scholarly journals Study on the High Temperature Friction and Wear Behaviors of Cu-Based Friction Pairs in Wet Clutches by Pin-on-Disc Tests

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Er-Hui Zhao ◽  
Biao Ma ◽  
He-Yan Li

This work is devoted to the study of the high temperature friction and wear behaviors of Cu-based friction pairs in wet clutches under different temperatures, rotation speeds, and loads. Pin-on-disc tests are carried out on the UMT-3. The friction coefficient, wear factor, and high temperature wear mechanism are primarily analyzed. The results show that as the temperature rises from 120°C to 420°C, the friction coefficient increases from 0.28 to 0.35 at first and then decreases to 0.30, when the vibration of friction coefficient is significantly identified. Meanwhile, the wear factor grows gradually from K=7.9×10-8 g/Nm to K=41.8×10-8 g/Nm at first and then grows sharply to K=112.2×10-8 g/Nm. The main wear mechanisms are abrasive wear and ploughing wear when the temperature is below 345°C, and the wear seriously deteriorates when the temperature exceeds 345°C, when the wear mechanism changes to adhesive wear and delamination wear.

2019 ◽  
Vol 969 ◽  
pp. 86-92 ◽  
Author(s):  
B.P. Chiranth ◽  
C. Siddaraju ◽  
R.K. Mishra ◽  
R. Sasikumar ◽  
R. Sathiskumar ◽  
...  

High-temperature wear and friction properties of ZE41 alloy were evaluated using a pin on disc tribometer. The microstructure of the alloy has the equiaxed grains of 72±20µm decorated with the rare earth rich precipitates. Result shows that wear rate decreases upto 100°C and then increases until 250°C for all the loading conditions. The wear mechanism study revealed that the underlying thin oxide tribolayer minimizes the wear rate upto 100°C. Above 100°C, thickening of oxide layer due to enhanced oxidation rate results in breakage of the layer. Further, the increase of temperature softens the alloy which deforms and fractures in the subsurface at low critical load resulting in more delamination wear. The combined effects of oxidation and delamination wear are accentuated with the increase of load and temperature resulting in the increase of the wear rate. Comparing the influence of load and temperature on the wear rate, contact load is more.


2016 ◽  
Vol 24 (05) ◽  
pp. 1750057 ◽  
Author(s):  
DEJUN KONG ◽  
BENGUO ZHAO

A high-velocity oxygen fuel (HVOF)-sprayed NiCrBSi coating on H13 hot work die steel was processed with laser remelting; and the surface-interface morphologies, concentrations of chemical elements, and phases of the coating were analyzed with scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD), respectively. The friction-wear behaviors of the coating at high temperatures were investigated by the means of ball/plane contact. The effects of high temperature on the coefficient of friction (COF) and wear performance are discussed. The results show that the coating is dense and tightly bonded to the substrate at the interface. The average COFs at 500[Formula: see text]C, 600[Formula: see text]C, and 700[Formula: see text]C are 0.3749, 0.3609, and 0.4556, respectively. The wear mechanism is slight adhesive wear at 500[Formula: see text]C, and primarily oxidative wear and fatigue wear at 600[Formula: see text]C. The wear mechanism at 700[Formula: see text]C is oxidized wear and fatigue wear in the early stage, and mainly adhesive wear in the later stage. During high-temperature wear, an oxide film is formed on the coating surface, decreasing the wear resistance of the coating, which is primarily dependent on the compounds of Ni, Cr, B, Si, and C and the oxides of Si.


2012 ◽  
Vol 602-604 ◽  
pp. 2210-2213
Author(s):  
Tao Ding ◽  
Yu Mei Li ◽  
Qiu Dong He ◽  
Wen Jing Xuan

An experimental study on friction and wear properties of carbon strip rubbing against copper contact wire was carried out on a pin-on-disc frictional tester with and without windy conditions. The result shows that wear rate of pin specimen increases observably with increasing sliding distance with and without windy conditions. While the coefficient of friction slightly decreases with increasing of electric current with and without the wind. Observing the SEM morphology of pin specimens, it can be found that delamination wear is a main wear mechanism under no windy condition. While arc erosion is a dominant wear mechanism with windy condition. Worn surfaces of the materials were analyzed by an energy dispersive X-ray spectroscopy. It can be observed that oxidation wear occurs in the frictional process due to arc erosion and high temperature rise.


2021 ◽  
pp. 089270572110286
Author(s):  
Xinyue Zhang ◽  
Dekun Zhang ◽  
Kai Chen ◽  
Handong Xu ◽  
Cunao Feng

The complex movement of artificial joints is closely related to the wear mechanism of the prosthesis material, especially for the polymer prosthesis, which is sensitive to motion paths. In this paper, the “soft-soft” all-polymer of XLPE/PEEK are selected to study the influence of motion paths on the friction and wear performance. Based on the periodic characteristics of friction coefficient and wear morphology, this paper reveals the friction and wear mechanism of XLPE/peek under multi-directional motion path, and obtains the quantitative relationship between friction coefficient and the aspect ratios of “∞”-shape motion path, which is of great significance to reveal and analyze the wear mechanism of “soft” all-polymer under multi-directional motion path. The results show that the friction coefficient is affected by the motion paths and have periodicity. Morever, under the multi-directional motion paths, the wear of PEEK are mainly abrasive wear and adhesive wear due to the cross shear effect, while the wear of XLPE is mainly abrasive wear with plastic accumulation. In addition, the friction coefficient is greatly affected the aspect ratios Rs-l of “∞”-shape and loads. Meanwhile, the wear morphologies are greatly affected by the aspect ratios Rs-l of “∞”-shape, but less affected by loads.


2011 ◽  
Vol 80-81 ◽  
pp. 60-63
Author(s):  
Xue Qing Yue ◽  
Hua Wang ◽  
Shu Ying Wang

Incorporation of metallic elements, titanium and copper, into carbonaceous mesophase (CM) was performed through mechanical alloying in a ball mill apparatus. The structures of the raw CM as well as the Ti/Cu-added CM were characterized by X-ray diffraction. The tribological behavior of the Ti/Cu-added CM used as lubricating additives was investigated by using a high temperature friction and wear tester. The results show that, compared with the raw CM, the Ti/Cu-added CM exhibits a drop in the crystallinity and a transition to the amorphous. The Ti/Cu-added CM used as lubricating additive displays an obvious high temperature anti-friction and wear resistance effect, and the lager the applied load, the lower the friction coefficient and the wear severity.


Friction ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 315-331 ◽  
Author(s):  
Haoliang Tian ◽  
Changliang Wang ◽  
Mengqiu Guo ◽  
Yongjing Cui ◽  
Junguo Gao ◽  
...  

AbstractTo reduce the friction coefficient of cobalt-cemented tungsten carbide (WC-12Co) wear-resistant coatings, graphene was compounded into WC-12Co powder via wet ball milling and spray granulation. Self-lubricating and wear-resistant graphene coatings were prepared via detonation gun spraying. The presence, morphologies, and phase compositions of graphene in the powders and coatings that are obtained through different powder preparation processes were analyzed. The analysis was performed using the following technologies: energy-dispersive X-ray-spectroscopy (EDXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The mechanical properties of the coatings were studied using a microhardness tester and a universal drawing machine. The friction and wear properties of the coatings were studied using an SRV-4 friction and wear tester. The results showed that the graphene content in the WC-12Co coating modified with graphene was higher than that without modification; graphene was embedded in the structure in a transparent and thin-layer state. The adhesive strength of this coating at approximately 25 °C was approximately 60.33 MPa, and the hardness was approximately 984 HV0.3. After high-temperature treatment, the adhesive strength and hardness of the graphene oxide (GO)/WC-12Co coating decreased slightly (the lowest adhesive strength of 53.16 MPa was observed after treatment at 400 °C, and the lowest hardness of approximately 837 HV0.3 was observed after treatment at 300 °C). Compared to the friction coefficient (0.6) of the WC-12Co coating obtained at room temperature, the friction coefficient of the GO/WC-12Co coating was decreased by approximately 50% of that value. The graphene-modified coating was continuously exposed to the wear tracks on the surface of the contacting materials during friction, and a lubricating film was formed in the microareas in which the wear tracks were present. The coating exhibited improved self-lubricating and wear-resistant effects compared to the unmodified WC-12Co coating. The results of this study demonstrated that graphene could be effective in self-lubrication and wear-reduction in a temperature range of 100–200 °C, as a friction coefficient of 0.3 was maintained.


Author(s):  
Junjiao Han ◽  
Qian Qiu ◽  
Keyan Ning ◽  
Ming Han ◽  
Nan Zhang ◽  
...  

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 682
Author(s):  
Liang Sun ◽  
Wenyan Zhai ◽  
Hui Dong ◽  
Yiran Wang ◽  
Lin He

Cr3C2-Ni cermet is a kind of promising material especially for wear applications due to its excellent wear resistance. However, researches were mainly concentrated on the experiment condition of room temperature, besides high-temperature wear mechanism of the cermet would be utilized much potential applications and also lack of consideration. In present paper, the influence of Mo content on the high-temperature wear behavior of in-situ Cr3C2-20 wt. % Ni cermet was investigated systematically. The friction-wear experiment was carried out range from room temperature to 800 °C, while Al2O3 ceramic was set as the counterpart. According to experimental results, it is indicated that the coefficient of friction (COF) of friction pairs risen at the beginning of friction stage and then declined to constant, while the wear rate of Cr3C2-20 wt. % Ni cermet risen continuously along with temperature increased, which attributes to the converted wear mechanism generally from typical abrasive wear to severe oxidation and adhesive wear. Generally, the result of wear resistance was enhanced for 13.4% (at 400 °C) and 31.5% (at 800 °C) by adding 1 wt. % Mo. The in-situ newly formed (Cr, Mo)7C3 ceramic particle and the lubrication phase of MoO3 can effectively improve the wear resistance of Cr3C2-20 wt. % Ni cermet.


2011 ◽  
Vol 311-313 ◽  
pp. 92-95 ◽  
Author(s):  
Kui Chen ◽  
Tian Yun Zhang ◽  
Wei Wei

Polypropylene/organo-montmorillonite (PP/OMMT) composites were investigated by XRD. Friction and wear behaviors of this composites sliding against GCr15 stainless steel were examined on M-2000 text rig in a ring-on-block configuration. Worn surfaces of PP and its composites were analyzed by SEM. The result shows that PP macromolecule chains have intercalated into OMMT layers and form intercalated nanocomposites. With the increase of mass fraction of OMMT, both wear rate and friction coefficient of composites first decrease then rise. With the increase of load, from 150 N, 200 N to 250 N, wear rate of composites increases, while friction coefficient reduces. The wear mechanisms of composites are connected with the content of OMMT. Composites were dominated by adhesive wear, abrasive wear and adhesive wear accompanied by abrasive wear respectively with the increase of OMMT content.


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