Effect of Brake Disc Surface Texture on Friction Behavior during Running-in

Abstract This paper presents the findings of comparative research conducted to find out the braking performance of a Mo/NiCrBSi coated automobile brake disc. The friction and wear behavior of the Mo/NiCrBSi coating (CD) used for the disc material was evaluated using a laboratory scale disc-pad dynamometer and compared with a reference disc (RD). The coating was deposited by means of the atmospheric plasma spray process on a grey cast iron substrate. Braking tests were performed according to the SAE-J2430 test standard. Disc microstructures were characterized by SEM and XRD. It was found that the bonding strength was good with an infinite rating between the accumulated coating layer and the substrate. The results show that the coated brake disc has a comparable coefficient of friction and that the amount of wear is lower than that of the reference disc. The addition of ductile phases to the disc coating was beneficial in reducing the coefficient of friction to an acceptable degree and also effectively improving wear resistance.

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Investigation of Friction Temperature in Railway Disc Brake

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.479-481.202 ◽

2012 ◽

Vol 479-481 ◽

pp. 202-206

Author(s):

Wan Hua Nong ◽

Fei Gao ◽

Rong Fu ◽

Xiao Ming Han

Keyword(s):

Finite Element ◽

Contact Pressure ◽

Friction Pair ◽

Brake Disc ◽

Finite Element Software ◽

Disc Surface ◽

Friction Temperature ◽

Steel Disc ◽

Braking Force ◽

Braking Process

The distribution of temperature on the rubbing surface is an important factor influencing the lifetime of a brake disc. With a copper-base sintered brake pad and a forge steel disc, up-to-brake experiments have been conducted on a full-scale test bench at a highest speed of 200 Km/h and a maximum braking force of 22.5 KN. The temperature distributions on brake disc surface have been acquired by an infrared thermal camera, and the contact pressure on the contact surface of the friction pair has been calculated by the finite element software ABAQUS. The results show that the area and thermal gradient of the hot bands increase with the increase of braking speed and braking force. The hot bands occur in priority at the radial location of r=200 mm and r=300 mm, and move radially in the braking process. The finite element modelling calculation indicates that the distribution of the contact pressure on the disc surface in radial direction is in a "U"-shape. The maximum contact pressure occur at the radial locations of r=200 mm and r=300 mm, and the minimum contact pressure occur in the vicinity of the mean radius of the disc. The conformity of contact pressure distributions with the practical temperature evolutions indicates that the non-uniform distribution of the contact pressure is the factor resulting in the appearance of hot bands on the disc surface.

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The Effect of Surface Texture on Lubricated Fretting

Materials ◽

10.3390/ma13214886 ◽

2020 ◽

Vol 13 (21) ◽

pp. 4886

Author(s):

Agnieszka Lenart ◽

Pawel Pawlus ◽

Andrzej Dzierwa ◽

Slawomir Wos ◽

Rafal Reizer

Keyword(s):

Coefficient Of Friction ◽

Surface Texture ◽

Friction And Wear ◽

Normal Load ◽

Disc Surface ◽

The Coefficient Of Friction ◽

42Crmo4 Steel ◽

Ball Diameter ◽

Steel Balls ◽

Effect Of Surface

Experiments were conducted using an Optimol SRV5 tester in lubricated friction conditions. Steel balls from 100Cr6 material of 60 HRC hardness were placed in contact with 42CrMo4 steel discs of 47 HRC hardness and diversified surface textures. Tests were carried out at a 25–40% relative humidity. The ball diameter was 10 mm, the amplitude of oscillations was set to 0.1 mm, and the frequency was set to 80 Hz. Tests were performed at smaller (45 N) and higher (100 N) normal loads and at smaller (30 °C) and higher (90 °C) temperatures. During each test, the normal load and temperature were kept constant. We found that the disc surface texture had significant effects on the friction and wear under lubricated conditions. When a lower normal load was applied, the coefficient of friction and wear volumes were smaller for bigger disc surface heights. However, for a larger normal load a higher roughness corresponded to a larger coefficient of friction.

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Modeling the Average and Instantaneous Friction Coefficient of a Disc Brake on the Basis of Bench Tests

Materials ◽

10.3390/ma14164766 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4766

Author(s):

Wojciech Sawczuk ◽

Armando Miguel Rilo Cañás ◽

Dariusz Ulbrich ◽

Jakub Kowalczyk

Keyword(s):

Friction Coefficient ◽

Regression Models ◽

Design Parameters ◽

Railway Vehicle ◽

Brake Disc ◽

Operational Parameters ◽

International Union ◽

Disc Surface ◽

Disc Brakes ◽

Multiple Regression Models

This article presents the results of tests conducted on the average and instantaneous friction coefficients of railway vehicle disc brakes. The tests were carried out independently of various states of wear on the friction linings and the brake disc. The requirements of the International Union of Railways (UIC) regarding the approval of brake linings for use were taken into account. Based on many years of research using a brake bench to test railway disc brakes, the authors developed multiple regression models for the average friction coefficient and fluctuations (tolerances) in the instantaneous friction coefficient and achieved 870 results. The models proposed three types of variables: the input braking parameters (speed, pressure, and mass to be braked), operational parameters (the wear on the friction linings and the brake disc), and design parameters (perforations in the form of holes on the disc surface). The above two models were validated on the basis of 384 brakes, and in subsequent stages a further evaluation was performed. The coefficients were determined to be, respectively, 0.99 for the model of the average friction coefficient and 0.71 for the model of tolerance (fluctuations) of the instantaneous friction coefficient.

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Influence of stress state of brake disk on parameters of microgeometry of its surface that is out of contact area

Transport of the Urals ◽

10.20291/1815-9400-2021-2-35-39 ◽

2021 ◽

pp. 35-39

Author(s):

Yu. V. Krivosheya ◽

◽

D. S. Krivosheya ◽

Keyword(s):

Stress State ◽

Contact Area ◽

Surface Deformation ◽

Disk Surface ◽

Main Trend ◽

Brake Disc ◽

Brake Disk ◽

Coverage Area ◽

Tensile Stresses ◽

Disc Surface

The paper shows results of the study dedicated to influence of contact area stress state on a trend of changes for roughness and waviness parameters of brake disc surface located on the periphery of contact with a brake pad in the coverage area of preferred compression and tensile stresses. It also displays that the main trend of surface deformation under the influence of growing mechanical compression stresses consists in increase of altitude and decrease of step parameters of roughness and waviness. The authors have established that in the coverage area of tensile stresses the roughness and the waviness of the brake disk surface returns to initial values determined in condition of absence of external power influence. On the basis of the results, the authors have explained the process of waviness appearance on the brake disc surface. Results of the study are recommended for the application at solving tasks on friction and wear.

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Thermal Analysis of Two Wheeler Brake Disc Using ANSYS

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.787.301 ◽

2015 ◽

Vol 787 ◽

pp. 301-305

Author(s):

V. Ganesh ◽

T. Abinaya

Keyword(s):

Thermal Analysis ◽

Stainless Steel ◽

Computer Software ◽

Frictional Resistance ◽

Brake Disc ◽

Conventional System ◽

Disc Surface ◽

Braking Force ◽

Transient Thermal ◽

Two Wheeler

This paper deals with the transient thermal analysis of brake disc of Variable Braking Force (VBF) system using computer software ANSYS. Generally, brake system is designed to apply frictional resistance to stop the vehicle. In VBF system the frictional resistance applied to the brake disc can be varied by changing the effective disc radius based on the pillion load. The rotor disc is commonly manufactured using cast iron (CI) or stainless steel (SS). In this work, these materials are taken for analysing the temperature distribution of VBF system. In addition to, an effort has been made here to suggest the best suited material for brake disc. By the way, it is evident that the rise in disc surface temperature is higher for VBF system compared with conventional system (constant effective disc radius (r) = 110mm).

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Thermal Stress Analysis of Water-Cooling Brake Disc Based on 3D Thermo-Mechanical Coupling Model

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.314-316.1581 ◽

2011 ◽

Vol 314-316 ◽

pp. 1581-1586 ◽

Cited By ~ 1

Author(s):

Wen Xian Tang ◽

Yun Di Cai ◽

Cheng Cheng ◽

Qiu Yun Huang

Keyword(s):

Thermal Stress ◽

Stress Field ◽

Circumferential Stress ◽

Brake Disc ◽

Water Cooling ◽

Mechanical Coupling ◽

Emergency Braking ◽

Disc Surface ◽

Thermal Stress Field ◽

Fully Coupled

As the key part of offshore drilling drawworks brake system, the brake disc plays a vital role in guaranteeing the working reliability and operational security of the drawworks. To obtain the distributions and variations of thermal stress field in the water-cooling bake disc in an emergency braking, the 3D thermo-mechanical coupling theoretical model and FEM were established in this paper. Meanwhile the displacement and thermal boundary conditions for solution were determined, and then fully coupled analysis of thermal stress field in the disc was carried out by using ABAQUS software. The analysis results showed that, temperature field and stress field in the process of emergency braking were fully coupled. The temperature, radial stress and circumferential stress on the disc surface were presented as a hackle. The circumferential stress was significantly greater than the radial stress. Thermal stress has a periodic effect on the brake disc during braking, so the circumferential stress is the main factor that accounts for the initiation and propagation of crack on the brake disc surface.

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Design, Development and FE Thermal Analysis of a Radially Grooved Brake Disc Developed through Direct Metal Laser Sintering

Materials ◽

10.3390/ma11071211 ◽

2018 ◽

Vol 11 (7) ◽

pp. 1211 ◽

Cited By ~ 8

Author(s):

Gulam Sayeed Ahmed ◽

Salem Algarni

Keyword(s):

Thermal Analysis ◽

Effective Means ◽

Laser Sintering ◽

Maximum Temperature ◽

Brake Disc ◽

Disc Brake ◽

Direct Metal Laser Sintering ◽

Design Modification ◽

Disc Surface ◽

Brake Performance

The present research work analyzed the effect of design modification with radial grooves on disc brake performance and its thermal behavior by using additive manufacturing based 3D printed material maraging steel. Temperature distribution across the disc surface was estimated with different boundary conditions such as rotor speed, braking pressure, and braking time. Design modification and number of radial grooves were decided based on existing dimensions. Radial grooves were incorporated on disc surface through Direct Metal Laser Sintering (DMLS) process to increase surface area for maximum heat dissipation and reduce the stresses induced during braking process. The radial grooves act as a cooling channels which provides an effective means of cooling the disc surface which is under severe condition of sudden fall and rise of temperatures during running conditions. ANSYS software is used for transient structural and thermal analysis to investigate the variations in temperatures profile across the disc with induced heat flux. FE based thermo-structural analysis was done to determine thermal strains induced in disc due to sudden temperature fluctuations. The maximum temperature and Von Mises stress in disc brake without grooves on disc surface were observed which can severely affect thermal fatigue and rupture brake disc surface. It was been observed by incorporating the radial grooves that the disc brake surface is thermally stable. Experimental results are in good agreement with FE thermal analysis. DMLS provides easy fabrication of disc brake with radial grooves and enhancement of disc brake performance at higher speeds and temperatures. Therefore, DMLS provides an effective means of implementing product development technology.

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