scholarly journals Development of Highly Hydrogenated DLC Coatings for Solid Lubricant Applications in Space

2005 ◽  
Author(s):  
A. Vanhulsel ◽  
R. Jacobs ◽  
K. Van Acker ◽  
E. Roberts ◽  
F. Velasco ◽  
...  
Keyword(s):  
Wear Rate ◽  
Friction And Wear ◽  
Applied Load ◽  
Solid Lubricant ◽  
Solid Lubricants ◽  
Ambient Atmosphere ◽  
Test Environment ◽  
Load Range ◽  
Dlc Coatings ◽  
Aisi 52100 Steel

The development of advanced solid lubricants is of considerable importance to space tribology. The most common solid lubricant coatings today are based on MoS2, lead or PTFE. However, none of these coatings can simultaneously fulfill all specifications, with regard to friction and wear, under ambient atmosphere and in vacuum. Consequently research is currently being aimed at further improvements in advanced solid lubricant coatings. One approach is to optimize Diamond Like Carbon (DLC) coatings to meet the specifications. In this study, the feasibility of highly hydrogenated DLC coatings (∼ 50 at% hydrogen) for solid lubricant applications is assessed. The coatings were deposited on AISI 52100 steel substrates and tested in ball-on-disc tribometers in air, vacuum and dry nitrogen environments. It was found that the test environment has the most decisive effect on both friction and wear rate, while these parameters are only slightly affected by varying the applied load under a given atmosphere. It was concluded that highly hydrogenated DLC coatings are capable of yielding ultra-low friction values in vacuum (μ = 0.008). The average friction coefficient range obtained in humid air, dry nitrogen and vacuum for the range of applied loads were respectively 0.22 to 0.27, 0.02 to 0.03, and 0.007 to 0.013. Coating lifetime was over 100 000 cycles for the entire load range tested in air and nitrogen, but was affected by the applied load as far as tests in vacuum are considered. The specific wear rate was lower than 1×10–5 mm3 N-1 m-1 under all test conditions, which was considered favourable.

Effects of Some Solid Lubricants Suspended in Oil Toward Controlling the Wear Performance of a Cast Iron

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
B. K. Prasad ◽  
S. Rathod ◽  
M. S. Yadav ◽  
O. P. Modi
Keyword(s):  
Cast Iron ◽  
Wear Rate ◽  
Solid Lubricant ◽  
Frictional Heating ◽  
Applied Pressure ◽  
Solid Lubricants ◽  
Specific Response ◽  
Test Environment ◽  
Wear Performance ◽  
Wear Response

The present investigation deals with the examination of the sliding wear response of a gray cast iron in oil lubricated condition over a range of applied pressure. The composition of the oil lubricant was changed by adding 5.26 wt % solid lubricant particles. The solid lubricants used were graphite, talc, MoS2, and lead. The observed wear response of the samples has been substantiated through the characteristics of wear surfaces, subsurface regions, and debris particles and discussed in terms of specific response of different microconstituents, such as ferrite, pearlite, and graphite present therein. Operating wear mechanisms were assessed through the observed features of wear surfaces, subsurface regions, and debris. The wear rate increased with applied pressure. The slope of the wear rate versus pressure plots was low up to a critical pressure. This was followed by a sudden rise in the slope at higher pressures irrespective of the test environment. The frictional heating was affected by pressure in a manner practically identical to that of the wear rate. The presence of graphite, MoS2, and lead in the oil led to a substantial decrease in the wear rate and severity of frictional heating. The oil plus lead lubricant mixture was observed to offer best results in terms of reduced wear rate and lower frictional heating. This was followed by the ones containing graphite and MoS2 while talc caused the wear performance of the samples to deteriorate over that of the bare oil. However, the severity of frictional heating decreased in general in the oil containing solid lubricant particles. Seizure brought about high frictional heating and wear rate.

Friction and Wear Behaviors of Solid Lubricants/Polyimide Composites in Liquid Mediums

2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Alkaline Solution ◽  
Dry Friction ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Polyimide Composites ◽  
Inorganic Fillers ◽  
Ptfe Composites

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.

Tribological and Corrosion Behavior of HVOF Sprayed Cr3C2-NiCr with Nickel Cladded Graphite and Hexagonal Boron Nitride

2021 ◽  
Author(s):  
M. Oechsner ◽  
T. Engler ◽  
H. Scheerer ◽  
Y. Joung ◽  
K. Bobzin ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Friction And Wear ◽  
Room Temperature ◽  
Solid Lubricant ◽  
Hexagonal Boron Nitride ◽  
Solid Lubricants ◽  
Wear Behaviour ◽  
Wear Volume ◽  
Coating Microstructure ◽  
Sprayed Coatings

Abstract High-velocity oxyfuel (HVOF) sprayed coatings of Cr3C2-NiCr containing solid lubricants such as nickel cladded graphite and hexagonal boron nitride were successfully developed and characterised with the aim of optimizing their friction and wear behaviour. HVOF technology was used for the integration of solid lubricants to achieve strong cohesion between particles while minimizing thermal decomposition. Coating microstructure and composition were measured and correlated to the results of tribological and corrosion tests. The integration of the solid lubricant greatly reduced friction and wear volume at room temperature, but the lubricating effect was highly dependent on atmosphere and temperature. Cr3C2-NiCr with hBN, however, tends to exhibit more stable wear resistance over a wider temperature range and can be used at temperatures beyond 450 °C.

Tribological Behavior of Ni-Based Self-Lubricating Composites at Elevated Temperatures

2015 ◽  
pp. 72-106
Author(s):  
Jianliang Li ◽  
Dangsheng Xiong ◽  
Yongkun Qin ◽  
Rajnesh Tyagi
Keyword(s):  
High Temperature ◽  
Friction And Wear ◽  
Solid Lubricant ◽  
Elevated Temperatures ◽  
Wear Behavior ◽  
Composite Coatings ◽  
Solid Lubricants ◽  
Friction And Wear Behavior ◽  
Nickel Base ◽  
Self Lubricating Composites

This chapter illustrates the effect of the addition of solid lubricants on the high temperature friction and wear behavior of Ni-based composites. Ni-based composites containing solid lubricant particles both in nano and micrometer range have been fabricated through powder metallurgy route. In order to explore the possible synergetic action of a combination of low and high temperature solid lubricant, nano or micro powders of two or more solid lubricants were added in the composites. This chapter introduces the fabrication of the Ni-based self-lubricating composites containing graphite and/or MoS2, Ag and/or rare earth, Ag and/or hBN as solid lubricants and their friction and wear behavior at room and elevated temperatures. The chapter also includes information on some lubricating composite coatings such as electro-deposited nickel-base coating containing graphite, MoS2, or BN and graphene and their tribological characteristics.

Application of WS2 in Solid Lubricant Coating for Metal

2013 ◽  
Vol 652-654 ◽  
pp. 1904-1907 ◽  
Author(s):  
Suo Xia Hou ◽  
Hui Gao ◽  
Xiao Ming Jia
Keyword(s):  
Friction And Wear ◽  
Solid Lubricant ◽  
Solid Lubricants ◽  
Feasibility Analysis ◽  
Solid Lubrication ◽  
Wear Testing ◽  
Metallic Materials ◽  
Solid Lubricant Coating ◽  
Wide Range ◽  
Performance Research

WS2has excellent tribological properties; it is emerging of lubricating materials. MoS2is commonly used solid lubricants and wide range of applications, but its poor heat resistance. WS2can well make up for the inadequate performance of the MoS2, but uses it as a solid lubricant in performance research on metallic materials. By friction and wear testing, the paper gets feasibility analysis of the application that WS2instead of MoS2in the field of solid lubrication, while exploring the synergies between them, laying the foundations for the manufacture of new types of composite lubrication coatings.

Transfer Lubrication for High Temperatures: A Review

1985 ◽  
Vol 107 (4) ◽  
pp. 437-443 ◽  
Author(s):  
J. K. Lancaster
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Friction And Wear ◽  
Solid Lubricant ◽  
Film Formation ◽  
Solid Lubricants ◽  
Research Information ◽  
Auxiliary Component ◽  
Factors Influencing ◽  
Film Failure

Transfer lubrication is defined as lubrication provided by the continuous transfer of solid lubricant to sliding/rolling interfaces. The lubricant may either be incorporated within a self-lubricating composite or supplied from an auxiliary component. Both routes require similar research information on the factors influencing film formation, friction and wear, and film failure. This paper reviews what is known about these aspects for solid lubricants appropriate to high temperature applications (≥300°C). Areas are identified in which further research is needed.

scholarly journals Friction and Wear Mechanisms of Cu/ta-C Coatings Under PAO-4 and PAO-4 with MoDTC Lubrication

2020 ◽  
Vol 01 (04) ◽  
pp. 183-187
Author(s):  
Decelyne Elly Binjua ◽  
Seock-Sam Kim ◽  
Young-Jun Jang ◽  
Jong-Kuk Kim
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Friction And Wear ◽  
Vacuum Arc ◽  
Dlc Coatings ◽  
Base Oil ◽  
Tetrahedral Amorphous Carbon ◽  
Friction And Wear Mechanisms ◽  
Alpha Olefin ◽  
Filtered Cathodic Vacuum Arc

The tribological behavior of various types of DLC coatings in formulated and non-formulated lubricants are needed for proper usage of these coatings. In this research, the friction and wear mechanism of four different DLC coatings in poly-alpha-olefin type 4 (PAO-4) with and without MoDTC were investigated using ball-on-disc tribometer. One ta-C (tetrahedral amorphous carbon) and three Cu/ta-C (copper doped ta-C) with different sputter power of 50 W, 150 W, and 200 W coatings were deposited on silicon wafers by using FCVA (filtered cathodic vacuum arc) technique for this research. The results indicate that ta-C coating on silicon wafer has the lowest average friction coefficient (CoF) and better wear resistance than Cu/ta-C coating when lubricated under PAO-4 oil with MoDTC. Cu/ta-C with sputter powers of 150 W and 200 W exhibited the highest average friction coefficient under PAO-4 oil with MoDTC. Meanwhile, the average CoF for all samples were similar under PAO-4 base oil. In terms of wear, ta-C coating showed the highest wear rate under PAO-4 base oil then followed by Cu/ta-C with sputter power of 50 W. Nonetheless, Cu/ta-C with sputter powers of 150 W and 200 W exhibited significantly low wear rate under PAO-4 base oil compared to PAO-4 oil with MoDTC.

Preparation of PAI Composite Coatings and its Tribological Behaviors

2014 ◽  
Vol 941-944 ◽  
pp. 1612-1615
Author(s):  
Rui Min Sun ◽  
Hui Zhao ◽  
Yong Heng Zhou
Keyword(s):  
Thermal Properties ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Heat Resistance ◽  
Friction And Wear ◽  
Applied Load ◽  
Rate Increase ◽  
Composite Coatings ◽  
Ptfe Composite ◽  
Best Value

PAI/SiC-and PAI/SiC/PTFE-composite coatings were prepared, which were deposited on Al substrates using spraying technology to improve their surfaces performance. Friction and wear of PAI composite coatings were evaluated on a ball-on-block wear tester, and thermal properties were investigated by TG. It is found that, the friction coefficient and wear rate of PAI coatings reaches the best value when the content of SiC and PTFE is 10 wt % and 0.8wt% respectively, and the friction coefficient of the composites coatings decrease but the wear rate increase with increasing applied load; TG curves shows that the PAI composite coatings have excellent heat resistance. Furthermore, the surface of PAI coatings is perfect without bubbling, desquamating and cracking when it is heated for 2 hour at 250◦C in turn three cycles.

Comparative Study of Friction and Wear Behavior of Diamond-Like Carbon Coating under Various Lubricants

2011 ◽  
Vol 189-193 ◽  
pp. 1288-1291
Author(s):  
Li Ning Wu ◽  
Xin Feng ◽  
Yan Qiu Xia ◽  
Jun Ying Hao
Keyword(s):  
Friction And Wear ◽  
Silicone Oil ◽  
Wear Behavior ◽  
Wear Properties ◽  
Dlc Coatings ◽  
Original Surface ◽  
Aisi 52100 ◽  
Aisi 52100 Steel ◽  
Friction And Wear Properties ◽  
Lubrication Conditions

The friction and wear properties of AISI 52100 steel and DLC coatings were evaluated while being lubricated with silicone oil, PAO and PAG lubricants by using a reciprocating ball-on-disk sliding UMT tester. The morphologies of original surface and worn surfaces for the DLC and Ti doped DLC coatings were observed by using a scanning electron microscope. The results show that the DLC coatings have better tribological properties than AISI 52100 steel under silicone oil, PAO and PAG lubrication conditions. In addition, the DLC coatings have much better wear resistance than the AISI 52100 steel.

scholarly journals Wear Life of Bonded MoS2 Film Lubricant

2021 ◽  
Author(s):  
Naofumi Hiraoka
Keyword(s):  
Fatigue Life ◽  
Wear Rate ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Careful Consideration ◽  
Specific Wear Rate ◽  
Wear Life ◽  
Mos2 Film ◽  
Pre Treatment ◽  
Lubrication Properties

Bonded MoS2 film lubricants are widely used in industry as solid lubricants. It has excellent lubrication properties, but it also has characteristics that require careful consideration. As is well known, its friction and wear are greatly affected by the environmental atmosphere and its wear life depends on the pre-treatment of the substrate. It was found that in many cases the wear life could not be correctly estimated by a specific wear rate and could be explained by the fatigue life, especially under high loading conditions. The atmosphere dependent wear life can also be explained by the fatigue life.

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