Hard armor

Dual hardness armor plate armor-soft steel and armor-aluminum ... 

Chrome-nickel Ni, 1-5 Great hardness Armor plate for... 

Spectra Shield is a product of AlliedSignal that is made by means of a woven fabric of Spectra polyethylene fiber. Figure 4.28 shows a schematic of cross-plied (0°/90°) Spectra fibers in a resin matrix. Helmets, hard armor for vehicles, and soft body armor are shown in Fig. 4.29. The helmet manufacture involves a special version of Spectra Shield, a special shell design, and a three-way adjustable liner of shock absorbing foam padding. These helmets were used by the UN peacekeeping troops from France in 1993 and were introduced to police forces in the US and Europe. A soft body armor of polyethylene fiber consists of five Spectra Shield plies that slide into the pockets in the body armor. 

The proposed end applications of Kevlar (Yang, 1989) and related fibers include ballistic and fire protective apparel, hard armors, reinforced tires and rubber goods, various forms of composites, filament wound pressure vessels, marine ropes, optical cables and industrial gloves. Almost all of them utilize the high tensile properties and high heat-resistance. 

The properties of the most important LCP fibers are listed in Table 1.2. The key application areas for LCP fibers include hard armor (vehicles, helmets), soft ballistic protection (vests), cut protection (gloves), and a variety of composite uses that include honeycomb structure, pressure vessels, and rubber reinforcement. Ropes and cables find utility in the mooring of huge offshore structures such as oil-drilling platforms and the reinforcement and support of optical cables. LCP fibers also find specialty niche markets such as sails for racing yachts, specialized fishing nets, etc. 

Geosynthetic-enhanced TRMs, FFRs, and GCSs. Also, it cannot be overstated how important geotextiles are as filters used beneath hard armor systems such as riprap and articulating blocks. 

Other hard armor systems Long-term (indefinite) moderate to very high flows low to moderate waves low to moderate sediment yields range of fill materials durable and low maintenance High to very high costs no to delayed vegetation estabhshment no to low vegetation density may prevent infiltrahon special deploymenl/equipment requirements... 

Uses. Apphcations for boron carbide relate either to its hardness or its high neutron absorptivity ( B isotope). Hot-pressed boron carbide finds use as wear parts, sandblast no22les, seals, and ceramic armor plates but in spite of its hardness, it finds Httie use as an abrasive. However, this property makes it particulady usehil for dressing grinding wheels. 

Armor. Sihcon carbide is used as a candidate in composite armor protection systems. Its high hardness, compressive strength, and elastic modulus provide superior baUistic capabihty to defeat high velocity projectile threats. In addition, its low specific density makes it suitable for apphcations where weight requirements are critical (11). 

Special quality steels - A vast range of special quality steels is made in electric arc furnaces by adding other metals to form steel alloys. The most commonly known of these is stainless steel, which has chromium and nickel added to form a corrosion-resistant steel. There are very many others however the very hard steels used to make machine tools, the steels specially formulated to make them suitable for engineering, steels developed to survive for decades the hostile environment of nuclear reactors, light but strong steels used in aerospace, extra tough steels for armor plating - to name but a few. 

In our previous work [11], it has been shown that the reduction of NO with CH4 on Ga and ln/H-ZSM-5 catalysts proceeds through the reactions (1) and (2), and that CH4 was hardly activated by NO in the absence of oxygen on these catalysts. Therefore, NO2 plays an important role and the formation of NO2 is a necessary step for the reduction of NO with CH4. In the works of Li and Armor [17] and Cowan et al. [18], the rate-determining step in NO reduction with CH4 on Co-ferrierite and Co-ZSM-5 catalysts is involved in the dissociative adsorption of CH4, and the adsorbed NO2 facilitates the step to break the carbon-hydrogen bond in CH4. It is suggested that NO reduction by use of CH4 needs the formation of the adsorbed NO2, which can activate CH4. 

The civilian advances were accompanied, and often led, by advances in military ordnance. Iron and steel became the basis of swords, spears, arrows, guns, cannon, armor, tanks, warships, and more. In fact, the motivation for inventing and developing new hard materials was often the desire for improved military ordnance. This continues with searches for better body armor, and the inverse searches for more penetrating projectiles. 

The hardness of boron carbide (carbon hexaboride) is not well defined because it is made as sintered compacts which have variable densities, compositions, and defect densities. It is very hard (up to 4400kg/mm2), and of relatively low density, so it has been used extensively as body-armor (McColm,... 

Typical APC-T (Armor-Piercing, Capped Tracer) Projectile, shown in Fig 1-8, consists of hardened steel monobloc body and cap of forged alloy steel. The AP cap is heat-treated to have a hard exterior and a relatively soft core. The softer core protects the hardened point from breakage by distributing the stress during impact and thus helps the penetration thru armor. Then the BD fuze functions to detonate a HE chge located in the cavity at the rear of the body... 

Bullet Splash. It is the dispersion of finely divided or iRoicoci Histsi producsd by s bullet upon impact with armor plate or other hard objects... 

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