Anti-wear agents

Abstract

This article groups molybdenum disulfide, antimony sulfide, lead sulfide, zinc sulfide, sulfur, copper chips, tin powder and aluminium powder under the term “anti-wear agents”. The mechanism described is that sulfur-bearing additives first form an adsorbed film on the friction surface and, through frictional chemical reaction with the steel counterpart under high temperature, form a lubricating transfer film; e.g. with MoS₂ the Mo changes from +4 to +6 and the film is mainly FeS₃, FeSO₄, FeO and MoO₃. This changes contact from dry metal–polymer to polymer–polymer, improving wear resistance, load capacity and protection of the counterpart.

The article also notes that copper, tin and aluminium powders act as high-temperature binders — tin powder melts at 232 ℃ and aluminium powder at 660 ℃, covering the high-temperature range of friction-material use — and that some sulfides, e.g. lead sulfide, are toxic and being phased out. Reported purities in the supplier table include MoS₂ ≥60%, Cu ≥99%, Sn ≥99% and Al ≥99%, with particle sizes around 180–325 mesh.

Key facts

• Grouping: MoS₂, antimony sulfide, PbS, ZnS, sulfur, copper chips, tin powder, aluminium powder
• Mechanism: adsorbed film → frictional chemical reaction → lubricating transfer film on the steel counterpart
• MoS₂ example: Mo(+4)→Mo(+6); transfer film mainly FeS₃, FeSO₄, FeO, MoO₃
• Metal powders as binders: Sn mp 232 ℃, Al mp 660 ℃ (cover high-temperature use range)
• Reported purities: MoS₂ ≥60%; Cu ≥99%; Sn ≥99%; Al ≥99% (supplier table)
• Note: lead sulfide is toxic and being phased out (per original article)
• Verification method cited: SEM surface analysis plus XPS measurement of transfer-film binding energy

The original article is in Chinese; see the Chinese version for the full text. This page provides the English title, abstract and key facts only — translated and compiled from the original, without full verbatim translation.