The paper presents the influence of various systems of lubricating additives which determine the performance of the friction materials of brake linings. The base hybrid friction material formulation was modified with various types of lubricating additives. These additives are divided into groups containing commonly used lubricating materials: carbons and sulphides, compounded in various proportions, influencing the formation and structure of the so-called third body layer (TBL) on the surface of the brake disc because of braking. Raman Spectroscopy (RS), time of flight Secondary Ion Mass Spectroscopy (ToF-SIMS) and high-resolution scanning electron microscopy with an X-ray analyser (SEM-EDS) equipped with a focus ion beam (FIB) were used for chemical and morphological analysis of the surface layer of brake disc after breaking tests. The results of the physicochemical analysis of TBL were correlated with the results of tribological tests (according to the SAE-J2522 procedure, commonly known as AK-Master) on a brake dynamometer adapted to the measurements of acoustic signals (NVH – noise, vibration, and harshness). The obtained results confirm the important role played by the so-called third body layer, formed on the surface of the brake disc for safety (COF), durability (wear of friction elements) and the acoustic spectrum accompanying braking.

The analyzed topic refers to the corrosion resistance and changes in microhardness of the heat-treated (HT) hot-dip zinc coating deposited on bolts. The research aimed to evaluate the influence of the HT on the increase of the coating hardness and changes in anticorrosion properties. Hot-dip zinc coating was deposited in industrial conditions (acc. EN ISO 10684) on chosen bolts (M12x60). The achieved results were assessed based on corrosion resistance tests in neutral salt spray (salt chamber) and microhardness measurements. Tests were conducted in accordance with the adopted fractional plan, generated in the DOE module of the Statistica software. Using the conjugate gradient method optimal parameters of HT were determined. The conducted tests proved that the controlled heat treatment may increase the hardness of the hot-dip zinc coating without a significant deterioration in its basic protective function (corrosion resistance). The observed changes in the hardness and corrosion resistance of the zinc coating are a consequence of changes in its structure.

Exhaust emissions from vehicles are the subject of numerous studies and legal acts. In the European Union, exhaust emissions are regulated by “Euro” emission standards, which limit emissions of gaseous pollutants such as CO, CO2, HC, and NOx, as well as the particulate matter (PM) and particle number (PN). Solid particles consist of a number of micro-contaminants, inter alia polycyclic aromatic hydrocarbons (PAHs) and their nitrated and oxygenated derivatives. Despite their highly mutagenic and carcinogenic character, these micro-contaminants are not regulated in Euro emissions standards. This paper presents both a general discussion of the phenomenon of particulate formation in and emission from direct injection gasoline engines, as well as a wide range of results on the subject. The subject of the micro-contaminants in solid particles from modern gasoline vehicles is explored. The samples of solid particles were collected from 11 groups of vehicles according to the WLTP test methodology. Solid particles from gasoline vehicles were analyzed via various analytical techniques, including ion chromatography (IC) to measure selected anion concentrations, gas chromatography with mass spectroscopy (GC-MS) to study 16 PAHs and selected PAH derivatives, scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS) for images and elemental composition, and microwave plasma atomic emission spectroscopy (MP-AES) for qualitative screening analysis of 19 elements. The study of non-regulated compounds is crucial in efforts to establish the influence of solid particles on health and the environment. Furthermore, extended studies can provide a basis for further research on vehicle emissions or other fields, such as medicine or material engineering.

The paper presents the influence of various systems of abrasive additives which determine the performance of the friction materials of brake pads. A friction material was used for the tests, in which the base recipe was modified with various types of abrasive additives: 1. “low steel” – of low steel content, containing aluminium and chromium oxides; 2. “hybrid” – containing in addition to abrasive components from the low steel family, abrasive components such as zirconium silicate, magnesium oxide or iron oxides, which are characteristic of the family of asbestos-free organic materials (NAO); and 3. “mild hybrid” – containing abrasive components found in the friction materials of the NAO family, on the formation and structure of the so-called third body on the surface of the brake disc as a result of braking. High-resolution scanning electron microscopy with an X-ray analyser (SEM-EDS) equipped with a focus ion beam (FIB) was used to study film thickness, morphology, and chemical composition. The results of the physicochemical analysis of the third body were correlated with the results of tribological tests on a brake dynamometer adapted to the measurements of acoustic signals (NVH – noise, vibration and harshness). The tests were carried out in accordance with the SAE-J2522 procedure, commonly known as AK-Master. The obtained results confirm the important role played by the so-called third body, formed on the surface of the brake disc for safety (COF), durability (wear of friction elements) and the acoustic spectrum accompanying braking.

Many countries worldwide have introduced a limit for solid particles larger than 23 nm for the type approval of vehicles before their circulation in the market. However, for some vehicles, in particular for port fuel injection engines (gasoline and gas engines) a high fraction of particles resides below 23 nm. For this reason, a methodology for counting solid particles larger than 10 nm was developed in the Particle Measurement Programme (PMP) group of the United Nations Economic Commission for Europe (UNECE). There are no studies assessing the reproducibility of the new methodology across different laboratories. In this study we compared the reproducibility of the new 10 nm methodology to the current 23 nm methodology. A light-duty gasoline direct injection vehicle and two reference solid particle number measurement systems were circulated in seven European and two Asian laboratories which were also measuring with their own systems fulfilling the current 23 nm methodology. The hot and cold start emission of the vehicle covered a range of 1 to 15 × 1012 #/km with the ratio of sub-23 nm particles to the >23 nm emissions being 10–50%. In most cases the differences between the three measurement systems were ±10%. In general, the reproducibility of the new methodology was at the same levels (around 14%) as with the current methodology (on average 17%).

Background: Investigating the general corrosion resistance of Ti(C,N) type coatings on a prosthetic nickel alloy in the aspect of their use as protective coatings on prosthetic and orthodontic elements. Methods: Five groups of Ni-Cr alloy samples covered with Ti(C,N) type coatings differing in their carbon and nitrogen contents were used for the tests. The reference group included alloy samples without coatings. The samples were held for 105 days (2520 h) in salt spray chambers and examined by means of the NSS (neutral salt spray) and SWAAT (sea water acetic acid test) tests. After the periods of 14, 28, 81 and 105 days, the samples were removed and weighed, and their weight losses were determined. Results: In the case of each type of Ti(C,N) coating, the mass loss was lower than the mass loss of a sample without a coating, which makes it possible to state that coatings improve the corrosion resistance. No significant differences in the resistance were observed between the particular coatings. The corrosion rate of the examined coatings is close to parabolic. Conclusions: Ti(C,N) type coatings improve the resistance of a prosthetic Ni-Cr alloy and can be used as protective coatings for prosthetic and orthodontic elements.

The Euro 4 regulation, applicable since 2016 for L-category vehicles (i.e., two and three-wheelers, and mini cars) reduced the emission limits, but also introduced a new cycle, the WMTC (World Harmonized Motorcycle Test Cycle). The emission studies of Euro 4 motorcycles are limited, and most importantly there are no published studies comparing the results of different laboratories applying the new cycle. In this study we compared the particle and gaseous pollutants of one Euro 4 motorcycle measured in two laboratories in 2017 and 2020. The gaseous pollutant results had a variance (one standard deviation of the means) of 0.5% for CO2, 4–19% for CO, NOx, HC (hydrocarbons) and SPN (Solid Particle Number). The particulate matter mass results had higher variance of 50–60%. Additional tests with open configuration to mimic dilution at the tailpipe gave equivalent results to the closed configuration for the gaseous pollutants and SPN. The total particles (including volatiles) had significant differences between the two configurations, with the closed configuration giving higher results. The main conclusion of this study is that the new procedures have very good reproducibility, even for the SPN that is not regulated for L-category vehicles. However, the measurement of total particles needs attention due to the high sensitivity of volatile particles to the sampling conditions.

Appropriate driving technique, in compliance with eco-driving principles, remains an effective method to reduce fuel consumption. The selection of the correct gear is one of the pertinent factors when driving a car with a manual gearbox. In this study we have analyzed fuel overconsumption based on data recorded in real traffic conditions for vehicles driven by experienced drivers, using a black-box model. It was found that the total share of trip time with a lower than optimal gear selected amounted to from c.a. 3% for motorway driving up to 28% on rural roads. The mean fuel consumption reduction factor (following selection of the next gear up) amounted to from c.a. 2% up to 20%, depending on the selected gear and type of driving. Unfortunately, the potential for reduction of fuel consumption is not evenly distributed over the entire operating area of the engine. Thus, the cumulative reduction of fuel consumption, due to selection of the optimal gear, amounted to from c.a. 0.2% for motorway driving up to 3–6%, for urban and rural driving. It was shown that due to the selection of the appropriate gear, there still exists a real possibility of reduction of fuel consumption, even in the case of experienced drivers.

This paper describes a holistic development and testing approach for a battery electric vehicle (BEV) prototype based on a self-supporting body platform originating from a vehicle powered by an internal combustion engine. The topic was investigated in relation to the question of whether conversion of existing vehicle platforms is a viable approach in comparison to designing a new vehicle ab initio. The scope of work consisted of the development stage, followed by laboratory and on-road testing to verify the vehicle’s performance and driveability. The vehicle functionality targeted commercial daily use on urban routes. Based on the assumed technical requirements, the vehicle architecture was designed and components specified that included various sub-systems: electric motor powertrain, electronic control unit (ECU), high-voltage battery pack with battery management system (BMS), charging system, high and low voltage wiring harness and electrically driven auxiliary systems. Electric sub-systems were integrated into the existing vehicle on-board controller area network (CAN) bus by means of enhanced algorithms. The test methodology of the prototype electric vehicle included the vehicle range and energy consumption measurement using the EU legislative test cycle. Laboratory testing was performed at different ambient temperatures and for various characteristics of the kinetic energy recovery system. Functional and driveability testing was performed on the road, also including an assessment of overall vehicle durability. Based on the results of testing, it was determined that the final design adopted fulfilled the pre-defined criteria; benchmarking against competing solutions revealed favorable ratings in certain aspects.

The analyzed topic refers to the wear resistance and friction coefficient changes resulting from heat treatment (HT) of a hot-dip zinc coating deposited on steel. The aim of research was to evaluate the coating behavior during dry friction after HT as a result of microstructure changes and increase the coating hardness. The HT parameters should be determined by taking into consideration, on the one hand, coating wear resistance and, on the other hand, its anticorrosion properties. A hot-dip zinc coating was deposited in industrial conditions (according EN ISO 10684) on disc-shaped samples and the chosen bolts. The achieved results were assessed on the basis of tribological tests (T11 pin-on-disc tester, Schatz®Analyse device, Sindelfingen, Germany), microscopic observations (with the use of optical and scanning microscopy), EDS (point and linear) analysis, and microhardness measurements. It is proved that properly applied HT of a hot-dip zinc coating results in changes in the coating’s microstructure, hardness, friction coefficient, and wear resistance.