Nose cones

The development of the principles of nucleation and growth eady in the twentieth century (2) ultimately led to the discovery that certain nucleating agents can induce a glass to crystallize with a fine-grained, highly uniform microstmcture that offers unique physical properties (3). The first commercial glass-ceramic products were missile nose cones and cookware. 

A siHcon carbide-bonded graphite material in which graphite particles are distributed through the siHcon carbide matrix has high thermal shock resistance and is suitable for appHcations including rocket nose cones and nozzles and other severe thermal shock environments (155) (see Ablative materials). 

Fig ure 5-22. Upstream view of the inlet casing assembly. The nose cone is supported by struts that also allow entry of cooling steam and instrumentation into the cone. 

Figure 5-23. Interior of the nose cone showing terminus of the cooling steam line. The interior shielding consists of a 2-in. (50.8-mm) insulation thickness.

Figure 5-24. The struts transmit thrust ioads imposed on the nose cone by fiue gases to the iniet casing and its supports.

Radome Also called radiation dome. It is a cover for a microwave antenna used to protect the antenna from the environment on the ground, underwater, and in the air (aircraft nose cone, etc.). The dome is basically transparent to electromagnetic radiation and structurally strong. Different materials have been used such as wood, rubber-coated air-supported fabric, etc. The most popular is the use of glass fiber-TS polyester RPs. The shape of the dome, that is usually spherical, is designed not to interfere with the radiation. 

Thermal-Gradient Infiltration. The principle of thermal-gradient infiltration is illustrated in Fig. 5.15b. The porous structure is heated on one side only. The gaseous reactants diffuse from the cold side and deposition occurs only in the hot zone. Infiltration then proceeds from the hot surface toward the cold surface. There is no need to machine any skin and densification can be almost complete. Although the process is slow since diffusion is the controlling factor, it has been used extensively for the fabrication of carbon-carbon composites, including large reentry nose cones. 

Other applications include missile nozzles and nose cones, aerospace fasteners, heating elements, and glass bottle machinery components. 

Hypersonic aircrafts and reentry vehicles such as Sanger, Hermes, Express, need reusable hot structures. Typical examples are nose cones, wing leading edges, winglets, flaps, rudders, shingles etc. 

Teflon was introduced to the public in 1960 when the first Teflon-coated muffin pans and frying pans were sold. Like many new materials, problems were encountered. Bonding to the surfaces was uncertain at first. Eventually the bonding problem was solved. Teflon is now used for many other applications including acting as a biomedical material in artificial corneas, substitute bones for nose, skull, hip, nose, and knees ear parts, heart valves, tendons, sutures, dentures, and artificial tracheas. It has also been used in the nose cones and heat shield for space vehicles and for their fuel tanks. 

The ions present in the gaseous mixture are sampled through a small hole mounted at the tip of a nose cone situated at the end of the reaction zone and mass analyzed with a quadruple mass filter. 

One attractive property of beryllium is its nonsparking quality, which makes it useful in such diverse applications as the manufacture of dental appliances and of nuclear weapons. Beryllium-copper alloys find use as components of computers, in the encasement of the first stage of nuclear weapons, in devices that require hardening such as missile ceramic nose cones, and in the space shuttle heat shield tiles. Because of the use of beryllium in dental appliances, dentists and dental appliance makers are often exposed to beryllium dust in toxic concentrations. 

ABLATION- The removal of surface material from a body by vaporization, melting, chipping, or other erosive process specifically, the intentional removal of material from a nose cone or spacecraft during high-speed... 

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