scholarly journals Effect of Carbonaceous Components on Tribological Properties of Copper-Free NAO Friction Material

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1163 ◽  
Author(s):  
Hsun-Yu Lin ◽  
Huy-Zu Cheng ◽  
Kuo-Jung Lee ◽  
Chih-Feng Wang ◽  
Yi-Chen Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Fiber ◽  
Carbon Black ◽  
Expanded Graphite ◽  
Aquatic Organisms ◽  
Friction Material ◽  
Wear Loss ◽  
Natural Graphite ◽  
Friction Materials ◽  
Artificial Graphite

Copper helps to accelerate heat transfer during the braking process, allowing the brake materials to produce a stable coefficient of friction (COF), which in turn reduces wear loss and braking noise. However, its properties are also quite harmful to aquatic organisms. Finding a suitable replacement that fits all functions of copper for brake materials is not an easy feat. In this paper, six different carbonaceous components (coke, carbon black, carbon fiber, artificial graphite, natural graphite and expanded graphite) were substituted for copper in non-asbestos organic (NAO) friction materials. The hardness, thermal conductivity and tribological behaviors of these copper-free NAO friction materials were examined. Experimental results indicate that carbonaceous components improve lubrication and assist the friction composites with generating friction layers on the worn surface. Specimens containing coke, carbon black or carbon fiber exhibit broken friction layers, whereas specimens containing artificial graphite, natural graphite or expanded graphite exhibit quite adherent and smooth friction layers. Among all the copper-free carbon containing specimens, the specimen containing expanded graphite appears to be the best choice. It has the highest thermal conductivity, a relatively low wear loss and a relatively high and stable COF.

scholarly journals Effect of Lubricating Phase on Microstructure and Properties of Cu–Fe Friction Materials

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 313 ◽  
Author(s):  
Xiaoyang Wang ◽  
Hongqiang Ru
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Carbon Black ◽  
Tribological Properties ◽  
Mass Fraction ◽  
Bending Strength ◽  
High Strength ◽  
Wear Loss ◽  
Powder Metallurgy Method ◽  
Friction Materials

Cu–Fe-based friction materials with flake graphite, granulated carbon black, and high-strength graphite as lubricating phase were prepared by the powder metallurgy method. The effects of different types and mass fraction of lubricating phase on the microstructure, mechanical properties, and tribological properties were investigated. The results show that when the mass fraction of granulated carbon black is 5 wt%, it is easy to form a good interface with the matrix, but the interface is prone to pores and cracks when its mass fraction is 10 wt%. The bending strength and compressive strength properties of the composites increased with increasing in the mass fraction of granulated carbon black and reached the maximum of 40 MPa and 70 MPa at 5 wt% granulated carbon black, after which bending strength and compressive strength all decreased. The friction coefficient and the wear loss of the materials initially decreased as the mass fraction of granulated carbon black increased and obtained minimum of 0.436 and 0.145 mm when the mass fraction of granulated carbon black was 5 wt%, then ascended. Compared with the sample with 5 wt% high-strength graphite as lubricating phase, the sample with 5 wt% granulated carbon black as lubricating phase had better sintering performance, mechanical properties, and tribological properties.

Abrasion Performances of Stainless Steel/Carbon Fiber Reinforced Polyetheretherketone (PEEK) Friction Material

2007 ◽  
Vol 329 ◽  
pp. 511-518 ◽  
Author(s):  
Hua Fu ◽  
Bo Liao ◽  
Bao Chen Sun ◽  
Ai Ping Liu ◽  
Fang Juan Qi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Carbon Fiber ◽  
Friction Material ◽  
Resin Matrix ◽  
Wear Loss ◽  
Fiber Reinforced ◽  
Molding Process ◽  
Stainless Steel Fiber ◽  
Higher Temperature ◽  
Carbon Fiber Reinforced

A semi-metallic stainless steel/carbon fiber reinforced PEEK-based friction material was developed in this paper. The composite was PEEK 19.63wt%, stainless steel fiber 7.57 wt%, carbon fiber 10.97 wt%, cashew 6.51 wt% and fillers 55.33%. The molding process was blending for about 30 seconds at higher speed, pre-heating at the temperature of 80 for 30min, molding at 320 and pressure 35Mpa for 3min/mm, then post-curing at the temperature of 80 for 30min , 150 for 30min270 for 30min320 for 180min. The results of abrasion test showed that the developed material N3 had higher and steady friction coefficient and low abrasion value. The SEM morphology study showed that the wear mechanism was particle abrasion at low temperature but adherence abrasion as well as particle abrasion occurred at higher temperature. The cohesive strength of the composite and the heat-resistant property of resin matrix were the key factors affected wear loss. The abrasion depended on the strength of transformed films and matrix.

scholarly journals Thermal and Mechanical Properties of Expanded Graphite/Paraffin Gypsum-Based Composite Material Reinforced by Carbon Fiber

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2205 ◽  
Author(s):  
Bo Zhang ◽  
Yuanyuan Tian ◽  
Xiaoyan Jin ◽  
Tommy Lo ◽  
Hongzhi Cui
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Composite Material ◽  
Energy Storage ◽  
Carbon Fiber ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Expanded Graphite ◽  
Building Envelope ◽  
Thermal And Mechanical Properties

Phase change material (PCM) is a kind of thermal energy storage material. Solid-liquid PCM composite materials must overcome the issues of material leakage and low thermal conductivity before they are suitable for widespread use in the fields of building and industry. In this study, porous expanded graphite (EG) is used as a carrier, which absorbs the PCM to fabricate EG/paraffin composites (EG/P) containing 90.6% paraffin, and a latent heat of up to 105.3 J/g was measured. Because gypsum board is widely used in buildings, therefore, EG/P composites are suitable to be integrated into gypsum to develop expanded graphite/paraffin gypsum-based composite material (EGPG) for thermal energy storage. In order to optimize the performance of EGPG, carbon fiber (CF) is used to reinforce their thermal and mechanical properties. The test results show that when 1 wt % CF is incorporated into the EGPG, the thermal conductivity increased 36.0%, and thus EGPG shows superior thermal control through the significantly increased efficiency of heat transfer. After 1 wt % CF was added, the flexural and compressive strength of EGPG were increased by 65.6% and 6.4%, respectively. The improved thermal and mechanical performance of EGPG modified by CF demonstrates that it is a structural-functional integrated building material suitable for building envelope system.

scholarly journals The Control of Volume Expansion and Porosity in Carbon Block by Carbon Black (CB) Addition for Increasing Thermal Conductivity

2020 ◽  
Vol 10 (17) ◽  
pp. 6068
Author(s):  
Min Il Kim ◽  
Jong Hoon Cho ◽  
Byong Chol Bai ◽  
Ji Sun Im
Keyword(s):  
Thermal Conductivity ◽  
Molecular Weight ◽  
Carbon Black ◽  
Volume Expansion ◽  
Phase Change Materials ◽  
Low Molecular Weight ◽  
Carbon Block ◽  
Artificial Graphite ◽  
Carbonization Process ◽  
Low Molecular Weight Compounds

The graphite block as a phase change materials (PCMs) was manufactured by graphitization of a carbon block. Carbon blocks were prepared by filler (cokes or graphite) and binder (pitch). The binder-coated filler was thermally treated for carbonization. The gases generated from the evaporation of low molecular weight components in the binder pitch during the carbonization process were not released to the outside. Consequently, porosity and volume expansion were increased in artificial graphite, and thereby the thermal conductivity decreased. In this study, to prevent the decrease of thermal conductivity in the artificial graphite due to the disadvantages of binder pitch, the carbon block was prepared by the addition of carbon black, which can absorb low molecular weight compounds and release the generated gas. The properties of the prepared carbon blocks were analyzed by SEM, TGA, and thermal conductivity. The addition of carbon black (CB) decreased the porosity and volume expansion of the carbon blocks by 38.3% and 65.9%, respectively, and increased the thermal conductivity by 57.1%. The CB absorbed the low molecular weight compounds of binder pitch and induced the release of generated gases during the carbonization process to decrease porosity, and the thermal conductivity of the carbon block increased.

scholarly journals EXPERIMENTAL STUDIES ON MECHANICAL, FRICTION AND WEAR OF NON ASBESTOS ORGANIC BRAKE LININGS FOR LIGHT MOTOR VEHICLE

2013 ◽  
pp. 272-280
Author(s):  
M.P. NATARAJAN ◽  
B. RAJMOHAN ◽  
S. DEVARAJULU
Keyword(s):  
Fly Ash ◽  
Friction Coefficient ◽  
Glass Fiber ◽  
Coefficient Of Friction ◽  
Motor Vehicle ◽  
Experimental Studies ◽  
Friction Material ◽  
Wear Loss ◽  
Friction Materials ◽  
Brake Lining

In this study, flyash based non asbestos organic brake lining composition of more than 14 ingredients was investigated to study the effect of ingredients on various behavior of friction properties. Two types of friction materials with different combinations were developed: i) fly ash range (10 %to 60%) and ii) without fly ash based friction materials were investigated to study the effect of ingredients on the friction characteristics and wear. The main focus on the average normal coefficient of friction, hot coefficient of friction (Fade and recovery), wear loss, mechanical, as the function of the relative amount of the ingredient. The results also showed that the friction coefficient of fly ash based friction material was better in the range of 0.35 to 0.48 when compared barites based brake linings in the range of 0.46 to 0.58. The materials such as potassium titanate(terraces), wollastonite, friction dust powder have strongly influence on friction coefficient. The wear résistance of the brake linings was strongly affected by the presence of rock wool calcium hydroxide and zircon silicate. The presence of glass fiber, twaron fiber, glass fiber has increased the strength of the friction material. All these samples were tested on chase type friction tester at automobile ancillary unit.

scholarly journals Full-Scale Dynamometer Test of Composite Railway Brake Shoes – Study on the Effect of the Reinforcing Fibre Type

2018 ◽  
Vol 12 (3) ◽  
pp. 204-208 ◽  
Author(s):  
Piotr Wasilewski
Keyword(s):  
Thermal Conductivity ◽  
Glass Fibre ◽  
Steel Fibre ◽  
Friction Material ◽  
Full Scale ◽  
Test Results ◽  
Friction Materials ◽  
Average Temperature ◽  
The Difference ◽  
Dynamometer Test

Abstract When designing or developing friction materials, it is crucial to predict how the modification of the formulation will affect their properties. Fibres are introduced in the composition of the phenolic-based brake friction materials to improve their mechanical strength. Apart from reinforcing the composite, fibres can also affect its tribological and thermophysical properties. In this study two composite friction materials are compared. The difference between the materials was the type of reinforcing fibre used in the formulation – in one case it was glass fibre, in the other steel fibre. Thermal diffusivity of both materials was measured and thermal conductivity was calculated. Frictional characteristics determined by means of full-scale dynamometer tests are analysed and discussed. Substitution of glass fibre with steel fibre led to increase in the friction coefficient. Maximum average temperature below wheel surface, observed during the test of the material containing steel fibre, was lower as compared to the test results of the material with glass fibre in its formulation, despite higher heat flux in the course of brake applications. Thermal conductivity of the friction material was enhanced by including steel fibre in the formulation.

Preparation of Fe-Cu-Based Friction Material and its Adoption in Automobile Mechanical Mechanism

2021 ◽  
Vol 871 ◽  
pp. 170-175
Author(s):  
Hao Li ◽  
Bo He
Keyword(s):  
Wear Resistance ◽  
Carbon Fiber ◽  
Friction And Wear ◽  
Room Temperature ◽  
Fiber Material ◽  
Friction Material ◽  
Powder Metallurgy Method ◽  
Friction Materials ◽  
Carbon Fiber Material ◽  
Friction Performance

To prepare a kind of Fe-Cu-based friction material with good friction performance and wear resistance, and apply it to the brake structure of automobile machinery, the powder metallurgy method is used to prepare the friction materials in the standard with 4% Ni, 4% Mo and 2% Sn as the auxiliary material, SiC, Al2O3, and zircon sand as the basic friction material, 8% graphite and 3% MoS2 as the lubricating component. Meanwhile, 50% Fe and 20% Cu is used for the preparation of friction materials. The friction and wear resistance can be increased by increasing the carbon fiber content of 0-8% concentration of the material. The results show that the friction coefficient of the Fe-Cu-based friction material is relatively gentle after the addition of 2% carbon fiber, and the compactness peaks, reaching 93.3%. Its shear strength and impact strength peak, which are 37.42Mpa and 6.7J/cm2 respectively. 4% carbon fiber material with a hardness of 120.2 HV is the hardest one, followed by 2% carbon fiber material with a hardness of 118.1 HV. Added with 2% carbon fiber, the abrasion amount of the friction-based material is 0.0027 g at room temperature and-0.0008 g at 400°C after 60 minutes respectively. With all indicators considered, the result shows that the friction performance and wear resistance of Fe-Cu-based friction materials can be increased by adding 2% carbon fiber during the preparation of basic friction materials.

Sign in / Sign up

Export Citation Format

Share Document