Boron fiber or boron filament is an amorphous product which represents the major industrial use of elemental

boron Boron is a chemical element; it has symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the boron group it has three ...

. Boron fiber manifests a combination of high strength and high

elastic modulus An elastic modulus (also known as modulus of elasticity (MOE)) is a quantity that describes an object's or substance's resistance to being deformed elastically (i.e., non-permanently) when a stress is applied to it. Definition The elastic modu ...

. 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 Aerospace is a term used to collectively refer to the atmosphere and outer space. Aerospace activity is very diverse, with a multitude of commercial, industrial, and military applications. Aerospace engineering consists of aeronautics and astron ...

structures as a component of

composite material A composite or composite material (also composition material) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or physical properties and are merged to create a ...

s, as well as limited production consumer and sporting goods such as golf clubs 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

is deposited on an even

tungsten Tungsten (also called wolfram) is a chemical element; it has symbol W and atomic number 74. It is a metal found naturally on Earth almost exclusively in compounds with other elements. It was identified as a distinct element in 1781 and first ...

wire substrate which produces diameters of 4.0 mil (102 micron) and 5.6 mil (142 micron). It consists of a fully borided

core with

amorphous In condensed matter physics and materials science, an amorphous solid (or non-crystalline solid) is a solid that lacks the long-range order that is a characteristic of a crystal. The terms "glass" and "glassy solid" are sometimes used synonymousl ...

. Boron fibers and sub-millimeter sized crystalline boron springs are produced by

laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word ''laser'' originated as an acronym for light amplification by stimulated emission of radi ...

-assisted

chemical vapor deposition Chemical vapor deposition (CVD) is a vacuum deposition method used to produce high-quality, and high-performance, solid materials. The process is often used in the semiconductor industry to produce thin films. In typical CVD, the wafer (electro ...

. Translation of the focused laser beam allows to produce even complex helical structures. Such structures show good mechanical properties (

450 GPa, fracture strain 3.7%, fracture stress 17 GPa) and can be applied as reinforcement of ceramics or in micromechanical systems.

References

{{Fibers Fibers Boron