Wear behaviour of cast aluminium silicon (Al-Si) alloy in Dot 4 brake fluid

Abstract

The frictional sliding behaviour of cast Al-Si alloy was investigated with and without DOT 4 hydraulic brake fluid lubrication/environments. Cast Al-Si specimen was produced from wrought alloy and the specimen surface was metallurgically prepared. The as-cast product was characterized with aid of micro-hardness tester, the chemical composition was analysed by X-ray fluorescence (XRF), while X-ray diffraction (XRD) was used to identify phases present, microstructures and surface examinations were done on a high resolution metallurgical Optical Microscope. The properties of the polished and worn sample surfaces were examined by Scanning electron microscope (SEM) equipped with Energy dispersive X-ray (EDS) facilities. A 6mm diameter alumina ball under varying normal loads (3-10 N) was rubbed against the surface of the cast Al-Si coupon specimen. The dry and wet sliding wear behaviour was assessed based on the CoF-sliding time behaviour. From the results, the average CoF values of 0.9064 for dry and 0.2038 for wet contacts were obtained. Comparatively, 1.03E-06 and 4.21E-07 minimum wear intensities; and 467290 and 132170 wear resistances were obtained for dry and wet contacts respectively. Behaviour of cast Al-Si in DOT4 were compared with its performance in DOT3 regarding the hydraulic brake system application.

Wear and Corrosion of Wrought A6061 Aluminium Alloy in DOT3 Brake Fluid

“…The wear tests (dry and wet) were performed to determine the wear rate of the A6061 alloy material with and without fluid. The wear test jig machine was designed and operated according to the SAE-J1154-1983; considering ASTM G-119-04 and it has been described in the previous reports [8]. The alternative system described in SAE J1703 is a stroking test procedure used to assess the lubricating quality of DOT3 brake oil on the wear of Al alloy piston.…”

“…Thus they are designed and manufactured with adequate consideration for their surface protection with the view to reducing the effects of wear and corrosion on surface [4][5][6][7]. Hydraulic brake and clutch master cylinders and pistons are widely made from aluminium alloys and steels [8,9]. Both faced the problems of wear (result of abrasion, high temperature resulting from two mating parts without oil, poor materials composition, and poor lubrication formulation of brake oil content).…”

“…This makes it to be alkaline and has strong potential to attack aluminium alloy components in the brake system. Studies have been widely reported on the subjects of wear, corrosion and tribocorrosion of different Al alloys [2][3][8][9][10][11]. Aluminium alloy wears have been accessed using tribometers, while their corrosions have been studied in diverse active and aggressive media (acid, base and alkali).…”

“…Aluminium alloy wears have been accessed using tribometers, while their corrosions have been studied in diverse active and aggressive media (acid, base and alkali). A few reports are available on either wear or corrosion of cast A6061 alloy [8,15] but not on the as-received wrought A6061 aluminum alloy in less aggressive organic media such brake oil environments (pH range 10.0 to 11.5) or related hydraulic fluids for automobile and hydraulic pumps applications. The reason for this work is that it is part of a research project of which the following publications are already in public domain [8,[16][17][18][19][20][21].…”

“…A few reports are available on either wear or corrosion of cast A6061 alloy [8,15] but not on the as-received wrought A6061 aluminum alloy in less aggressive organic media such brake oil environments (pH range 10.0 to 11.5) or related hydraulic fluids for automobile and hydraulic pumps applications. The reason for this work is that it is part of a research project of which the following publications are already in public domain [8,[16][17][18][19][20][21]. The results showed certain degrees of aggressiveness of the brake fluid to cast AA6061 alloy which revealed some weakness in the production of quality brake fluid likely resulting from the adulteration.…”