Aerospace industry, materials used

Advanced materials, chemistry, 2-5 Aerospace industry, materials used, 236 Agglomeration, control using colloid chemical principles, 89-91, 92/ Aging studies... 

Boron Trichloride. Approximately 75—95% of the BCl consumed iu the United States is used to prepare boron filaments by CVD (7). These high performance fibers are used to reinforce composite materials (qv) made from epoxy resius and metals (Al, Ti). The principal markets for such composites are aerospace industries and sports equipment manufacturers. 

Why Do We Need to Know This Material The d-block metals are the workhorse elements of the periodic table. Iron and copper helped civilization rise from the Stone Age and are still our most important industrial metals. Other members of the block include the metals of new technologies, such as titanium for the aerospace industry and vanadium for catalysts in the petrochemical industry. The precious metals—silver, platinum, and gold—are prized as much for their appearance, rarity, and durability as for their usefulness. Compounds of d-block metals give color to paint, turn sunlight into electricity, serve as powerful oxidizing agents, and form the basis of some cancer treatments. 

One of the unique issues in the development of advanced-performance materials is that they are very product-specific, and their development requires expensive prototype iteration and performance testing. The product development is people- and design-intensive and usually results in a niche market for the material that is, the specific product slate for which the material has been designed and tested. Many of the applications are in high-tech industrial products like aerospace components, so the total volume of material used will be small. Thus, attractive commercialization schemes require that the material have intrinsic value that will justify a high margin, or there must be a product application for which the value can be captured in the end product. 

Anodic alumina oxides find steadily growing application in various spheres of technology. Traditionally, they are most popular in civil industrial engineering for producing protective and decorative surface finish in panels and different objects. These applications are well reviewed in the literature.321 Anodic alumina is also widely used in the aircraft and aerospace industry for adhesive bonding of aluminum structures,322-324 composite materials, etc. 

CNF is an industrially produced derivative of carbon formed by the decomposition and graphitization of rich organic carbon polymers (Fig. 14.3). The most common precursor is polyacrylonitrile (PAN), as it yields high tensile and compressive strength fibers that have high resistance to corrosion, creep and fatigue. For these reasons, the fibers are widely used in the automotive and aerospace industries [1], Carbon fiber is an important ingredient of carbon composite materials, which are used in fuel cell construction, particularly in gas-diffusion layers where the fibers are woven to form a type of carbon cloth. 

By far the most common industrial refractories are those composed of single or mixed oxides of Al, Ca, Cr, Mg, Si, and Zr (see Tables 1, 4, and 6). These oxides exhibit relatively high degrees of stability under both reducing and oxidizing conditions. Carbon, graphite, and silicon carbide have been used both alone and in combination with the oxides. Refractories made from these materials are used in ton-lot quantities, whereas silicides are used in relatively small quantities for specialty application in the nuclear, electronic, and aerospace industries. 

More recently, we have seen other new plastics arrive, including such exotic, high performance materials as the polybenzimidazoles, polyoxadiazoles, polyperfluorotriazines, polyphenylenes, and such inorganic materials as the boron polymers, the metalloxanes, and the polysilazanes, to name only a few. These exotic materials are mostly development products today, they are very expensive and will undoubtedly find their first uses, if any, in the aerospace industry which requires the high performance offered by these materials and can afford to pay for them. Some of these new materials will become commercial successes, others will not. 

Engineering thermoplastics have also been used in preimpregnated constructions. The thermoplastic is thoroughly dispersed as a continuous phase in glass, other resins, carbon fibers (qv), or other reinforcement. Articles can be produced from these constructions using thermoforming techniques. For example, the aerospace industry uses polyetheretherketone (PEEK) in woven carbon-fiber tapes (26). Experimental uses of other composite constructions have been reported (27) (see also COMPOSITE MATERIALS, POLYMER-MATRIX). 

These materials have been used for many years in the aerospace industry for... 

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