THE LOAD-CARRYING PROPERTIES OF METAL DIALKYL DITHIOPHOSPHATES: THE EFFECT OF CHEMICAL STRUCTURE

The extreme pressure (e.p.) and mixed lubrication or antiwear (a.w.) properties of a range of metal dialkyl dithiophosphates have been examined using the four ball machine. The results show that the nature of the metal atom is a major factor in determining these properties, and that the factors governing e.p. and a.w. activities are different. Thus the order of decreasing e.p. activity is Bi(II1) 2 Ag(I), Pb(I1)> Sb(III)