Temperature effect of friction and wear characteristics for solid lubricating graphite

2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540018
Author(s):  
Yeonwook Kim ◽  
Jaehoon Kim

Graphite is one of the effective lubricant additives due to its excellent high-temperature endurance and self-lubricating properties. In this study, wear behavior of graphite used as sealing materials to cut off hot gas is evaluated at room and elevated temperature. Wear occurs on graphite seal due to the friction of driving shaft and graphite. Thus, a reciprocating wear test to evaluate the wear generated for the graphite by means of the relative motion between a shaft material and a graphite seal was carried out. The friction coefficient and specific wear rate for the changes of applied load and sliding speed were compared under different temperature conditions considering the actual operating environment. Through SEM observation of the worn surface, the lubricating film was observed and compared with test conditions.

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 319
Author(s):  
Zhiguo Lu ◽  
Chuanyu Du ◽  
Qingcai Chen ◽  
Tianying Niu ◽  
Na Wang ◽  
...  

The friction and wear characteristics of spike-tooth material (65Mn steel) of Spike-Tooth Harrow in a two-stage peanut harvester were studied in this paper. The friction and wear tests of pin and disc on 65 manganese steel were carried out on the tribometer, then the wear loss and the friction coefficient were studied. The wear loss of the pin was acquired by calculating the mass of the pin before and after the experiment using an electronic balance. According to the actual working environment of peanut spring-finger, four variable parameters are set up: load, speed, soil moisture and soil type. The friction and wear characteristics of pins were studied under different loads, speeds and different soil environments. After wearing, the worn surface of the material was observed by scanning microscope and the wear mechanism was studied. The experimental results show that the wear of the pin increases with the increase of load and decreases with the increase of rotational speed in the same rotation number. Especially in the case of the sandy soil with 20% in moisture, a maximum wear loss of the pin is achieved.


2011 ◽  
Vol 306-307 ◽  
pp. 425-428
Author(s):  
Jing Li ◽  
Xiao Hong Fan ◽  
De Ming Sun

Fe-28Al and Fe-28Al-10Ti alloys were prepared by mechanical alloying and hot pressing. The phases and dry sliding wear behavior were studied. The results show that Fe-28Al bulk materials are mainly characterized by the low ordered B2 Fe3Al structure with some dispersed Al2O3 particles. Fe-28Al-10Ti exhibits more excellent wear resistance than Fe-28Al, especially after long distance sliding wear test. There are obvious differences in wear mechanisms of Fe-28Al and Fe-28Al-10Ti alloys under different testing conditions. Under the load of 100N, there is plastic deformation on the worn surface of Fe-28Al. The main wear performance of Fe-28Al-10Ti is particle abrasion, the characteristics of which are micro cutting and micro furrows, but micro-crack and layer splitting begin to form on the surface of Fe-28Al. Under the load of 200N, serious plastic deformation and work-hardening lead to rapid crack propagation and eventually the fatigue fracture of Fe-28Al. Plastic deformation is the main wear mechanism of Fe-28Al-10Ti under the load of 200N, which are characterized by micro-crack and small splitting from the worn surface.


Author(s):  
Arabinda Meher ◽  
Manas Mohan Mahapatra ◽  
Priyaranjan Samal ◽  
Pandu R. Vundavilli

In the present study, the statistical analysis on tribological behavior of RZ5/TiB2 magnesium-based metal matrix composites is carried out using Taguchi design and analysis of variance (ANOVA) technique. Taguchi analysis using signal-to-noise ratio indicates that the sliding distance and wt.% TiB2 are the most significant factors in evaluating weight loss and coefficient of friction, respectively. The regression equation is formulated utilizing the ANOVA technique to study the output responses based on the input abrasive wear test experimental results. The regression equation is validated through a comprehensive study taking a series of abrasive wear tests and indicates the percentage deviation of regression modeling is in the range of ± 10%. The individual and combined effect of wear parameters on tribological behavior are investigated through the main effect plots and response surface plots. The micrograph of the worn surface of RZ5/TiB2 composites is studied using field emission scanning electron microscope (FESEM), indicating the formation of an oxide layer on the worn surface.


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.


2006 ◽  
Vol 20 (25n27) ◽  
pp. 4407-4412 ◽  
Author(s):  
MIN-SOO SUH ◽  
BUP-MIN KIM ◽  
SEOCK-SAM KIM

Tribological experiments were conducted on a ball-on-disk, unlubricated, with a speed of V ≈ 140 mm/s , V ≈ 70 mm/s , with an applied load between 20 and 100N, and with different combinations of ceramic materials. A wear test was conducted on disk material zirconia with regard to various ceramic ball materials (zirconia, alumina, silicon carbide and silicon nitride). The results show that the properties of the counter materials cause a difference in friction and wear characteristics.


2013 ◽  
Vol 300-301 ◽  
pp. 1254-1258 ◽  
Author(s):  
Xiao Ren Lv ◽  
Xu Yao Huo ◽  
Guang Zu Qu ◽  
Shi Jie Wang

In order to choose the rubber material and improve the service life of Progressing Cavity Pump (PCP ) when exploiting offshore crude oil, it is important to analyze friction and wear behaviour of stator and rotor of PCP in the mixture of crude oil with different water content. The friction and wear test about Nitrile -Butadiene Rubber (NBR) and Fluorine Rubber (FKM) were carried on ring-on-block tester, the wear loss was observed by electron microscope, the wear mechanism was also discussed. The results show that: (1) FKM owns better wearing resistance than NBR in the mixture of crude oil with different water content; (2) when the content of water in the mixture is less than 26%, the frictional coefficient of sample is 0.05, due to the oil film between the friction pairs; (3) when the content of water in the mixture is more than 26%, the frictional coefficient increases to 0.4, because of the water film between the friction pairs.


2009 ◽  
Vol 79-82 ◽  
pp. 2199-2202 ◽  
Author(s):  
Joon Ho Seo ◽  
Jin Yong Kim ◽  
Seung Uk Park ◽  
Hyun Chul Kim ◽  
Byung Chul Na ◽  
...  

The piston pin contact in a typical automotive engine is an example of a highly loaded. Therefore, for piston pin design several aspects are important. Among them are function, cost, NVH, fuel economy, durability, and impact on other design aspects of the engine. Continuously contacting with piston pin, the face of connecting rod, brings about abnormal wear such as unfairwear or earlywear. because the engine get more powered and one requirement for a good fuel economy is to achieve a low level of mechanical friction. In this study, modern low friction coatings and treatment at the piston pin interface aimed to investigate the potential. The profile of coated specimens were observed by non-contact type optical surface measuring system and the friction-wear behaviors of coated specimens were investigated by using piston pin wear tester. Piston pin wear test was performed to analyze the friction and wear behavior. The results showed that the application of low friction coatings and treatment effectively improved tribological performance of the piston pin


2017 ◽  
Vol 30 (2) ◽  
pp. 247-253 ◽  
Author(s):  
Ye Zhu ◽  
Yingshuang Shang ◽  
Haibo Zhang ◽  
Lianjun Ding ◽  
Yunping Zhao ◽  
...  

Poly(ether sulfone) (PES) with high coefficient of friction (COF) and wear rate needs treatment to enhance its tribological property in engineering plastic area. Here, the low surface energy of perfluorocarbon chains terminated poly (ether sulfone) (PES-F) had been used to improve the tribological property of such self-lubricating materials. In this research, the performance enhancement due to the existence of perfluorocarbon group on the material surface was discussed on improvement of anti-friction and wear resistance. On the premise of mechanical strength guarantee, the variation regularity of COF and volume wear rate of PES-F were quantitatively analyzed through the pin-on-disc wear test apparatus, combined with X-ray photoelectron spectroscopy analysis. It was found that PES-F exhibited the best tribological property during the initial phases of friction test, attributing to the highest content of F on the material surface. Observation of PES-F worn surface and wear debris revealed that the COF and wear rate of modified PES were decreased not only due to the effect of perfluorocarbon group but also by the change of worn surface morphology, both of which were the main reasons for anti-friction and anti-wear property enhancement.


Proper lubrication and surface modification are key factors to improve the tribological behavior of interacting sliding surfaces under lubricated conditions. Surface texturing of interacting surfaces has found to be an emerging technique that modifies the surfaces deterministically by producing surface features in the form of surface asperities or grooves with specific shape, size and distribution. The present paper address the impact of positive surface textures (protrusions) and number of positive textures in the sliding direction on friction and wear behavior of parallel sliding contacts. The square shaped positive surface textures are created on the specimen by ink-jet followed by chemical etching process. The sliding experiments are conducted on pin on disc friction and wear test rig by providing different sliding conditions such as plain dry, plain with lubricant and textures with lubricant between the interacting surfaces. The results indicated that the textures with lubricated condition exhibit lower friction and wear compared to other two conditions. Furthermore, it is reported that among the tested samples, the textured sample with number of textures three in sliding direction has shown a prominent effect in reducing friction and wear of parallel sliding contact.


2011 ◽  
Vol 314-316 ◽  
pp. 1083-1086 ◽  
Author(s):  
Jian Ming Yang ◽  
Yi Qiang He ◽  
Hua Qiang Li ◽  
Bin Qiao ◽  
Jin Song Chen

Take electrolytic copper powder and SiC powder as the raw materials, apply powder injection moulding to prepare SiCp/Cu composite, while the test result shows that only Cu and SiC exist in the sintered composite, the SiC particles evenly distribute within the Cu substrate. The friction coefficient and the morphology and elemental composition of the worn composite surface are measured in the fiction and wear test. The result shows that the friction coefficient of composite increase in a more gentle pace with the prolonging of the sliding time; the adhesion and plastic deformation of the worn surface of the composite containing 10 vol.% SiCp is light, and there exists certain abrasive wear; while the worn surface of the composite containing 15 vol.% SiCp show obvious abrasive wear, and there exist dense mechanically mixed layer; in addition to the inherent elements of the composite of Cu, Si and C, the worn surface also contains the elements of Fe and O.


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