Multilayered diamond mechanical seal rings under biodiesel lubrication and the full sealing conditions of pressurized water

authors	Shabani, M; Carrapichano, JM; Oliveira, FJ; Silva, RF
nationality	International
journal	WEAR
author keywords	CVD diamond; Multilayers; Mechanical seal rings; biodiesel
keywords	DRY LINE CONTACT; NANOCRYSTALLINE DIAMOND; TRIBOLOGICAL BEHAVIOR; FACE MATERIALS; THIN-FILMS; PERFORMANCE; COATINGS; GROWTH; CARBON; TOOLS
abstract	A mechanical sealing tribosystem based on multilayer microcrystalline/nanocrystalline diamond (MCD/NCD) coatings is proposed. The tribological behaviour was investigated in ring-on-ring self-mated planar contact configuration. Tests were carried out under biodiesel lubrication and pressurized water (2 bar) sealing conditions. A 3D optical confocal profilometer was used to obtain for the first time the wear coefficients of seal rings, revealing a value of k=6.3 x 10(-10) mm(3)/N.m for biodiesel lubrication that is two orders of magnitude lower than for reciprocating sliding ball-on-flat experiments. The advantage of the multilayer strategy was demonstrated in the sealing of pressurized water, where full sealing conditions were achieved within the P x V range of 0.75-5.5 MPa ms(-1). For these coatings, full delamination is prevented due to structural discontinuity at the MCD/NCD interfaces whereas for a MCD monolayer coating, premature failure takes place and sealing is not reached. (C) 2017 Elsevier B.V. All rights reserved.
publisher	ELSEVIER SCIENCE SA
issn	0043-1648
isbn	1873-2577
year published	2017
volume	384
beginning page	178
ending page	184
digital object identifier (doi)	10.1016/j.wear.2017.01.058
web of science category	Engineering, Mechanical; Materials Science, Multidisciplinary
subject category	Engineering; Materials Science
unique article identifier	WOS:000404316400019