Evaluation of Sulfides as Solid Lubricant: Lubricity of Compounded Sulfides

2021 ◽  
Vol 901 ◽  
pp. 164-169
Author(s):  
Tomohiro Sato ◽  
Shuhei Ishikawa ◽  
Kenichi Saitoh ◽  
Masanori Takuma ◽  
Yoshimasa Takahashi
Keyword(s):  
Powder Metallurgy ◽  
Solid Lubricant ◽  
Cylindrical Specimen ◽  
Specimen Surface ◽  
Friction Test ◽  
Base Oil

Sulfide was used as solid lubricant, and MoS2 was popular. It was used industry as powder shape. Sulfur as oil additive; ZDDP, MoTDC were also well known. These composites make tribofilm which prevent seizure, scoring and some tribological troubles. In this paper, sulfides were synthesized by powder metallurgy technics. In addition, these sulfides were mixed with bronze powders and sintered as cylindrical specimen. As a result of the friction test in the lubricated condition, tribofilm were covered with specimen surface. By XPS observation, sulfides and oxides were detected on the specimen surface. In the test, additive was not contained in the lubricant because PAO as base oil was adapted. However, sulfide in the specimen affect the making the tribofilm, especially when bornite (Cu5FeS4) was used.

Micro-Pore Structure and Mechanical Properties of High Temperature Self-Lubricating Biomimetic TiC/FeCrWMoV Cermets

2007 ◽  
Vol 546-549 ◽  
pp. 2273-2278 ◽  
Author(s):  
Yan Jun Wang ◽  
Zuo Min Liu
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Pore Structure ◽  
Network Structure ◽  
Sweat Gland ◽  
Solid Lubricant ◽  
Rayleigh Distribution

A new cermet sinter with sweat-gland micro-pore structure has been developed by powder metallurgy technology in vacuum. The effects of the pore-forming materials on micro-pore structure and Y2O3 additions as well mechanical properties of TiC/FeCrWMoV cermets were investigated. Some typical sweat-gland micro-pores were formed while compound additives TiH2 and CaCO3 adding into the sinter matrix. The porosity of the cermet sinters changes from 20% to 28% with the compound additives from 6% to 8%, and the micro-pores of sinters exist a regularized and interpenetrated network structure just like human’s sweat-gland one and obeying to Rayleigh Distribution. As such the sinters could be easily infiltrated with high-temperature solid lubricant. For improving the property of the ceramet sinter, the elements Y2O3 of 0.6～0.8% (vol. fraction ) was also added into the sinter matrix and its effect on the sinter has been also discussed .

Superlow Friction of WS2 Coatings in Ultrahigh Vacuum at Low Temperature

2005 ◽  
Author(s):  
Masanori Iwaki ◽  
Thierry Le Mogne ◽  
Julien Fontaine ◽  
Jean-Michel Martin ◽  
Shuichiro Watanabe ◽  
...  
Keyword(s):  
Low Temperature ◽  
Lamellar Structure ◽  
Solid Lubricant ◽  
Ultrahigh Vacuum ◽  
Tribological Performance ◽  
Silicon Substrates ◽  
Friction Test ◽  
Aisi 52100 ◽  
Steel Aisi ◽  
Pin On Disk

Today molybdenum disulfide (MoS2) is the most commonly used solid lubricant for vacuum applications. Its good tribological performance is considered to be due to its lamellar structure. Coefficient of friction in the millirange (so-called “superlow friction” or “superlubricity”) has already been observed in ultrahigh vacuum at ambient temperaturure for pure and stoichiometric MoS2 coatings. On the other hand, tungsten disulfide (WS2) is also a solid lubricant which has a lamellar structure and works as well as MoS2 in vacuum. However, it is not widely used nor well studied due to its high cost, and until today there is no report of the achievement of the superlow friction in vacuum. In the present work, we report the superlow friction of WS2 coatings obtained in ultrahigh vacuum and at low temperature. Pin-on-disk reciprocating friction test for RF sputtered WS2 coatings on silicon substrates mated against counterpart steel (AISI 52100) pins were conducted in ultrahigh vacuum (3×10−7 Pa) at temperatures ranging from −130 to +200°C. The origin of this superlow friction was discussed.

Tribological Properties of Cu Based Friction Composites with In Situ Synthesized TiC Filler

2010 ◽  
Vol 160-162 ◽  
pp. 35-47 ◽  
Author(s):  
Bai Ming Chen ◽  
Zheng Yu Zhang ◽  
Ming Xu Wang ◽  
Guo Cai Han ◽  
Liang An
Keyword(s):  
Powder Metallurgy ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Solid Lubricant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wear Rates ◽  
Ti Content

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.

Moringa oil with pristine and fluorinated carbon nanofibers as additives for lubrication

2021 ◽  
pp. 1-26
Author(s):  
Nadiege Nomede-Martyr ◽  
Yves Bercion ◽  
Bilas Philippe ◽  
Marc Dubois ◽  
Henry Joseph ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Ambient Temperature ◽  
Carbon Nanofibers ◽  
Solid Lubricant ◽  
Solid Lubricant Additives ◽  
Adsorption Effect ◽  
Base Oil ◽  
Antiwear Properties ◽  
Fluorinated Carbon ◽  
Moringa Oil

Abstract This paper focuses on the influence of local moringa oil on the performances of lubricants formed from blend of dodecane and pristine or fluorinated carbon nanofibers at ambient temperature. The friction experiments have been evaluated using a reciprocating ball on plane tribometer. Moringa oil is designed to be used as a bio-additives in lubricant formulations. First, the addition of small amounts of moringa oil in dodecance allowed a reduction about 50% of the base oil friction performances. In a second part, a comparative study investigates the friction properties of their blends with pristine carbon nanofibers (CNFs) and fluorinated ones (CF0.85) which are intended to be used as solid lubricant additives. An adsorption effect of fatty acid molecules is showed with CNFs particles unlike CF0.85. Whatever was the percentage of moringa oil added, the more promising results were obtained with CF0.85. Physicochemical characterizations of the tribofilms evidence the good antiwear properties of the lubricants.

The Effect of Selected Grease Components on the Wear Behavior of Grease-Lubricated Gears

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Hansjörg Schultheiss ◽  
Thomas Tobie ◽  
Karsten Stahl
Keyword(s):  
Solid Lubricant ◽  
Wear Behavior ◽  
Solid Lubricants ◽  
Oil Viscosity ◽  
Base Oil ◽  
Additive Type ◽  
Expected Performance ◽  
Lubrication Conditions ◽  
Oil Type ◽  
Selection Of

For gears that are operated at slow speeds, wear is often the failure mode that limits gear lifetime. Gears running at slow speeds are often lubricated with grease. The composition of the grease has a significant effect not only on gear lifetime but also on lubrication costs. Therefore, the selection of a suitable grease for a given gear application requires a good knowledge of its expected performance in regard to wear. In order to better understand the wear behavior of gears lubricated with grease, an understanding of the influence that different grease components, e.g., base oil type and viscosity, thickener type, additive type, and solid lubricants, have on gear wear behavior is important. In this paper, systematic investigations on the influence of different grease components on the wear behavior of slow running, case carburized gears were conducted using the FZG back-to-back gear test rig. The emphasis of the experimental work presented herein lies on the effect that the base oil viscosity and type, additive type, type of soap thickener, as well as the type and concentration of solid lubricants have on the gear wear behavior at low pitch line velocities. The investigations showed that the base oil type and viscosity only have a slight effect on gear wear behavior under boundary lubrication conditions. However, the thickener type and especially the additive type as well as the solid lubricant type significantly affect the wear behavior of gears running at slow speeds and lubricated with grease.

Surface Finish in Hard Machining by PVD-Coated End-Mills Using Solid Lubricant

2008 ◽  
Author(s):  
Shantisagar Biradar ◽  
Geeta Lathkar ◽  
S. K. Basu
Keyword(s):  
Surface Roughness ◽  
Solid Lubricant ◽  
Hard Machining ◽  
Dry Machining ◽  
End Mill ◽  
Base Oil ◽  
Die Steel ◽  
End Mills ◽  
Mill Cutter ◽  
Relationship Of

The paper deals with machining of High C–High Cr die steel with Ti N, TiAlN Coated end mill cutter, using solid lubricant and obtaining a generalised relationship of surface roughness dependent on input parameters, based on response surface methodology. The hardness ratio of the tool and the workpiece, as one of the important parameters, having significant influence under near-dry machining condition, was studied under minimum quantity of oil using solid-lubricant (MOS2) mixed with base oil SAE-20 in different proportion.

Lubricant and tribological properties of zinc compound in palm oil

2019 ◽  
Vol 71 (10) ◽  
pp. 1177-1185 ◽  
Author(s):  
Muhammad Aizat Md Alias ◽  
Mohd Fadzli Bin Abdollah ◽  
Hilmi Amiruddin
Keyword(s):  
Tribological Properties ◽  
Palm Oil ◽  
Friction And Wear ◽  
Viscosity Index ◽  
Acid Number ◽  
Friction Test ◽  
Content Type ◽  
Base Oil ◽  
Digital Microscope ◽  
Zinc Compound

Purpose This paper aims to investigate the composition of lubricant and the enhancement of tribological properties using palm oil as a parent base oil mixed with an organo-zinc compound as an additive. Design/methodology/approach The oil samples were prepared by mixing organo-zinc compound additive, zinc dioctyldithiophosphate (ZnDoDP) and zinc diamyldithiocarbamate (ZDDC), at 0 to 3.0 Wt.% concentrations with commercialised palm oil which were then homogenised using an ultrasonic homogeniser. The oil samples were then tested for their oil properties through elemental analysis, their viscosity index, flashpoint and acid number. Next, the friction test was performed using a four-ball tribometer, and the worn surfaces of the balls were observed using a digital microscope. Findings The results showed that commercialised palm oil with 2.0 Wt.% of ZnDoDP had excellent characteristics regarding its lubricant properties, such as its viscosity index, coefficient of friction and wear compared to commercialised palm oil with the addition of 2.0 Wt.% of ZDDC. Originality/value To the best of the authors’ knowledge, this is the first study to compare the effect of the concentration of ZnDoDP and ZDDC on the lubricant and triological properties of vegetable oil (palm).

An Attack on the Contamination Problem in the Electron Microscope

1967 ◽  
Vol 25 ◽  
pp. 368-368
Author(s):  
J. J. Kelsch ◽  
A. Holtz
Keyword(s):  
Electron Microscope ◽  
Pressure Gradient ◽  
Ionization Potential ◽  
Simple Solution ◽  
Specimen Surface ◽  
Contamination Rate ◽  
Local Pressure ◽  
High Ionization ◽  
Hydrocarbon Molecules ◽  
Contamination Problem

A simple solution to the serious problem of specimen contamination in the electron microscope is presented. This is accomplished by the introduction of clean helium into the vacuum exactly at the specimen position. The local pressure gradient thus established inhibits the migration of hydrocarbon molecules to the specimen surface. The high ionization potential of He permits the use of relatively large volumes of the gas, without interfering with gun stability. The contamination rate is reduced on metal samples by a factor of 10.

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