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

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.

2015 ◽  
Vol 642 ◽  
pp. 30-33 ◽  
Author(s):  
Jian Liang Li ◽  
Juan Juan Chen ◽  
Dang Sheng Xiong ◽  
Yong Kang Zhang ◽  
Yong Kun Qin ◽  
...  

The graphene containing Ni-based composite coatings with different graphene addition amounts were prepared on 45 steel surface by using dipulse composite electrodeposition technology. The tribological behavior of composite coating was tested by against GCr15 steel pin under the dry condition. The friction coefficient of composite coating is 20-30% lower than pure Cr coating, their wear rates are almost in the same magnitude. Compared with 45 steel, the friction coefficient of composite coating decreases and wear rate falls over 50%.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Haizhong Wang ◽  
Zenghong Song ◽  
Dan Qiao ◽  
Dapeng Feng ◽  
Jinjun Lu

The tribological performance of Si3N4ball sliding against Ti3SiC2disc lubricated by lithium-based ionic liquids (ILs) was investigated using an Optimol SRV-IV oscillating reciprocating friction and wear tester at room temperature (RT) and elevated temperature (100°C). Glycerol and the conventional imidazolium-based IL 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (L-F106) were used as references under the same experimental conditions. The results show that the lithium-based ILs had higher thermal stabilities than glycerol and lower costs associated with IL preparation than L-F106. The tribotest results show that the lithium-based ILs were effective in reducing the friction and wear of Si3N4/Ti3SiC2contacts. [Li(urea)]TFSI even produced better tribological properties than glycerol and L-F106 both at RT and 100°C. The SEM/EDS and XPS results reveal that the excellent tribological endurance of Si3N4/Ti3SiC2contacts lubricated by lithium-based ILs was mainly attributed to the formation of surface protective films composed of various tribochemical products.


2014 ◽  
Vol 881-883 ◽  
pp. 1597-1600 ◽  
Author(s):  
Narissara Mahathaninwong ◽  
Sirikul Wisutmethangoon ◽  
Thawatchai Plookphol ◽  
Jessada Wannasin ◽  
Suchart Chantaramanee

Tensile properties of rheo-cast 7075-T6 Al alloy produced by Gas Induced Semi-Solid (GISS) technique was investigated as a function of temperatures from 25°C to 250 °C in order to assess the potent of high temperature applications. It was found that the ultimate tensile strength and yield strength of the alloy decreased steadily with increasing temperature. There was loss in strength of about 33% at 200°C and 46% at 250 °C comparing to the strength at room temperature. At T = 250 °C, the ultimate tensile strength and yield strength of the rheo-cast 7075-T6 Al alloy were higher than those of the wrought 7075-T651 Al alloy. Keyword: 7075 Al alloy; Gas Induced Semi Solid (GISS) technique; Elevated temperature tensile.


2010 ◽  
Vol 160-162 ◽  
pp. 35-47 ◽  
Author(s):  
Bai Ming Chen ◽  
Zheng Yu Zhang ◽  
Ming Xu Wang ◽  
Guo Cai Han ◽  
Liang An

The Cu based friction composites using graphite as solid lubricant with different weight rations of Ti, i.e. 8 wt.%, 12 wt.%, 16 wt.%, 20 wt.%, were sintered by powder metallurgy (P/M) method. The structure of the composites was characterized by X-ray diffraction (XRD) and the tribological properties was studied on block-on-ring tester. XRD results verified presence of TiC phase which was in-situ synthesized through reaction of Ti and graphite in the composites, and the content of TiC was increased with the increased Ti content. The in-situ synthesized TiC phase which was fine and distributed uniformly improved tribological properties of Cu based friction composites significantly. The hardness, wear rates and friction coefficient of composites were increased with increasing amount of in-situ synthesized TiC.


2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Xinliang Li ◽  
Hong Yin ◽  
Yu-Feng Li

In this work, layered ternary Cr2AlC powders with high purity and a size of 0.5–1 μm were synthesized by solid-state reaction method. NiCr–Cr2AlC composites have been prepared by spark plasma sintering (SPS) process. The composites' tribological properties were evaluated against alumina ball under dry sliding condition from room temperature to 600 °C. Compared with unmodified NiCr alloy, Cr2AlC addition has an effect on reduction of friction coefficient of NiCr–Cr2AlC composites at the temperatures up to 400 °C. Especially, in comparison with NiCr alloy, the wear rates of NiCr–Cr2AlC composites significantly decrease from 10−4 mm3/(N·m) to 10−5–10−6 mm3/(N·m) from room temperature to 600 °C (except for 200 °C). The NiCr–20 wt % Cr2AlC composite exhibited excellent tribological properties with a friction coefficient of 0.3–0.4 and a wear rate of about 10−6 mm3/(N·m) from 400 °C to 600 °C. Through the analysis of scanning electron microscope (SEM) and X-ray photoelectron spectroscope (XPS), it is clarified that effective improvement of tribological properties of NiCr–Cr2AlC composites is attributed to a glaze layer consisting of NiO, Cr2O3, Al2O3, and NiCr2O4, which is formed by tribo-oxidation during wear process.


2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Shengyu Zhu ◽  
Jun Cheng ◽  
Zhuhui Qiao ◽  
Yuan Tian ◽  
Jun Yang

High temperature self-lubricating NiAl matrix composites with addition of CuO (15, 20, and 25 wt.%) were fabricated by powder metallurgy technique, and the tribological behavior from room temperature to 1000 °C was investigated. It was found that Ni–Cu and Al2O3 phases formed during the fabrication process due to reaction of NiAl and CuO. The tribological results showed that the composite with addition of 25 wt.% CuO has a favorable friction coefficient of about 0.2 and excellent wear resistance with the magnitude of 10−6 mm3 N−1 m−1 at high temperatures (800 and 1000 °C).


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.


2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Chong-Chong Mao ◽  
Yu-Feng Li

SrSO4 ceramic was prepared by hot-pressed sintering and its friction behavior was investigated against the Al2O3 ball under the dry sliding condition from room temperature to 800 °C. From room temperature to 400 °C, the tribological properties of SrSO4 ceramic are quite poor with the friction coefficients of 0.65–0.83 and the wear rates of about 10−3 mm3/Nm. With the testing temperature increasing to 600 °C and 800 °C, a brittle to ductile transition of SrSO4 takes place because of the activated slip systems. The friction coefficient and wear rate of SrSO4 ceramic also obviously decrease to 0.37 and about 10−4 mm3/Nm at 800 °C. The significant improvement of the tribological properties is ascribed to the formation of a smooth and continuous SrSO4 lubricating film with excellent ductility and low shear strength at elevated temperature. SrSO4 is considered to be a potential candidate for high-temperature solid lubricant with excellent lubricity.


2020 ◽  
Vol 10 (5) ◽  
pp. 663-670
Author(s):  
Zhigang Wang ◽  
Jun Li ◽  
Daquan Li

In order to make full use of the wear resistance and antifriction of the mixed reinforced particles, improve the performance and utilization rate of the composite material, and reduce its wear amount, in this study, graphite and aluminum composite materials with different graphite concentration were prepared by powder metallurgy process. On this basis, the influence of different graphite concentration on the friction coefficient and wear amount of composite samples and different load on the wear amount of composite materials were discussed and analyzed. The results show that with the increase of graphite content, the friction coefficient and wear amount of the composite will decrease correspondingly. When the load is less than 30 N, the wear curve of the sample changes steadily. When the load is more than 30 N, the wear will increase sharply. Therefore, the analysis of the tribological properties of the graphite and aluminum composites based on the powder metallurgy process plays an important role in improving the utilization rate of the composite and reducing its wear.


Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1854
Author(s):  
Fei-xia Zhang ◽  
Yan-qiu Chu ◽  
Chang-sheng Li

This paper presents a facile and effective method for preparing Ni/NbSe2 composites in order to improve the wettability of NbSe2 and copper matrix, which is helpful in enhancing the friction-reducing and anti-wear properties of copper-based composites. The powder metallurgy (P/M) technique was used to fabricate copper-based composites with different weight fractions of Ni/NbSe2, and tribological properties of composites were evaluated by using a ball-on-disk friction-and-wear tester. Results indicated that tribological properties of copper-based composites were improved by the addition of Ni/NbSe2. In particular, copper-based composites containing 15 wt.% Ni/NbSe2 showed the lowest friction coefficient (0.16) and wear rate (4.1 × 10−5 mm3·N−1·m−1) among all composites.


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