The effect of abrasive additives on the tribotechnical properties of lubricants for the wheel–rail system

The paper studies the polishing power of a tribochemically active abrasive material based on a solid solution of iron and aluminum oxides, as well as a solid solution of aluminum and iron oxides modified by zirconium oxide and yttrium oxide additives, and the tribotechnical properties of a lubricant doped with these abrasive materials. The modified Al2O3·Fe2O3·ZrO2·Y2O3 powders prove to have an essentially higher polishing power producing a considerably lower surface roughness than that of the unmodified Al2O3·Fe2O3 powder. By varying the content of the modifying oxides, one can change the tribochemical activity of the abrasive powder and select the best composition depending on the material to be polished. The addition of these abrasive powders is shown to have an essential effect on the tribotechnical properties of the lubricant for the wheel–rail contact. The laboratory testing of the lubricant compositions suggests their effective applicability to the wheel–rail contact.