Some Composites of Synthetic Dichalcogenides

Tungsten diselenide Gallium/indium eutectic, carbon fibre/polyimide 193 

The composite of 52.9% tungsten disulphide in a cobalt and silver matrix, described as AF-SL 14, was one of a series of composites developed by the USAF, and was tested satisfactorily by several investigators . 

Probably the most controversial of all subjects associated with molybdenum disulphide has been that of corrosion. After the rapid increase in its application between about 1955 and 1962, there were widespread reports of corrosion arising from its use. In Europe thia was serious enough to result in a loss of confidence and a bad reputation from which it has probably still not completely recovered almost forty years later. 

In the United States it was already much more widely used than in Europe, including important applications in military aircraft and in the space programme. As a result there was a greater emphasis on analysing and overcoming the problem, but the association between molybdenum disulphide and corrosion still exists in many people s minds, in spite of the fact that the problem has been understood and controlled for well over twenty years. 

It is fair to say that some of the early reports were ill-founded, and magnified by rumour. There were also categorical reports from some users that molybdenum disulphide, even as free powder or burnished films, positively prevented or cured corrosion problems. These must in most cases have been equally ill-founded, although they provide an interesting parallel with the comments of Cramer in 1764, which were quoted in Chapter 1. 

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