Tribological Properties of Textured Cemented Carbide Surfaces of Different Wettability Produced by Pulse Laser

2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Xiuqing Hao ◽  
Hanlong Li ◽  
Xiaolu Song ◽  
Liang Li ◽  
Ning He

The micro/nanotextured cemented carbide surface of different wettability was produced by laser scanning and fluorinated treatment. The tribological properties of the untextured, oleophobic and oleophilic micro/nanotextured surface were investigated experimentally including the effects of crank speed and contact pressure by a reciprocating friction and a wear tester. For all tested surfaces, the friction coefficient of the surface decreased as both the increasing crank speed and contact pressure increased. Compared to the untextured surface, the friction coefficient of the micro/nanotextured surface was significantly decreased, being sensitive to the wettability of the surface. Besides, the tribological properties of the oleophobic micro/nanotextured surface were superior to the oleophilic micro/nanotextured surface under the same experimental conditions. The improvement in tribological properties of the oleophobic micro/nanotextured surface could be attributed to the low wettability, which was beneficial to rapid accumulation of the lubricating oil on the surface.

2017 ◽  
Author(s):  
Xiuqing Hao ◽  
Xiaolu Song ◽  
Liang Li ◽  
Ning He

The micro/nano textured cemented carbide surface of different wettability was produced by laser scanning and fluorinated treatment. The tribological properties of the un-textured, oleophobic and oleophilic micro/nano textured surface were investigated experimentally including the effects of crank speed and contact pressure by a reciprocating friction and a wear tester. For all tested surfaces, the friction coefficient of the surface decreased as both the increasing crank speed and contact pressure increased. Compared to the un-textured surface, the friction coefficient of the micro/nano textured surface was significantly decreased, being sensitive to the wettability of the surface. Besides, the tribological properties of the oleophobic micro/nano textured surface were superior to the oleophilic micro/nano textured surface under the same experimental conditions. The improvement in tribological properties of the oleophobic micro/nano textured surface could be attributed to the low wettability, which was beneficial to rapid accumulation of the lubricating oil on the surface.


2015 ◽  
Vol 75 (11) ◽  
Author(s):  
N. Nuraliza ◽  
S. Syahrullail ◽  
M.N. Musa

The use of vegetable oil-based lubricant as a lubricant in various applications has increased and it is eyed by the industry due to its superior tribological properties, besides possessing the potential to replace petroleum-based lubricants. Palm olein is one of alternative lubricants that could be suitable and attractive as a lubricant to be studied due to its advantages and large production in the country. Thus, in this study, the behavior of palm olein characteristics was investigated by using pin-on-disc experiment, in which a hemispherical pin was loaded against the rotating grooved disc. The experiments via sliding were performed with pin-on-disc tester using pure aluminum as the material for hemispherical pin and SKD11 for disc. The test was implemented by dropping continuous flow of palm olein as lubricating oil on sliding surface at different loads applied, which were 10N, 50N, and 100N. The wear rate of the pin and the friction coefficient were also investigated. Moreover, the surface roughness before and after the experiment was analyzed as well. All the results obtained were compared to hydraulic oil and engine oil-SAE 40. From the analysis, the friction coefficient acquired from lubricated with palm olein was the lowest for both conditions. The wear rate obtained for the three lubricants increased from 10N to 100N load for palm oil, but decreased for hydraulic and engine oil-SAE 40. Meanwhile, the wear rate obtained for lubrication with hydraulic oil showed the lowest value compared to Engine oil-SAE 40 and double fractionated palm olein. 


Author(s):  
Xianguo Hu ◽  
Yucheng Wu ◽  
Guangcheng Yuan ◽  
Peng Huang ◽  
Hefeng Jing

This paper summarizes the tribological properties of MoS2 nano-particles with about 30 nm under different frictional conditions. By four-ball tribometer, the results showed that as the nano-MoS2 content is over 0.5 wt% the extreme pressure of lubricating oil is higher than to 30% than that of lubricating oil with same content of common MoS2. The nano-MoS2 particles can decrease the friction coefficient of lubricating oil obviously. However the results showed that their friction reductions have not obvious difference by the ring-on-block tribometer. The analyses of surface composition conducted by XPS and SEM images showed that the nanoparticles form a protective film (WO3) allowing an increase in the load capacity of rubbed pairs. The main advantage of the nanoparticles is ascribed to the release and furnishing of the nanoparticles from the valley onto the rubbing metal surface and their confinement at the interface.


2020 ◽  
Vol 10 ◽  
pp. 184798042094665
Author(s):  
Yong Liu ◽  
Yi Dong ◽  
Yangang Zhang ◽  
Siyuan Liu ◽  
Yu Bai

Two processes of physical liquid phase stripping and chemical redox reduction were used to obtain graphene sheets. Fourier transform infrared spectroscopy and Raman spectroscopy test methods were used to compare and analyze the structure and disorder of graphene. The obtained graphene was modified with oleic acid and stearic acid. The dispersion stability of graphene as a lubricating oil additive was investigated by natural sedimentation method and spectrophotometry. The tribological properties of the graphene dispersion were investigated by a four-ball friction and wear tester. Scanning electron microscope and energy spectrometer were used to characterize and analyze the microscopic morphology and composition of the worn surface. The results showed that the modified liquid phase stripping graphene demonstrated the best anti-wear and anti-friction properties of the dispersion, the lowest friction coefficient is 0.0677, and the average friction coefficient is reduced by about 26%.


Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 486
Author(s):  
Guoqiang Zheng ◽  
Youxi Lin

Tool wear is the main factor of tool failure in cutting difficult-to-machine materials. This paper aims to analyze the anti-friction mechanism of laser machining micro-groove cemented carbide. Firstly, micro-grooves were prepared on the cemented carbide surface by laser processing. Secondly, we conducted an analysis of the mechanical properties of laser texturing by measuring hardness. Finally, we studied the anti-friction mechanism of micro-grooves by a wear test (ASTM G133-05). Results show that surface hardness increases after laser treatment. The friction coefficient and surface wear of micro-groove cemented carbide are significantly reduced compared with the conventional surface. The friction coefficient of PE and OB decreased by 20.6% and 10.7%, respectively. It is found that the direction of micro-grooves determines whether metal debris can be removed—the stronger the ability to remove metal debris, the better the tribological properties of the micro-groove surface.


Author(s):  
Ying Yan ◽  
Xuelin Lei ◽  
Yun He

The effect of nanoscale surface texture on the frictional and wear performances of nanocrystalline diamond films under water-lubricating conditions were comparatively investigated using a reciprocating ball-on-flat tribometer. Although the untreated nanocrystalline diamond film shows a stable frictional state with an average friction coefficient of 0.26, the subsequent textured films show a beneficial effect on rapidly reducing the friction coefficient, which decreased to a stable value of 0.1. Furthermore, compared with the nanocrystalline diamond coating, the textured films showed a large decreasing rate of the corresponding ball wear rate from 4.16 × 10−3 to 1.15 × 10−3 mm3/N/m. This is due to the fact that the hydrodynamic fluid film composed of water and debris can provide a good lubrication environment, so the entire friction process has reached the state of fluid lubrication. Meanwhile, the surface texture can greatly improve the hydrophilicity of the diamond films, and as the texture density increases, the water contact angle decreases from 94.75° of the nanocrystalline diamond film to 78.5° of the textured films. The proper textured diamond film (NCD90) exhibits superior tribological properties among all tested diamond films, such as short run-in period, low coefficient of friction, and wear rate.


Jurnal METTEK ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Dedison Gasni ◽  
KM Abdul Razak ◽  
Ahmad Ridwan ◽  
Muhammad Arif

Penelitian ini bertujuan untuk mengetahui efek dari penambahan minyak kelapa dan sawit terhadap sifat fisik dan tribologi pelumas SAE 40. Vegetabel oil, seperti; minyak kelapa dan sawit, memiliki nilai viskositas indek yang tinggi dan sifat pelumasan yang baik terutama didaerah boundary lubrication jika dibandingkan dengan mineral oil (SAE 40). Hal ini disebabkan karena vegetabel oil memiliki kandungan fatty acids yang tidak dimiliki oleh mineral oil. Keunggulan lain dari minyak kelapa dan sawit adanya sifat yang ramah lingkungan karena mudah terurai di alam dan dapat diperbaharui. Pada penelitian ini sifat yang baik dari minyak kelapa dan sawit ini akan dimanfaatkan sebagai zat aditif pada minyak pelumas SAE 40. Pengujian dilakukan terhadap sifat fisik dan tribology dengan penambahan 5%, 10%, 15%, dan 20% berat dari minyak kelapa dan sawit ke dalam minyak pelumas SAE 40. Pengujian sifat fisik terdiri dari pengukuran viskositas pada temperatur 400C dan 1000C dan viskositas index. Pengujian sifat tribologi untuk menentukan keausan dan koefisien gesek berdasarkan ASTM G99 dengan menggunakan alat uji pin on disk. Dari hasil pengujian diperoleh bahwa dengan penambahan minyak kelapa dan sawit kedalam minyak pelumas SAE 40 terjadi peningkatan viskositas indeks. Peningkatan viskositas indeks sebanyak  17% dengan penambahan 20% minyak sawit. Terjadi perubahan sifat tribologi dengan penambahan minyak sawit, berupa penurunan keausan dan nilai koefisien gesek dibandingkan dengan penambahan minyak kelapa. This study aims to determine the effect of coconut and palm oils as additives to physical and tribological properties of SAE 40 lubricating oil . Vegetable oils, such as; coconut oil and palm oil, have high viscosity index and good lubrication properties, especially in boundary lubrication compared to mineral oil. This is due to vegetable oil having fatty acids that are not owned by mineral oil. The advantages of coconut oil and palm oil are environmentally friendly properties because they are biodegradable and renewable. In this study, the good properties of coconut and palm oils will be used as additives in SAE 40 lubricating oil. Tests are carried out on the physical and tribological properties with the addition of 5%, 10%, 15%, and 20% by weight of coconut and palm oils into SAE 40 lubricating oil. Physical properties testing consists of measuring viscosity at temperatures of 400C and 1000C and viscosity index. The tribological test is to determine wear and coefficient of friction based on ASTM G99 using a pin on disc test equipment. From the test results,  it was found that coconut and palm oils as additives into SAE 40 lubricating oil could increase in viscosity index. The increase of  the viscosity index was 17% by adding 20% of palm oil. There was a change of tribological properties in the form of decreasing on the wear and the coefficient of friction with the addition of palm oil compare to addition of coconut oil.


Author(s):  
Mohammad Mehdi Kasaei ◽  
Marta C Oliveira

This work presents a new understanding on the deformation mechanics involved in the Nakajima test, which is commonly used to determine the forming limit curve of sheet metals, and is focused on the interaction between the friction conditions and the deformation behaviour of a dual phase steel. The methodology is based on the finite element analysis of the Nakajima test, considering different values of the classic Coulomb friction coefficient, including a pressure-dependent model. The validity of the finite element model is examined through a comparison with experimental data. The results show that friction affects the location and strain path of the necking point by changing the strain rate distribution in the specimen. The strain localization alters the contact status from slip to stick at a portion of the contact area from the pole to the necking zone. This leads to the sharp increase of the strain rate at the necking point, as the punch rises further. The influence of the pressure-dependent friction coefficient on the deformation behaviour is very small, due to the uniform distribution of the contact pressure in the Nakajima test. Moreover, the low contact pressure range attained cannot properly replicate real contact condition in sheet metal forming processes of advanced high strength steels.


2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu

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.


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