A Test of Molybdenum Disulfide Lubricants in Radiation and Vacuum Environments

Abstract

Tests have been conducted on two MoS2 -base solid-film lubricants, one containing gold and sodium silicate and the other containing bismuth and aluminum phosphate, having potential for application under severe environmental conditions. The lubricant with gold was applied to test races of 440 C steel and René 41 and exposed with a reactor to 1.5 × 1011 ergs/g(C) of gamma and 8.2 × 1016 neutrons/cm2 (E > 0.1 MeV). The test specimens were subsequently evaluated in sliding-wear tests at temperatures as high as 1200 deg F. Both lubricants were tested in vacuum (∼10−6 torr) and in air on size R-3 ball bearings, which were run at 6000 rpm in servomotors. No significant radiation effects were detected with the MoS2 :Au lubricant on 440 C steel in tests at room temperature and 600 deg F. In tests at room temperature, 600 deg F, and 1200 deg F on René 41, the data indicated a possible radiation effect at 600 deg F but not at the other temperatures. In two vacuum tests on bearings, the MoS2 :Au lubricant gave a mean running time of about 110 h. The MoS2 :Bi film gave a mean life of 96 h in the first test and 853 h in the second test.