scholarly journals Effect of Silicon Carbide Nanoparticles on the Friction-Wear Properties of Copper-Based Friction Discs

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 587
Author(s):  
Changsong Zheng ◽  
Zhiwei Ma ◽  
Liang Yu ◽  
Xu Wang ◽  
Liangjie Zheng ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Variable Coefficient ◽  
Automatic Transmission ◽  
Applied Pressure ◽  
Friction Torque ◽  
Bench Test ◽  
Friction Materials ◽  
Wear Characteristics ◽  
Rotating Speed ◽  
Silicon Carbide Nanoparticles

To study the influence of nano-additives on the friction-wear characteristics of friction materials, the nano-sized silicon carbide particles which have excellent chemical and physical properties are considered to add in composite to form the modified friction material. The influence of the silicon carbide nanoparticles (SCN) on the friction-wear characteristics of copper-based friction materials (CBFM) is investigated via the SAE#2 (made in Hangzhou, China) clutch bench test with the applied pressure, rotating speed, and automatic transmission fluid (ATF) temperature taken into account. Moreover, the variations of friction torque and temperature are considered to evaluate the friction performance, and the variable coefficient is employed to describe the friction stability. The wear characteristics of friction materials are investigated by the disc changes in thickness and micro-morphology. The results show that the CBFM with SCN can provide a higher friction torque, which increased by 30% to 50% compared with CBFM. The variable coefficient of CBFM with SCN changes from 674 to 52 with the rotating speed raised from 600 rpm to 3000 rpm, which shows that the friction stability is relatively worse. Furthermore, the micromorphology shows that the CBFM with SCN has lower porosity and surface roughness, which increases the microscopic contact area and the coefficient of friction (COF). Simultaneously, the reduction in porosity also leads to a decrease in the cooling quality, bringing about a rapid temperature rise. Thus, the wear amount of CBFM with SCN increases significantly, especially for the friction disc in the axial middle position.

Experimental study on the friction stability of paper-based clutches concerning groove patterns

2019 ◽  
Vol 72 (4) ◽  
pp. 541-548 ◽  
Author(s):  
Liang Yu ◽  
Biao Ma ◽  
Man Chen ◽  
He Yan Li ◽  
Jikai Liu
Keyword(s):  
Experimental Study ◽  
Surface Temperature ◽  
Design Methodology ◽  
Automatic Transmission ◽  
Applied Pressure ◽  
Friction Torque ◽  
Content Type ◽  
Rotating Speed ◽  
Wet Clutch ◽  
Transmission Fluid

Purpose This paper aims to study and compare the friction stability of wet paper-based clutches with regard to the radial grooves (RG) and waffle grooves (WG). Design/methodology/approach This paper presents an experimental study of a wet clutch concerning the effect of groove patterns on the friction torque and surface temperature. The friction stabilities of RG and WG are investigated with the applied pressure, rotating speed and automatic transmission fluid (ATF) temperature taken into consideration. Findings The friction torque and surface temperature of WG are larger than those of RG under the same operating condition. The friction torque difference between RG and WG grows with the increase of applied pressure and narrows with the increase of ATF temperature. Additionally, their temperature difference expands via increasing the rotating speed and ATF temperature or reducing the applied pressure; in this way, not only the variable coefficient difference between RG and WG can be narrowed, but also the friction stability of the clutch can be improved dramatically. Originality/value This paper explains the thermodynamic differences between RG and WG; moreover, it is verified experimentally that WG has a better friction stability than RG.

scholarly journals Comparison of the Friction and Wear Characteristics between Copper and Paper Based Friction Materials

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2988 ◽  
Author(s):  
Yu ◽  
Ma ◽  
Chen ◽  
Li ◽  
Ma ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Friction And Wear ◽  
Applied Load ◽  
Friction Material ◽  
Wear Depth ◽  
Friction Materials ◽  
Wear Characteristics ◽  
Rotating Speed ◽  
Ambient Temperatures ◽  
Friction And Wear Characteristics

Copper-based friction material (CFM) and paper-based friction material (PFM) are the two most commonly used clutch friction materials. The friction and wear characteristics of these two kinds of friction materials under dry conditions were investigated by the pin-on-disc test over a broad range of applied loads, rotating speeds and ambient temperatures. Before experiments, the running-in test was conducted to stabilize the coefficient of friction (COF) and wear amount of the test samples. After experiments, the metallographic micrographs of the tested samples were presented to investigate the wear mechanisms. Experimental results showed that both the COF and wear depth of the CFM are much greater than these of PFM. The COF of CFM decreases with the increase of applied load, and changes slightly with the variation of rotating speed, whereas it increases first and then decreases with the increase of ambient temperature. However, the COF of PFM decreases dramatically with the increase of the rotating speed and ambient temperature, while it remains stable at first and then decreases slowly as the applied load increases. Additionally, under such three working conditions, the wear depth of CFM changes linearly, while the wear depth of PFM varies greatly. This study can be used as a guide for selecting friction materials for clutches with different applications.

scholarly journals Numerical and Experimental Studies of the Attenuation Characteristics of Friction Torque in a Wet Multidisc Clutch

2021 ◽  
Vol 11 (2) ◽  
pp. 814
Author(s):  
Man Chen ◽  
Bin Zhang ◽  
Yuqing Feng ◽  
Liang Wang ◽  
He Wang
Keyword(s):  
Growth Rate ◽  
Numerical Model ◽  
Contact Pressure ◽  
Applied Pressure ◽  
Experimental Studies ◽  
Friction Torque ◽  
Bench Test ◽  
Single Pair ◽  
Attenuation Characteristics

A numerical model is proposed to calculate both the contact pressure and the friction torque (FT) of the friction components considering the spline friction in a wet multidisc clutch, which is verified by the bench test. The results indicate that the spline friction of components is an important factor causing the axial attenuation of contact pressure on friction pairs. As the applied pressure increases, the attenuation amplitude of contact pressure increases gradually. In addition, the average single-pair FT decreases with the increasing number of friction pairs, thus leading to the decrease of the growth rate of total FT. Therefore, when the number of friction pairs reaches a certain number, it is not reliable to obtain a good torque enhancement, indicating that the effect of spline friction needs to be weakened to reduce the attenuation of contact pressure.

Influences of the uneven contact pressure and the initial temperature on the hot judder behavior in a multi-disc clutch

2019 ◽  
Vol 234 (4) ◽  
pp. 500-514 ◽  
Author(s):  
Liang Yu ◽  
Biao Ma ◽  
Il yong Kim ◽  
Heyan Li
Keyword(s):  
Contact Pressure ◽  
Friction Surface ◽  
Heat Dissipation ◽  
Dynamic Models ◽  
Initial Temperature ◽  
Friction Torque ◽  
Bench Test ◽  
Radial Temperature ◽  
Actual Structure ◽  
Rotating Speed

This paper presents an investigation of the hot judder behavior in a multi-disc clutch with the uneven contact pressure and the initial temperature taken into account. Considering the actual structure of clutch, the pressure function is achieved to describe the uneven contact pressure distribution due to the circlip constraint. Moreover, the pin-on-disc test is conducted to obtain the formula of the coefficient of friction with the contact pressure, surface temperature, and rotating speed involved. The thermal and dynamic models are established and coupled to evaluate the hot judder behavior. The results demonstrate that the uneven contact pressure has a slight influence on the clutch hot judder, but it expands the radial temperature difference on the friction surface; meanwhile, the friction torque generated on the friction surface closer to the circlip is larger. Although the increase of initial temperature can shorten the clutch engagement time, the clutch hot judder will be shriller, as verified in the SAE#2 bench test. Furthermore, in order to reduce the clutch hot judder, the circlip should be optimized to smooth the radial contact pressure, and the advanced thermal management method should be applied to strengthen the clutch heat dissipation.

The Effect of Stirring Tool Surface Condition on Wear Characteristics in Friction Stir Welding (FSW) Process

2021 ◽  
Vol 880 ◽  
pp. 57-62
Author(s):  
Normariah Che Maideen ◽  
Salina Budin ◽  
Koay Mei Hyie ◽  
Nor Azirah Mohd Fohimi
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Surface Condition ◽  
Welding Process ◽  
Wear Characteristics ◽  
Rotating Speed ◽  
Friction Stir ◽  
Ticn Coating ◽  
Tool Surface

Stirring tool is one of the important factor that contribute to the successful of Friction Stir Welding (FSW). Role of tool, is to heat the welding zone and stir the material along the process. Many studies have been conducted by other researchers to improve the performance of stirring tool. Similar to this work, it is aimed to investigate and analyze the effect of stirring tool surface condition on wear characteristics in friction stir welding process. Four tools have been fabricated with pre-determined surface condition. Tool 1: H13 without heat treatment and without coating. Tool 2: H13 with heat treatment only. Tool 3: H13 with TiCN coating only and Tool 4: H13 with heat treatment and with TiCN coating. Friction stir welding was performed to test and verify the performance of fabricated tools. Process parameter used are 1270 RPM for rotating speed while 218 mm/min for welding speed. From the result, Tool 4 performed better in terms of physical wear as well as wear rate.

Wear characteristics of additively manufactured AlSi10Mg against EN-31 and silicon carbide abrasive sheet counter bodies using box Behnken design approach

2021 ◽  
pp. 146442072110570
Author(s):  
Raj Mohan Radhakrishnan ◽  
Venkatraman Ramamoorthi ◽  
Raghuraman Srinivasan
Keyword(s):  
Silicon Carbide ◽  
Wear Rate ◽  
Weight Ratio ◽  
High Strength ◽  
Design Approach ◽  
Box Behnken Design ◽  
Wear Characteristics ◽  
Testing Facility ◽  
En 31 ◽  
Sliding Distance

High strength-to-weight ratio materials are used in the automotive and aerospace industries, and AlSi10Mg is suitable for those applications. The research aims to compare and investigate the wear characteristics of selective laser melted AlSi10Mg pin against two counter bodies, EN-31 hardened steel, and silicon carbide abrasive sheet. The wear rate of additively manufactured AlSi10Mg pin at 0° building orientation was investigated using the box Behnken design approach to identify the suitable wear parameters with the pin on the disc testing facility. Based on analysis of variance, the interaction of load with sliding distance significantly influenced the wear rate of AlSi10Mg in both counter body cases. The adhesion and abrasion wear mechanism were observed in AlSi10Mg with EN-31 and silicon carbide abrasive sheet, respectively. The findings reveal the effect of two counter bodies on the SLMed AlSi10Mg wear phenomenon. Finally, severe wear was observed in the AlSi10Mg pin against the silicon carbide counter body.

scholarly journals Direct Observation of Transition from Solid-State to Molecular-Like Optical Properties in Ultrasmall Silicon Carbide Nanoparticles

2018 ◽  
Vol 122 (46) ◽  
pp. 26713-26721 ◽  
Author(s):  
David Beke ◽  
Anna Fučíková ◽  
Tibor Z. Jánosi ◽  
Gyula Károlyházy ◽  
Bálint Somogyi ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Optical Properties ◽  
Solid State ◽  
Direct Observation ◽  
Silicon Carbide Nanoparticles

scholarly journals Influence of the Lubrication Oil Temperature on the Disengaging Dynamic Characteristics of a Cu-Based Wet Multi-Disc Clutch

2021 ◽  
Vol 11 (23) ◽  
pp. 11299
Author(s):  
Liangjie Zheng ◽  
Biao Ma ◽  
Man Chen ◽  
Liang Yu ◽  
Qian Wang
Keyword(s):  
Dynamic Characteristics ◽  
Hydrodynamic Lubrication ◽  
Friction Pair ◽  
Automatic Transmission ◽  
Friction Torque ◽  
Asperity Contact ◽  
Uniformity Coefficient ◽  
Lubrication Oil ◽  
The Impact ◽  
First Time

Clutch disengaging dynamic characteristics, including the disengaging duration and the variations of friction pair gaps and friction torque, are crucial to the shifting control of an automatic transmission. In the present paper, the influence of lubrication oil (ATF) temperature on disengaging dynamic characteristics is investigated through a comprehensive numerical model for the clutch disengaging process, which considers the hydrodynamic lubrication, the asperity contact, the heat transfer, the spline resistance, and the impact between the piston and clutch hub. Moreover, the non-uniformity coefficient (NUC) is proposed to characterize the disengaging uniformity of friction pairs. As the ATF temperature increases from 60 °C to 140 °C, the clutch disengaging duration shortens remarkably (shortened by 55.1%); besides, the NUC sees a decreasing trend before a slight increase. When the ATF temperature is 80 °C, the distribution of friction pair gaps is most uniform. During the disengaging process, the increase of ATF temperature not only accelerates the change of the lubrication status between friction pairs but also contributes to the decrease of contact torque and hydrodynamic torque. This research demonstrates for the first time, evidence for clutch disengaging dynamic characteristics with the consideration of ATF temperature.

scholarly journals Синтез наночастиц карбида кремния методом лазерного пиролиза смеси моносилана и ацетилена

2020 ◽  
Vol 54 (11) ◽  
pp. 1233
Author(s):  
И.А. Ершов ◽  
Л.Д. Исхакова ◽  
В.И. Красовский ◽  
Ф.О. Милович ◽  
С.И. Расмагин ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Gas Phase ◽  
Reaction Zone ◽  
Phase Reaction ◽  
Synthesis Reaction ◽  
Flow Ratio ◽  
Laser Synthesis ◽  
Gas Phase Reaction ◽  
Silicon Carbide Nanoparticles ◽  
Sic Particles

The conditions of the laser-enhanced synthesis reaction of silicon carbide nanoparticles are determined and the nanoparticles are characterized. The gas-phase reaction of laser synthesis of SiC particles is observed at SiH4/C2H2 flow ratio in the range of 1.6-3.2. The temperature in the reaction zone was ~1400--1500ºC. Silicon carbide nanoparticles ~6 nm in diameter are produced and their composition is studied.

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