Life cycle assessment is a methodology to assess environmental impacts associated with a product or system/process by accounting resource requirements and emissions over its life cycle. The life ...cycle consists of four stages: material production, manufacturing, use, and end-of-life. This study highlights the need to conduct life cycle assessment (LCA) early in the new product development process, as a means to assess and evaluate the environmental impacts of (nano)enhanced carbon fibre-reinforced polymer (CFRP) prototypes over their entire life cycle. These prototypes, namely SleekFast sailing boat and handbrake lever, were manufactured by functionalized carbon fibre fabric and modified epoxy resin with multi-walled carbon nanotubes (MWCNTs). The environmental impacts of both have been assessed via LCA with a functional unit of '1 product piece'. Climate change has been selected as the key impact indicator for hotspot identification (kg CO
eq). Significant focus has been given to the end-of-life phase by assessing different recycling scenarios. In addition, the respective life cycle inventories (LCIs) are provided, enabling the identification of resource hot spots and quantifying the environmental benefits of end-of-life options.
Emissions from disc brake wear adversely affect the air quality in cities. Finite Element Analysis (FEA) approaches focussing on the macroscopic wear of pads and rotors can be found in the ...literature, but none of these take the wear and emission dependence of the local contact pressure and sliding speed into account. The aim of the present study is to further develop an FEA approach for simulation of macroscopic wear and airborne emission to include the dependences of local contact pressure and sliding speed by implementing wear and emission maps obtained by pin-on-disc tribometer tests. Results from a dyno bench test are compared with simulated results. The simulated rotor and pads wear, and airborne emissions are in line with the measured values.
•An FEA approach for simulation of disc brake wear and airborne emissions is presented.•Simulated wear and airborne emissions during an urban driving cycle are discussed.•Simulated results are compared with measured results from an inertia dyno bench test.•Simulated rotor and pads wear, and airborne emissions are both in line with the measured.
With regard to airborne particles with an aerodynamic diameter of less than 10 mu m (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 the possibility of reducing the PM10 fraction of the airborne particulate from brake wear by 50 wt%; ii) to enhance the general understanding on the physical and chemical phenomena underlying the brake wear process. The results achieved so far indicate that it is possible to design a disc brake system for a European standard car affording at least a 32 wt% PM10 emission reduction using a standard European pad and a heat-treated rotor. A further reduction to 65 wt% PM10 emission could be achieved with NAO pad material and the same heat-treated disc.
Pin-on-disc tribotesting is widely used to investigate the sliding behaviour of materials, including friction materials used in braking systems. The evaluation of the average contact temperature is ...paramount to understand the acting friction and wear mechanisms, and to determine the role of the materials. In the present work, the tribological behaviour of a commercial low-metallic friction material during dry sliding against a pearlitic cast iron has been investigated and the evolution of pin and disc temperature was recorded. The temperature distributions in the pin and the disc were modelled using a finite element analysis with three different approaches, i.e. considering a perfect contact, the separated bodies concept, and the presence of a third body between the sliding surfaces. The results were then discussed by considering the damaging phenomena occurring at the sliding contact. Wear was found to be nearly mild in nature in agreement with the contact temperatures that were determined to be lower than 100 °C. During sliding, a limited third body was formed, made of a partially covering friction layer on the pin surface, and a thin and irregular oxide layer on the cast iron wear track. The approach based on the perfect contact with thermal continuity at the interface was found to better fit the experimental temperature records and to be in substantial agreement with the observed wear phenomena occurring at the pin–disc interface.
With 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 the possibility of reducing the PM10 fraction of the airborne particulate from brake wear by 50 wt%; ii) to enhance the general understanding on the physical and chemical phenomena underlying the brake wear process. The results achieved so far indicate that it is possible to design a disc brake system for a European standard car affording at least a 32 wt% PM10 emission reduction using a standard European pad and a heat-treated rotor. A further reduction to 65 wt% PM10 emission could be achieved with NAO pad material and the same heat-treated disc.
Aluminum alloys are widely used in the automotive, aerospace and construction fields due to their excellent physico-mechanical properties. Nevertheless, the corrosion resistance of bare Al alloys is ...often insufficient to meet the requirements of several industrial applications and protection strategies are needed. Among these, anodizing is particularly effective since it can lead to the formation of a compact and thick dielectric oxide layer with barrier and corrosion protection capabilities.
However, anodizing of highly alloyed Aluminum alloys (e.g. those with an alloy element concentration higher than 5%
wt
) can be particularly challenging due to the presence of intermetallic precipitates within the Al matrix which generates micro-galvanic coupling events with an associated thickness inhomogeneity of the obtained anodic layer 1.
In this context, the work investigates ten new current waveforms for anodizing of Aluminum Silicon alloys (AlSix). Particular attention is devoted to the interplay among waveform parameters (e.g. duty cycle, peak and rest step intensities), oxide layer morphology and corrosion resistance. In particular, metallography, voltammetry and contact angle methods are used in order to correlate different figures of merit with the anodic layer morphological features.
It is concluded that a careful optimization of the current waveform parameters can modulate the: a) corrosion current; b) corrosion potential; c) breakdown potential; and d) polarization resistance; of coated specimens. In conclusion, the most effective waveforms are identified and coated Aluminum alloy specimens with a remarkable corrosion resistance are obtained.
1 M Bandiera, A Bonfanti, M Bestetti, F Bertasi, SAE International Journal of Advances and Current Practices in Mobility 3 (2), 973-979.
Aluminum Alloys as Anodes for Aluminum Batteries Bandiera, Marco; Pavesi, Arianna; Valota, Giorgio ...
Meeting abstracts (Electrochemical Society),
08/2023, Volume:
MA2023-01, Issue:
1
Journal Article
The development of batteries based on metals alternative to Lithium (e.g. Na, Mg, Zn, Al) requires the investigation of new electrodes and electrolytes. 1,2.
This is particularly true in the case of ...non-aqueous Aluminum batteries which typically include a pure (>99.8%) Aluminum anode which: a) suffer of poor cycling stability and low coulombic efficiency; b) is particularly subjected to dendrite growth; c) can undergo to corrosion phenomena upon cycling; and d) show a poor compatibility toward chloroaluminated electrolytes 3.
In this regard, the development of Aluminum alloys, alternative to pure Al anodes, is a challenging task which is barely investigated in the field of Aluminum ion batteries and requires experience in both battery electrochemistry and Aluminum metallurgy and casting.
In this scenario, the proposed work investigates the synthesis and characterization of ternary Aluminum, alloys comprising Si, Ti and B as alloying elements, as anodes for Al-ion batteries 4. Deposition/stripping measurements, impedance spectroscopy, metallographic analysis, EDXS and XRD techniques unveil the complex interplay existing between the microstructures of the alloys and the obtained electrochemical performance. It is demonstrated that a remarkable improvement in the: a) oxidation/reduction currents and overvoltages; and b) interfacial stability with the electrolyte; can be obtained, with respect to a conventional Al anode. Results allow to demonstrate that the investigation of Aluminum alloys can be crucial for the development of future Aluminum batteries.
1 F Bertasi, C Hettige, F Sepehr, X Bogle, G Pagot, K Vezzù, E Negro, S J Paddison, S G Greenbaum, M Vittadello, V Di Noto, ChemSusChem, 2015, 8 (18), 3069-3076
2 F Bertasi, F Sepehr, G Pagot, SJ Paddison, V Di Noto, Advanced Functional Materials 2016, 26 (27), 4860-4865
3 Y Zhang, S Liu, Y Ji, J Ma, H Yu, Advanced Materials 2018, 30 (38), 1706310
4 Italian Patent Application n° 102022000024522
Numerical wear simulation of the pad to rotor interface can be used in the design processes of disc brakes to optimize the positions of the pistons, study how the wear affects brake squeal and ...foresee the environmental impact due to particulate matter emissions. The reliability and validity of these kinds of simulations relies on an accurate prediction of the wear propagation. The aim of this work is to investigate to which extent finite element (FE) based wear simulations can be used with this purpose. A simplified FE model of a front brake in medium-sized European passenger cars has been developed in ANSYS v15 and combined with a routine that allows simulation of wear of both contact surfaces at the pad to rotor interface. The wear models implemented are based on the results from wear test conducted in a pin on disc tribometer. The FE model is used to simulate a test cycle consisting of 200 stops in a dyno bench. Three different friction materials are evaluated and the simulations are validated by comparison to experimental observations in the dyno bench. Despite the simplified FE model used, a good agreement was found between the simulations and experimentally observed results.
The reduction of particulate emissions is of increased importance in our society. In 2013 the road transport contribution to PM10 and PM2.5 emissions in the EU region counted for 11% and 16% ...respectively of the total emission. Related to these road transport emissions, the non-exhaust fraction equals almost the 50% of the exhaust one. One major contributor to the non-exhaust fraction is wear particles generated from automotive disc brakes. Despite that the pad-to-rotor contact in disc brakes is an important non-exhaust contributor; a lot of research questions remains about the wear mechanisms that are dominating the production of particulate emissions.This paper discusses the use of FEA to simulate wear and temperature distribution in a pin-on-disc tribometer, especially design for particulate research. The aim is also to estimate important contact parameters, such as contact temperature and contact pressure distribution, which cannot be obtained directly from the measurements.A FE-model of the pin-on-disc tribometer has been developed in the finite element package ANSYS v15. The model includes the 3D geometry of the test specimens and the specimen holder. Transient thermal analysis is used to simulate the temperature distribution in the system due to frictional heating in the sliding contact between the pin and the disc. Furthermore, a customized procedure has been implemented to simulate the wear of the pin. To validate the FE-simulation, the result is compared to experimental results for a typical pad-to-rotor material combination found in European braking systems.The result shows that the models can be used to simulate the frictional heating of the system and makes it possible to estimate the heat partition between the pin and the disc, as well as the contact temperature during a test. It is also explained the evolution of wear and deformation during time and their contribution to the pin displacement.
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