The mechanism of iron phosphide formation during boundary friction in the presence of organic phosphates and phosphites

Abstract

Thermochemical and mechanochemical reactions of tricresyl phosphate, tributyl phosphate, and tributyl phosphite with an iron surface are studied. A possible mechanism of iron phosphide formation under severe boundary friction conditions is proposed. The antiscoring behavior of phosphine in a vaseline oil solution is studied for the first time. It is found that (a) iron powders modified by tricresyl phosphate or tributyl phosphite do not yield iron phosphide at a temperature of 710°C in vacuum but are reduced to iron phosphide by birch coal; (b) at a temperature of 760°C in a flow reactor, tricresyl phosphate produces a much greater amount of solid phosphorous-containing residue than tributyl phosphite; (c) at a temperature of 760°C in a flow reactor, tributyl phosphite produces white phosphorus; (d) phosphine improves effectively the antiscoring properties of vaseline oil.