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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Experimental system for drilling simulated lunar rock in ultrahigh vacuum

An experimental apparatus designed for studying drillability of hard volcanic rock in a simulated lunar vacuum of 5 x 10 to the minus 10th power torr is described. The engineering techniques used to provide suitable drilling torque inside the ultrahigh vacuum chamber while excluding all hydrocarbon are detailed. Totally unlubricated bearings and gears were used to better approximate the true lunar surface conditions within the ultrahigh vacuum system. The drilling system has a starting torque of 30 in-lb with an unloaded running torque of 4 in-lb. Nominal torque increase during drilling is 4.5 in-lb or a total drilling torque of 8.5 in-lb with a 100-lb load on the drill bit at 210 rpm. The research shows conclusively that it is possible to design operational equipment for moderate loads operating under UHV conditions without the use of sealed bearings or any need of lubricants whatsoever.

Roepke, W. W.↗
NASA NTRS1985

Manipulator for Heating and Cooling in Ultrahigh Vacuum

In sample-transfer system for use in ultrahigh vacuum, samples mounted on threaded circular holder transferred to flip mechanism of manipulator by simple translation and rotation. Flip mechanism contains electrode assembly and thermocouple that make direct contact with sample. Copper plate and flexible strap attached to receiving block to cool sample. Simple modifications allow broad range of sample temperatures (150 to 1,750 K) and direct temperature measurements, while retaining advantage of additional degree of freedom provided by flip mechanism of precise manipulator.

Outlaw, R.↗
NASA NTRS1990

The surface variation of Ti-14Al-21Nb as a function of temperature under ultrahigh vacuum conditions

The effect of temperature, at conditions of ultrahigh vacuum, on the surface composition of the Ti-14Al-21Nb (in wt pct) alloy was investigated in samples heated to 1000 C in 100 C increments. Results of AES spectroscopy revealed that the Ti-14Al-21Nb alloy surface is extremely sensitive to temperature. At 300 C, the carbon and oxygen began to rapidly dissolve into the alloy, and at 600 C, bulk S segregated to the surface. The variation in the surface composition was extensive and different over the temperature range studied, indicating that there may be substantial changes in the hydrogen transport.

Lee, W. S.↗
NASA NTRS1978

Exploratory Thermal-mechanical Fatigue Results for Rene' 80 in Ultrahigh Vacuum

A limited study was conducted of the use of strainage partitioning for predicting the thermalmechanical fatigue life of cast nickel-base superalloy Rene' 80. The fatigue lives obtained by combined inphase thermal and mechanical strain cycling between 400 C (752 F) and 1000 C (1802 F) in an ultrahigh vacuum were considerably shorter than those represented by the four basic partitioned inelastic strainrange fatigue life relationships established previously for this alloy at 871 C (1600 F) and 1000 C (1832 F) in an ultrahigh vacuum. This behavior was attributed to the drastic decrease in ductility with decreasing temperature for this alloy. These results indicated that the prediction of the thermal-mechanical fatigue life of Rene' 80 by the method of strainrange partioning may be improved if based on the four basic fatigue life relationships determined at a lower temperature in the thermal-mechanical strain cycle.

Sheinker, A. A.↗
NASA NTRS1967

Ultrahigh vacuum gauge having two collector electrodes

A gauge for measuring ultrahigh vacuums with great accuracy is described. It provides a means for ionizing the gas whose pressure is being measured, and consists of a collector electrode, a suppressor, radiation shielding, and a second collector.

Torney, F. L., Jr.↗