceramic was prepared by reactive spark plasma sintering under n2atmosphere. Boron carbide is known to suffer from a loss in compressive strength in high pressure events due to amorphization. Boron carbides are often used in ballistic armor, taking advantage of exceptional hardness and low density. B4c,tetra boron carbide,boron carbide,boron carbide ceramic.
Boron carbide, b4c, is an extremely hard ceramic material discovered in 1899. Boron carbide for lightweight ceramic armor, and more inside. After several thousand holes, manual operation becomes an onerous task. Ceramic armor components coorstek manufactures lightweight, superior ballistic performance ceramic components for armor integration. As an abrasive, it is used in powdered form in the lapping fine abrading of metal and ceramic products, though its low oxidation temperature of 400500 c 750930 f makes it unable to withstand the heat of grinding hardened. S ince the dawn of history, weapons and armor have been in a lifeanddeath struggle. This advanced ceramic, in the form of plates or tiles inserted into ballistic. Defense armor components coorstek technical ceramics. For example, hardtosinter silicon carbide sic is processed as a liquidphase sintered ceramic. Pdf ceramics based on reactively sintered boron carbide. Level iii and iv ratings for complete armor systems incorporating cerashield armor ceramic components. The ceramic armor industry on the source of type of material. Contact panadyne to discuss your sintered b4c application.
This latter reaction was associated with the onset of substantial. Molten metal reacts with free carbon and with carbon that originates in b4c to form a ceramic composite. Its unique properties from high heat capacity and outstanding thermal conductivity to easy machinability, lubricity, low dielectric constant and superior dielectric strength make boron nitride a truly outstanding material. Boron carbide b 4 c is one of the worlds hardest manufactured materials. Boron carbide foam is low density permeable material with numerous applications. Boron carbide ceramic was prepared by reactive spark plasma sintering under n. Boron carbide, sic, ceramic metal composite, alumina and others. Boron carbide composites are today favoured for ceramic plates protecting against smaller projectiles, such as used in body armour and armoured helicopters. It is the hardest material produced in tonnage quantities. Norbide hotpressed boron carbide technical data productdescription norbide hotpressed boron carbide b 4 c is one of the hardestmaterials known and offers excellentchemical and wear resistance for demanding applications such as blastnozzles, monumentnozzles and armor components. To manufacture ceramic components with high relative density, fine boron carbide powder with sinter additives is moved, processed with conventional ceramicshaping methods and sintered or hot pressmolded at temperatures above 2,000 c in an inert gas. Sinter grade boron carbide powders are specially sized to aid in the manufacturing of sintered ceramic partsthey are typically. An interesting aspect of the ballistic performance of armor grade ceramic tiles was experimentally investigated by sarva et al. Beside these qualities, other ceramic materials have.
Boron carbide ceramics industrial ceramics and glass. Operating environment high temperature,high grinding,high. The result ing composite has high cohesive strength and. Boron carbide is well known as an extremely hard material. Composite armor systems based on these materials o er highest protection in combination with significant reduction in weight. These, and other properties, make them useful in armour applications. The ceramics generally have relatively low density and high hardness. Expired lifetime application number inventor richard a fine. Boron carbide can be used as a powder with various grain sizes or as a ceramic component. The chemical formula of boron carbide is b 4 c and is the third hardest material known to man. Of these boron carbide is the hardest and lightest, but also the most expensive and brittle. Silicon carbide sic owing to its excellent priceefficiency ratio, alumina is the preeminent ceramic armor material for vehicular applications.
Owing to its excellent priceefficiency ratio, alumina is the preeminent ceramic armor material. The effect of carbon on the sintering of borondoped sic was studied. Manufacturers of fnished ceramic armor systems have achieved n. Pdf the use of advanced ceramics for armour systems allows the defeating of. A method of providing fastener holes in extremely hard ceramic armor comprises the steps of. Us4824624a us06684,930 us68493084a us4824624a us 4824624 a us4824624 a us 4824624a us 68493084 a us68493084 a us 68493084a us 4824624 a us4824624 a us 4824624a authority us united states prior art keywords billet boron carbide ceramic plugs method recited prior art date 19841217 legal status the legal status is an assumption and. With a vickers hardness of 30 gpa, it is one of the hardest known materials, behind cubic boron nitride and diamond. Paxis has several patents and is iso9001 certified. The price of sic tiles manufactured by means of a pressureless.
The mohs hardness of this boron carbide ceramic is about 9. Washington mills is the only manufacturer of boron carbide b4c. Lee and yoo 2001 conducted an analysis of a ceramicmetal armor system, in which the strain rate effect was considered and the ballistic limits for different ceramicmetal back plate ratios were derived. Screening of silicon precursors for incorporation into boron. The mechanisms by which a ceramic armour failsis quite complex, and involve failure. High density tungsten carbide ceramics, dymat 2000, krakow, poland, 2329 september 2000.
It is refractory and chemically inert, but less resistant to oxidation than silicon carbide. The ceramics are silicon carbide, boron carbide, titanium. Boron carbide technically known as nonoxide ceramics enable highest protection levels at lowest possible weight. The use of boron carbide for armor applications has increased dramatically in recent years, with the ceramic carbide rapidly becoming the material of choice for military and law enforcement personnel.
Boron nitride is an advanced synthetic ceramic material available in solid and powder form. Oct 15, 2015 boron carbide is well known as an extremely hard material. It is expected to preserve its supremacy above the period of prediction period, due to greater demand for innovative ceramic armor in defense uses. Advanced metals and ceramics for armor and antiarmor. The most expensive ceramic used in armor, and the second hardest material on earth behind diamond, it is also much lighter than alumina.
Ceramic materials for lightweight ceramic polymer armor. It is perhaps the hardest of materials which can be processed as a conventional ceramic, and its applications are concentrated where hardness is the principal requirement, including grit blasting nozzles, bearings, lightweight ballistic armor, etc. As an essential business, agsco corporation will remain open in both illinois and new jersey. Investigation of a combination of mechanical properties of the nanostructural ceramics showed its advantage. Feb 09, 2001 boron carbide b 4 c is one of the hardest materials known, ranking third behind diamond and cubic boron nitride. While in the green or biscuit form it can be machined relatively easily into complex geometries. Originally discovered in mid 19 th century as a byproduct in the production of metal borides, boron carbide was only studied in detail since 1930 boron carbide powder see figure. The material has high wear resistance, high compressive strength and low density and is usually produced by hot pressing or hot isostatic pressing techniques to achieve better sintering. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. It is used in wear parts, abrasives for ultrasonic cutting and lapping, nuclear shielding, ceramic armor, and as a sintering aid. The first and second being diamond and cubic boron nitride respectively. B4c,tetra boron carbide,boron carbide,boron carbide.
Experimental data obtained from numerous journals and conference proceedings, by researchers of various disciplines, covering over thirty years are documented in this report. Gnp ceramic s boron carbide microgrits can be used in a variety of applications such as. At the higher end of performance, silicon carbide sic and boron carbide b 4 c are used with densities of about 3,100 and 2,500k. Boron carbide bulletproof plate ceramic stanford advanced. Ceramic materials for lightweight ceramic polymer armor systems. The free carbon present in the green compact was found to react with the sio 2 covering the surfaces of the sic particles. Lee and yoo 2001 conducted an analysis of a ceramic metal armor system, in which the strain rate effect was considered and the ballistic limits for different ceramic metal back plate ratios were derived.
Ccerashield armor ceramics are not rated by the national institute of justice n. Boron carbide is one of the hardest manmade materials available in commercial quantities that has a finite melting point low enough to permit its relatively easy fabrication into shapes. During the last three decades of the 20th century, a variety of ceramics, including aluminum nitride aln, aluminum oxide al 2 o 3, boron carbide b 4 c, silicon carbide sic, titanium diboride tib 2, tungsten carbide wc. Boron carbide b 4 c is one of a number of boron carbon compounds, but is the one most frequently used as a ceramic material. This report compiles and documents a ceramic armor material database. Silicon carbide is well known as being a ceramic that can be employed as part of an effective armour solution to defeat small arms ammunition. Boron carbide can be machined in green, biscuit, or fully dense states. With a mohs hardness between 9 and 10, boron carbide is one of the hardest synthetic substances known, being exceeded only by cubic boron nitride and diamond. Ultralight ceramic armor materials based on nanostructural. The resulting ceramic product is one of the hardest materials available behind cubic boron nitride and diamond.
Boron carbide chemical formula approximately b 4 c is an extremely hard boron carbon ceramic and covalent material used in tank armor, bulletproof vests, engine sabotage powders, as well as numerous industrial applications. Silicon carbide is often mixed with boron carbide, but monolithic silicon carbide is also used in production of armor materials. Boron carbide b4c properties and information about boron. Boron carbide is exceptionally hard only diamond and cubic boron nitride materials are known to have a higher hardness. Under optimal process conditions such sintering results in a decrease of the sintering temperature and synthesis time, and the addition of ultradispersed fraction increases.
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