Frictional Behavior and Surface Failure of Human Enamel

The frictional behavior and surface failure of human enamel under sliding in water was examined. A large plowing component of friction was observed. For normal loads of up to 1kg, ductile behavior of the wear scar was apparent. Intermittent cracks were obrerved that appeared to propagate around the enamel rods.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67266/2/10.1177_00220345730520063001.pd

Wear of Fluorapatite Single Crystals : V. Influence of Environment on Frictional Behavior and Surface Failure

The influence of environment on the frictional behavior and surface failure of fluorapatite single crystals was evaluated for sliding in air, water, and dimethylformamide. The coefficient of friction was independent of environment. The ductile-to-brittle transition, however, occurred at a lower load in water than in air.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68110/2/10.1177_00220345730520050501.pd

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