The Fabrication and Testing of Glass Matrix Composite Cylinders for Gun Barrel Liner Applications.

摘要

The feasibility of fabricating glass matrix composite (COMPGLAS)(TM) cylinders for use as gun barrel liners was investigated. The system of borosilicate glass reinforced with discontinuous graphite fibers was utilized to fabricate three different composite configuration concepts by the fabrication methods of hot isostatic pressing (HIP), uniaxial creep-forming of cylindrical segments, and the machining of cylinders from hot-pressed billets. Analytical design studies performed at the Saco Defense Systems Division of Maremont Corp. indicated that the latter method, where the fibers were randomly oriented in the radial and tangential directions with no fibers in the axial direction, was the most favorable configuration. Three cylindrical liners were diamond core drilled from the hot-pressed billet, final machined to a .50 caliber bore, assembled into metal sleeves and jackets, and test fired for a total of 10 shots single fire. Although two of the three composite liners showed evidence of a few very small circumferential cracks at one end of the bore before firing, the cracks did not grow as a result of firing. The firing tests indicated that the use of a low modulus, fracture tough, ceramic composite such as graphite fiber reinforced glass is capable of withstanding the pressure stresses resulting from firing without failure and exhibits considerable potential as a gun barrel liner. (Author)