Effect of Visco-Elastic Property on Friction Characteristics of Paper-Based Friction Materials for Oil Immersed Clutches

1998 ◽  
Vol 120 (2) ◽  
pp. 393-398 ◽  
Author(s):  
Tomoyuki Milayzaki ◽  
Takayuki Matsumoto ◽  
Takashi Yamamoto
Keyword(s):  
Pore Diameter ◽  
Testing Machine ◽  
Friction Material ◽  
Diameter Distribution ◽  
Friction Characteristic ◽  
Volume Percentage ◽  
Friction Materials ◽  
Friction Characteristics ◽  
Friction Testing ◽  
The Relationship

The friction characteristic of paper-based friction materials is one of the most important factors that influence the shifting performance of oil immersed clutches in automobile automatic transmissions. Visco-elasticity and porosity of the material are considered to be important properties that may control the friction characteristics of the material. In this study, the relationship between the friction characteristics and the visco-elasticity of a paper-based friction material is discussed. In order to vary the visco-elasticity while retaining the ingredients almost constant in a paper-based friction material, the formulation of the sample materials required changing the compression rate during the clutch plate bonding process and changing the volume percentage of resin. The properties of the sample materials such as porosity (pore diameter, pore diameter distribution, porosity percentage), and visco-elastic deformation in the compressive and the shearing directions, etc. were measured. In order to clarify the relationship between the friction and visco-elasticity of friction material, friction characteristics were measured. Friction characteristics of the sample materials were evaluated by a breaking-away test and continuous slip tests with a newly designed friction testing machine. From the experimental results, which showed that the lower the longitudinal modulus of the friction material, the higher the friction coefficient, it was found that friction characteristics of oil immersed paper-based friction materials are influenced by the visco-elasticity.

Frictional Characteristic of Polyoxymethylene/Steel-40Cr under Different Lubrication Condition

2019 ◽  
Vol 951 ◽  
pp. 97-100
Author(s):  
Hao Chai ◽  
Xiao Yong Pan ◽  
Wei Zhou ◽  
Yu Mei Bao
Keyword(s):  
Friction Force ◽  
Contact Area ◽  
Testing Machine ◽  
Stribeck Curve ◽  
Hysteresis Phenomenon ◽  
Friction Characteristics ◽  
Friction Testing ◽  
Frictional Characteristic ◽  
Pin On Disc ◽  
Lubrication Condition

The friction characteristics of POM-40Cr are studied. The influence of each factor including the roughness, lubricant, pressure, contact area and speed on the friction force are determined by rotating motion pin-on-disc experiments in CETR-UTM friction testing machine. At the same time, the Stribeck curve of POM-40Cr is observed according to the change of velocity. Finally, the friction hysteresis phenomenon is studied by reciprocating pin-on-block experiments.

Numerical Simulation and Process Optimization of Automotive Friction Materials in Warm Pressing Forming

2013 ◽  
Vol 788 ◽  
pp. 57-60
Author(s):  
Chun Cao ◽  
Chun Dong Zhu ◽  
Chen Fu
Keyword(s):  
Process Optimization ◽  
Heating Temperature ◽  
Maximum Energy ◽  
Heating Time ◽  
Product Performance ◽  
Forming Process ◽  
Friction Materials ◽  
Forming Technology ◽  
The Relationship ◽  
Temperature Heating

Warm pressing forming technology has been gradually applied to the forming of automotive friction materials. How to ensure product performance to achieve the target at the same time achieve the maximum energy saving is the research focus of this study. In this paper, by using finite element method, the field of automotive friction materials in warm pressing forming was analyzed, reveals the relationship between the temperature field and the heating temperature/heating time. Furthermore, the energy consumption was analyzed and compared it with hot pressing forming process. The results will have significant guiding to the process optimization in warm pressing forming.

Optimization of Organic Fibres%[Kevlar/Arobocel/Acrylic] in NAO Brake Pad Application and its Effect on Thermal Stability & Friction Characteristics

2012 ◽  
Vol 531-532 ◽  
pp. 8-12
Author(s):  
M.A. Sai Balaji ◽  
K. Kalaichelvan
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Minimum Weight ◽  
Friction Material ◽  
Brake Pad ◽  
Temperature Zone ◽  
Good Thermal Stability ◽  
Friction Testing ◽  
Brake Application ◽  
The Stability

Organic fibres (Kevlar/ Arbocel / Acrylic) have good thermal stability, higher surface area and bulk density. The optimization of organic fibres percentage for thermal behaviour is considered using TGA. The temperature raise during brake application will be between 150-4000 C and this temperature zone is very critical to determine the fade characteristics during friction testing. Hence, three different friction composites are developed with the same formulation varying only the Kevlar, Arbocel and Acrylic fibres which are compensated by the inert filler namely the barites and are designated as NA01, NA02 and NA03 respectively. After the fabrication, the TGA test reveals that the composite NA03 has minimum weight loss. The friction coefficient test rig is then used to test the friction material as per SAE J661a standards. The results prove that the brake pad with minimum weight loss during TGA has higher friction stability. Thus, we can correlate the thermal stability with the stability of friction.

scholarly journals Mechanical and Microstructural Characteristics of Calcium Sulfoaluminate Cement Exposed to Early-Age Carbonation Curing

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3515
Author(s):  
Weikang Wang ◽  
Xuanchun Wei ◽  
Xinhua Cai ◽  
Hongyang Deng ◽  
Bokang Li
Keyword(s):  
Cement Paste ◽  
Pore Diameter ◽  
Performance Enhancement ◽  
Diameter Distribution ◽  
Early Age ◽  
Calcium Sulfoaluminate ◽  
Starting Point ◽  
And Performance ◽  
Curing Pressure ◽  
Carbonation Curing

: The early-age carbonation curing technique is an effective way to improve the performance of cement-based materials and reduce their carbon footprint. This work investigates the early mechanical properties and microstructure of calcium sulfoaluminate (CSA) cement specimens under early-age carbonation curing, considering five factors: briquetting pressure, water–binder (w/b) ratio, starting point of carbonation curing, carbonation curing time, and carbonation curing pressure. The carbonization process and performance enhancement mechanism of CSA cement are analyzed by mercury intrusion porosimetry (MIP), thermogravimetry and derivative thermogravimetry (TG-DTG) analysis, X-ray diffraction (XRD), and scanning electron microscope (SEM). The results show that early-age carbonation curing can accelerate the hardening speed of CSA cement paste, reduce the cumulative porosity of the cement paste, refine the pore diameter distribution, and make the pore diameter distribution more uniform, thus greatly improving the early compressive strength of the paste. The most favorable w/b ratio for the carbonization reaction of CSA cement paste is between 0.15 and 0.2; the most suitable carbonation curing starting time point is 4 h after initial hydration; the carbonation curing pressure should be between 3 and 4 bar; and the most appropriate time for carbonation curing is between 6 and 12 h.

Paper 16: Friction in Wet Clutches

1967 ◽  
Vol 182 (14) ◽  
pp. 132-138 ◽  
Author(s):  
E. M. Evans ◽  
J. Whittle
Keyword(s):  
Coefficient Of Friction ◽  
Power Transmission ◽  
Sliding Speed ◽  
Friction Materials ◽  
Friction Characteristics ◽  
Sliding Surfaces ◽  
Base Oils ◽  
Wet Friction ◽  
Friction Clutch ◽  
The Coefficient Of Friction

This paper is intended to demonstrate that designers of wet clutches for power transmission can obtain the optimum friction characteristics for specific applications by considering the interaction between friction materials and lubricants. A friction clutch plate rig is described and the friction results obtained are presented. It is shown that a wide variation of coefficients of friction and frictional characteristics in wet friction clutches can be obtained by changing the oils and friction materials. In particular the coefficient of friction is dependent upon (1) the oil, (2) the materials of the sliding surfaces, (3) sliding speed, and (4) temperature. It is also shown that the coefficient of friction is affected by ( a) refining treatment given to the oil, ( b) different base oils, and ( c) additives.

scholarly journals Friction Characteristics of Graphite for Brake Friction Materials.

1996 ◽  
Vol 33 (10) ◽  
pp. 782-787 ◽  
Author(s):  
Yoshiyuki SUGAI ◽  
Kennosuke IIDA ◽  
Masao ARAI ◽  
Katsuji SEKI
Keyword(s):  
Friction Materials ◽  
Friction Characteristics

Study on Characteristics of Ultrasonic Velocity for the Concrete under Stress

2013 ◽  
Vol 438-439 ◽  
pp. 220-223 ◽  
Author(s):  
Ling Zhang ◽  
Chun Ling Yan
Keyword(s):  
Ultimate Strength ◽  
Ultrasonic Velocity ◽  
Ultrasound Examination ◽  
Testing Machine ◽  
Strength Level ◽  
Growth Trend ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
Three Stages ◽  
The Relationship

Cube concrete (150×150×150mm) of five ages (7, 14, 21, 28 and 35 days) under different stress conducted the ultrasound examination by non-metallic detector and universal testing machine. The results show that the relationship curve of the stress and the ultrasonic velocity can be divided into three stages, the smooth straight stage, the linear deceleration stage and the attenuation destruction stage from the load beginning to the ultimate strength for the same age. There is a growing trend about the ultrasonic velocity with the increase of the age to concrete samples of C10 and C20 in the same loading; however, the overall growth trend of the velocity is not obvious to concrete samples of C30, C35, C40 and C45. It also shows that the relationship curve of strength level and the velocity can be divided into two distinct stages, the sharply increasing stage (C10-C30) and the fluctuating stage (C30-C45). Simultaneously, the paper further illustrates and explains the reasons to appear these stages and the phenomena.

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