Research shows that there is an increasing interest in alternative friction materials that do not harm human health and the environment, especially after the harmful effects of asbestos were revealed ...and its use was banned. This study evaluates the potential of apricot kernel shell, an agricultural waste, to be used as a bio-material in brake pad compositions. Composites containing different granule sizes and amounts of apricot kernel shell were experimentally tested for friction performance using a dynamometer. The addition of apricot kernel shell to the brake pad compositions slightly increased the noise level but improved the coefficient of friction. These findings reveal the potential of using apricot kernel shells as an economical and environmentally friendly material in brake pad compositions.
This study aims to develop asbestos-free and environmentally friendly brake pads using apus bamboo powder (Gigantochloa apus). In the experiments, bamboo powder, resin, and catalyst were used as the ...raw materials and varied to ensure the quality of the prepared brake pads. To analyze the performance of brake pads, the fabricated brake pads are subjected to physicochemical tests (such as microscopic tests and functional group analysis) and mechanical tests (such as puncture tests, compression tests, and friction tests). The research results showed that adjusting the composition of the raw materials allowed a change in the performance of the brake pad, including porosity, morphological structure, and mechanical properties. Indeed, the condition of the low porosity on the inside of the brake pad strategically optimizes the compression strength of the material, making this design ideal for applications that require high resistance to compression loads. This study shows the possibility of apus bamboo powder as an alternative to asbestos in the production of non-asbestos brake pads, offering a safer and environmentally friendly solution as well as giving ideas for supporting current issues in the sustainable development goals (SDGs).
A growing worldwide awareness of the need for environmental sustainability has increased the demand for fibers in all possible applications. Utilizing agrowaste biofiber from Cardiospermum ...halicababum that has been untreated/surface-processed to create biofiber-based brake friction composites is the primary focus of this research. A standard manual retting technique was used to extract these fibers, which were then subjected to alkali and silane treatments. The fibers were then tested for their physiochemical characteristics. A standard industrial manufacturing procedure produced brake friction composites in brake pad form using surface-processed / untreated Cardiospermum halicababum fibers. The brake pads' performance was compared to industry-standard commercial pads. As per SAE J 661, the Chase test evaluated their tribological performance. According to the findings, brake pads made from silane-treated Cardiospermum halicacabum fibers exhibited a higher friction coefficient than those made from alkali-treated and untreated fibers. The worn surface of the tested pads was examined using a scanning electron microscope, revealing distinctive characteristics such as plateau formations and plowing. The pads were ranked by considering different criteria using the Extensive Evaluation Method.
Display omitted
•Cardiospermum halicacabum fibers, an agro-waste, were explored for brake pad applications.•Surface treatment was applied for Cardiospermum halicacabum fibers.•Silane-treated Cardiospermum halicacabum fibers-based brake pads had good µ behavior.•An extensive evaluation method ranked the performance of developed pads.
Solid lubricants like metal sulfides and fluorides are important ingredients in stabilizing the friction in brake pads. It is essential to consider the oxidation temperature and the compatibility of ...the metal sulfides. This study emphasises the importance of incorporating a variety of solid lubricants based on oxidation temperature regimes. Low-temperature solid lubricants such as molybdenum disulfide, iron sulfide, and bismuth sulfide, as well as high-temperature solid lubricants such as tin(II)sulfide, tin(IV)sulfide, and calcium fluoride were used in the preparation of brake pads. The combination of low and high-temperature solid lubricant mix was tested for tribological performance in brake pads. The results show the necessity of using both low and high-temperature solid lubricants to enhance the tribological performance of brake pads.
•Diverse solid lubricants in brake friction composites.•High and low-temperature solid lubricants for enhanced brake performance.•The combination of solid lubricants cut brake costs by reducing the use of costlier one.
In this study, asbestos-free automotive brake pads produced from palm kernel fibers with epoxy-resin binder was evaluated. Resins varied in formulations and properties such as friction coefficient, ...wear rate, hardness test, porosity, noise level, temperature, specific gravity, stopping time, moisture effects, surface roughness, oil and water absorptions rates, and microstructure examination were investigated. Other basic engineering properties of mechanical overload, thermal deformation fading behaviour shear strength, cracking resistance, over-heat recovery, and effect on rotor disc, caliper pressure, pad grip effect and pad dusting effect were also investigated. The results obtained indicated that the wear rate, coefficient of friction, noise level, temperature, and stopping time of the produced brake pads increased as the speed increases. The results also show that porosity, hardness, moisture content, specific gravity, surface roughness, and oil and water absorption rates remained constant with increase in speed. The result of microstructure examination revealed that worm surfaces were characterized by abrasion wear where the asperities were ploughed thereby exposing the white region of palm kernel fibers, thus increasing the smoothness of the friction materials. Sample S6 with composition of 40% epoxy-resin, 10% palm wastes, 6% Al2O3, 29% graphite, and 15% calcium carbonate gave better properties. The result indicated that palm kernel fibers can be effectively used as a replacement for asbestos in brake pad production.
This research investigates the effect of different abrasives (red mud, steel slag, and flyash) on the tribological characteristics of non-asbestos brake friction materials. Three distinct brake ...friction composites were produced by changing the proportions of essential components such as red mud, steel slag, and fly ash while maintaining the proportions of other parental ingredients. Consequently, friction composites with different abrasives were developed and evaluated for mechanical, chemical, and physical properties as per industrial standards. Using the Chase friction test equipment, the tribological characteristics were determined experimentally in line with IS2742 part-4. The experimental results indicate that fly ash particles in friction composites exhibited consistent fade and recovery behaviours with a lower wear rate. In comparison, steel slag based friction composites exhibited a better recovery behaviour. SEM analysis showed plateau development, pits, fractures, and various other features on the surface of the examined brake pads.
The tribological performance of C/C–SiC paired semi-metallic brake pads suitable for automobiles was investigated in this study. Factors on tribological properties of semi-metallic brake pads such as ...the contents of phenolic resin, copper fibers, steel fibers and MoS2 were tested by the orthogonal experimental. According to the SAE-J2522 test procedure, an optimized compositional formulation was derived based on the brake test results combined with fuzzy comprehensive evaluation. The wear mechanism of brake pairs was discussed, and the compositional formulation of the brake pad was further optimized after the analysis of the friction surface morphology before and after braking. The results showed that copper fibers had the greatest effect on the friction performance of brake pads. Copper fibers contributed to stabilization of the coefficient of friction (COF) and effectively improved the wear resistance. However, at higher braking speeds (≥120 km/h), the copper fibers were converted from fibrous to flaky and softened, acting as a solid lubricant on the friction surface, resulting in a low COF of brake pads. The tribological performance of brake pads could be improved by reducing the content of copper fiber and increasing the content of hard particles.
Stick-slip phenomena at a low-velocity range are investigated to study the effect of brake pad size on friction instability, focusing on the contact plateaus on the pad. The friction test is ...performed using commercial brake pads in three different sizes. The results show that smaller pads produce higher stick-slip amplitudes within narrower velocity ranges. Friction levels are influenced by the total contact plateau area, whereas the stick-slip amplitude was affected by the size of high-pressure plateaus. The pronounced stick-slip with small pads is attributed to the large high-pressure plateaus that increase the static friction further with stick time, indicating that a smaller brake assembly could lead to a high propensity of friction-induced noise and vibrations.
The development of brake pads using eco-friendly materials was spurred by the health risks associated with the use of brake pads based on asbestos. In this experiment, the frictional substance used ...to develop vehicle brake pads, which was based on asbestos, was replaced with carbon nanotubes made from rice husk. The impacts of the wear parameter were evaluated experimentally using Taguchi-Grey's (GRA) multi-response analysis. The wear rate, wear depth, and coefficients of friction were the three multi-response variables that were selected. The modified sol-gel and solution-stir-cast technique was used to develop the brake pads. The results show an ideal point of 1.5 wt% carbon nanotube made from rice husk, a 20 N applied load, a 3 m/s sliding speed, a 25 m sliding distance with 2.15 mg/m, a wear depth of 5 mm, and a COF of 0.42. At a 95% confidence level, the predicted and experimental GRA were fairly similar. The designed brake pad system's achieved frictional qualities meet industry requirements. It is known that silver nanoparticle modified carbon nanotubes made from rice husk biomass may be utilised to make high-friction brake pads using the advanced method.
PDF
