DEVELOPMENT OF IMPROVED HIGH TEMPERATURE SOLID LUBRICANT CONCEPTS

SOLID LUBRICANTION HAS BEEN ACCEPTED AS A UNIQUE METHOD OF IMPROVING BEARING LIFE UNDER EXTREME CONDITIONS OF TEMPERATURE, LOAD, AND SPEED. THE CHALCOGENIDES (COMPLEX SULFUR CONTAINING COMPOUNDS) HAVE LONG BEEN IDENTIFIED AS SOLID LUBRICANTS (MOLYBDENUM DISULFIDE IS A DICHALCOGENIDE) THAT PROVIDE SATISFACTORY PERFORMANCE LIFE FOR ROLLING BEARINGS. THE COMPLEX METAL CHALCOGENIDES HAVE SHOWN GOOD PERFORMANCE AS A SOLID LUBRICANT FOR CERAMIC ROLLING BEARINGS IN HIGH TEMPERATURE BEARING TESTS. TO BENEFIT FROM THE APPLICATION OF THE SOLID LUBRICANT TECHNOLOGY AN UNDERSTANDING OF THE RELATIONSHIP BETWEEN PROPERTIES OF THE CHALCOGENIDES AND THE SUBSTRATE (BEARING) MATERIALS ALONG WITH THE IN-SERVICE ENVIRONMENT IS ESSENTIAL. THIS PHASE I PROJECT WILL INVESTIGATE THE PROPERTIES OF THE COMPLEX METAL CHALCOGNIDES TO CHARACTERIZE THEM AS THEY INTERACT WITH THE CERAMIC AND SUPER ALLOYS USED IN THE HIGH THRUST, WIDE TEMPERATURE RANGE OF THE ADVANCED ENGINE. THIS RESEARCH WILL INVESTIGATE THE PROPERTIES OF THE COMPLEX CHALCOGENIDES IN TEMPERATURES OF -65 DEG F (COLD SOAK TEST) AND 1500 DEG F (WEAR LIFE PERFORMANCE TEST). THE RESULTS WILL ESTABLISH AN IMPORTANT DATA BASE FOR THE EFFECTIVE LUBRICATION OF CERAMIC AND SUPER ALLOY COMPONENTS PROVIDING LONG TERM OPERATION UNDER WIDE SPECTRUM OF OPERATING CONDITIONS WHICH REPRESENTS AN IMPORTANT GOAL AND A BASIC REQUIREMENT FOR THE ADVANCED LIMITED-LIFE SMALL TURBINE ENGINE.