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Wyniki wyszukiwania dla: AIRBORNE WEAR PARTICLES
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Effective density of airborne wear particles from car brake materials
PublikacjaPeople living in urban environments are subject to high health risks due to various anthropogenic sources of airborne particulate matter, including wear of transport vehicle brakes. Studies of airborne particles often require an estimate of the effective particle density, a property that allows correct matching of mass and size characteristics measured by different aerosol instruments. In this study we investigated the effective...
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A Study on Emission of Airborne Wear Particles from Car Brake Friction Pairs
PublikacjaThe emission of airborne wear particles from friction material / cast iron pairs used in car brakes was investigated, paying special attention to the influence of temperature. Five low-metallic materials and one non-asbestos organic material were tested using a pin-on-disc machine. The machine was placed in a sealed chamber to allow airborne particle collection. The concentration and size distribution of 0.0056 to 10 μm particles...
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Emission and properties of airborne wear particles from train brake friction materials based on novolac phenolic resins and butadiene rubbers
PublikacjaThe emission of airborne particulate matter from a train brake depends on the formulation of its friction material. This study investigates the emission and properties of wear particles from train brake friction materials based on straight or resorcinol-modified novolac phenolic resin and nitrile or styrene butadiene rubber used as binding ingredients. The wear particles are generated by a pin-on-disc tribomachine inside an aerodynamic...
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Correlations between the wear of car brake friction materials and airborne wear particle emissions
PublikacjaAirborne wear particles emitted from transport vehicle brakes are one of the main sources of toxic metals in inhalable particulate matter. Prediction of wear particle emissions may become more accurate if the relationship between the wear and particle emission characteristics is known. An experimental study was performed to investigate proportional correlations between the mass wear, 0.01–0.42 μm particle emission measured by a NanoScan...
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Emission of 1.3–10 nm airborne particles from brake materials
PublikacjaOperation of transport vehicle brakes makes a significant contribution to airborne particulate matter in urban areas, which is subject of numerous studies due to the environmental concerns. We investigated the presence and number fractions of 1.3–10 nm airborne particles emitted from a low-metallic car brake material (LM), a non-asbestos organic car brake material (NAO) and a train brake cast iron against a cast iron. Particles...
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Quantification of ultrafine airborne particulate matter generated by the wear of car brake materials
PublikacjaThe wear of car brakes is one of the main sources of airborne particulate matter in urban environments. Ultrafine wear particles are of special environmental interest since they can easily penetrate the human body through inhalation and cause various diseases. In the present study, the contribution of ultrafine particles to airborne particulate matter emitted from car brake materials was investigated under different friction conditions....
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Analysis of airborne metal containing particles with EDX/EDS detectorsin electron microscopes
PublikacjaIn years 2006-2010 particulate matter analysis was undertaken for dust samples collected from Gdansk and London area in orderto compare their morphology and composition. Part of those studies was devoted to analysis of particulate matter (PM) bearingmetals. Characterization of the morphology and size of the particles collected onto the filters was performed using a scanning electronmicroscope (SEM) and transmission electron microscope...
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A pin-on-disc study of airborne wear particle emissions from studded tyre on concrete road contacts
PublikacjaStudded tyres wear surfaces of winter roads, generating inhalable airborne particles. In this study, four concrete road materials and two stud geometries were investigated in terms of wear, road material hardness and airborne particle concentration. The sliding contact between studded tyres and road materials was studied using a pin-on-disc machine in a clean chamber. The results show that the normal load and the stud size have...
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Airborne wear particle emission from train brake friction materials with different contents of steel and copper fibres
PublikacjaThis study investigated the influence of the amount of steel and copper fibres in a train brake friction material on the tribological performance, emission intensity and characteristics of airborne wear particles. The particles were generated on a pin-on-disc tribometer under controlled friction and environmental conditions. It was found that the steel fibre results in a more intensive emission of 0.3–10 μm particles compared to...
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Porosity and shape of airborne wear microparticles generated by sliding contact between a low-metallic friction material and a cast iron
PublikacjaThe wear of brakes in transport vehicles is one of the main anthropogenic sources of airborne particulate matter in urban environments. The present study deals with the characterisation of airborne wear microparticles from a low-metallic friction material / cast iron pair used in car brakes. Particles were generated by a pin-on-disc machine in a sealed chamber at sliding velocity of 1.3 m/s and contact pressure of 1.5 MPa. They...
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A concept for reducing PM 10 emissions for car brakes by 50%
PublikacjaWith regard to airborne particles with an aerodynamic diameter of less than 10 μm (PM10), in countries in the European Union, the mass of brake emissions equals approximately 8–27% of the total traffic-related emissions. Using a research methodology combining tests at different scale levels with contact mechanics simulations and PM10 chemical characterization, the REBRAKE EU-financed project had the following aims: i) to demonstrate...
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Influence of permanent magnetic field on wear performance of dry sliding contacts
PublikacjaResults of experimental studies concerning the influence of permanent magnetic field on wear of dry sliding contact are presented.It was found that magnetic field of horizontal orientation is causing temporary reduction of material's hardness. It also facilitates and accelerates removal process of wear particles from the contact zone.Formation of bulges, consisting of accumulated and compacted anti-ferromagnetic material produced...
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Sliding bearings with sintered bronze bush lubricated by contaminated water with solid particles – Theoretical and experimental studies
PublikacjaSliding journal bearings lubricated with water coming directly from the environment are a solution used in shipbuilding, pumps and hydropower. However, the working fluid or surrounding water cannot always be filtered because of design limitations, which often causes the problem of premature wear of these sensitive bearings. The research conducted made it possible to assess the wear of sliding bearings lubricated with water containing...
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Optimization of Single-Sided Lapping Kinematics Based on Statistical Analysis of Abrasive Particles Trajectories
PublikacjaThe chapter presents the influence of selected kinematic parameters on the geometrical results of the single-sided lapping process. The optimization of these parameters is aimed at improving the quality and flatness of the machined surfaces. The uniformity of tool wear was assumed as main optimization criterion. Lapping plate wear model was created and in detail was analyzed. A Matlab program was designed to simulate the abrasive...
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Study on Dry Sliding Wear and Friction Behaviour of Al7068/Si3N4/BN Hybrid Composites
PublikacjaHybrid aluminium metal matrix composites have the potential to replace single reinforced aluminium metal matrix composites due to improved properties. Moreover, tribological performance is critical for these composites, as they have extensive application areas, such as the automotive, aerospace, marine and defence industries. The present work aims to establish the tribological characteristics of Al7068/Si3N4/BN hybrid metal matrix...
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Modeling of lapping plate wear and conditioning in single-sided lapping
PublikacjaIn order to achieve higher quality on worked surfaces with lower roughness, very high accuracy of shape and dimensions it is crucial to improve conventional finishing technologies and to develop new working principles. Single-sided lapping is one of the most effective planarization technologies and it is determined by a number of factors and boundary conditions. The most significant influence over a dimensional and profile accuracy,...
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Real-time monitoring of volatiles and particles emitted from thermoplastic filaments during 3D printing
PublikacjaThe proliferation of consumer-grade three-dimensional (3D) printers using fused deposition, also known as fused filament fabrication, has given rise to concerns over the exposure of users to potentially harmful substances. Thermoplastic filaments made of different polymers are extruded through a heated printer nozzle and deposited layer by layer on a build platform to form the printed object. This process leads to the emission...
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Wear of electroplated diamond tools in lap-grinding of Al2O3 ceramic materials
PublikacjaCurrent development of modern products, together with ever-increasing demands for their operation and usage, necessitate the search for new processing methods. Abrasive machining is widely used in many industrial areas, especially for processing difficult-to-machine materials such as advanced ceramics. Grinding with lapping kinematics, also called lap-grinding, is still one of the innovative methods of abrasive processing being...
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Tribological Properties of Ni-P/Si3N4 Nanocomposite Layers Deposited by Chemical Reduction Method on Aluminum Alloy AW-7075
PublikacjaThe article presents the results of tribological tests of Ni-P/Si3N4 nanocomposite and Ni-P nickel layers deposited on the AW-7075 aluminum alloy by chemical reduction method, and the AW-7075 alloy without coating. Nanocomposite layers were produced using Si3N4 siliconnitride in the form of a polydisperse powder whose particle sizes ranged from 20 to 25 nm. The influence of the content of the dispersion phase layer material on...
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