Research and Evaluation of Materials for Thermocouple Application Suitable for Temperature Measurements Up to 4500°F on the Surface of Glide Re-entry Vehicles

Résumé du livre

The thermoelectric output versus temperature of a W/W 26Re thermocouple was measured to 5800 deg F. Thermoelectric sensitivity was relatively high over the entire temperature range. Thermoelectric output on new thermocouple systems versus temperature was also measured with respect to W--26Re commercial wire for Re, Re-W, Re--Ru, Re--Rh, Re--Pt, Re--Ir, Re--Mo, Re--Os, Mo, Mo--W, Mo-Re, and Ir--Re alloy materials. Of the alloys studied, Re-10Ru and Re--12W showed the greatest potential for hightemperature thermocouple application. The oxides BeO, ThO/sub 2/, and HfO/sub 2/ are compared as electrical insulators. Beryllia is best, but with proper geometry ThO/sub 2/ and HfO/sub 2/ would also be satisfactory. Boron nitride was found to react with W and W--26Re materials above 3700 deg F in He. The melting points of many rare earth oxides, zirconates, and hafnates were determined. Weight losses of Ir, Ir-10Re, Os, Ir-- 50Os, and Ir--20Os at 0.1 atmosphere pressure at approximately 4400 deg F were measured. The test shows that Ir--20Os alloy, with a measured melting point of 4600 deg F, should make satisfactory sheathing material for short time service.