Study of tribological properties of graphite/copper-ferrum matrix self-lubricating composites prepared by induction sintering at elevated temperature

Author(s):  
Chuanqi Fu ◽  
Chi Yu ◽  
Juncai Sun ◽  
Zhou Wang
2014 ◽  
Vol 24 (1) ◽  
pp. 307-318 ◽  
Author(s):  
Jie Yao ◽  
Xiaoliang Shi ◽  
Wenzheng Zhai ◽  
Ahmed Mohamed Mahmoud Ibrahim ◽  
Zengshi Xu ◽  
...  

2010 ◽  
Vol 33 ◽  
pp. 458-462 ◽  
Author(s):  
Chuan Qi Fu ◽  
Zhou Wang

The molybdenum disulfide(MoS2)/copper(Cu)-ferrum(Fe) matrix self-lubricating composites with various amounts of MoS2 additives were prepared by induction heating sintering method combined with the alloying of the Cu-Fe matrix with various metallic elements. As the temperature was increased from room temperature to 800°C, the mechanical and tribological properties of the composites were measured using the universal testing machine and MRH-3 friction-wear tester. The phase compositions and worn surface morphologies of the composites were analyzed by means of X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Meanwhile, wear mechanisms were discussed. It was found that the mechanical and friction/wear properties of MoS2/Cu-Fe matrix self-lubricating composites were related to the induction frequencies and the contents of the MoS2 as the solid lubricant. The increased MoS2 content resulted in increased mechanical and friction/wear properties at first and then decreased subsequently. The composites with proper MoS2 contents and induction frequencies have the lower the friction coefficients and wear rate at room temperature to 800°C. Meanwhile, the self-lubricating films were mainly made up of some compositions, such as pearlite, cementite, sulphide, solid solution alloy of Mo and Fe, molybdenum oxide in elevated temperature; the wear mechanism of composites has been changed from abrasive wear to ploughing wear.


2011 ◽  
Vol 291-294 ◽  
pp. 34-40
Author(s):  
Hua Tang ◽  
Wen Jing Li ◽  
Chang Sheng Li

The YBa2Cu3Ox/Ag and Bi2Sr2CaCu2Ox/Ag self-lubricating composites were prepared using powder metallurgic method. The crystal structure and morphology of the as-synthesized samples were characterized by XRD and SEM. The YBa2Cu3Ox/Ag and Bi2Sr2CaCu2Ox/Ag self-lubricating composites were found to compose of superconductor phase and Ag phase. The tribological properties from ultra-low temperature to room temperature of the composites were studied by pin-on-disk friction test. It was found that the friction coefficients of pure YBa2Cu3Ox(YBCO) and Bi2Sr2CaCu2Ox(BSCCO) were both dropped abruptly when the temperature cooled below the superconducting transition temperature. At room temperature, the friction coefficient of pure YBa2Cu3Oxis 0.68~0.95, when mixing 15wt% Ag, the friction coefficient of the sample decreased to the lowest value 0.11. The friction coefficient of pure Bi2Sr2CaCu2Ox is 0.15~0.17, When Ag content reach 10wt%, the coefficient was lowest (average value is 0.13). The addition of appropriate amount of Ag obviously improve the tribological property of YBCO, while only slightly meliorate that of BSCO. On the other hand, the YBCO/Ag composites exhibit better tribological properties than BSCCO/Ag composites at higher load under the same experimental condition.


Wear ◽  
2021 ◽  
pp. 204166
Author(s):  
Xuhui Pei ◽  
Yin Du ◽  
Xiaoxiao Hao ◽  
Hanming Wang ◽  
Qing Zhou ◽  
...  

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wei Feng ◽  
Lei Yin ◽  
Yanfeng Han ◽  
Jiaxu Wang ◽  
Ke Xiao ◽  
...  

Purpose This paper aims to explore the possibility of converting the nitrile butadiene rubber (NBR) water-lubricated bearing material into a self-lubricating bearing material by the action of polytetrafluoroethylene (PTFE) particles and water lubrication. Design/methodology/approach A group of experimental studies was carried out on a ring-on-block friction test. The physical properties, tribological properties and interface structure of PTFE-NBR self-lubricating composites filled with different percentages of PTFE particles were investigated. Findings The experimental results indicated that the reduction in friction and wear is a result of the formation of the lubricating film on the surface of the composites. The lubricating film was formed of a large amount of PTFE particles continuously supplied under water lubrication conditions and the PTFE particles here can greatly enhance the load capacity and lubrication performance. Originality/value In this study, the tribological properties of PTFE particles added to the NBR water-lubricated bearing materials under water lubrication were investigated experimentally, and the research was carried out by a ring-on-block friction test. It is believed that this study can provide some guidance for the application of PTFE-NBR self-lubricating. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2020-0187/


2019 ◽  
Vol 361 ◽  
pp. 196-205 ◽  
Author(s):  
Yingyi Liu ◽  
Nuo Xu ◽  
Yuan Wang ◽  
Yongtao Yao ◽  
Haiying Xiao ◽  
...  

2016 ◽  
Vol 68 (5) ◽  
pp. 611-616 ◽  
Author(s):  
Zujian Shen ◽  
Fei Geng ◽  
Xinxin Fan ◽  
Zhichen Shen ◽  
Haiyan Wang

Purpose This paper aims to investigate and prepare the composite polyurea greases with excellent thermal stability and tribological properties. Design/methodology/approach In this paper, composite Ba-based (Ba, barium) tetra-polyurea lubricating greases were prepared with two different methods: mixing Ba-based gelatinizer and tetra-polyurea gelatinizer by a physical method; and introducing barium carboxylate into tetra-polyurea molecules by a chemical method. The properties of the products, such as heat stability, water resistance and friction performance, were analyzed with thermogravimetry, water-resistance test and four-ball friction test. Findings The results indicated that the products obtained by chemically introducing barium carboxylate into tetra-urea molecules showed better elevated temperature tribological properties, and the disadvantages of the polyurea greases with high temperature hardening were also obviously improved. The cone penetration rate at 180°C for 24 h is only 3 per cent. The friction coefficient can be decreased to 0.44 and the last non-seizure load value was increased from 560 N to 1,120 N without any other additives. Originality/value The research is significant because the prepared composite grease showed excellent performances, such as the outstanding thermal stability, water resistance and excellent extreme pressure and anti-wear properties, which may be widely applied in steel, metallurgy, bearings and other industrial fields.


2013 ◽  
Vol 668 ◽  
pp. 3-8 ◽  
Author(s):  
Jian Rong Sun ◽  
Chang Sheng Li ◽  
Hua Tang ◽  
Zhi Cheng Guo ◽  
Jin Ying Zi Liu

The composites of Ni-W-Cr-Fe-Cu-MoS2-Graphite with nano-MoS2 were prepared by powder metallurgy. Its tribological properties were investigated using the UTM-2 Nano+Micro Tribometer from room temperature to 600°C. The effects of amount of MoS2 and Ni-W-Cr prealloy powder, load, and temperature on the tribological properties were investigated and discussed. The results indicated that the addition of 43~45wt.% Ni-W-Cr prealloy powder had a strengthening effect on the hardness, anti-press and tensile strength. The tensile strength of the composite decreases with the addition of Nano-MoS2 and graphite, and the friction coefficient decrease with increase of the additives over the wide temperature range of 25°C∼600°C. The friction coefficients and wear rates of the composites reach the optimization value at 2.5wt.% MoS2,While its wear rates increase with the increasing temperature and load.


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