Study of Tribological Properties of MoS2/Cu-Fe Matrix Self-Lubricating Composites Prepared by Induction Sintering at Elevated Temperature

2010 ◽  
Vol 33 ◽  
pp. 458-462 ◽  
Author(s):  
Chuan Qi Fu ◽  
Zhou Wang
Keyword(s):  
Elevated Temperature ◽  
Tribological Properties ◽  
Room Temperature ◽  
Testing Machine ◽  
Solid Solution Alloy ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
Mechanical And Tribological Properties ◽  
Surface Morphologies ◽  
Self Lubricating Composites

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.

Tribological Properties of Fe-Cu-MoS2 and Self-Lubricating Behaviors

2011 ◽  
Vol 268-270 ◽  
pp. 389-394 ◽  
Author(s):  
Chuan Qi Fu ◽  
Jun Cai Sun ◽  
Zhou Wang
Keyword(s):  
Tribological Properties ◽  
Testing Machine ◽  
High Wear Resistance ◽  
Solid Solution Alloy ◽  
Wear Properties ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Temperature Load ◽  
Surface Morphologies ◽  
Hot Press Sintering

The Fe-Cu-MoS2composites with different adding amount of MoS2as lubricant were prepared by induction sintering method. Their mechanical and tribological properties from room temperature (RT) to 800°C were tested by universal testing machine and high temperature tribometer. The effects of amounts of MoS2, temperature, load and sliding distance on the friction and wear properties of composite were discussed. The structure of the composite was analyzed by XRD and worm surface morphologies were observed by SEM. It was found that MoS2was decomposed during the hot-press sintering process. Meanwhile, solid solution alloy of Mo and Fe, and sulfides were formed in composite, which were responsible for low-friction and high wear-resistance at elevated temperature, respectively. Hardness and anti-compress strength can be improved by adding 8 wt. % MoS2. The friction coefficients and wear rates of composites decrease with the increase of adding amount of MoS2until a critical value of 8 wt. %. The composite with 8 wt. % MoS2shows the optimum tribological properties over the temperature range of RT~800°C.

scholarly journals High-Temperature Friction and Wear Properties of NiCr/hBN Self-Lubricating Composites

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 356 ◽  
Author(s):  
Xuewei Zhu ◽  
Xiaofeng Wei ◽  
Yuxiang Huang ◽  
Fu Wang ◽  
Pengpeng Yan
Keyword(s):  
Tribological Properties ◽  
Wear Mechanism ◽  
Wear Surface ◽  
Friction And Wear ◽  
Room Temperature ◽  
Powder Metallurgy Method ◽  
Wear Properties ◽  
Dust Composition ◽  
Friction And Wear Properties ◽  
Self Lubricating Composites

NiCr/hBN self-lubricating composites with hBN solid-lubricant contents of 8%, 9%, 10%, 11%, and 12% (mass fractions) were prepared by powder-metallurgy method. Their tribological properties at room temperature and 600, 700, and 800 °C were studied. SEM and XRD were performed to analyze their wear-surface morphology and abrasive-dust composition. Results indicate that the NiCr/hBN self-lubricating composites have favorable tribological properties at room temperature and 600 °C. The optimum comprehensive friction and wear performance are achieved at 10% hBN, and the main wear mechanism is abrasive wear. At 700 and 800 °C, the friction and wear properties of NiCr/hBN self-lubricating composites obviously decline. The wear surface experiences oxidation and the spinel oxides Cr2O3, NiCr2O4, and CrBO3 are formed. The main wear mechanism becomes combined scratching and glue form of adhesive wear, leading to greatly increased wear rate for the NiCr/hBN sel-lubricating composites.

scholarly journals Study on the Mechanical and Tribological Properties and the Mechanisms of Cr-Free Ni-Based Self-Lubricating Composites at a Wide Temperature Range

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 268 ◽  
Author(s):  
Penglin Zhang ◽  
Gaopan Zhao ◽  
Wenzhen Wang ◽  
Bin Wang ◽  
Peiying Shi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tribological Properties ◽  
Wear Mechanisms ◽  
Room Temperature ◽  
Fracture Mechanisms ◽  
Powder Metallurgy Method ◽  
Mechanical And Tribological Properties ◽  
Lubricating Film ◽  
Ag Particles ◽  
Self Lubricating Composites

A Cr-free Ni-based self-lubricating composites with MoS2 and Ag as lubricants were fabricated by the powder metallurgy method. The microstructures were examined. The mechanical properties and tribological behaviors of the composites were evaluated from room temperature to 800 °C. The fractography was observed and the fracture mechanisms were analyzed. The morphologies and the phase compositions of worn surfaces were determined and the wear mechanisms were elaborated. The results indicate that MoS2 did not completely decompose after sintering, and the NiMoAl-MoS2-Ag composite has the best tribological properties (0.22, 1.68 × 10−5) at 800 °C. The main wear mechanisms are micro-ploughing and plastic deformation. The improvement of tribological properties was attributed to the formation of the lubricating film consisting of NiO, Mo oxides, various molybdates, and Ag particles. The reactions resulting in these compositions are proposed. The mechanical properties degrade with the rise of temperature and the addition of lubricants. Both NiMoAl and NiMoAlAg alloys exhibit micro-void accumulation fracture while the composites with MoS2 reveal intergranular fracture.

Comparison in Tribological Properties of YBa2Cu3OX/Ag and Bi2Sr2CaCu2OX/Ag Self-Lubricating Composites

2011 ◽  
Vol 291-294 ◽  
pp. 34-40
Author(s):  
Hua Tang ◽  
Wen Jing Li ◽  
Chang Sheng Li
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Room Temperature ◽  
Superconducting Transition ◽  
Friction Test ◽  
Average Value ◽  
Structure And Morphology ◽  
Disk Friction ◽  
Pin On Disk ◽  
Self Lubricating Composites

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.

scholarly journals Physical Stability and Viscoelastic Properties of Co-Amorphous Ezetimibe/Simvastatin System

2019 ◽  
Vol 12 (1) ◽  
pp. 40 ◽  
Author(s):  
Justyna Knapik-Kowalczuk ◽  
Krzysztof Chmiel ◽  
Karolina Jurkiewicz ◽  
Natália Correia ◽  
Wiesław Sawicki ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Viscoelastic Properties ◽  
Room Temperature ◽  
Physical Stability ◽  
Ternary Systems ◽  
Storage Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Conditions ◽  
First Time

The purpose of this paper is to examine the physical stability as well as viscoelastic properties of the binary amorphous ezetimibe–simvastatin system. According to our knowledge, this is the first time that such an amorphous composition is prepared and investigated. The tendency toward re-crystallization of the amorphous ezetimibe–simvastatin system, at both standard storage and elevated temperature conditions, have been studied by means of X-ray diffraction (XRD). Our investigations have revealed that simvastatin remarkably improves the physical stability of ezetimibe, despite the fact that it works as a plasticizer. Pure amorphous ezetimibe, when stored at room temperature, begins to re-crystallize after 14 days after amorphization. On the other hand, the ezetimibe-simvastatin binary mixture (at the same storage conditions) is physically stable for at least 1 year. However, the devitrification of the binary amorphous composition was observed at elevated temperature conditions (T = 373 K). Therefore, we used a third compound to hinder the re-crystallization. Finally, both the physical stability as well as viscoelastic properties of the ternary systems containing different concentrations of the latter component have been thoroughly investigated.

scholarly journals Structure, Oxidation Resistance, Mechanical, and Tribological Properties of N- and C-Doped Ta-Zr-Si-B Hard Protective Coatings Obtained by Reactive D.C. Magnetron Sputtering of TaZrSiB Ceramic Cathode

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 946
Author(s):  
Ph. V. Kiryukhantsev-Korneev ◽  
A. D. Sytchenko ◽  
S. A. Vorotilo ◽  
V. V. Klechkovskaya ◽  
V. Yu. Lopatin ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Oxidation Resistance ◽  
Tribological Properties ◽  
Protective Coatings ◽  
Elastic Recovery ◽  
Protective Film ◽  
X Ray Diffraction ◽  
Energy Dispersion Spectroscopy ◽  
X Ray ◽  
Mechanical And Tribological Properties

Coatings in the Ta-Zr-Si-B-C-N system were produced by magnetron sputtering of a TaSi2-Ta3B4-(Ta,Zr)B2 ceramic target in the Ar medium and Ar-N2 and Ar-C2H4 gas mixtures. The structure and composition of coatings were studied using scanning electron microscopy, glow discharge optical emission spectroscopy, energy-dispersion spectroscopy, and X-ray diffraction. Mechanical and tribological properties of coatings were determined using nanoindentation and pin-on-disk tests using 100Cr6 and Al2O3 balls. The oxidation resistance of coatings was evaluated by microscopy and X-ray diffraction after annealing in air at temperatures up to 1200 °C. The reactively-deposited coatings containing from 30% to 40% nitrogen or carbon have the highest hardness up to 29 GPa and elastic recovery up to 78%. Additionally, coatings with a high carbon content demonstrated a low coefficient of friction of 0.2 and no visible signs of wear when tested against 100Cr6 ball. All coatings except for the non-reactive ones can resist oxidation up to a temperature of 1200 °C thanks to the formation of a protective film based on Ta2O5 and SiO2 on their surface. Coatings deposited in Ar-N2 and Ar-C2H4 demonstrated superior resistance to thermal cycling in conditions 20-T−20 °C (where T = 200–1000 °C). The present article compares the structure and properties of reactive and “standard-inert atmosphere” deposited coatings to develop recommendations for optimizing the composition.

Effect of preparation process on elevated temperature tribological properties of composite polyurea grease

2016 ◽  
Vol 68 (5) ◽  
pp. 611-616 ◽  
Author(s):  
Zujian Shen ◽  
Fei Geng ◽  
Xinxin Fan ◽  
Zhichen Shen ◽  
Haiyan Wang
Keyword(s):  
Thermal Stability ◽  
Elevated Temperature ◽  
Tribological Properties ◽  
Water Resistance ◽  
Physical Method ◽  
Heat Stability ◽  
Wear Properties ◽  
Excellent Thermal Stability ◽  
Content Type ◽  
Polyurea Grease

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.

Preparation and Wear Properties of (Al3Zr+ZrB2)P/2124 Composites Material with In Situ Process

2012 ◽  
Vol 616-618 ◽  
pp. 1736-1740
Author(s):  
Lei Jiao ◽  
Yu Tao Zhao ◽  
Zhong Zhong Zhang ◽  
Yan Wei Yang ◽  
Ming Rui Zhang
Keyword(s):  
Magnetic Field ◽  
Composite Materials ◽  
Sliding Friction ◽  
Testing Machine ◽  
Test Methods ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
Matrix Metal ◽  
The Matrix

With pulse magnetic field, it is use 2124-K2ZrF6-KBF4 as matrix metal to produce chemical reaction to gain (Al3Zr+ZrB2) p/2124 composite materials in this paper. In this paper, For the sake of researching the microstructure, the morphology, the size and the matrix distribution characteristics of the reinforced grain of prepared composite material , those test methods are used, such as optical microscopy, scanning electron microscope, X-ray diffraction analysis and so on. We will research the magnetic field strength how to influence size and distribution of Al3Zr +ZrB2 particle and the abrasion performance of (Al3Zr+ZrB2)P/2124 composite materials in the room temperature. Wear experiment is proceeding in the CETR UMT 3-V the testing machine and sliding friction is friction way with pin-disc but without lubricant, then analyzes the wear mechanism.

Microstructures, mechanical and tribological properties of VN films deposited by PLD technique

RSC Advances ◽  
2016 ◽  
Vol 6 (40) ◽  
pp. 33403-33408 ◽  
Author(s):  
Hongjian Guo ◽  
Bo Li ◽  
Jianyi Wang ◽  
Wenyuan Chen ◽  
Zhenyu Zhang ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Room Temperature ◽  
Laser Deposition ◽  
Vanadium Nitride ◽  
Deposition Technique ◽  
Mechanical And Tribological Properties

Consistent stoichiometric FCC structured vanadium nitride films were fabricated by plused laser deposition technique at room temperature and 300 °C, and their microstructures, mechanical and tribological properties were investigated.

Preparation and Tribological Behavior of Self-Lubrication Composites Ni-W-Cr-Fe-Cu-MoS2-Graphite at Elevated Temperature

2013 ◽  
Vol 668 ◽  
pp. 3-8 ◽  
Author(s):  
Jian Rong Sun ◽  
Chang Sheng Li ◽  
Hua Tang ◽  
Zhi Cheng Guo ◽  
Jin Ying Zi Liu
Keyword(s):  
Tensile Strength ◽  
Elevated Temperature ◽  
Powder Metallurgy ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Room Temperature ◽  
Tribological Behavior ◽  
Strengthening Effect ◽  
Wear Rates ◽  
Increasing Temperature

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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