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Replacing high-strength frictional materials with lightweight composite alternatives is currently a global challenge for researchers. In this work, aluminum alloy (AA2900)-based metal-matrix composites reinforced with 6 wt.% α-alumina were fabricated then subjected to T6 heat treatment followed by case hardening. The resulting composite samples exhibited improved hardness, strength behavior, and stress–strain behavior along with good ductility and formability when microwave sintered. Good microstructural bonding was observed for all samples, which can be attributed to the finer α-Al2O3 particulates used as the reinforcement and the microwave sintering process. The mechanical and wear properties of the composites were compared with existing aerospace brake pad material. Data for wear characteristics versus the number of landings for the existing brake pad material were considered as the benchmark data, and the feasibility of replacing it with the developed composites was evaluated.

The subject of the experiments was the tribological properties of typical brake pads and disc characteristics. For the experiment was used Grey Cast Iron brake disc and semi metallic, low steel quantity and ceramic brake pads. The breaking process was imitated. The experiment was conducted at 0.75, 1.25 and 1.76 m/s sliding speed using 0.85 MPa contact pressure. The experiments lasted 10 minutes. The results of the experiments showed that best tribological characteristics have ceramic brake pads, despite the fact that brake disc temperature rapidly increase the with ceramic brake pads, but the friction coefficient (and braking torque) was the best. Semi metallic and low steel braking pads had very similar friction coefficient values, but wear and disc temperature values were more dissimila

This research article deals with the comparative performance analysis of the nanocomposite SiC-Ni-P coating on the edge and chamfer parts of the brake pad. The coating is used to provide a smooth s...

The article investigates the effect of microalloying on the wear resistance of brake pads, namely the effect of carbon and aluminum concentration on the contents, morphology and dispersion of cementite in cast iron with the introduction of modifiers of Si-Ca and Si-Ca-Ba-Ce, which allowed to optimize the composition of manganese gray cast iron by the criterion of the lowest wear intensity. The obtained regularities of graphitization of manganese gray cast irons alloyed with aluminum, when modified by ligatures of the Si-Ca and Si-Ca-Ba-Ce system make it possible to establish the optimal contents of these ligatures in cast iron, which ensures its satisfactory structure without interdendritic graphite and without exceeding the allowable the content of secondary cementite, which provides a minimum wear intensity of heavily loaded brake pads in dry friction. In order to determine possible directions for optimizing the chemical composition of friction gray cast irons modified with the Si - Ca - Ba - Ce alloy, a regression equation was constructed on the basis of accelerated tribotechnical tests, which describes the dependence of the wear rate of brake pads on the content of the main alloying elements: aluminum, manganese, carbon. Tribotechnical tests were carried out according to the scheme of a full factorial experiment; the concentrations of aluminum, manganese and carbon were variable factors. Factors were varied at two levels: at the upper level and at the lower level. The minimum wear rate of cast irons corresponds to the concentration of carbon and manganese at the upper level. The aluminum concentration does not affect the wear rate of cast irons, that is, the aluminum concentration can correspond to the lower level of variation. The authors of the article proved that the modification of friction cast irons with a complex master alloy containing barium and cerium gives the most stable and reliable results in the context of preventing the formation of graphite inclusions located between grains. Therefore, despite an increase in the number of graphite inclusions in cast irons with an increase in carbon concentration in cast irons, the wear rate of cast irons decreases. In this case, graphite continues to play the role of a solid lubricant, and an increase in the number of graphite inclusions without increasing their size has a positive effect on the wear rate of cast irons.

Friction and wear characteristics of 6061 Al alloy composite reinforced with sub-micron Al2O3 particles (Al/Al2O3 submicron composite) against commercial semi-metallic brake pad material were determined in dry sliding condition at different loads and sliding speeds using a pad-on-disc configuration. The tribological performance of Al/Al2O3 submicron composite was evaluated against conventional grey cast iron brake rotor material under same conditions. The Al/Al2O3 submicron composite exhibited lower wear rate than grey cast iron, specifically at brake power intensity (PV) lower than 6 MPa-m/s. Al/Al2O3 submicron composite also resulted in much lower wear of the semi-metallic brake pad material at higher brake power intensity (above PV = 6 MPa-m/s) compared to grey cast iron. This is attributed to the better heat dissipation in Al/Al2O3 submicron composite causing the brake pad material to operate at much lower temperature. Up to a sliding speed of 2 m/s, a 20% higher coefficient of friction was observed with brake pad material sliding against grey cast iron. Higher sliding speeds were marked with negligible difference in friction. The scanning electron microscope (SEM) with energy-dispersive spectrum (EDS) analyzer was used to examine the morphology and chemical composition of worn surfaces and then investigate the underlying wear mechanisms.

The main objective of this paper is to evaluate the braking performance of the brake pads made of non asbestos organic friction material. In this sense we compared two friction materials used for brake pads for small and medium-sized vehicles. Braking tests were performed on a vehicle with a spark-ignition engine and two variants of braking system on the front axle: ventilated brake discs, made of cast iron and brake pads made of semi-metallic material, approved according to ECE R90 standards and the second variant with ventilated brake discs, made of cast iron and brake pads made of NAO composite material, produced in the lab. The obtained results offer the possibility to draw conclusions regarding the braking performance requirements in order to validate the recipe of the friction material developed based on an original formula.

The brake pad material was fabricated using asbestos-free agro-waste sugar cane bagasse ash (SCBA) at low cost by a compression molding technique. SCBA in varying proportions (0%, 5%, and 10% weight) was added to the composite mixture containing epoxy resin as a binder. The size of the SCBA particle was 300 µm. The fabricated brake pad was subjected to mechanical, physical, and tribological analyses. The obtained results were compared with conventional asbestos-based brake pad material. The results showed that the sample having 10% SCBA as filler content has high tensile strength, flexural strength, density, low water, and oil absorption. Also, the hardness test and impact test results revealed the suitability of SCBA in brake pad material.

The brake pad is one of the imperative portions of the braking system of any automobile; which is mounted on a brake-disc rotor on each wheel; the brake pads were made by different types of materials. In recent research focuses on using Titanium (Ti) alloy-based brake pads for sophisticated cars (lightweight automobiles) and sports cars because of its high fracture toughness at low density. The most commonly preferred grade of Ti alloy is Grade 2 with 99.5% pure, but in the recent research, it was found that the Ti alloy grade 5 has good thermal stability; so, it can withstand a high tribo-thermal zone like the braking system. This study aims to investigate the frictional wear behaviour of the Ti alloy grade 5 and its performance and it is improved furtherly coating with Titanium Aluminium Nitride (TiAlN). The TiAlN is coated over the Ti alloy using Cathodic Arc Deposition (CAD) method; its surface properties such as surface hardness, surface morphology, surface roughness, and coating thickness are characterized. The wear test is conducted to the TiAlN coated Ti discs as per ASTM G99 (American Society for Testing and Materials) in against OHNS balls (Oil Hardened Nickel Steel). The Coefficient of Friction (COF) of the TiAlN coated Ti alloy has been reduced twice the time when compared with the uncoated Ti alloy. The surface morphology of the worn surfaces studied after the wear test to study the causes of the phenomenon. It reveals that the enhanced surface properties and better resistance to micro thermal effects are reasons for the improved wear resistance of the TiAlN coated Ti alloy.

Hybrid aluminum matrix composites (HAMCs) are the second era of composites that can possibly substitute single strengthened composites because of improved properties. The present investigation used stir casting techniques to fabricate the hybrid metal matrix composites with different volume fractions Al-χ%TiO2- χ % SiC (χ −2.5%, 5%, 7.5%). This paper examines the feasibility and relevance of the growing minimum effort of hybrid composites (AA6061-TiO2-SiC) for brake pad applications in automobile industries. An optical electron microscope (OEM) was used in HAMCs, which indicates that the reinforcement is very scattered in the Al matrix alloy and the porosity level is adopted for the stirring composites. The mechanical properties such as Tensile strength (TS), Hardness (BHN), density and impact strength of the hybrid composites have been seen as either practically identical or better than the earthenware strengthened composites. This is seen from past research that identifies the direct reinforcement of the composites due to the proximity of the hardened porcelain phases, while the indirect reinforcement arises from the thermal mismatch between the matrix and reinforcement during the solidification process. It has been reasoned that the hybrid composites offer greater flexibility and dependability in the structure of potential parts relying on the fortification's mix and organization.

Copper plays a vital role in the performance of brake friction materials due to its better thermal conductivity and fade resistance. But owing to the negative impact towards to the aquatic life, the usage of copper in brake material formulations is reduced considerably in developed nations. Research is being carried out globally to reduce the copper with single ingredient or combination in brake materials. Thus the present study dealt with the development of brake pads using a commercially available alloy of aluminum and iron (Mechanomade) in the formulation with other ingredients. To compare the performance, three other brake pads were also developed by replacing mechanomade with copper, aluminum, and iron in the formulation. The developed brake pads were analysed for the physical, chemical, mechanical and thermal properties as per standard industrial practice. The tribological characteristics were analysed using Chase test following SAE J661. It was evident from the test results that Iron aluminum alloy based brake pads showed good fade and recovery characteristics. To study in detail regarding the worn surface characteristics, Scanning Electron Microscope with Elemental mapping was used.

Brakes are very important component in any vehicle, used to stop the motion of it either by applying mechanical or hydraulic pressure on brake pads. By engaging and disengaging of braking action, the surface of brake components (or) materials is ruined after some time. Therefore, it is important to study and develop a new composition of brake materials which provides optimum coefficient of friction along with increasing wear resistance to the materials. Hence, new combination has been formulated for fabrication of brake composite material using powder metallurgy method which consist of copper-tin alloy mixed with silicon carbide as a base materials, aluminium oxide as an abrasive material with varying volume percentage of graphite and talc powder as a friction modifiers. The pin-on-disc test was performed on brake composite material to analyse their tribological properties namely friction and wear. From tribo-test, it was observed that all composites give the friction coefficient in the range of ∼0.33–0.51 and the loss of materials in the range of ∼79–131 mg. Further, the mechanical, thermal stability and surface characterization were also carried out on brake composites using universal testing machine, vicker’s hardness tester, thermogravimetric analyser and scanning electron microscope respectively. These results reveal a very marginal change in hardness, increase in compressive strength by increase of talc concentration to the matrix, uniform distribution of reinforcement into the matrix and multi stage degradation of material loss in thermograph.

International audience; The stiction phenomenon which results in the adhesion of the brake pad to the disc brake of a vehicle has been investigated from a corrosion point of view. Asbestos-free organic pad that contains copper associated with a cast iron disc was investigated and compared to a model system which consisted in a ceramic pad (chemically inert) associated with the same cast iron disc. The whole system was described as a thin-layer cell of electrolyte and was studied using different electrochemical methods including polarization curves and impedance spectroscopy. The influence of the cell geometry was pointed out, but the corrosion of the system is enhanced due to the presence of copper in the pad. Indeed, the copper dissolves from the pad and redeposits on the disc. This was confirmed by scanning electron microscopy observations and Raman spectroscopy. A mechanism taking into account the thin-layer geometry was then proposed to account for the role of metallic additive (in this case copper) on the corrosion of the disc.

The aim of this work is to fabricate aluminum, boron carbide (B4C) based aluminum matrix composites (AMCs) using easy and cost effective powder metallurgy (P/M) route. Here, Al–Mg–Si composites having different weight fractions of B4C (3.5,7.0,10.5,14.0 and 17.5 wt%) were synthesized to study the dry sliding wear behavior with respect to automobile brake pad material. The surface morphology and elemental composition of fabricated composite material were characterized by Scanning Electron Microscope (SEM) and energy dispersive x-ray spectroscopy (EDS) respectively. Further, dry sliding wear tests were conducted with respect to i.e. applied loads, sliding distances and reinforcements for the performance analysis of synthesized AMCs. A linear regression model was used to optimize the control factors. Furthermore, explore the effects of reinforcements on density, Vickers hardness, wear rate and worn out surface morphology. Further, the analysis also revealed the critical wear mechanisms with their wear debris for improvement in the AMCs. The hardness of aluminum composite (17.5% B4C/Al–Mg–Si) showed 54.15% higher value than matrix alloy. Furthermore, it was observed that AMCs showed significant improvement on the various factors e.g., applied load (L), sliding distances (SD) and reinforcements (R) than that of aluminium matrix alloy.

Braking performance is dependent on friction materials of tribological components, generally metal and pad. The pad consists of a composite of thermosetting resin and reinforcement material that exhibits mechanical and wear resistant, heat conduction, lubricant, and others. Slate is a natural rock composed of extremely fine materials that brings interesting tribological properties, in addition, its industrial current activity generates a significant amount of mineral waste, which is a problem for the environment. The objective of this work was to propose a technological alternative as a new friction element based on slate particulate as tribological reinforcement in composite based on phenolic resin as a matrix, besides that, minimize the environmental impact due to the inadequate disposal of these slate tailings and add value to the mineral, classifying it as a residue to be used industrially and no longer as waste. In this sense, the effect of the amount of slate on the friction properties of the brake pads made was investigated. As the brake pad material, four different slate containing formulations were proposed, manufactured and analyzed, and as the brake wheel gray iron was chosen. The friction and wear characteristics were determined by Pin-on-Disk type tribological tests, the pair was composed by disk (pad formulations) and pin of gray iron, representing the brake wheel. The coefficients of friction of the composites were shown to be regular and stable, with an average of 0.44 between the samples. Among the results obtained, the formulation containing 40 % of slate and 35 % of phenolic resin, presented the most satisfactory parameters compared to commercial friction materials in current use.

In this research work, palm seed power (0–9 wt%, step of 3%; four composites sample, namely P0, P3. P6, P9) were used to reinforce master batch of friction composite materials containing phenolic resin binder, steel swarf fibre, cashew, alumina, graphite, copper and zinc. The fabrications were as per standard industrial practice via hot compression moulding route. Thereafter, samples were cut and characterized for their tribological characteristics on specifically designed braking dynamometer using grey cast iron disc as per TS 555 and TS 9076 standards. Physical and mechanical properties such as hardness and density of the samples were also determined. Further, multi-criteria-decision-making like Preference Selection Index methods are used to ascertain ranking of material alternatives based on performance criteria. Both the subjective analysis and PSI output are in agreement with each other. Hence, such techniques often found suitable for decision-making or ranking of materials alternatives when performance criteria are of conflicting in nature.

In this paper, the mechanical and tribological behaviours of various compositions of aluminium 6063 alloy – clay (Al-clay) composites for brake pad applications were studied. The Al-clay composites with 5–30 wt% of clay particles of grain size of 60 BSS (250 microns) were developed through stir casting route. The wear characteristics of Al-clay in dry sliding conditions were subjected to a series of Denison T62 HS pin-on-disc wear tests. The action of two different loads (4 and 10 N), three sliding speeds of 200, 500 and 1000 rpm were investigated. The results of the mechanical and wear tests as well as the metallographic investigation of optical, scanning electron microscopy and energy dispersive X-ray microscopy revealed an improvement in the tensile strength, hardness and wear resistance in the composites with 10–25 wt% clays. The best values were obtained at 15 wt%. Wear rate was highly influenced by applied load and sliding speed. The developed composites with 15–25 wt% clay addition were similar to conventional semi metallic brake pad in terms of wear and friction properties. Keywords: Sliding wear, Surface analysis, Sliding friction, Hardness, Three-body abrasion

Laser cladding is a promising surface treatment for refurbishing worn-out cast-iron brake rotors. Previous studies on laser-cladded brake rotors have demonstrated their extensively higher wear and greater airborne particle emissions, compared with traditional cast iron rotors. In order to overcome this, a commercial non-asbestos organic (NAO) brake material is tested against Fe-based laser-cladded and traditional cast-iron brake rotors. Two low-metallic brake pad materials are also tested as references. The materials’ coefficients of friction, specific wear rates and particle number concentrations are evaluated. The results indicate that the NAO brake material showed lower wear and had fewer particle emissions than the low-metallic brake materials when deployed against both cast iron and laser-cladded brake rotors. The NAO/laser-cladding friction pairing showed wear, particle concentration and fraction of fine particles (sub 1 μm) equivalent to those of the low-metallic/cast-iron friction pairing, creating significant potential for application in refurbishing worn-out cast-iron brake rotors.

Purpose The purpose of this study is to investigate the influence of commercially available iron–aluminum alloy compared to copper, iron and aluminum powders on the tribological performances of friction composites. The main objective is to replace copper from the friction composite formulations. Design/methodology/approach In this study, friction composites were fabricated as of standard brake pads using commercially available iron–aluminum alloy and compared to copper powder, iron powder and aluminum powder-based without varying the other ingredients. The brake pads were developed as per the industrial procedure. The physical, mechanical and thermal properties of the developed brake pads were analyzed as per industrial standards. Tribological properties were analyzed using the chase test. Initial speed and deceleration tests in a real-time braking scenario were performed using a full-scale inertia brake dynamometer. Worn surface analysis was done using a scanning electron microscope. Findings The results indicate that iron–aluminum alloy (mechanomade)-based friction composites possess good physical, chemical, thermal and mechanical properties with stable fade and recovery characteristics due to its composition and flake morphology. During initial speed and deceleration braking conditions, iron–aluminum alloy also showed good tribological behavior. Originality/value This paper explains the influence of commercially available iron–aluminum alloy in friction composites in enhancing tribological performance by its composition and flake morphology, which could potentially replace copper in friction composites by solving subsequent problems.

A brake pad has been developed employing a hybrid of cane wood and palm fruit fibre as filler material. The filler materials were extracted and processed; however, the palm fruit fibre was further treated with NaOH to remove oil remnants. After proper drying, the filler materials were ground and sieved into 150 µm particle size. The experimental design was set up using Central Composite Design in Design Expert software. The design varied the percentage composition of the filler materials and the binder. At constant press time of 8 min, press temperature of 160 ℃ and curing time of 2 h, 20 test samples were produced and tested for mechanical and physical properties. These include hardness, wear rate and water absorption. The Fourier transform infrared analyses showed that both cane wood and palm fruit fibres have active alcohol (O–H) and amine (C–N) functional groups. The experimental results were analysed and optimised using response surface methodology and validated using the analysis of variance tool of the Design Expert software. An optimal 30% resin, 3.48% palm fruit fibre and 6.52% cane wood composition by mass was developed, which gave a product with 98.25 MPa hardness, 4.13 mg/m wear rate and 0.494% water absorption. This result indicated that hybridised cane wood–palm fruit fibre is a good filler material for brake pad production.

Multi-functionality of copper (Cu) in friction materials renders its replacement extremely difficult. However, rising ecological concerns and the imminent ban on its usage make it mandatory to look for an efficient substitute. The present paper explores a possibility to replace particulate Cu filler by stainless steel swarf (SSS) in the brake-pads. A series of five realistic multi-ingredient brake-pads containing SSS as a focussed ingredient was developed by increasing its amount from 0 to 20 wt% in the step of 5%. In another set of pads 10% of SSS was replaced by 10 wt% Cu n particulate form keeping all ingredients same to compare the performance of two fillers. These pads were characterized for their physical, mechanical and tribological properties. Tribo-performance using realistic test parameters was evaluated on the brake inertia dynamometer as per JASO C 406 standard. It was observed that with an increase in the amount of SSS, almost all the properties of brakes pads, including wear resistance improved significantly. Nonetheless, Cu- containing pad proved slightly better in recovery ratio and wear performance by 10%, but inferior in the case of fade µ (µ-coefficient of friction) and recovery µ. Worn surface analysis with scanning electron microscope (SEM) confirmed that SSS had poor interfacial adhesion with the matrix which led to a higher wear of SSS filled pads as compared to the Cu filled pads.

The study analyzes the effects of family of steel fibers on the thermo-mechanical, tribological and corrosive properties of Phenolic resin-based friction material. Tribological studies were performed on chase testing machine following SAE J661 standards. The brake seizure (corrosive stiction) due to corrosion is studied based on ISO 6315 test standard. The series of fibers used in this study include mild steel fibers, annealed steel fibers, and stainless steel fibers. The percentage by weight of fiber in all the composites was kept as constant at 12 % (Low metal series). For the purpose of comparison, another composite with 24 wt. % of stainless steel fiber was used in this study (High metal content). Experiments showed that the friction coefficient in general decreases with increasing temperature up to 300 °C and then was stable. Mild steel fiber reinforced composites fared better in fade and wear performance followed by annealed steel fibers. The highest friction (with poor consistency) and wear are found in the higher content of stainless steel fiber-based composite. Wear mechanism was studied by using scanning electron microscope.

Non exhaust brake emission is one of the important issue concerns with health and environment. In brakes operation, wear debris are released in atmosphere and pollute the environment. Brake pad is classified in to three categories namely metallic, non-metallic and Non Asbestos Organic (NAO). Constituent elements of a brake pad are a reinforcement, binder, friction modifier, abrasive, filler and elanstomer. As per report of WHO and Environment Protection Agencies, some of the metals oxidised and produces toxic gaseous. Toxicity leads and creates bad effect on human health. The Environment Protection Agencies set a limit and ban on some elements. This paper focuses on remedies over environment and health issue because of brake pad emission. It is an important to reduce percentage of toxic elements at source and develop novel material compositions which are less dangerous to the environment and human health. Also, it satisfies all requirements of a brake pad material as per international standards.

The past decade, the automotive brake friction material based on continuous research and developments phase out the asbestos and the friction product market increase the asbestos free friction material as a safer alternative. As a result, the friction industries was developing the different quality of brake lining and brake pads each with their own unique composition, yet performing the very same task and claiming to be better than others. The selection of brake friction materials is based more on tradition and experimental trial and error rather than fundamental understanding. This review was common ingredients used in brake lining, brake pad and its business trend.

The main objective of this research work is to develop an environmentally friendly brake pad with the incorporation of bio based binder, filler, reinforcement and friction modifiers. This study suggests that maintaining the high friction stability at high speed and load for a brake pad material can be sustained by cardanol resin, a natural resin binder. The tribo test procedure of JASO 406C was performed on two different cardanol (15CF and 20 CF) compositions by maintaining the two test parameters such as pressure sensitivity (effectiveness test). Result shows that 3–(8,11,14-Pentadecatrienyl) phenol Cardanol in phenolic resin is found to be more superior and most suitable binder resin combination, for the given ingredients compared to using only a cardanol resin as a binder in brake pad. Furthermore, the morphology of wear debris, contact plateaus and transient patches are analysed by scanning electron microscope.

The main objective of this research work is to develop an environmentally friendly brake pad with the incorporation of bio-based binder, filler, reinforcement and friction modifiers. This study suggests that maintaining the high friction stability at high speed and load for a brake pad material can be sustained by cardanol resin, a natural resin binder. The tribo test procedure of JASO 406C was performed on two different cardanol (15CF and 20 CF) compositions by maintaining the two test parameters such as pressure sensitivity (effectiveness test). The result shows that 3-(8,11,14-Pentadecatrienyl) phenol cardanol in phenolic resin is found to be more superior and most suitable binder resin combination, for the given ingredients compared to using only a cardanol resin as a binder in brake pad. Furthermore, the morphology of wear debris, contact plateaus and transient patches are analyzed by scanning electron microscope.

Braking system is an important system of automobiles responsible for providing better performance and safety. The basic purpose of Braking system is to reduce the speed of moving body by providing adequate resistance, which ultimately converted into heat energy. Brake pad material plays important role in controlling the vehicle with considering input parameters like stopping distance, vehicle speed, braking force and performance parameters like coefficient of friction, noise level, fade and recovery. As speed control cannot be achieved by single-phase material so it constitutes several ingredients. Nowadays various classes of friction materials are available based on their constituents like metal, semi-metals, non-metals, ceramic and organic materials. Base composition consists of reinforcement, filler, binder, elastomer, friction modifier and abrasive. Initially asbestos material was used as filler material but worn out particle released after continuous friction pollutes the environment. Also harmful effects on human being like cancer were pointed out by many researchers. Hence, several attempts made by researchers to find an alternative friction materials. In this paper, various possible constituents of composite friction material are reviewed and evaluated their results to study their effects.

This paper focuses on investigating wear behavior of Austenitic stainless steel-304 using pin-on-disc wear testing tribometer in as-received condition. Wear behavior is of particular concern as the frictional force and coefficients of friction are known to influence the wear significantly. In this study, we have taken austenitic stainless steel (304) as a pin which makes point contact against the mating surface of alumina ceramic disc. Sliding distance and speed are maintained constant during the P-o-D experiments. Experimental runs carried out with load on the pin at three different weights. The scientific data so obtained, viz wear, frictional force, and coefficient of friction are plotted employing Origin Graphs. The microstructure of worn-down surface is characterized using a Scanning Electron Microscope. Results obtained found with a good agreement of wear behavior of austenitic stainless steels. Frictional force and coefficient friction fluctuated severely when the load is applied. The SEM investigations indicate that moderate loading on stainless steel will preserve anti-galling characteristics while offering resistance to wear. However, the 3 kg loading on the pin exhibited a microscopic scale transfer, adhesion and spalling of the material of the pin during sliding. SEM studies revealed that moderate loading preserved anti-galling characteristics of the material of the pin. Results of these investigations will have an impact on applications leading to orthopedic stainless steel implants used against broken bones which are analogous to ceramic. The wear tests have bearing on the products used in ceramic brake pads, ceramic disc brakes of automobiles and railway trucks.

The coupling bionic surface is generally prepared by laser melting on the surface of a gray iron brake hub, which can allow the brake hub to achieve excellent wear resistance and fatigue resistance. The designs of most previous experiments have been based on independent units that were uniform in their distribution patterns. Although some progress has been made in the optimization of cell features, there is still room for further improvement with respect to bionics and experimental optimization methods. Here, experiments on units with non-uniform distributions of different distances were used to rearrange and combine the bionic elements. This paper is that the original uniform distribution laser melting strengthening model was designed as a non-uniform distribution model, and the heat preservation and tempering strengthening effect of continuous multiple melting strengthening on the microstructure of the melting zone is discussed. The mechanism of crack initiation and the mode of crack propagation were analyzed. The relationship between the internal stress in the melting zone and the crack initiation resistance was also discussed. In this paper, the mechanism of different spacing distribution on the surface of gray cast iron by laser remelting is put forward innovatively and verified by experiments, which provides a solid theoretical basis for the follow-up industrial application.

This paper presents the wear analysis of brake pad and disc of an automobile using pin on disc experimental setup. The brake pad, consisting of silicon carbide and many other binding and filling materials, is stamped with the graphene nanoplatelets. The graphene nanoplatelets are mixed with the cast iron which is usually used as disc for braking assembly of an automobile. The pins for the experimental purpose were made from the regular commercial brake pad and stamped brake pad. The mixing of the graphene in the cast iron disc is done by the stir die casting method. The experiments were conducted to find out the wear volume, coefficient of wear rate and coefficient of friction. The wear parameters for the commercial brake pad assembly with and without graphene nanoplatelet are compared.

The aim of this paper is to simulate the process of wear mechanism of brake pad in braking operation to evaluate the weight loss due to wear and the specific wear coefficient for different bake pad materials. It is a key component of transportation including industrial equipment; friction brake plays a critical role in their routine work as well as safety activity. The braking system's role in an automotive is to slow or stop the automobile entirely by converting its kinetic energy to heat energy by friction. The pad and rotor interaction causes friction heat, so the brake pad must absorb heat rapidly to survive high temperatures, but not wear. This work analyzes and discusses various environment friendly and healthy option materials to asbestos. Brake pad friction substance is made up of different materials such as binders, filler content, additives, and reinforcements to satisfy the specifications and adjust their percentage effects on the tribological properties. Over the past few days, the brake pads have been manufactured of asbestos material with enough electrical, tribological, as well as physical properties, but that causes cancer and many other health issues, and therefore, its use is redundant. Three samples with specific mixtures are used with varying ratio of ingredients as well as observing their impact on the tribological characteristics like brake pad friction and wear. Weight loss observed for the asbestos material for the same loading condition is more as compared to the non-asbestos material.

Non-exhaust wear emissions from disc brakes affect the air quality in cities throughout the world. These emissions come from the wear of the contact surfaces of both the pads and disc. The tribological and emissions performance of disc brakes strongly depend on the contact surface characteristics of the pads and discs. The surfaces of conventional pads are scorched by heating it to several hundred degrees to make the resin carbonize down to a few millimetres deep into the pad. This is done to have a shorter run-in period for new pads. It is not known how scorching will affect the amount of airborne particle emissions. Therefore, the aim of the present study is to investigate how pad scorching influence the airborne particle emissions. This is done by comparing the pin-on-disc tribometer and inertia dyno bench emission results from a Cu-free friction material run against a grey cast iron disc. Three types of modified friction material surfaces have been tested: scorched, extra-scorched and rectified. The results show that the level of scorching strongly affects the airborne particle emissions in the initial phase of the tests. Even if the scorched layer is removed (rectified) before testing, it seems like it still has a measurable influence on the airborne particle emissions. The results from the tribometer tests are qualitatively in line with the inertia dyno bench test for about the first forty brake events, thereafter, the airborne particle emissions are higher for the scorched pads. It can be concluded that it seems that the level of scorching has an adverse influence on both the tribological performance and level of particle emissions.

The motive of this paper is to produce Non-Asbestos Organic brake pad for the automotive application using bamboo fibre reinforced with binder epoxy resin, friction reducer wheat and filler material kaolin clay. Three different brake pads were developed and named A, B and C with various compositions of the materials using hand layup technique. For detail understanding of the material nature varied mechanical testing was done, the properties examined are Tensile strength, Hardness and physical traits like porosity, density too was tested with varied testing standards, the surface analysis was done by SEM for the topological imaging. The unique nature of bamboo fibre brought a great influence in the brake pads in both physical and mechanical traits hence it can be said that replacement of the conventional brake pads can be done with this bamboo reinforced brake pad.

When the surface of gray cast iron is subjected to laser irradiation and melted and then re-solidified, a material can be obtained that has a superior structure and properties to the base metal. On the surface of gray iron brake drums, the surface of the raw material can be processed into a bionic coupling surface with different shapes, structures, and soft and hard tissues similar to the surface of an organism. The wear resistance and fatigue resistance of brake drum surfaces can be greatly improved. However, the relative wear characteristics of the friction pairs in brake systems show that performance improvements in brake systems are the result of appropriately matching the brake drum and brake pad. This paper studies the wear relationship between three kinds of commonly-used brake pads (semi-metallic, organic asbestos-free, and ceramic) and different biomimetic models of brake drum samples. The interaction mechanism and failure mode between three kinds of brake pads and bionic samples were determined. According to the wear test results, the matching relationship between the brake pads and the brake drum was analyzed and determined, which provides a basis for the application of bionic brake drums.

The development of automobile brake pad using locally sourced palm kernel fiber was carried out. Asbestos, a carcinogenic material, has been used for decades as a friction material. This development has thus prompted a couple of research efforts geared towards its replacement for brake pad manufacture. Palm kernel fiber was used as an alternative filler material in conjunction with various quantities of epoxy resin as the matrix. Three sets of compositions were made, and the resulting specimens subjected to physical and mechanical tests using standard materials, procedures, and equipment. The essence is to determine their suitability and hence possible performance in service. The result showed that sample C with 40% palm kernel fiber content having hardness, compressive strength, abrasion resistance, specific gravity, water absorption, and oil absorption of 178 MPa, 96.2 MPa, 1.67 mg/m, 1.8 g/cm3, 1.86%, and 0.89%, respectively, had an optimum performance rating. It was equally ascertained that increase in the filler content had the effect of increase in hardness, wear resistance, and specific gravity of the composite brake pad, while water and oil absorption got decreased when compared with results obtained by other researchers using conventional brake pads made of other friction materials including asbestos. This is an indicator that palm kernel fiber is a possible and effective retrofit for asbestos as a filler material in automotive brake pad manufacture.

This study investigated the wear performance of phenolic composites under various conditions. Samples of brake pad material (UCV018) were subjected to friction and wear tests against grey cast iron...

The role of metallic fibers, present in brake pad materials, have been investigated with particular attention to the formation of the friction layer. The aim of the research was to establish an effective approach for the development of less polluting copper-free friction materials. Starting from a reference material, two more compositions were prepared: one obtained just by removing copper; in another, the quota of the removed copper fibers was replaced by steel fibers. The samples were wear tested and the results compared with those obtained with the reference material. The worn surfaces exhibit specific features, like cracks and compacted wear debris, that provide useful indications for interpreting the main wear phenomena and for a further development of novel friction materials.

Studying about different materials for brake pads is necessary as the asbestos brake pads causing the harmful effects and these should be phased out. There are many alternatives for asbestos are investigated from different journals. In this review paper some of the most suitable environment friendly and best performed compositions are presented. Fibres made of agricultural wastes like banana peels, palm wastes, aramid fibres, flax fibres etc. are studied. By using bio source raw materials like condensed tannins and furfural alcohol a bio sourced thermo set resin was developed and used and tested for a new application: as a resin matrix of automotive brake pads. The manufacturing procedure developed is particularly easy. Automotive brake pads based on this green resin were characterized and showed better braking properties and wear resistance when used under real car, full scale test conditions. Different alternatives for filler materials, Different binders like phenolic resin, epoxy resin are also studied and it effects on the performance of brake pads are presented. Formulations that are made by varying compositions of filler, fibre, binder etc. and possibility of replacing the existing formulations and its effect on the physical and tribiological properties of the brake pad are studied.

Copper (Cu) is almost an essential constituent of friction materials (FMs) since it shows multi-functionality in performance. However, it is being banned due to its adverse effects on aquatic life. In the present research work, iron-aluminum (FA25) alloy particles were explored for Cu replacement. With the help of fixed parent composition, five types of brake-pads were manufactured with variations in FA25 alloy content as 0, 5, 10, 15, and 20 wt%. One more kind of pad was developed containing Cu in 10 wt% for the sake of comparison. The brake-pads were characterized for physical, mechanical, thermal, tribological properties and noise-vibration (NV) performance. The 10 wt% alloy proved to be the optimum amount to replace the Cu with superior performance if fade resistance and counterface friendliness can be compromised slightly.

In this study, through severe reduced-scale braking tests, we investigate the wear and integrity of organic matrix brake pads against gray cast iron (GCI) discs. Two prototype pad materials are designed with the aim of representing a typical non-metal NAO and a low-steel (LS) formulation. The worn surfaces are observed with SEM. The toughness of the pad materials is tested at the raw state and after a heat treatment. During braking, the LS-GCI disc configuration produces heavy wear. The friction parts both keep their macroscopic integrity and wear appears to be homogeneous. The LS pad is mostly covered by a layer of solid oxidized steel. The NAO-GCI disc configuration wears dramatically and cannot reach the end of the test program. The NAO pad suffers many deep cracks. Compacted third body plateaus are scarce and the corresponding disc surface appears to be very heterogeneous. The pad materials both show similar strength at the raw state and similar weakening after heat treatment. However, the NAO material is much more brittle than the LS material in both states, which seems to favor the growth of cracks. The observations of crack faces suggest that long steel fibers in the LS material palliate the brittleness of the matrix, even after heat damage.

Full-carbon/ceramic brake pairs have been recently proposed to achieve profound applications of C/C–SiC brake materials in brake systems with a high-energy load. Severe wear rate and a high and unstable coefficient of friction (COF) of the traditional C/C–SiC disc-pads pairs prevented further development of this material. In this study, FeSi75 alloy and Cu were mixed to form an infiltration agent to modify the C/C–SiC composites. We examined the braking performance of the Fe–Si–Cu modified C/C–SiC brake pads mated with traditional needled C/C–SiC brake disc using a lab-scale dynamometer. The results revealed that the Fe–Si–Cu blending modification yielded a significant wear reduction of the brake disc and pads. After a series of braking tests, the worn surface morphology was characterized, and the wear resistance improvement mechanism was analyzed.

Running-in process of low metallic brake pads and cast iron discs are investigated using full scale inertia brake dynamometer designed for particle emission studies. The airborne particles are measured using ELPI+ and collected on filters. The pads and disc contact surfaces are studied using microscopy techniques. It is observed that the particle emissions from the new pads and discs are significantly higher compared with the used ones and indicates importance of proper running-in of the pads and disc for wear particle emission tests. The results also indicate that pads and disc pairs which are able to stabilize friction behavior faster will produce less particle emissions which could influence the strategies of brake material formulations or steps during their production. QC 20170630