摘要

Oil-soluble stannous oleate (SO) has been synthesised using oleic acid and SnO and its molecular structure confirmed. The tribological performances of SO and of complexes of SO with organosulphur or organophosphate compounds as lubricant additives in a VG26 white oil have been evaluated using a four-ball friction and wear tester. The results show that SO exhibits good antiwear, load-carrying, and friction-reducing properties in the base stock, which are better than those of ZDDP. When 2.0% SO is added, the wear-scar diameter reduced to 70% of that for the base stock alone, and the maximum non-seizure load increased by 2.4 times. The friction coefficient was clearly reduced when SO was added. Synergistic effects were observed between SO and tricresol phosphate as regards the antiwear and load-carrying properties, while a synergistic effect occurred only in terms of the antiwear properties for SO and a sulphur-based olefin. The elemental composition of the boundary lubricating film was examined by means of Auger electron spectroscopy (AES). The analytical results of AES indicate that the good performance of SO is attributable to the formation of a boundary lubricating film containing Sn on the rubbed surface.

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