Effect of Type and Relative Amount of Solid Lubricants and Abrasives on the Tribological Properties of Brake Friction Materials

The tribological properties of polyimide (PI) composites reinforced with graphite or MoS2 sliding in liquid alkali and water as well as dry friction were investigated using a ring-on-ring tester. The results show that the friction coefficient (μ) and wear rate (W) for both graphite/PI and MoS2/PI composites in different liquid mediums are μdry>μwater >μalkali and Wwater>Wdry >Walkali. Results also indicate that the friction coefficient and wear rate of the PI composites filled with different solid lubricants are μMoS2 >μgraphite and W MoS2 >Wgraphite in different liquid mediums. In addition, the hydrophobic inorganic fillers are fit for the reinforcement of polymer-based composites sliding in liquid mediums. It is also concluded from the authors’ work that the wear rate and friction coefficient of polymer-based (such as PI, PTFE) composites in the alkali lubricated conditions is lowest among all the friction conditions. This may be attributed to the ionic hydration in the alkaline solution.

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Tribological properties of brake friction materials with steel fibers

Metals and Materials International ◽

10.1007/s12540-009-0027-6 ◽

2009 ◽

Vol 15 (1) ◽

pp. 27-32 ◽

Cited By ~ 24

Author(s):

Sung Bin Park ◽

Keun Hyung Cho ◽

Sola Jung ◽

Ho Jang

Keyword(s):

Tribological Properties ◽

Steel Fibers ◽

Friction Materials

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The Improved Friction Properties of Bonded MoS2 Films by MAO Treating of Al Substrate

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.275-277.1911 ◽

2013 ◽

Vol 275-277 ◽

pp. 1911-1914 ◽

Cited By ~ 1

Author(s):

Han Jun Hu ◽

Hui Zhou ◽

Yu Gang Zheng ◽

Kai Feng Zhang ◽

Zhi Hua Wan

Keyword(s):

Tribological Properties ◽

Solid Lubricants ◽

Ceramic Coatings ◽

Test System ◽

Test Method ◽

Test Results ◽

Specimen Test ◽

Micro Arc Oxidation ◽

A New Technique ◽

Porous Microstructures

The bonded MoS2 films are widely used as solid lubricants in aerospace mechanisms due to their excellent tribological properties. Traditionally, the MoS2 was directly bonded on the Al substrate that was only treated by the technique named of sandblast. For improving the tribological properties of MoS2 films, micro arc oxidation (MAO) instead of sandblast was introduced as a new technique for treating of Al substrate. In this article, the tribological properties of MoS2 films which were bonded on different surface of Al substrate as mentioned above were discussed, respectively. It was concluded from the test results that the MoS2 films bonded on substrate treated by MAO have better tribological properties than those samples treated by sandblast. The endurance life against abrasion of the former is as high as twenty times of the latter by the stand test method of ball on disk using the UMT Multi-Specimen Test System. This test results could be illustrated by the following reasons. The first is the porous microstructures of MAO ceramic coatings on the Al substrate. The coatings have numerous pits to be good at increasing the binding force with the MoS2 films, and the pits can also provide a MoS2 lubricants reservoir during processes of friction. Both of them improved the MoS2 film’s ability of wear-protective. The second is that hardness of the coating is higher than the Al, and this ensures well wearing resistance, especially in practical application to big load-supporting moving parts, such as bearing, gear, etc…

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Effects of rare-earth oxides on the microstructure and properties of Fe-based friction materials synthesized by in situ carbothermic reaction from vanadium-bearing titanomagnetite concentrates

RSC Advances ◽

10.1039/c9ra03271a ◽

2019 ◽

Vol 9 (36) ◽

pp. 20687-20697

Author(s):

Dajun Zhai ◽

Yue Shui ◽

Keqin Feng ◽

Yanyan Zhang

Keyword(s):

Rare Earth ◽

Tribological Properties ◽

Rare Earth Oxides ◽

Frictional Material ◽

Friction Materials ◽

Microstructure And Properties ◽

Iron Based

In this work, we prepared an iron-based frictional material from vanadium-bearing titanomagnetite concentrates by in situ carbothermic reaction with improved tribological properties.

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Microstructure and tribological properties of laser cladded self-lubricating nickel-base composite coatings containing nano-Cu and h-BN solid lubricants

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2018.12.017 ◽

2019 ◽

Vol 359 ◽

pp. 485-494 ◽

Cited By ~ 17

Author(s):

Yue Zhao ◽

Kai Feng ◽

Chengwu Yao ◽

Pulin Nie ◽

Jian Huang ◽

...

Keyword(s):

Tribological Properties ◽

Composite Coatings ◽

Solid Lubricants ◽

Base Composite ◽

Nickel Base

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Improving the tribological properties of AISI M50 steel using Sns/Zno solid lubricants

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2019.153494 ◽

2020 ◽

Vol 821 ◽

pp. 153494 ◽

Cited By ~ 3

Author(s):

Ammar H. Elsheikh ◽

Jingui Yu ◽

Ravishankar Sathyamurthy ◽

M.M. Tawfik ◽

S. Shanmugan ◽

...

Keyword(s):

Tribological Properties ◽

Solid Lubricants ◽

M50 Steel

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Influence of slag weight fraction on mechanical, thermal and tribological properties of polymer based friction materials

Materials & Design ◽

10.1016/j.matdes.2015.10.097 ◽

2016 ◽

Vol 90 ◽

pp. 76-83 ◽

Cited By ~ 25

Author(s):

Zhanhong Wang ◽

Guihua Hou ◽

Zirun Yang ◽

Qiong Jiang ◽

Feng Zhang ◽

...

Keyword(s):

Tribological Properties ◽

Weight Fraction ◽

Friction Materials ◽

Slag Weight

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Improving the Tribological Properties of Technical Polymers with Metal Sulphide Compounds

Lubricants ◽

10.3390/lubricants9090091 ◽

2021 ◽

Vol 9 (9) ◽

pp. 91

Author(s):

Andreas Hausberger ◽

Tanja Stiller ◽

Clemens Kappl ◽

Lars Hensgen ◽

Florian Grün

Keyword(s):

Wear Rate ◽

Tribological Properties ◽

Glass Fibre ◽

High Performance ◽

Solid Lubricants ◽

Solid Lubrication ◽

Wear Behaviour ◽

Rate Reduction ◽

Tribological Behaviour ◽

Metal Sulphide

Technical thermoplastic materials (e.g., PEEK, PPA and POM) are widely used for tribological applications combined with different filler systems (e.g., glass- or carbon fibres) because of their excellent mechanical properties. The friction and wear behaviour of thermoplastics can be specifically improved by solid lubrication systems such as graphite, PTFE and MoS2. Besides these systems, others such as WoS2 and MnS are becoming scientifically interesting. This work investigates the influence of different solid lubricants—alternative metal sulphides and polymer-based—in combination with different glass fibre contents on the tribological behaviour of unfilled PEEK and glass fibre-filled PPA. For this purpose, compounds were produced and injection-moulded into tribological test specimens that were subsequently tested. It is particularly evident for both matrix materials that the solid lubricant SLS 22 shows a 25% wear rate reduction when compared to MoS2 and, in addition, the proportion of fibre content in PPA shows an additional wear rate reduction by a factor of 10. The friction level could be kept at a similar level compared to the usually utilised solid lubricants. The investigations showed the potential use of metal sulphide filler systems in high-performance thermoplastic with enhanced tribological properties as alternatives to the well-established solid lubricants.

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