Study of thermally stable lubricants for automotive ceramic gas turbines

摘要

When developing thermally stable lubricating oils for automotive ceramic gas turbines (CGT oil), such target properties as thermostability, oxidation stability, anti-wear, load carrying, and anti-coking properties have been sought. Among the above properties, those of thermostability, oxidation stability, and anti-wear property were difficult to provide simultaneously in developed lubricants. Five types of pentaerythritol ester (PE ester) were chosen from butyric acids to caprylic acid and the relationship between antiwear property, oxidation stability, and thermal stability was determined. The chosen five types of lubricants showed a poor anti-wear property, but the property was improved when a mixture of PE ester of valeric acid and m-phenoxyphenoxy m-biphenyl, whose thermostability and oxidation stability were very good, was used as a base oil. The addition of two types of amine antioxidant phosphorus base anti-wear agent 1 (tricresyl phosphate) and phosphorus containing anti-wear agent 2 (acidic amine salt of phosphorous acid ester) metal deactivator, and sulfur containing aromatic compound (m-bisphenylmercaptobenzene) were found to act as a new antioxidant to mixed base oils and allowed development of automotive CGT oil -GTR-G 701 in which filial targets were achieved.