Effects of frictional heat on the tribological properties of Ni3Al matrix self-lubricating composite containing graphene nanoplatelets under different loads

Author(s):  
Yuchun Huang ◽  
Xiaoliang Shi ◽  
Kang Yang ◽  
Xiyao Liu ◽  
Zhihai Wang

In order to analyze the effects of frictional heat on the tribological performance of Ni3Al matrix self-lubricating composite containing 6.2 vol.% graphene nanoplatelets (NB), the dry sliding friction tests of Ni3Al-based alloy and NB against GCr15 steel ball are undertaken under different loads from 3 to 18 N. The effects of different amount of frictional heat on the friction and wear mechanism of NB are also studied. The results show that tribological performance of NB is better than that of Ni3Al-based alloy under same working conditions. The addition of graphene nanoplatelets promotes the formation of stable glaze layer on worn surface. In addition, graphene nanoplatelets enhance the thermal conductivity of NB, which makes the surface temperature of wear scar of NB in a proper range (about 413 ℃) at 13 N and avoids the serious friction and wear caused by the accumulation of frictional heat. At 13 N, NB shows the lower friction coefficient (0.32) and wear rate (3.6 × 10−5 mm3·N−1·m−1). It is attributed to the appropriate local temperature (about 413 ℃) of worn surface, resulting in the formation of stable glaze layer with good friction reducing and wear resistance on worn surface. This study was meaningful for optimizing applied loads to realize the appropriate frictional heat and good tribological behavior of NB.

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 732
Author(s):  
Yeoh Jun Jie Jason ◽  
Heoy Geok How ◽  
Yew Heng Teoh ◽  
Farooq Sher ◽  
Hun Guan Chuah ◽  
...  

This study investigated the tribological behaviour of Pongamia oil (PO) and 15W–40 mineral engine oil (MO) with and without the addition of graphene nanoplatelets (GNPs). The friction and wear characteristics were evaluated in four-ball anti-wear tests according to the ASTM D4172 standard. The morphology of worn surfaces and the lubrication mechanism of GNPs were investigated via SEM and EDS. This study also focuses on the tribological effect of GNP concentration at various concentrations. The addition of 0.05 wt % GNPs in PO and MO exhibits the lowest friction and wear with 17.5% and 12.24% friction reduction, respectively, and 11.96% and 5.14% wear reduction, respectively. Through SEM and EDS surface analysis, the surface enhancement on the worn surface by the polishing effect of GNPs was confirmed. The deposition of GNPs on the friction surface and the formation of a protective film prevent the interacting surfaces from rubbing, resulting in friction and wear reduction.


2013 ◽  
Vol 774-776 ◽  
pp. 94-98
Author(s):  
Dao Yuan Pan ◽  
Peng Peng Wu ◽  
Zhong Xue Gao ◽  
Yu Zeng Zhang

Based on actual working conditions and parameters of the hydraulic steering gear, the purpose is optimizing the rubber seal of steering gear by different rubbers mixing technology. Compare the five kinds of rubber with metal of the friction characteristics in dynamic fit, it can obtain a performance excellent rubber real in the specific operation conditions. And then improve the overall service life of the steering gear. It is first prepared the same hardness TPU and PVC and blends that the ratio is 3:7, 5:5and7:3 in this article. The pros and cons of the five rubbers are analyzed in friction and wear properties of the above experimental. The test curve of coefficient friction and wear with time has been done under different load at constant low speed. It determines TPU/PVC = 3:7 blends through friction and wear and wear mechanism of five rubbers with steel comparatively analyses, and the heat resistance and wear resistance of them are better than the other TPU/PVC blends and PVC under oil lubrication conditions.


2012 ◽  
Vol 476-478 ◽  
pp. 566-569
Author(s):  
Bao Guo Yuan ◽  
Hai Ping Yu ◽  
Ping Li ◽  
Gui Hua Xu ◽  
Chun Feng Li ◽  
...  

The effects of hydrogen on friction and wear properties of Ti–6Al–4V alloy sliding against GCr15 steel were investigated through dry sliding friction and wear tests in atmosphere at room temperature. Wear mechanism was determined by studying the morphology and chemical element of worn surface using SEM and EDS. Results show that friction coefficient decreases slightly and wear rate increases after hydrogenation. Wear mechanism is discussed.


2017 ◽  
Vol 24 (4) ◽  
pp. 485-494 ◽  
Author(s):  
Iskender Ozsoy ◽  
Adullah Mimaroglu ◽  
Huseyin Unal

AbstractIn this study, the influence of micro- and nanofiller contents on the tribological performance of epoxy composites was studied. The fillers are micro-Al2O3, micro-TiO2, and micro-fly ash and nano-Al2O3, nano-TiO2, and nanoclay fillers. The microfillers were added to the epoxy by 10%, 20%, and 30% by weight. The nanofillers were added to the epoxy by 2.5%, 5%, and 10%. Friction and wear tests were conducted using the pin-on-disc arrangement. Tribo elements consisted of polymer pin and DIN 1.2344 steel counterface disc. A load value of 15 N, a sliding speed of 0.4 m/s, a sliding distance of 2000 m, and dry atmospheric conditions were applied to test conditions. The results show that the friction coefficients and the specific wear rates of the nanofilled composites increase as the filler content increases. For microfiller-filled epoxy composites, these values decrease as filler content increases. The tribological performance of epoxy composites is enhanced by the addition of microfillers, and the higher enhancement is reached with the addition of 30% fly ash filler. Finally, the pin and disc worn surface images show the presence of adhesive and some abrasive wear mechanisms.


2008 ◽  
Vol 373-374 ◽  
pp. 572-575 ◽  
Author(s):  
Wen Gang Chen ◽  
Yu Zhou Gao ◽  
Hui Chen Zhang ◽  
Y.J. He

Sliding experiments lubricated with hydroxyl silicate magnesium particles as additive were performed under ambient condition and different loads by using an AMSLER friction and wear tester. The surface topographies and compositions of worn surface of 45 steel rings were analyzed by SEM and EDAX. The experimental results show that the friction load had great effect on generation of the frictionally-formed protective coating. No protective coating formed on the worn steel surface under lower friction load. However, a smooth and continuous protective coating can be developed on the worn surface of the steel when the friction load is high enough. The chemical composition of the protective coating is roughly the same as the additive. The additive can be fractured, stretched and flowed along the sliding direction under high contacting stress and instantaneous flash temperature, which result in coating being formed.


2013 ◽  
Vol 645 ◽  
pp. 133-136
Author(s):  
Peng Qiao ◽  
Yan Qiu Xia ◽  
Xiang Yu Ge

Overbased calcium sulfonate complex greases have excellent friction and wear properties and have been widely used in metallurgy and mining equipment. The effects and tribological performance of molybdenum dialkydithiocarbamate (MoDTC) and ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([C2OHMim][NTf2]), 1-(2-hydroxyethyl)-3-hexylimidazolium bis (trifluoromethylsulfonyl) imide ([C2OHHim][NTf2s]), added in overbased calcium sulfonate complex grease as additives were investigated by using reciprocating ball-on-disk sliding friction tester. The results showed that the two kinds of additives with a certain range of concentration could improve the tribological properties of greases.


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.


2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Ch. Sri Chaitanya ◽  
R. Narasimha Rao

Abstract The tribological behavior of the 10%, 20%, 30%, and 40% cenosphere-filled epoxy syntactic foams in terms of the wear rate and the friction coefficient of the foams were reported using a pin on disc tribometer in the present study. The influence of the wear parameters like applied pressure, sliding speed, and the sliding distance on the tribological performance of syntactic foams was reported. Syntactic foams with 40% cenosphere volume fraction exhibit better tribological properties over the other syntactic foams. The worn surface examination shows the adhesive dominant wear mechanism and the wear debris with broken cenosphere particles.


2016 ◽  
Vol 868 ◽  
pp. 18-22
Author(s):  
Hai Xia Guo ◽  
Nan Qu ◽  
Jian Feng Yang ◽  
Jun-Ichi Matsushita ◽  
Seung Ho Kim ◽  
...  

Two types of CuFe matrix composites with different reinforcements: silica and alumina particulates were developed using powder metallurgy. The mechanical properties were determined from Brinell hardness and flexural strength. The dry sliding friction and wear performance of the composites were investigated by the friction test. The results indicated that mechanical properties of alumina were superior to those of silica. The friction tests of the composites showed that the alumina reinforcement particle provides better braking performance. A wear track examination of composites showed that same abrasive wear. Our results indicated that composites with alumina reinforcement particles of high compatibility are to be preferred for braking performance.


Author(s):  
Yuchun Huang ◽  
Xiaoliang Shi ◽  
Kang Yang ◽  
Jialiang Zou ◽  
Qiao Shen ◽  
...  

The elastic and plastic deformations have significant effect on the tribological properties of the graphene-reinforced Ni3Al matrix self-lubricating composites. The primary purpose of this study is to investigate the tribological behavior and wear mechanisms of graphene-reinforced Ni3Al matrix self-lubricating composites by researching the effects of different loads and the corresponding friction heat on the elastic or plastic deformation. The dry sliding tribology tests of graphene-reinforced Ni3Al matrix self-lubricating composites are carried out at the loads of 7, 10, 13, and 16N, respectively. The elastic or plastic deformation is judged by comparing the yield stress with the contact stress analyzed by the numerical simulation method. It is found that graphene-reinforced Ni3Al matrix self-lubricating composites exhibit good tribological properties at 13 N due to the elastic deformation, leading to the formation of relatively stable wear resistant layer. Graphene-reinforced Ni3Al matrix self-lubricating composites show poor tribological performance at 16 N for the plastic deformation, resulting in the destruction of the wear resistant layer and the generation of surface cracks and material spalling. From the mechanical mechanism of wear, the plastic deformation and thermal stress are the important factors to lead to the material spalling. The results could be used to guide the selection of suitable working conditions for having good tribological performance of low wear and long service life.


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