THE INFLUENCE OF USING CONDITIONS ON TRIBOLOGICAL PROPERTIES OF BRAKE SYSTEMS WITH COMPOSITE DISCS
Journal Title: Tribologia - Year 2019, Vol 284, Issue 2
Abstract
This paper presents the results of studies on the influence of automotive vehicle parking time on levels of the friction coefficient and wear that influence the braking efficiency of brake systems with composite discs. Discs have been produced of hypereutectic aluminium-silicon alloy (AlSi18NiMgCu) in which the Si precipitates are a reinforcing phase. On the basis of the parking time of a vehicle for a repair, the minimal (τ = 0 h) and maximal (τ = 240 h) time for an exposition on atmospheric factors has been determined, Velocities, unit pressures of brake pad on the disc rotor, and the braking distance are the equivalent of a braking distance of an vehicle with mass of 1300kg running through an built-up area with a velocity of 30 or 50 kmh. On the basis of experiment’s results, it has been stated that a car parking time of 48h causes an oxidising of the matrix, which results in a friction coefficient decrease up to 0.18 on the sliding distance of 600–700 m, As a result of the wear of the oxide layer, the friction coefficient acquired a value (>0.3) after about 600–700 m friction distance, which equals 600 rotations of the wheel. A longer parking time (240 h) causes a considerably lower decrease in friction forces, because the oxide layer will be sealed.<br/><br/>
Authors and Affiliations
Andrzej Posmyk, Jerzy Myalski
FAT CELL BURNING DURING HYDRODYNAMIC SWEAT LUBRICATION
This paper presents hydrodynamic lubrication of human skin by the thin layer sweat restricted on the tight fitting sportswear surface during the sport training. The aim of this paper is to determine the influence of the...
IMAGE-BASED ANALYSIS OF WEAR STATE OF CERAMIC NITRIDE CUTTING TOOLS AFTER MACHINING OF NODULAR CAST IRON
This paper presents the results of the wear of nitride ceramic tools, uncoated and coated with CVD-Al2O3/TiN layer, in the machining of pearlitic-ferritic nodular cast iron-EN-GJS-500 grade. Investigations include the to...
WŁAŚCIWOŚCI TRIBOLOGICZNE SPIEKÓW CERAMICZNYCH Al2O3/ZrO2
W pracy przedstawiono właściwości mechaniczne i tribologiczne spieków kompozytowych Al2O3/ZrO2 o różnej proporcji faz Al2O3 i ZrO2. Są to materiały chętnie stosowane w węzłach tarcia suchego ze względu na relatywnie nisk...
MODELLING THE ACTUAL SURFACE COOPERATION DURING TURNING ACCOMPANYING THE DRY FRICTION PROCESS
The article presents the actual surface geometrical structure achieved during turning (in terms of 3D), which was converted into a CAD model. Such modelled surfaces of tribological nodes will undergo numerical simulation...
Siły adhezji i kohezji występujące w parabolicznych mikrołożyskach
W przedstawionej pracy badany jest wpływ adhezji i kohezji na rozkład ciśnienia oraz siłę nośną w hydrodynamicznych, parabolicznych, poprzecznych mikrołożyskach ślizgowych. Rozpatrywane mikrołożyska ślizgowe o średnicy c...