Reciprocating friction and wear of polyimide composites filled with solid lubricants

2018 ◽  
Vol 38 (4) ◽  
pp. 363-370 ◽  
Author(s):  
Jingfu Song ◽  
Gai Zhao ◽  
Qingjun Ding ◽  
Jinhao Qiu
Keyword(s):  
Friction Coefficient ◽  
High Performance ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Friction Reduction ◽  
Frictional Material ◽  
Performance Engineering ◽  
Ultrasonic Motors ◽  
Polyimide Composites ◽  
Engineering Polymers

AbstractHigh-performance engineering polymers are a potential frictional material candidate for mechanical systems with moving parts, especially at high load and speed conditions. In this study, reciprocating friction and wear of aramid fibers/polyimide composites filled with graphite, MoS2or Polytetrafluoroethylene, respectively, were systematically investigated on a Pin-on-Flat test rig. The experimental setup was simplified into friction materials reciprocating against a phosphor bronze pin to simulate the rotor/stator contact state in ultrasonic motors. A comparative study on friction reduction and wear resistance of polyimide composites indicated that graphite showed the best lubricity with low friction coefficient and wear rate. Experimental results of pressure time average velocity measurements showed that frequencies ranging from 3 to 11 Hz played a significant role on the friction coefficient variations of these porous polyimide composites, whereas increasing pressure from 4 to 6 MPa had little effect on friction reduction. Then, the microstructure of the worn surface of the three different materials was observed by scanning electron microscope to reveal the wear mechanisms. This study is expected to provide a good guidance for porous polyimide composites application in ultrasonic motors.

Friction and Wear Behaviors of Solid Lubricants/Polyimide Composites in Liquid Mediums

2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Alkaline Solution ◽  
Dry Friction ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Polyimide Composites ◽  
Inorganic Fillers ◽  
Ptfe Composites

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.

Effect of Ultrasonic Vibration on the Friction and Wear Properties of GCr15/45# Steel Frictional Pairs Lubricated by n-Al2O3 Additives

2012 ◽  
Vol 538-541 ◽  
pp. 1920-1923
Author(s):  
Yu Lin Qiao ◽  
Shan Lin Yang ◽  
Yan Zang ◽  
Xin Yu Dong ◽  
Qing Sheng Cui
Keyword(s):  
Friction Coefficient ◽  
Ultrasonic Vibration ◽  
Photoelectron Spectroscopy ◽  
Friction And Wear ◽  
Ball Bearing ◽  
Wear Scar ◽  
Friction Reduction ◽  
Wear Volume ◽  
Wear Properties ◽  
Friction And Wear Properties

The friction and wear properties of GCr15/45# steel frictional pairs lubricated by n- Al2O3 additives under ultrasonic vibration or not were studied. The scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS) and energy dispersive spectrometer (EDS) were carried out to analyse the wear scar surface. The effect mechanism of ultrasonic vibration on friction pairs was discussed. The results indicated that ultrasonic vibration could decrease the friction and wear of GCr15/45# friction pairs, when the content of n-Al2O3 was 0.5wt%, the effect of ultrasonic vibration on friction pairs was most obvious. The friction coefficient, wear volume and wear scar depth under ultrasonic vibration decreased 10%, 34% and 13%, respectively. The friction reduction and anti-wear mechanism of n-Al2O3 was single “micro ball bearing” without ultrasonic vibration, and it changed to “micro ball bearing” and adsorption penetration film with ultrasonic vibration, so the friction coefficient and wear volume was reduced.

scholarly journals Wear Characteristics of the Material Specimen and Method of Predicting Wear in Floating Spline Couplings of Aero-Engine

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Xiangzhen Xue ◽  
Sanmin Wang ◽  
Jie Yu ◽  
Liyun Qin
Keyword(s):  
Friction Coefficient ◽  
High Performance ◽  
Friction And Wear ◽  
Wear Depth ◽  
The Finite Element Method ◽  
Wear Coefficient ◽  
Material Specimen ◽  
Aero Engine ◽  
Spline Coupling ◽  
Involute Spline

In order to reduce wear and design high-performance spline coupling, the friction coefficient, wear coefficient, and wear depth of 14 groups of material specimens were tested using multifunctional friction and wear tester. The effect of materials, loads, rotation speed, and surface treatment on friction coefficient, wear coefficient, and wear depth was investigated. A method using an Archard’s equation based on the finite element method to calculate the wear depth of 14 groups of material specimens was proposed, and the results were consistent with the experimental results. Then, the wear of a floating involute spline coupling of aero-engine was predicted using this method. It can be concluded that carburizing and silvering can decrease the friction coefficient. The wear and wear coefficient decreased after carburizing. So, it is necessary to take 18CrNi4A with carburization and 32Cr3MoVA with nitridation as the material of the spline coupling in aero-engine to minimize wear. Furthermore, the method presented to predicate the wear of spline coupling in this work provided a good fundament for the fatigue prediction methodology of spline coupling.

The influence of laser surface texture on the tribological properties of friction layer materials in ultrasound motors

2021 ◽  
pp. 135065012110527
Author(s):  
Xijun Hua ◽  
Julius Caesar Puoza ◽  
Peiyun Zhang
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Dry Friction ◽  
Friction And Wear ◽  
Ultrasonic Motor ◽  
Area Ratio ◽  
Ultrasonic Motors ◽  
Increase Rate

Ultrasonic motors are typically driven by the dry friction force between the rotor and the stator; the friction pairs’ high friction coefficient and low wear rate are two essential elements for improving the operational stability with longer service life. In this research article, high-precision microgroove arrays were manufactured on the surfaces of the stator and rotor of the TRUSM60 ultrasonic motor using laser machining. Dry friction and wear tests between the stator and the rotor were carried out with pin-on-disc using HSR-2M high-speed reciprocating friction and wear tester to determine the tribological properties of the ultrasonic motor. According to a different distribution of microgrooves on the two contact surfaces, the influence of smooth surface, single-sided texture, and double-sided texture on the friction pair's friction performance were discussed. The results show that the textured surface can substantially increase the coefficient of friction of the contact surface and reduce the rate of wear. The one-sided textured phosphor bronze surface with a microgroove width of 200μm and an area ratio of 20% had the highest coefficient of friction of 0.334 and a friction increase rate of 36.3%. Similarly, the single-sided textured Polyimide surface attained the highest friction coefficient of 0.355 and friction increase rate of 44.9% when the groove width is 150μm and the area ratio is 30%. A higher friction coefficient of the double-sided texture can be obtained through reasonable parameter configuration than the single-sided texture. The included angle of 0° between the two textured surfaces produced the highest friction coefficient of 0.368 and the wear rate of the phosphor bronze and polyimide surfaces were 2.01 × 10−4 mm3/N-m and 1.949 × 10−3 mm3/N-m, respectively. The result provides an essential benchmark for enhancing the tribological performance of ultrasonic motors and increasing the output torque.

scholarly journals Exploring the friction and wear behaviors of Ag-Mo hybrid modified thermosetting polyimide composites at high temperature

Friction ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 893-904 ◽  
Author(s):  
Chunjian Duan ◽  
Ren He ◽  
Song Li ◽  
Mingchao Shao ◽  
Rui Yang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
High Performance ◽  
Friction And Wear ◽  
Bulk Temperature ◽  
Transmission Electron ◽  
Different Temperatures ◽  
New Type ◽  
Polyimide Composites

AbstractPolyimide composites have been extensively used as motion components under extreme conditions for their thermal stability and special self-lubricating performance. In the present study, Ag-Mo hybrids as lubricant fillers were incorporated into thermosetting polyimide to prepare a new type of tribo-materials (TPI-1) at high temperature. Comprehensive investigations at different temperatures reveal that the newly developed TPI-1 exhibits a better reduction in friction and wear rate below 100 °C, but all of them increase significantly when the bulk temperature exceeds 250 °C. The wear mechanisms demonstrated that sandwich-like tribofilms with different layers were established at different temperatures, which was further verified by characterization of scanning electron microscope (SEM), Raman spectroscopy, and transmission electron microscope (TEM). Considering the high-performance TPI coupled with Ag-Mo hybrids, we anticipate that further exploration would provide guidance for designing TPI tribo-materials that would be used at high temperatures.

Mechanical and Tribological Properties of Polyimide Composites for Reducing Weight of Ultrasonic Motors

2019 ◽  
Vol 799 ◽  
pp. 65-70
Author(s):  
Yuan Hao Yu ◽  
Gai Zhao ◽  
Jing Fu Song ◽  
Qing Jun Ding
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Polymer Composites ◽  
Tribological Properties ◽  
Travelling Waves ◽  
Polyphenylene Sulfide ◽  
Light Weight ◽  
Mechanical And Tribological Properties ◽  
Ultrasonic Motors ◽  
Polyimide Composites

The travelling waves ultrasonic motors (TWUM) with nonmagnetic, large torque, high precision and simple structure was driven by frictional force, which had been applied aerospace, intelligent and precise instruments. In order to reduce the total weight of TWUM, the phosphor bronze stator with the biggest density among the all parts of TWUM (8.89 g/cm3) were substituted with light weight polymer or polymer composites. This study designed and prepared one types of low density polyimide (PI) composite (1.41g/cm3) reinforced with carbon fibers (CF) which can reduce the weight of stator over 85%. Importantly, this PI composite can meet the main requirements of TWUM, such as high elastic modulus, wear resistance, and suitable friction coefficient. The output stalling torque of TWUM with CF/PI stator still have 0.22 N·m (18.3% compared with TWUM with phosphor bronze stator). Moreover, this study systematically investigated the mechanical and tribological properties of CF/PI composite. For comparison, the pure PI, polyetheretherketone (PEEK) and polyphenylene sulfide (PPS) were also analyzed to reveal the wear mechanisms. The experimental results indicated that CF/PI had better wear resistance and lower friction coefficient than other polymer sliding against Si3N4. This light weight polymer composites would be an ideal candidate to reduce the weight of TWUM, which can broaden the lightweight application in the field of aerospace.

Effect of Ultrasonic Vibration on Friction and Wear Properties of GCr15/45# Steel Frictional Pairs under Oil Lubrication

2011 ◽  
Vol 295-297 ◽  
pp. 2102-2105 ◽  
Author(s):  
Yu Lin Qiao ◽  
Shan Lin Yang ◽  
Yan Zang ◽  
Dong Wang
Keyword(s):  
Friction Coefficient ◽  
Ultrasonic Vibration ◽  
Friction And Wear ◽  
Friction Reduction ◽  
Wear Volume ◽  
Oil Lubrication ◽  
Wear Properties ◽  
Friction And Wear Properties ◽  
Surface Morphologies ◽  
Scanning Electron

Ultrasonic vibration friction and wear experiments were carried out by MFT-R4000 reciprocating friction and wear tester bonded with ultrasonic device. The surface morphologies of wear scars were examined by scanning electron microscope (SEM). The influences of ultrasonic vibration on friction reduction and anti-wear properties of GCr15/45# steel frictional pairs under different loads were discussed. The experimental results showed that, the friction of GCr15/45# steel frictional pairs could be reduced by ultrasonic vibration, and the reduction of friction coefficient became more obvious as the loads increasing. The friction coefficient measured under ultrasonic vibration is 12% lower than it measured without ultrasonic vibration when the load was 50N. However, the wear of frictional pairs increased under ultrasonic vibration, and the amplitude of wear volume enlarged with the loads increase, which is 63% at the load of 50N.

Sign in / Sign up

Export Citation Format

Share Document