Influence of Additives Concentration on the Electrical Properties and the Tribological Behaviour of Three Automatic Transmission Fluids

Autor: Eduardo Rodriguez, Jose Luis Viesca, Antolin Hernández Battez, NOELIA RIVERA RELLÁN, Alejandro García Tuero, Alfonso Fernández-González
Rok vydání: 2022
Předmět:
Zdroj: Lubricants; Volume 10; Issue 11; Pages: 276
Scopus
ISSN: 2075-4442
Popis: Placing an electric motor (EM) inside the transmission housing of a hybrid electric vehicle (HEV) implies that the automatic transmission fluid (ATF) needs to accomplish additional requirements. Among these requirements, electrical compatibility is of critical significance. This study investigated the influences of the additive concentrations of three commercial ATFs on their electrical compatibilities and tribological performances. Two variations of each ATF with different concentrations of the original additive packages were prepared. The viscosity, electrical conductivity, permittivity, resistivity, dielectric dissipation factor, breakdown voltage, and tribological performance of the nine resulting ATFs were measured. All the ATFs were found to be electrically compatible and showed dissipative performance and sufficiently high breakdown voltage, even at increasing additive concentrations. The tribological performances of the ATFs formulated with the API (American Petroleum Institute) Group III base oils had improved wear reduction at the highest additive concentrations; the better wear performance was related to the formation of iron phosphates and polyphosphates on the worn surface.
Databáze: OpenAIRE