Fiber Reinforced Friction Material Research Articles

Effect of mullite on the friction stability of carbon fiber-reinforced friction material

PurposeThe purpose of this paper is to investigate the effect of mullite on the mechanical properties and friction of carbon fiber (CF)-reinforced friction material.Design/methodology/approachCF-reinforced friction materials with varying content of mullite were fabricated by hot press molding, and then the tribological properties were tested on the MRH-3-type tribometer under ambient conditions with the ring-on-block configuration.FindingsThe experimental results indicated that the addition of mullite increased the density and compressive strength of friction material. However, the flexural strength of friction material decreased by 16% with the addition of 15 Wt.% mullite. The friction coefficient was proportional to the mullite content. Friction material with 12.5 Wt.% mullite showed the highest friction stability under different loads, whereas friction material with 10 Wt.% mullite exhibited the highest friction stability under different sliding speeds.Originality/valueBy boosting the resistance to deformation under load and increasing the specific heat capacity, mullite contributed significantly to the friction stability of the friction material.

Fiber-reinforced friction materials: Experimental, statistical and computational universal analysis

In this paper, the experimental, statistical and computational universal analysis methods applicable to most fiber-reinforced friction materials (FMs) are presented for four natural wollastonite fibers (WFs) with different length-to-diameter (L/D) ratios. Machine learning (ML) methods for friction coefficient prediction of friction materials are compared and screened. Numerical statistics and calculations are used in conjunction with the use of finite element (FE) models to determine the performance metrics and friction wear mechanisms of FMs. The experimental and computational results show that the artificial neural network (ANN) model performs the best in COF prediction with an accuracy of 0.961. The friction fluctuation, friction stability and integrated friction performance of the WF-containing samples are better than those of the blank samples. For the first time, the FE model was used to explain the swirling phenomenon on the wear surface of FMs. This study provides new ways and ideas for the design, experimentation, data processing and application of friction composites.

Friction-Wear Characteristics of Carbon Fiber Reinforced Paper-Based Friction Materials under Different Working Conditions

To study the friction and wear performance of carbon fiber reinforced friction materials under different working conditions, paper-based friction materials with different fibers were prepared. Experiments on the SAE#2 test bench were conducted to study the infectors including friction torques, surface temperature, coefficient of friction (COF), and surface morphologies. The results were analyzed, which indicated that the carbon fiber reinforced friction material could provide a higher friction torque and a lower temperature rising rate under the applied high pressure and high rotating speed conditions. As the pressure increased from 1 MPa to 2.5 MPa, the friction torque of plant fiber reinforced material increased by 150%, the friction torque of carbon fiber reinforced material increased by 400%, and the maximum temperature of plant fiber reinforced and carbon fiber reinforced material reached the highest value at 1.5 MPa. Thus, carbon fibers not only improved the COF and friction torque performance but also had advantages in avoiding thermal failure. Meanwhile, carbon fiber reinforced friction materials can provide a more stable COF as its variable coefficient (α) only rose from 38.18 to 264.62, from 1 MPa to 2.5 MPa, which was much lower than the natural fiber reinforced friction materials. Simultaneously, due to the good dispersion and excellent mechanical properties of PAN chopped carbon fibers, fewer pores formed on the initial surface, which improved the high wear resistance, especially in the intermedia disc.

Damping Behaviour of Multi-Walled Carbon Nanotubes Grafting on Carbon Fiber Reinforced Friction Material


 
 
 An automobile's braking system plays an important role to control the vehicle at various operating speeds. At present, the brake friction industry is mainly focused on effectiveness of braking in addition to aesthetic considerations of an automobile. In this research, carbon fiber reinforced friction material is developed by grafting multi-walled carbon nanotubes functionalized (MWCNTS-F) on CF surface. The surface of CF is basically chemically inert and hydrophobic in nature and needs to be modified by grafting MWCNTS-F on its surface to increase hydroxyl or carboxyl groups. An attempt is made to improve the bonding strength between CF, polymer matrix and the remaining ingredients. Carbon fiber content after surface modification is varied in weight percentor wt% (2%, 3%, 4% and 5%) and mixed with the remaining ingredients of friction material. Composite sheets are prepared using hand lay-up method and characterized for damping, SEM, TGA and FTIR analysis. It is observed that MWCNTS-F grafted on CF 3 wt% possess good damping results. The results also reveal that, optimum selection of ingredients and surface treatment method on CF is the main reason for improvement of the composite’s interfacial adhesion and damping behavior.
 
 

The effect of lignin on the physicomechanical, tribological, and morphological performance indicators of corn stalk fiber-reinforced friction materials

The effect of lignin on the physicomechanical, tribological, and morphological characteristics of corn stalk fiber-reinforced friction materials was investigated in this study by testing various lignin contents and fabricated composites. Experimental results indicated that a decrease in lignin content benefits the fade resistance, wear resistance, and recovery behaviors of the friction materials. Sample FMC-3 containing fibers with a lignin content of 6.7% exhibited the optimum friction stability and wear performance among the tested samples; it has fade rate of 10.2%, recovery rate of 105.3%, and sum wear rate of 1.817 × 10−7 cm3 (N · m)−1. Worn surface analyses revealed that a suitably low content of lignin may improve fiber-matrix interface bonding and stable secondary plateau formation, which effectively enhance the tribological behavior of friction materials.

Tribological Behavior of Multi-walled Carbon Nanotubes Grafted Carbon Fiber-reinforced Friction Material

Friction characteristics of multi-walled carbon nanotubes grafted carbon fiber-reinforced friction material (MWCRFM), asbestos fiber-reinforced friction material (AFRFM), and oxidized carbon fiber-reinforced friction materials (OCRFM) are investigated in this work using a wear test apparatus. The surface of carbon fiber (CF) is chemically inert and hydrophobic in nature and possesses poor bonding performance with polymer matrix. Hence, in this work, an attempt is made to improve the bonding behavior between CF and remaining ingredients. CF surface is modified by two surface treatment methods. First, oxidation and second grafting multi-walled carbon nanotubes functionalized (MWCNT-F) on CF surface. CF content after surface modification is taken as (5 wt%) and mixed with remaining ingredients of friction material. Composite sheets are prepared by using hand layup method. Three types of friction materials, (MWCRFM), (AFRFM), and (OCRFM) are developed and analyzed for coefficient of friction and wear rate using wear test apparatus. These materials are also characterized for SEM. MWCNTs-F on CF surface is observed. Sample specimens are cut from the composite sheets and the influence of performance properties like speed, load, and time on friction and wear is studied. The back ground for this research work is to identify the best configuration of materials and surface treatment method on CF for the improvement of tribological properties of friction material. The behavior of the samples is also analyzed using regression analysis L9 (3 × 3) experimental design method for three different loads, time periods, and speeds. The results reveal that braking load and time plays an important role to control the friction and wear characteristics of MWCRFM. It was also observed that MWCNT-F grafted on CF possess less wear rate and high coefficient of friction compared to other formulations of materials.

Effect of Surface Treatments on Tensile and Flexural Properties of Carbon Fiber Reinforced Friction Material

Effect of Surface Treatments on Tensile and Flexural Properties of Carbon Fiber Reinforced Friction Material

Effect of surface treatments on damping behavior of carbon and glass fiber reinforced friction material

Effect of surface treatments on damping behavior of carbon and glass fiber reinforced friction material

Effects of bamboo fibers on friction performance of friction materials

The mechanical properties of bamboo ( Phyllostachys heterocycla) fiber were evaluated. The friction and wear performance of the bamboo fiber-reinforced friction materials (BFRFMs) were tested on a constant speed friction tester. The results showed that the friction coefficient of BFRFMs (reinforced with 3 wt.%, 6 wt.% and 9 wt.% bamboo fibers) was higher than those of the non-BFRFM with identical ingredients and process conditions during the temperature increasing procedure. The friction coefficient of 12 wt.% BFRFMs decreased with increasing temperature during temperature increasing procedure, but fluctuation appeared at 200°C and then it decreased again with increasing temperature. The friction coefficients of BFRFMs with 3 wt.% bamboo fiber were higher than that with other bamboo fiber contents. Specific wear rate of BFRFMs increased with the temperature increasing during temperature-increasing procedure, and the wear rates of BFRFM with 3 wt.% fiber were lower than that of others. Morphologies of wear surfaces of friction materials were analyzed using scanning electron microscopy (SEM) and the friction characteristics were discussed. The results showed that carbonized bamboo fiber can reduce the specific wear rate and the noise and provide stable friction coefficient.

The Mechanical Properties of Natural Fiber

The jute fiber, bamboo fiber and wool fiber reinforced friction material were carried out Surface modification by 2wt.%NaOH solution. The tensile strength, elastic modulus, density and hardness of the composites were tested. The result showed that the Tensile Properties of modified jute fiber and bamboo fiber were improved, while the wool is the opposite. The density and hardness of composites has been reduced with fiber content increase. The morphology of the friction material surfaces was examined by SEM.

Finite Element Thermo Analysis of Friction Material Enhanced by Bamboo Fiber

The manufacturing engineering of bamboo fiber reinforced friction material was introduced in this paper. ANSYS was used to do adaptive meshing and establish the contact, impose constraints load and solve, then the temperature field of bamboo fiber reinforced friction material was obtained. The results showed that under the coupling effect of friction heat and pressure, Brake blocks and brake discs in the contact area showed local changes in temperature and stress characteristics. The thermal stress of coupled parts contact surface showed a inhomogeneous distribution. Contact pressure distribution and temperature distribution interact each other, the contact pressure distribution of the coupled parts affects the temperature distribution, and the local feature of temperature distribution of the coupled parts conversely affects the contact pressure distribution. It will provide an important theoretical basis for devising friction brake and selecting material of the friction pair.

Friction and wear behavior of carbon fiber reinforced brake materials

A new composite brake material was fabricated with metallic powders, barium sulphate and modified phenolic resin as the matrix and carbon fiber as the reinforced material. The friction, wear and fade characteristics of this composite were determined using a D-MS friction material testing machine. The surface structure of carbon fiber reinforced friction materials was analyzed by scanning electronic microscopy (SEM). Glass fiberreinforced and asbestos fiber-reinforced composites with the same matrix were also fabricated for comparison. The carbon fiber-reinforced friction materials (CFRFM) shows lower wear rate than those of glass fiber- and asbestos fiber-reinforced composites in the temperature range of 100°C-300°C. It is interesting that the frictional coefficient of the carbon fiber-reinforced friction materials increases as frictional temperature increases from 100°C to 300°C, while the frictional coefficients of the other two composites decrease during the increasing temperatures. Based on the SEM observation, the wear mechanism of CFRFM at low temperatures included fiber thinning and pull-out. At high temperature, the phenolic matrix was degraded and more pull-out enhanced fiber was demonstrated. The properties of carbon fiber may be the main reason that the CFRFM possess excellent tribological performances.

Studies on Mechanical, Friction, and Wear Characteristics of Kevlar and Glass Fiber-Reinforced Friction Materials

ABSTRACT Asbestos possesses properties that are ideally suitable for use as a friction material in automotive and a number of other applications. Animal and human studies carried out since the early 1900s have established that asbestos is carcinogenic and that exposure to especially asbestos dust causes a large number of diseases. Realizing the health hazards posed by asbestos, many countries started phasing out asbestos from all asbestos-containing products since the 1980s. Some of them imposed a total ban in the 1990s on the use of asbestos-containing friction products. This situation forced many manufacturers to look for alternatives to asbestos. But the efforts have only been partly successful. The search is, therefore, still on to find suitable substitutes for asbestos. Though steel wool, Kevlar, glass, and a number of other mineral fibers have been tried out on an experimental basis over the last two decades, glass and Kevlar fibers, in particular, have shown promise as potential substitutes for asbestos. These days, therefore, studies on polymer-based friction materials reinforced with glass, Kevlar, and ceramic fibers are being pursued with much fervor. However, conflicting views are prevailing even today as to the suitability of asbestos-free composites for automotive applications and freedom from the concomitant health risks posed by them. In the present work, therefore, phenolic resin matrix samples reinforced with different amounts of glass and Kevlar fibers were produced and characterized for their mechanical, physical, friction, and wear properties to assess their suitability for light passenger car applications. The study establishes that composites based on glass and Kevlar fibers show good mechanical, physical, friction, and wear characteristics, enhancing thereby their suitability for automotive applications. The property improvements achieved are correlated to the composition, microstructure, and the changes taking place on the surface of the friction composites.

Friction-wear characteristics of carbon fiber reinforced friction material

Friction-wear characteristics of carbon fiber reinforced friction material

Composites as friction materials: Recent developments in non‐asbestos fiber reinforced friction materials—a review

AbstractReplacement of conventional asbestos based friction materials has been called for because of bans on the use of asbestos. Research in this direction in the last decade has led to the development of more efficient asbestos‐free friction materials for automobiles. Fiber reinforced polymers show great promise for applications in modern vehicles. This review article focuses on the recent developments in the application of composites as friction materials. The first part of the article contains brief information about brakes, their action, brake materials, their desired properties, etc. The second part deals with the recent developments in non‐asbestos fiber reinforced friction materials.