Development and tribological characterization of fly ash reinforced iron based functionally gradient friction materials

Brake friction materials play an important role in automobiles to reduce speed and to stop the vehicles. Advances in friction materials were updated to ensure effective performances in braking systems and to provide the maximum safety and comfort. Presently eco-friendly friction materials have been used as a replacement for conventional friction materials. Many synthetic and natural products were identified and claimed as better alternatives to banned toxic materials like asbestos and copper. Friction materials developed from natural products are eco-friendly and assure a great promise when applied in modern vehicles. To develop innovative formulations, basic knowledge of common ingredients and their effects in friction materials was needed. This review focuses mainly on providing detailed information about the common ingredients used, processing methods and the characteristics of brake friction materials.

Regenerative braking is one of the most important features of a hybrid vehicle. Currently used regenerative braking systems add a considerable cost to the vehicle due to the electronics involved. The author presents here a novel method for implementing a regenerative brake strategy without changing the mechanical brake system, i.e., without adding complex electronic systems like ABS, of a low cost conventional vehicle which is converted to a low-cost HEV (hybrid electric vehicle) for front axle applications. The electric braking force is additional to the mechanical braking force applied by friction brakes under normal conditions. In a previous study, a similar strategy was discussed but for application on the rear axle only. This strategy pertains to the regenerative brake force being applied on the front axle of a rear wheel drive vehicle. The strategy is simulated over urban drivecycles and results are compared with NEDC drivecycle. The results show a potential of 30% of brake energy recuperation with the proposed strategy. The study also illustrates the relevance of the strategy to high traffic volume markets with low vehicle speeds.

Joining of the functionally gradient friction material to the backing plate for wind turbines using sinter-brazing technique

With the development of the global automotive industry, environmental pollution and driving safety have been major problems. This paper focuses on a novel integrated cooperative antilock braking system (ABS) controller, which is used for antilock regenerative braking systems (ARBS) and antilock mechanical braking systems (AMBS) for hybrid electric vehicles (HEV) driving on different road surfaces. An intelligent tire system is utilized to detect varying road surfaces to obtain friction information and optimal operation slip ratio. In addition, the HEV eight‐degree‐of‐freedom dynamics model is developed for ABS control, which includes the LuGre tire model. Adaptive backstepping and finite state machine controllers are explored to maintain optimal wheel slip and regenerate energy, based on wheel slip, battery state of charge (SOC), motor capability torque, and vehicle velocity, and to develop the switching rules of regenerative and mechanical braking systems. In order to evaluate the performance of regenerative and mechanical braking systems on harvesting energy and driving safety, the HEV and LuGre dynamic tire models are developed in MATLAB SIMULINK /SimDriveline. The estimation results of different road surfaces and slip controller effects are tested via the experiments and simulations, finding good braking performances and high regenerative efficiency in different maneuvers.

This paper proposes a novel method for evaluating the braking system on oil rig. The Evaluation indexes, braking capacity, response speed control accuracy and braking efficiency, are put forward according to the drilling safety, benefit, quality and so on. The experimental apparatus to the performances of brakes was built by measuring the relation between the braking pressure, torque and rotation speed. The performances of pneumatic disc brake, hydraulic disc brake and pneumatic band brake are researched by modeling, theoretical analysis and experiment. Based on quantitative analysis, the value analysis is used to quantitatively and qualitatively evaluate the indexes. Some suggestions were put forward for selecting the braking system according to the evaluation. The total evaluation standard system is first proposed and it avails to optimize and evaluate the braking system on oil rig and its automation. Traditional selective method based on experience can be revised and the conclusions also provide a new reference for researching the automation of braking system and other mechanical systems.

The tribological properties of abrasive-based novel friction materials, viz., Alumina, SiC, and SiO2, were characterized for physical and chemical properties. The wear and frictional performance were evaluated under various operating conditions like speed and pressure. Reduced scale prototype was set up to evaluate performance parameters. Worn surface of friction materials was analyzed over SEM to understand the surface wear. Result showed that under the different operating conditions, SiO2 has higher wear resistance followed by SiC and alumina that had least wear resistance. Apart from this, better friction properties were observed for SiO2 that was followed by alumina and SiC.KeywordsTribological propertiesFriction materialsWear analysis

Failure of Friction Brake Components against Rapid Braking Process: A Review on Potential Challenges and Developments

<div class="section abstract"><div class="htmlview paragraph">The driving range of the electric vehicle (EV) greatly restricts the development of EVs. The vehicles waste plenty of energy on account of automobiles frequently braking under the city cycle. The regenerative braking system can convert the braking kinetic energy into the electrical energy and then returns to the battery, so the energy regeneration could prolong theregenerative braking system. According to the characteristics of robustness in regenerative braking, both regenerative braking and friction braking based on fuzzy logic are assigned after the front-rear axle’s braking force is distributed to meet the requirement of braking security and high-efficient braking energy regeneration. Among the model, the vehicle model and the mechanical braking system is built by the CRUISE software. The paper applies the MATLAB/SIMULINK to establish a regenerative braking model, and then selects the UEDC city cycle for model co-simulation analysis. Finally, the feasibility of the proposed control strategy is demonstrated by the simulation results. It shows that the driving range of the EV could be effectively increased on the premise of satisfying the demand of the driver braking force.</div></div>

An antilock braking method based on sliding mode control (SMC) for electric vehicles (EVs) is proposed on the basis of antilock braking dynamics model, and hence an SMC controller of antilock braking system is designed. Aiming at the chattering of SMC, a method of parameter fuzzy optimization for exponential approach law is proposed, which can meet the requirements for small chattering, strong disturbance attenuation and fast convergence. In order to take full advantage of regenerative braking force, a method of braking force distribution between mechanical and electrical braking systems is elaborated. The simulations on the road with different friction coefficients show that the vehicle speed is in good agreement with the wheel speed during braking, and the slip ratio is kept within an optimal range. Adopting SMC based on fuzzy optimization, optimal slip ratio can be tracked fast and accurately. Furthermore, since the regenerative braking force is made full use of during braking, the energy recovery efficiency is high.

<div class="section abstract"><div class="htmlview paragraph">The most used rotor material is gray cast iron (GCI), known for its susceptibility to corrosion. The impact of corrosion on the braking system is paramount, affecting both braking performance and the emission of particulate matter. The issue becomes more severe, especially when the brakes are left stationary or unused for extended durations in humid conditions, as seen with electric vehicles (EVs). Brake disc corrosion amplifies the risk of corrosion adhesion between contacting surfaces, leading to substantial damage, increased quantity and mass of non-exhaust particulate emissions, and decreased braking effectiveness. In addition, brake pads' friction material plays a crucial role in generating the necessary stopping force, creating friction that transforms kinetic energy into heat. However, heightened pressure during braking elevates rotor temperatures, contributing to the degradation of the friction material. This degradation manifests in decreased mechanical strength, heightened pad-to-rotor force, wear, and reduced braking efficiency. To address all these challenges and meet the stringent Euro7 particulate emission standards, we have developed controlled wear-resistant nitrocarburized layers on cast iron surfaces with customizable thicknesses, compositions, and porosity coupled with a new generation of post-oxidized layers referred to as Smart-ONC®. These layers, known for their remarkable "self-healing" capabilities, are formed through a controlled, in-situ post-oxidation process by incorporating additional metals into the oxide layer to enhance corrosion resistance and fortify the surface against damage and potential failures. the dyno tests validated the integrity of the FNC-Smart ONC (Ferritic nitrocarburizing-Smart oxidation of the nitrocarburized layer) layers, affirming their ability to preserve mechanical properties without experiencing wear, delamination, or cracking. Notably, FNC-Smart ONC discs demonstrate pad material accumulation, effectively sustaining braking performance as an additional protective interface between pads and discs.</div></div>

In this work selected corrosion phenomena occurring in disc brake systems are reviewed. For the first time, a galvanic series, summarizing the electrochemical performance of several brake system components, is presented and case studies are discussed as well. The case studies focus on corrosion issues which are related with the three major components of a car disc brake system, namely the: a) Aluminum caliper; b) brake pads and associated friction materials; and c) cast iron disc. It is shown that: a) the parameters for the anodization of Aluminum calipers should be carefully tuned on the basis of the specific Al alloy, in order to obtain an anodic layer capable to withstand the galvanic coupling existing between the caliper and nobler components; b) friction materials composition must be optimized in order to avoid shear adhesion phenomena between brake pad and disc due to the growth of corrosion products at the interface between the two; and c) it is possible to mitigate the corrosion of cast iron brake discs by modulating the carbon morphology, alloy elements concentration and microstructure. The manuscript demonstrates that electrochemical techniques are of fundamental importance in order to pursue a corrosion-resistance-oriented design of future braking systems for automotive applications.

Selecting suitable materials for automotive brake discs is an important process in the construction and assembly of braking systems. Brake discs or rotors are important components that convert kinetic energy into thermal energy to enable efficient braking and ensure vehicle and occupant safety. The choice of brake disc material is important to ensure optimum performance, reliability and durability under various operating conditions. Several important properties such as efficient heat dissipation, high mechanical strength, wear resistance and constant friction properties should be considered when choosing a suitable material for brake discs. Historically, Gray cast iron (GCI) continues to be the number one choice for brake discs due to its excellent heat transfer capabilities, effective vibration damping, and cost effectiveness. GCI effectively withstands the high temperatures and mechanical stresses encountered during braking, providing reliable and consistent performance. However, advances in materials science and engineering are researching alternative materials for brake disc applications Titanium alloys such as Ti-6Al-4V offer exceptional favour such as lightweight design, high-calibre strength, and corrosion resistance. These properties make titanium alloys suitable for certain applications that require reduced weight and increased performance. TMC combines a titanium matrix with ceramic reinforcements to improve performance compared to conventional materials. There are various factors to consider when choosing the brake disc material, such as: B. Vehicle type, weight, intended use (racing, daily driving, etc.), operating temperature, and cost considerations. Thorough testing and evaluation are performed to ensure that selected materials meet required performance criteria such as braking efficiency, durability, wear resistance and heat aging resistance. As the automotive industry continues to advance, there is more R&D exploring advanced materials such as carbon-ceramic composites for high-performance and luxury vehicles. These materials provide excellent braking performance, weight savings and long life. Research Significance: The study of material selection for automotive brake discs will show results in the performance, reliability, and safety of braking systems. The aim is to identify suitable materials that improve braking efficiency, durability and thermal stability. Efforts in this area have led to improved braking performance through the development of materials with optimal friction properties. These materials result in shorter braking distances, increased responsiveness, and improved overall braking efficiency. Additionally, research is focused on identifying lightweight materials that maintain structural integrity and heat dissipation capabilities. This weight savings contributes to improved fuel efficiency, lower emissions, and improved vehicle handling and performance. Durability and longevity are important aspects studied in research. Materials with high mechanical strength and wear resistance are selected to ensure long-term durability and long service life. Effective heat dissipation is also an important factor. The aim of the research is to find materials with good thermal conductivity and stability. This prevents brake slippage and ensures smooth, reliable braking performance even under the most demanding conditions. Cost-effectiveness is also a consideration, as researchers strive to find materials that balance performance, durability, and cost. Identifying cost-effective materials without compromising safety and performance is critical for widespread adoption in the automotive industry. Methodology: Weighted Sum Method: It method is the mathematical approach by combines many factors or criteria by assigning weights to each of them. A weighted sum is calculated by the means of multiplying the weight of each one element by the corresponding value and summing it up. This method allows comprehensive evaluation and ranking of alternatives based on their weighted scores. It provides a simple and effective way to consider multiple factors at once and make decisions. Alternate Parameters: GRAY CAST IRON (GCI), TMC, AMC 1 & AMC 2, TI-ALLOY (TI-6AL-4V). Evaluation Parameters: Friction coefficient tµ), Wear rate (x10^ {-6} mm^ {3}/N/m), Specific gravity (Mg/m^ {3}), Compressive Strength (MPa), Specific heat (Cp (KJ/Kg. K)). Result: From the result it is seen that Gray cast iron (GCI) got the first rank where as is the Ti-Alloy (Ti-6Al-4V) having the lowest rank. Conclusion: The first ranking material gray cast (GCI) is obtained with the best and suitable material for automotive brake disc.

Electric vehicles (EVs) receive impressive concerns worldwide due to their efficiency for reducing environmental pollution. Consequently, automotive institutions and academics are facing many challenges to provide various techniques to increase the EVs reliability. One of the crucial parameters is the regenerative braking system (RBS) that helps for optimal usage of the battery stored energy and to extend the driving range. The current research presents a new regenerative braking strategy focusing on various driving cycles to compromise the implementation of the RBS braking control and mechanical braking system using the artificial neural fuzzy system (ANFIS). The tackled different drive cycles are New York City Cycle (NYCC), New European Driving Cycle (NEDC), Federal Test Procedure 72 (FTP-72) and Federal Test Procedure 75 (FTP-75). Furthermore, the basic concepts of the modelling of electric vehicles with different road conditions are considered to demonstrate the vehicle’s dynamics performance. The MATLAB/SIMULINK software package is used for developing the model to study the regenerative braking systems performance under different conditions. The simulation results of this study show that the proposed regeneration braking strategy improves regeneration efficiency by about 40 % and extends the driving travel distance per charge up to 31 %

The paper deals with possibilities of assessment of braking efficiency during evaluation of braking system at technical inspection of trucks in conditions of the Slovak Republic. The braking efficiency of the vehicle is evaluated by measuring the braking forces at the roller brake tester. The magnitude of these forces also depends on the loads of the measured vehicle. The paper analyses the results of the practical tests of the braking efficiency measurement of a truck of category N3 and of a vehicle combination consisting of vehicles of category N3 and O4. The analysed vehicle combination was gradually loaded in four different ways and a special situation was the measurement of the braking efficiency of the tractor itself. The instantaneous load on each axle was recorded with portable axle weights. The braking efficiency evaluation was carried out in accordance with the valid methodology, which allows the application of the direct evaluation method, the method of linear extrapolation, the method of the reference braking forces and the indicative evaluation. A vehicle with the same braking system may be assessed as roadworthy or not roadworthy. This is due to the application of different methods of evaluating the braking efficiency and different way of loads at the loading area.

This research work presents an innovative utility of Functionally Graded Aluminum Matrix Composite with Silicon Carbide as a friction material in clutches’ plate since it has an acceptable friction coefficient and a high wear resistance which may lead to longer working life. Functionally Graded Aluminum Matrix Composite’s properties are calculated using rule-of-mixture and power law, and simulated as layered geometry. Clutches designed based on the standard size and working conditions of clutches in mid-size and heavy automobiles. Functionally Graded Aluminum Matrix Composite’s behavior is examined considering statics, dynamics, thermal and wear. Analyses are done using Finite Element method, by ANSYS with boundary conditions that represent the actual working conditions of clutch in automobiles. The developed finite element model is validated by comparing it to literature and has achieved good agreement. Results are discussed by comparing functionally graded aluminum matrix composite’s clutch performance to aluminum matrix composite with 20% of silicon carbide clutch and e-glass clutch performances. FGAMC clutch showed excellent behavior considering static analysis where deformations were the least among the three materials. The thermal and free vibrational performance of the FGAMC were not the best but with very small differences compared to aluminum matrix composite and e-glass clutches. Very unwanted performance of FGAMC is recognized in forced vibration analysis, as it has very high stresses, strain and deformation compared to the other two materials. Structural transient behavior of FGAMC is acceptable as it has the lowest deformations and strains from the highest stresses but in small area of the contact surface of the clutch. Volume loss in FGAMC due wear is less compared to traditional aluminum matrix composite by more than 4 times.