Tribological behaviors of the thick metal coating for the contact mechanical seal under the water-lubricated conditions

Abstract

Purpose

The serious friction and wear problem occurs on the mechanical seal’s faces during the start-up stage of the high-speed turbopump for a liquid rocket engine. This paper aims to propose a kind of thick metal alloy coatings on the surface of the seal’s rotor so as reduce the friction and wear.

Design/methodology/approach

With the pin-disk (the graphite pin and the disk with the metal coating) tribology-tester, the tribological behaviors of four metal coatings are investigated. The special friction coefficients under the dry friction, boundary friction and different temperatures of water-lubricated conditions were obtained.

Findings

The test results show that the thick metal coating has a good performance of the wear resistance and friction reduction; and the friction coefficients of a Sn-Sb-Cu coating under the dry friction and water-lubricated conditions are 0.377 and 0.043, respectively, and the corresponding mass wear volumes are only 2.74 and 0.81 mg, respectively.

Originality/value

The thick metal coating scheme for the mechanical seal’s faces might lend itself to the harsh working conditions of the low-viscosity liquid rocket engine.

Citation

Zhang, G.-y., Dang, J.-q., Zhao, W.-g. and Yan, X.-t. (2019), "Tribological behaviors of the thick metal coating for the contact mechanical seal under the water-lubricated conditions", Industrial Lubrication and Tribology, Vol. 71 No. 2, pp. 173-180. https://doi.org/10.1108/ILT-01-2018-0047