Abstract: Disclosed herein is a method of coating a substrate with a zinc dialkyldithiophosphate (ZDDP) material, comprising the steps of selecting a substrate which is reactive with said ZDDP material; providing an atmosphere containing said ZDDP material at a predetermined concentration; exposing said substrate to said atmosphere for a sufficient period of time and at a sufficient temperature, so as to cause said ZDDP material to form a layered substrate having a layer of a ZDDP derivative material thereon; and annealing said layered substrate.