Brake Material Research Articles

Replacing copper in composites with waste foundry sand: A novel approach for Cu-free resin-based braking material

Cu-free resin-based brake material filled with waste foundry resin-bonded sand (waste sand) was prepared using the hot-pressing method. The changes in the physical and chemical properties of Cu and waste sand during braking were investigated, and their role in resin-based composites was discussed. The effects of the content of waste sand on the hardness, impact strength, indentation hardness, elastic modulus, friction coefficient, wear rate, micro-scratch friction coefficient, scratch depth, residual depth, and wear mechanism of resin-based brake material were investigated. Cu-contained composites generate Cu2O when braking at high temperatures, which adversely affects the friction and wear properties. Compared to Cu, waste sand was found to be more favorable for the overall friction and wear properties of resin-based composites. This suggests that waste sand can be used as a substitute for Cu in brake material. Waste sand is beneficial for improving the friction coefficient and stability of brake material through the formation of a friction layer. This layer can significantly impact the wear mechanism of brake material, particularly at high temperature (250–350 ℃). The brake material with 10–15% waste sand indicates excellent heat-fade resistance.

Study on Effect of Heat Treatment on C/C-SiC Brake Performance

After powder metallurgy and carbon/carbon brake materials, carbon-ceramic brake material (C/C-SiC) is a new generation of braking material. There are currently some batches of brake materials whose friction performance could be better: slightly higher than the standard. SiC was introduced into the C/C-SiC brake disc through Polymer Impregnation and Pyrolysis (PIP), and the composition and friction-wear performance C/C-SiC-SiCp were investigated. The findings indicate that the SiC introduced by PIP is amorphous, existing in the material’s pores, and the porosity is reduced to 7%. With the increase in speed, The C/C-SiC-SiCp braking curve demonstrates a transition from inverted trapezoidal to saddle-shaped. The line wear rate is reduced by 0.6 μm/cycle at medium and high speeds compared with C/C-SiC.

Study on the Influence of Friction and Wear Properties of High-Speed Rail Brake Materials under Humidity Environment and Temperature Conditions

A multi-functional friction and wear testing machine was used to test the pin disk wear of high-speed railway brake friction material under different disk temperatures (20 °C, 100 °C, and 200 °C) and different ambient humidities (55%, 95%). The test results show that the change in the disk temperature and different ambient humidities have significant effects on the frictional wear performance of the high-speed railway brake material. Under the conditions of 20 °C, 100 °C and 200 °C, the instantaneous friction coefficient and wear rate of the brake material decreased as the ambient humidity increased. The different ambient humidity caused severe surface damage to the brake materials, but the damage mechanisms were dramatically different. At constant temperature, the higher the ambient humidity, the lower the maximum equilibrium temperature of the disc.

High frictional stability of braking material reinforced by Basalt fibers

Frictional stability is a more accurate description of the friction state than coefficient of friction (COF) and wear rate. This work aims to develop Basalt fiber (BF)-reinforced braking material as high frictional stability friction materials. The findings demonstrate that using the BF can improve the mechanical, thermal properties and COF of the brake material while also enhancing the frictional stability, and restricting the friction fluctuation range between 0.040 and 0.110. The mechanism of frictional stability of BF is explained in detail under macro and micro levels. This work is expected to provide some reference value for the design and development of fiber-reinforced friction composites and the mechanism for interpretation of friction stability.

Process Optimization of Automotive Brake Material in Dry Sliding Using Taguchi and ANOVA Techniques for Wear Control

In this paper, an investigation of the load-dependent wear behavior of copper-free semi-metallic brake material is presented. The experiments were conducted in ambient thermal settings with varying sliding velocities (3.141 m/s, 2.09 m/s, and 1.047 m/s), normal load (60 N, 50 N, and 40 N), and sliding distance (4500 m, 3000 m, and 1500 m). Taguchi’s method was used in designing experiments to examine the output through an L9 orthogonal array. ANOVA was used to identify the consequence of interactions among different constraints. It also established the significant contribution of each process factor. The objective was set as the ‘smaller is better’ criterion to find minimum wear conditions. The impact of the normal load on the wear process was found to be maximum (71.02%), followed by sliding velocity (27.84%) and sliding distance (1.14%). The optimum condition for the minimum wear rate was found at 40 N normal load, 1500 m sliding distance, and 3.14 m/s sliding velocity. The results were confirmed with validatory friction experiment runs. The resulting error was within 10% error, which verified the experiment methods. The SEM investigation of worn surfaces of pin and disc confirmed abrasive wear and adhesive wear at 60 N and 40 N, respectively.

Tribological Properties of Laminate Composite Brake Material for High-Speed Trains

In this article, a laminate composite brake material was prepared by powder metallurgy techniques and proposed for use in the high-speed train braking system. The pad was a double-layer structure composed of prefabricated tribofilm (PTF, oxide-based materials) and metal-based materials. The friction and wear behaviors of the novel friction material with different thicknesses of PTF layer against steel rotor disc were investigated using a TM-I type braking dynamometer under initial braking speeds (IBS) of 50–350 km/h. It was found that the PTF pad exhibited stable friction behavior and wear rate in a large range of IBS (50–250 km/h), meeting the requirements of high-speed trains. During braking, the friction film formed on the worn surface was closely related to the friction and wear behavior. The PTF promoted the formation of a protective friction film, which provided a larger and flatter surface than that of metal-based materials. A relatively stable friction behavior and wear rate were maintained when the worn surface was covered with friction film.

Comparative Study on Thermal Analysis of Disc Brake Using ANSYS Simulation

The objective of this paper is to find a suitable material for disc brakes that can dissipate heat very fast to the environment than others. They are subjected to wear and tear, which might have an impact on their performance. The simulation findings will help us figure out the temperature, pressure, and heat that can be withstand at its maximum. If it manages to dissipate heat properly it can avoid the distortion, which will be produced in the disc, which leads to thermal cracking of the disc leading to disc failure. To eliminate such flaws, we need to develop a disc brake material that can endure a specific level of heat and friction while maintaining its efficiency over time. In this work, 3 different disc brake materials, namely Al356, cast iron, and SS420, are chosen for thermal analysis by using ANSYS simulations and the results will be compared among.

Selection of Automotive Brake Material Using Different MCDM Techniques and Their Comparisons

Selection of Automotive Brake Material Using Different MCDM Techniques and Their Comparisons

Tribology and Airborne Particle Emission of Laser-Cladded Fe-Based Coatings versus Non-Asbestos Organic and Low-Metallic Brake Materials

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.

Effect of Nano Sodium Titanate Whisker and Aramid Pulp on the Friction and Wear Behavior of Resin-Based Brake Material

The dependence of friction and wear behavior on nanosodium titanate whisker and aramid pulp in a designed resin-based brake material was systematically analyzed. Higher contents of aramid pulp enhanced the hardness of the brake materials. In addition, the maximum impact energy of the material reached 0.392 J/cm2 where the ratio of aramid pulp to sodium titanate whisker is 0.75. At same time, the friction coefficient was stable between 0.38 and 0.45, and the wear rate was 5%. The samples with higher contents of nanosodium titanate whiskers and aramid pulp showed more uniform furrows, fewer delaminated craters, more moderate layers transfer and more stable contact plateaus.

Comparison of tribology performance, particle emissions and brake squeal noise between Cu-containing and Cu-free brake materials

The present study developed two Cu-free brake materials using carbon fiber or carbon nanotube as the replacements for copper fiber and evaluated their tribology performance, particle emissions and brake squeal noise. Results show that the coefficients of friction (COFs) of the Cu-free brake materials are lower than that of Cu-containing brake material at the braking conditions with low and medium loads. At the high load braking condition, all the braking materials exhibit comparable COFs. Cu-free brake materials present larger specific wear rates than the Cu-containing brake material. However, the application of carbon fiber can reduce the particle number emission. All brake materials exhibit comparable brake squeal noise.

Effect of Nano Sodium Titanate/ Potassium Titanate Whisker on Tribology Behavior of Brake Materials

Here we developed a hot-pressed molded resin-based brake pad material reinforced by a nano sodium titanate whisker in comparison with nano potassium titanate whisker. The effect of the whiskers on the tribology behavior was investigated. Though nano sodium titanate whisker reinforced brake material showed higher porosity (+12.29% averagely) and lower hardness (-25.8% averagely) caused by the impurities, it exhibited improved ability in stabilizing the friction coefficient and enhancing 25.5%, 31.1%, 25.9% higher wear resistance, when the volume contents of whisker are 7.5%, 15% and 22.5%, respectively, compared to the nano potassium titanate whisker reinforced brake material. The wear mechanisms of the nano sodium titanate whisker reinforced brake materials were determined as embedded debris, delaminated crater, moderate layers transfer, uniform furrows, primary plateaus and secondary plateaus in similar size, indicating a main wear form of abrasive wear instead of adhesive wear.

Frictional Characteristics of Friction Brake Material Using Cantala Fibers as Reinforcement

Frictional Characteristics of Friction Brake Material Using Cantala Fibers as Reinforcement

Development of Silicon Based Ceramic Matrix Composite Brake Material for Military Aircrafts

Development of Silicon Based Ceramic Matrix Composite Brake Material for Military Aircrafts

Frictional Performance and Temperature Rise of a Mining Nonasbestos Brake Material during Emergency Braking

By simulating emergency braking conditions of mine hoisters, tribological experiments of a mining nonasbestos brake material sliding on E355CC steel friction disc investigated a pad-on-disc friction tester. It is shown that, under combined influence of braking velocity and pressure, the lubricating film and micro-convex-apices on wear surface would have complex physicochemical reactions which make the instant friction coefficient rise gradually while the instant surface temperature rises first and then falls. With the antifriction effect from lubricating film and the desquamating of composite materials, the mean friction coefficient decreases first, then rises, and decreases again with the increasing of initial braking velocity. And with the existence of micro-convex-apices and variation from increment ratio of load and actual contacting area, it rises first and then falls with the increasing of braking pressure. However, the mean surface temperature rises obviously with the increasing of both initial braking velocity and braking pressure for growth of transformed kinetic energy. It is considered that the friction coefficient cannot be considered as a constant when designing brake devices for mine hoisters. And special attention should be paid to the serious influence of surface temperature on tribological performance of brake material during emergency braking.

The Effects of Applied Load on Wear Behavior of Al-Quarry Dust Particle Composite Disc Sliding against Automobile Brake Material

The wear behavior of aluminium alloy (A356) reinforced with 5 wt. % of quarry dust particles composite disc was sliding against automobile brake friction lining pin was investigated. Dry sliding wear studies were investigated in pin-on-disc apparatus. The wear tests were carried out range of applied load 20 to 60 N and constant sliding velocity (0.5 m/s) under sliding distance of 500 m. The wear behavior of aluminium metal matrix composite (AMC) has been compared with the commercially used 25 grade Gray Cast Iron disc (GCI).The results showed that the wear rate of AMC disc decreased with increasing the applied load. However the wear rate of AMC disc with respective pin decreased with increasing the applied load. The coefficient friction increased with increasing the applied load. The scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDAX) used to investigate the disc and pin. The wear debris was analyzed by SEM image.

S1110601 AE計測による自動車用ブレーキ材料のトライボロジー特性評価([S111-06]第20回卒業研究コンテスト(6),機素潤滑設計部門)

S1110601 AE計測による自動車用ブレーキ材料のトライボロジー特性評価([S111-06]第20回卒業研究コンテスト(6),機素潤滑設計部門)

Wear Modalities and Mechanisms of the Mining Non-asbestos Composite Brake Material

The mining brake material is generally made of composite materials and its wear has important influences on the braking performance of disc brakes. In order to improve the braking reliability of mine hoisters, this paper did some tribological investigations on the mining brake material to reveal its wear modalities and mechanisms. The mining non-asbestos brake shoe and 16Mn steel were selected as braking pairs and tested on a pad-on-disc friction tester. And a SEM was used to observe the worn surface of the brake shoe. It is shown that the non-asbestos brake material has mainly five wear modalities: adhesive wear, abrasive wear, cutting wear, fatigue wear and high heat wear. At the front period of a single braking the wear modality is mainly composed of some light mechanical wear such as abrasive, cutting and point adhesive. With the temperature rising at the back period it transforms to some heavy mechanical wear such as piece adhesive and fatigue. While in several repeated brakings once the surface temperature rises beyond the thermal-decomposition point of the bonding material, the strong destructive high heat wear takes leading roles on the surface. And a phenomenon called friction catastrophe (FC) occurs easily, which as a result causes a braking failure. It is considered that the friction heat has important influences on the wear modalities of the brake material. And the reduction of friction heat must be an effective technical method for decreasing wear and avoiding braking failures.

CAD of Friction Material for Automobile Brake Using Artificial Neural Networks

The brake friction materials in an automotive brake system are considered as one of the key components for overall braking performance of a vehicle. Temperature sensitivity of friction materials has always been a critical aspect while ensuring their smooth and reliable functioning, and that sensitivity need to be constantly optimized. The performance of friction materials at elevated temperatures is defined by their fading performance.In this paper,a group of non-asbestos organic based friction materials containing different relative amounts of the ingredients of aluminosilicate fiber, steel fiber, phenolic resin and Cu powder mostly effecting on the tribological properties of designed brake material were manufactured by compression molding. Dry sliding friction characteristics of composites were tested on a model JF150D-II pad-on-disk type friction tester. A model of feed-forward artificial neural networks (ANN) consisting of four input neurons, six output neurons and one hidden layer, was used for the analysis and prediction of the correlation between material components and friction performance. The input parameters of ANN were the contents of four main components as aluminosilicate fiber, steel fiber, phenolic resin and Cu powder. The outputs were the friction coefficients of brake material against cast iron at six different operating tempetures from 100°C to 350°C. Based on ANN model trained successfully by 25 pieces samples, genetic algorithm(GA) was used to optimize the input parameters of compositions of brake material with the goal of minimizing fluctuation of friction coefficients at 100°C to 350°C. The optimum composition of brake material was obtained. The friction experiments of optimized material showed excellent stability of friction coefficients for automotive brake material as test temperatures increased from 100°C to 350°C. The neural network has impressive potential for solving time-consuming problems for the design of automobile brake material.

Effects of Sintering Temperature on Bending Property of C<sub>f</sub>/SiC Brake Material

With increasing of the speed of the train, the requirement of the performance of the braking friction materials is more and more higher. It is urgent to find new braking materials to satisfy the rigorous using environment. Cf/SiC has the broad application prospects when it is used as a new kind of braking material. On this article, in order to shorten preparation cycle and reduced production costs, short carbon fiber is substituted continuous carbon fiber felt. Cf/SiC brake materials were prepared by the way of molding compression-pressureless sintering with resin binder at 1800°C, 1850°C and 1900°C, respectively. The effect of sintering temperature on bending property of brake material was researched. The experimental results show that with the increase of sintering temperature, the bending strength of Cf/SiC brake materials rose first and then fell. If sintering temperature is too high, which will lead the crystal grain to grow up and the crack is easy to produce. Finally make the bending strength of composites reduced. When sintering at 1850°C, the bending strength of the specimen reached maximum. At the same experimental condition, the bending strength of Cf/SiC brake material sintered at 1850°C is 18.81MPa, compared to the sample sintered at 1800°C and 1900°C, the bending strength of the specimen is increased 14.56% and 5.26%, respectively. The toughening mechanism of carbon fiber debonding and fiber pull were generated in the process of bending fracture. The fracture model of composites is pseudo-ductile type.