Joining of Ceramic Tubes for Gun Barrel Applications (1000-739)

Triton Systems, Inc. (TSI) is proposing a joining method for silicon nitride tubular sections that addresses many of the unique technical and manufacturing challenges associated with gun barrel liner fabrication. The approach involves the use of an interlocking tube-tube joint design and brazing material (plus grain refiners). Localized heating, combined with preferential pressurization, ensures adequate flow and wetting of the brazing material on the faying surfaces. A subsequent post brazing cycle further converts the brazing material within the joint to compatible nitride compound and stabilizes the joint. Compared to conventional ceramic joining techniques based on metallic brazes, we believe our approach offers the following advantages for gun barrel applications: · Brazing material readily wets silicon nitride to produce a sound, pressure-tight, pore free joint. · Subsequent conversion of the brazing material to nitride compound affords numerous performance advantages: 1) superior ability to withstand repeated exposures to high temperature, 2) elimination/mitigation of thermal expansion mismatch stresses (common in ceramics joined with metallic brazes) increases joint shock resistance. · The use of localized heating (tube furnace, induction coil, etc.) simplifies tooling design and full-scale liner assembly and, therefore, offers more options for transitioning the design and process to a production environment.