The application apparatus was designed to fit under the bell jar of a vacuum system. The atmosphere in which the films were applied could thus be controlled by evacuating the bell jar and backfilling it with the desired atmosphere. Previous results (ref. 15) have shown that films applied in moist air are thicker and dense than films applied under dryer conditions. Thus the films used in these experiments were applied in moist air (10 000-ppm H20). A rider and disk (with applied MoS2 film) were inserted into the friction and wear apparatus, and the test chamber was sealed. Moist air (10 000-ppm H20) or dry argon was purged through the chamber for 15 minutes before the tests; this purge was continued throughout the tests. Moist air was used as a control atmosphere since it is typical of average atmospheric conditions (approximately 50 percent relative humidity). Dry argon was used since it is inert and nonoxidizing. The flow rate was 1500 cubic centimeters per minute, and the volume of the chamber was 2000 cubic centimeters. After the 15-minute purge, the disk was rotated at 1000 rpm, and a 1-kilogram load was gradually applied. The test temperature was 25' C. Each test was stopped after one kilocycle (1 min) of sliding. After removing the rider and disk from the friction apparatus, the contact areas were examined by optical microscopy and photographed. Surface profiles of the film-wear tracks were also taken. The rider and disk were then placed back into the apparatus, and the test procedure was repeated. The rider was not removed from the holder, and locating pins in the apparatus ensured it was returned to its original position. If you are looking for high quality, high purity, and cost-effective Molybdenum disulfide or the latest price, please email contact mis-asia.