Processes have-been developed for brazing honeycomb sandwich panels using molybdenum and columbium. core and facings These processes are being used to fabricate panels which simulate hot mono-coquet structures and modular-type heat shields. Elevated temperature tests are being conducted to determine thermal and strstructural capabilities of these panels.nTZM (Mo-0.5Ti-0.08Zr) molybdenum and D-36 (Cb-10Ti-5Zr) columbium alloys were chosen for use on the program. Paddler PFR-6 oxidation protection coating for TZM and Thompson-Remo-Wooldridge Cr-Ti-Si coating for D-36 were selected to protect the panels during high temperature testing.nSpecial tools and procedures were developed to fabricate the honey-comb core. All molybdenum welding was accomplished by electron beam techniques. A 4200° F cold wall vacuum furnace was used to braze the honeycomb test panels.nA quartz-lamp facility is was used to heat the panels for structural testing. The heat-shield panels will be tested in a 14-inch oxygen-propane hot-gas facility. A 3500° F cold wall vacuum test chamber will be used to determine material and honeycomb properties.
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