Molybdenum Disulphide Lubrication

In the 1970s and the early 1980s there was an enormous volume of research and development into the subject of molybdenum disulphide lubrication, much of which was supported by national governments for the benefit of defence, aviation or space activities. There were already some well-established practical guidelines for deciding when and how to use molybdenum disulphide, but there was still a considerable lack of universally-accepted theoretical understanding of some of the important and fundamental aspects of molybdenum disulphide technology. However, the state of knowledge was growing rapidly.

In the past fifteen years the situation with regard to the technology of molybdenum disulphide lubrication has stabilised in many respects, and a measure of consensus has been reached about some of the mechanisms involved. The use of molybdenum disulphide has become routine in some industries, and there are many well-established and reputable commercial products available. Except in the high-technology field of physical deposition techniques, especially sputtering, the output of new research publications has fallen from perhaps two hundred a year in the 1970s to fewer than ten a year in the 1990s. In spite of this maturing of the subject, it is clear that there are still many aspects in which disagreements persist about the mechanisms involved, and which as a result are unclear or misunderstood among current, and perhaps even more importantly, potential users.
One of the primary objectives of this book is to analyse the various aspects of molybdenum disulphide lubrication technology about which there are still disagreements or controversy, and to attempt to come to firm conclusions about some of the mechanisms involved. In particular, it will place emphasis on the importance and effects of burnishing and film consolidation.

Chapter headings and selected papers: Preface. History. Early beginnings. Range of applications. Occurrence and Extraction. Occurrence. Molybdenum and its Compounds. Oxides of molybdenum. Chemical uses of molybdenum. Properties of Molybdenum Disulphide. Intercalation compounds. Oxidation. Mechanism of Lubrication. Fundamentals of friction. Load-carrying capacity. Formation of Molybdenum Disulphide Films. Burnishing of soft films. Effects of moisture and other vapours on film formation. Properties of Molybdenum Disulphide Films. Friction. Effects of moisture and other vapours. Transfer in Lubrication. Transfer of molybdenum disulphide. Nature and location of the transfer source. Lubrication by Molybdenum Disulphide Alone. Different techniques of use. Sputtering and Other Physical Deposition Processes. Effect of substrate. Pulsed laser deposition. Bonded Films. Types of bonded film. Friction and wear properties of bonded films. Composites. Ceramic and inorganic composites. Electrical brushes and sliprings. Use in Oils and Greases. Interaction between molybdenum disulphide and liquids. Pastes and dispersions. Other Lamellar Solid Lubricants. Occurrence and properties. Transition metal dichalcogenides. Corrosion and Fretting. The chemical environment. Selection and Use. Selecting the type of solid lubricant. Subject index.