Preparation of Warm Compacted NbC Reinforced Iron-Based Composite and Its Tribological Behavior

2007 ◽  
Vol 534-536 ◽  
pp. 913-916
Author(s):  
Zhi Yu Xiao ◽  
Tungwai Leo Ngai ◽  
Li Pin Wen ◽  
Yuan Yuan Li

A 15 wt.% NbC particulate reinforced iron-based composite was prepared by using warm compaction PM technique. It possesses a high relative density of 98%, a tensile strength of 515 MPa, a hardness of HRC 58 and a remarkable tribological behavior. Warm compaction was used because it can provide compacts with high green density and also increase the formability of the mixed powder. Furthermore, it can provide green strength that is strong enough to handle compacts before sintering. Block on ring tribotester was employed to study the compact’s friction and wear behavior using GCr15 steel as counterpart. A load of 980 N was used. The friction coefficient was 0.085 when the number 20 engine oil as lubricant was used. The results showed that the sintered composite has excellent wear resistivity. This material was then applied in the valve-guide cup of a combustion engine and subject to 500 hour bench test. The cup showed good performance for this test and did not shown any severe wear on the working surface after the test was completed. Therefore, it is a suitable material for parts that are exposed to severe wear condition.

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 386
Author(s):  
Hakan Kaleli ◽  
Selman Demirtaş ◽  
Veli Uysal ◽  
Ioannis Karnis ◽  
Minas M. Stylianakis ◽  
...  

We investigated the tribological behavior of commercialized, fully synthetic engine oil upon the incorporation of reduced graphene oxide in seven different concentrations between 0.01 and 0.2 wt %. Stability of the prepared samples was assessed by turbidimetry and dynamic light scattering measurements, and their tribological properties through a reciprocating tribometer, using a steel ball on special cut steel blocks. The addition of 0.02 wt % of reduced graphene oxide led to an improvement of the tribological behavior compared to the pristine engine oil, by significantly lowering the friction coefficient by 5% in the boundary lubrication regime. Both the surfaces and the reduced graphene oxide additive were thoroughly characterized by microscopic and optical spectroscopy techniques. We also verified that a protective layer was formed between the worn surfaces, due to the presence of reduced graphene oxide. Carbon accumulation and various additive elements such as Ca, Zn, S and P were detected on the rubbing surfaces of both the ball and the block through energy-dispersive X-ray spectroscopy. Finally, it was shown that the wear scar diameter on the surface of the steel ball was lower by 3%, upon testing the engine oil sample containing reduced graphene oxide at concentration 0.02 wt %, compared to the control sample.


2019 ◽  
Vol 131 ◽  
pp. 605-619 ◽  
Author(s):  
Gayatri Paul ◽  
Subhasis Shit ◽  
Harish Hirani ◽  
Tapas Kuila ◽  
N.C. Murmu

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Peng Zhang ◽  
Kwang-Hee Lee ◽  
Chul-Hee Lee

A magnetorheological fluid (MRF) is one of many smart materials that can be changed their rheological properties. The stiffness and damping characteristics of MRF can be changed when a magnetic field is applied. This technology has been successfully employed in various low and high volume applications, such as dampers, clutches, and active bearings, which are already in the market or are approaching production. As a result, the sealing performance of MRF has become increasingly important. In this study, the wear properties of seals with MRFs were evaluated by a rotary-type lip seal wear tester. The test was performed with and without a magnetic field. The leakage time was monitored during the tests in typical engine oil conditions. The results showed that the wear resistance of the seal with MRF was decreased under the magnetic field.


2019 ◽  
Vol 26 (01) ◽  
pp. 157-162
Author(s):  
Davaasuren G ◽  
Gantulga G

It is vitally important for vehicle users that are to study the operating regime that may negative effect to the operation of the engine, to reduce its effect, to maintain the engine's reliability in accordance with the specific operating conditions. Quality of lubrication is one of the main factors that are improving of reliability and operational efficiency for any machinery their spare parts. So this paper presents to optimize of oil change intervals and to determine of wear rating of spare parts by content of metal particles in the internal combustion engine used oil. Дотоод шаталтат хөдөлгүүрийн тос солих хугацааг оновчлох нь Хураангуй:  Машин ашиглагчдын хувьд тухайн хөдөлгүүрийн ажиллагаанд сөрөг нөлөө үзүүлэх  ашиглалтын горимыг судалж, түүний хор нөлөөг багасгах болон ашиглалтын өвөрмөц  нөхцөлд тохируулан хөдөлгүүрийн найдварт ажиллагааг ханган зөв, ашигтай ажиллуулах  чадвартай байх нь асар их ач холбогдолтой юм. Аливаа машин техник , тэдгээрийн агрегат,  зангилаа эд ангийн удаан эдлэхүй, найдвартай ажиллагааг хангах, ашиглалтын үр ашгийг  дээшлүүлэх гол хүчин зүйлүүдийн нэг нь тосолгооны чанар байдаг учраас дотоод шаталтат  хөдөлгүүрийн ашигласан тосон дахь металлын агууламжыг илрүүлж, эд ангийн элэгдлийн  явцыг тодорхойлон, тос солих хугацааг оновчлох асуудлыг судалгааны хүрээнд авч үзлээ.  Түлхүүр үг: Хөдөлгүүрийн ашигласан тосны шинжилгээ, металл хольц, тосны бохирдол,  тортог, элэгдлийн элементийн хязгаар 


2019 ◽  
Vol 26 (07) ◽  
pp. 1850217 ◽  
Author(s):  
O. ÇOMAKLI ◽  
A. F. YETIM ◽  
B. KARACA ◽  
A. ÇELIK

The 31CrMoV9 steels were plasma nitrided under different gas mixture ratios to investigate an influence of nitrogen amount on wear behavior. The structure, mechanical and tribological behavior of untreated and nitrided 31CrMoV9 steels were analyzed with X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), microhardness device, 3D profilometer and pin-on-disk wear tester. The analysis outcomes displayed that the compound layer consists of nitride phases (Fe2N, Fe3N, Fe4N and CrN). Additionally, the thickness of the compound layers, surface hardness and roughness increased with increasing nitrogen amount in the gas mixture. The highest friction coefficient value was obtained at nitrogen amount of 50%, but the lowest value was seen at nitrogen amount of 6%. It was observed that wear resistance of 31CrMoV9 steel improved after plasma nitriding, and the best wear resistance was also obtained from plasma nitrided sample at the gas mixture of 94% H[Formula: see text]% N2.


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.


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