Boron Wire, a Light, Stiff, High Strength Material.

Boron wire as fiber reinforcement in a matrix, for instance, of epoxy resin has been used, among other applications, in the construction of a test segment of the loading hatch of a space shuttle. Representative mechanical properties in comparison with other high strength thin wires are tabulated. The production of such wire, as developed by the N. V. Philips Gloeilampenfabrieken, Eindhoven, Netherlands, is described in detail: tungsten wire is moved continuously through reaction chambers in which a gas mixture reacts with the tungsten and deposits boron on the wire. During continued reaction the tungsten core of the boron wire thus formed, as well as some W//2B created by the reaction, are consumed until only a boron wire remains. Structures, properties, and processing are discussed.