Boron fiber
Boron fiber or boron filament is an amorphous product which represents the major industrial use of elemental boron. Boron fiber manifests a combination of high strength and high elastic modulus.
A common use of boron fibers is in the construction of high tensile strength tapes. Boron fiber use results in high-strength, lightweight materials that are used chiefly for advanced aerospace structures as a component of composite materials, as well as limited production consumer and sporting goods such as golf [club (equipment)|golf club]s and fishing rods.
One of the uses of boron fiber composites was the horizontal tail surfaces of the F-14 Tomcat fighter. This was done because carbon fiber composites were not then developed to the point they could be used, as they were in many subsequent aircraft designs. Boron fiber is a primary reinforcement constituent in Hy-Bor, a prepreg blend of boron fiber and carbon fiber primarily used for high-performance aerospace and sporting goods applications.
In the production process, elemental boron is deposited on an even tungsten wire substrate which produces diameters of 4.0 mil and 5.6 mil. It consists of a fully borided tungsten core with amorphous boron.
Boron fibers and sub-millimeter sized crystalline boron springs are produced by laser-assisted chemical vapor deposition. Translation of the focused laser beam allows to produce even complex helical structures. Such structures show good mechanical properties and can be applied as reinforcement of ceramics or in micromechanical systems.