scholarly journals Tribological Evaluation of Lead-Free MoS2-Based Solid Film Lubricants as Environmentally Friendly Replacements for Aerospace Applications

Lubricants ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Parikshit Tonge ◽  
Amit Roy ◽  
Payank Patel ◽  
Charles J. Beall ◽  
Pantcho Stoyanov
Keyword(s):  
Friction And Wear ◽  
Tribological Behavior ◽  
Wear Test ◽  
Solid Lubricants ◽  
Ex Situ ◽  
Sustainable Environment ◽  
Aerospace Applications ◽  
Solid Film ◽  
Parallel Direction ◽  
Green Lubricant

Solid lubricants, such as MoS2 have been widely used in the aerospace industry with the primary purpose of reducing the friction and wear of tribological interfaces. MoS2 based solid film lubricants are generally doped with other compounds, which can help overcome some of their limitations related to environmental conditions. For instance, compounds like Sb2O3 and Pb have been traditionally used to improve the endurance life of these lubricants. However, with the recent zest in transferring to eco-friendly lubricants, there is a strong push to eliminate Pb based compounds. The main purpose of this work is to better understand the influence of Pb based compounds on the tribological behavior of MoS2 based solid film lubricants as well as to critically evaluate the performance of Pb free lubrication strategies. More specifically, the baseline ‘non-green’ lubricant was doped with Pb compound and Sb2O3 and the Pb compound in the ‘Green’ alternative lubricant was replaced by more Sb2O3. The wear test was done using a ball-on-disk tribometer for specific loads and for 5000 cycles. Ex-situ analysis was conducted using Scanning Electron Microscope (SEM), Atomic Force Microscopy (AFM), and micro-Raman to capture the interfacial processes of these lubricants at different loads. Overall, the non-green lubricant performed better in terms of the tribological behavior (i.e., lower friction and wear), which was attributed to the formation of a dense MoS2-based tribo-/transfer-film with the basal planes oriented in the parallel direction to the sliding. The finding on the interfacial phenomena provided critical insights into the development of novel green alternatives that may have the ability to replace Pb based compounds in the future for a sustainable environment.

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.

Self-Lubricating and Wear Resistant Epoxy Composites Incorporated With Microencapsulated Wax

2014 ◽  
Vol 81 (7) ◽  
Author(s):  
N. W. Khun ◽  
H. Zhang ◽  
C. Y. Yue ◽  
J. L. Yang
Keyword(s):  
Tribological Properties ◽  
Friction And Wear ◽  
Normal Load ◽  
Wear Test ◽  
Epoxy Composites ◽  
Wear Resistant ◽  
Working Parameters

Self-lubricating and wear resistant epoxy composites were developed via incorporation of wax-containing microcapsules. The effects of microcapsule size and content and working parameters on the tribological properties of epoxy composites were systematically investigated. The incorporation of microcapsules dramatically decreased the friction and wear of the composites from those of the epoxy. The increased microcapsule content or the incorporation of larger microcapsules decreased the friction and wear of the epoxy composites due to the larger amount of released wax lubricant via the rupture of microcapsules during the wear test. The friction of the composites decreased with increased normal load as a result of the promoted wear of the composites and the increased release of the wax lubricant.

Tribological Behavior of Mesophase Carbon Added with Titanium and Copper

2011 ◽  
Vol 80-81 ◽  
pp. 60-63
Author(s):  
Xue Qing Yue ◽  
Hua Wang ◽  
Shu Ying Wang
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Friction Coefficient ◽  
Ball Mill ◽  
Friction And Wear ◽  
Applied Load ◽  
Tribological Behavior ◽  
Metallic Elements ◽  
X Ray Diffraction ◽  
X Ray

Incorporation of metallic elements, titanium and copper, into carbonaceous mesophase (CM) was performed through mechanical alloying in a ball mill apparatus. The structures of the raw CM as well as the Ti/Cu-added CM were characterized by X-ray diffraction. The tribological behavior of the Ti/Cu-added CM used as lubricating additives was investigated by using a high temperature friction and wear tester. The results show that, compared with the raw CM, the Ti/Cu-added CM exhibits a drop in the crystallinity and a transition to the amorphous. The Ti/Cu-added CM used as lubricating additive displays an obvious high temperature anti-friction and wear resistance effect, and the lager the applied load, the lower the friction coefficient and the wear severity.

Short term tribological behavior of ceramic and polyethylene biomaterials for hip prosthesis

2021 ◽  
Vol 63 (5) ◽  
pp. 470-473
Author(s):  
Subramaniam Shankar ◽  
Rajavel Nithyaprakash ◽  
Balasubramaniam Rajasulochana Santhosh
Keyword(s):  
Silicon Nitride ◽  
Friction And Wear ◽  
Hip Prosthesis ◽  
Tribological Behavior ◽  
Ceramic Materials ◽  
Blood Stream ◽  
Wear Characteristics ◽  
Polyether Ether Ketone ◽  
Spherical Ball ◽  
Pin On Disc

Abstract Reduction in wear of artificial bio-implants results in the release of a lesser amount of wear particles into the blood stream. This paper focuses on analyzing the tribological behavior of ceramic and polyethylene bio-materials experimentally. Four different biomaterials namely Zirconia, Silicon Nitride, UHMWPE (ultra high molecular weight polyethylene) and PEEK (polyether ether ketone) are investigated for friction and wear coefficients using a pin on disc (PoD) tribometer. Alumina (Al2O3) is chosen as the disc material. Polyethylene based UHMWPE and PEEK are used as a pin material with the hemispherical end, while, Zirconia and Silicon Nitride ceramic materials are used in the form of spherical ball. 0.9 % NaCl (saline solution) is used as a lubricant medium. Zirconia showed a better reduction in friction and wear coefficient characteristics under lubrication conditions when compared with polyethylene and other ceramic materials. The estimated friction and wear coefficients would be helpful for surgeons and academicians to choose better wear-resistant bio-compatible materials for effectively design hip prosthesis. The present study compared the tribological behaviors of ceramic materials Si3N4 and ZrO2 and polyethylene materials PEEK and UHMWPE with a ceramic counterpart Al2O3 disc. In the lubrication case, ZrO2 showed a better reduction in friction and wear characteristics while in the dry case UHMWPE showed lesser wear characteristics.

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.

Modeling the abrasive wear behavior of in-situ synthesized magnesium RZ5/TiB2 metal matrix composites

2021 ◽  
pp. 095440892110655
Author(s):  
Arabinda Meher ◽  
Manas Mohan Mahapatra ◽  
Priyaranjan Samal ◽  
Pandu R. Vundavilli
Keyword(s):  
Abrasive Wear ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Tribological Behavior ◽  
Wear Behavior ◽  
Wear Test ◽  
Regression Equation ◽  
Matrix Composites ◽  
Worn Surface ◽  
Anova Technique

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.

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.

Material Modifications (Coatings, Treatments, etc.) for Tribological Applications

2021 ◽  
pp. 335-362
Keyword(s):  
Thermal Spray ◽  
Friction And Wear ◽  
Chemical Conversion ◽  
Heat Treating ◽  
Relative Effect ◽  
Solid Film

Abstract This chapter covers coatings and treatments that are used to improve the friction and wear behaviors of materials. It describes modifications that work by hardening contacting surfaces, including heat treating, vacuum coating, thermal spray, and plating, and those that separate or lubricate surfaces, including solid film, chemical conversion, and vacuum coatings, surface oiling and texturing, and lubricating platings. It compares and contrasts methods based on thickness and depth and their relative effect on friction, erosion, and wear.

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