Brazed Graphite-Metal Composites for Space Radiators

Brazing techniques for joining dissimilar materials considered for tube-to-armor joints of high-temperature graphite space radiators have been investigated. The combinations tested consisted of Cb-1Zr and type-316 stainless-steel alloys, each brazed with developmental alloys to Graphitite-G and an expanded form of pyrolytic graphite. Stability test results are reported for specimens brazed and aged 500 h at 1350°F (734°C) or thermally cycled 500 times between 350°F (177°C) and 1350°F under a pressure of 10⁻⁵ torr (max). Brazing and thermal stability tests indicated that compatible braze bonds can be made between the graphites and potential tube materials.