scholarly journals Rheological and tribological approaches as a tool for the development of sustainable lubricating greases based on nano-montmorillonite and castor oil

Friction ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 415-428
Author(s):  
José Enrique Martín-Alfonso ◽  
María José Martín-Alfonso ◽  
Concepción Valencia ◽  
María Teresa Cuberes
Keyword(s):  
Atomic Force Microscopy ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Castor Oil ◽  
Force Microscopy ◽  
Oil Blends ◽  
Atomic Force ◽  
Linear Viscoelastic ◽  
Nanoclay Content ◽  
Petrochemicals Industry

AbstractThis study investigates the development of novel montmorillonite/castor oil blends to formulate sustainable lubricating greases to promote the replacement of petrochemicals industry-derived materials by substances obtained from renewable sources. Specifically, the effect of the thickener concentration on the rheological, chemical, thermal, tribological properties, and atomic force microscopy (AFM) microstructure of these systems were studied. The results showed that the C20A nanoclay content could be used to modulate the viscosity values, the linear viscoelastic functions, and tribological properties of these montmorillonite dispersions. In general, these gel-like dispersions exhibited remarkable lubricant properties; the samples showed values of the friction coefficient and wear scars similar or lower than those obtained with model bentonite grease.

scholarly journals Nanocharacterization of Dental Materials by Atomic Force Microscopy and Their Thermal Degradation Evaluation

2021 ◽  
Vol 6 (1) ◽  
pp. 14
Author(s):  
Marius Pustan ◽  
Corina Birleanu ◽  
Sanda Mirela Pop
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Tribological Properties ◽  
Dental Materials ◽  
Time Duration ◽  
Force Microscopy ◽  
Mechanical And Tribological Properties ◽  
Filling Materials ◽  
Atomic Force ◽  
Restorative Materials

Restorative dental materials must be produced with special characteristics because they are operating in a medium environment with different humidity and temperature. These day-to-day factors play an important role in the lifetime of such dental restorative materials. Resin composites have been by far the most successful in dental applications by meeting several stringent design requirements that are difficult to achieve with homogeneous materials, such as ceramics and metal alloys. The mechanical and tribological properties of direct restorative filling materials are crucial not only to serve and allow similarity to human enamel and dentine, but also to compare composites between them and determine the objective criteria for their selection. The objective of this research is to investigate the mechanical and tribological properties of some commercial restorative materials using the atomic force microscopy technique as a function of the operating temperature. Therefore, restorative materials are expected to replace and perform as natural tooth materials. The demand is so great that most of the time, restorative filling materials replace enamel and dentin, which have very different mechanical properties, namely hardness and elastic modulus. The scope is to estimate the lifetime of such materials starting from their nano-behaviors under nano-wear, nano-friction, nano-mechanical tests. To conclude, nanoindentation is an attractive method for measuring the mechanical behavior of small specimen volumes in dental hard materials. Using this technique, the mechanical and tribological properties of nanocomposite resins were investigated. This technique only evaluates the tribo-mechanical properties of a very shallow surface region of a specimen that may have undergone damage associated with mechanical preparation that is required to achieve a satisfactory flat sample for testing. Experimental study has been carried out with several normal loads and time-duration tests, i.e., representing several steps of severity conditions for materials under investigation.

scholarly journals Tribological Properties of Bronze Containing Micro Sized Sulfide -Application of Atomic Force Microscopy-

2016 ◽  
Vol 11 (2) ◽  
pp. 195-202 ◽  
Author(s):  
Tomohiro Sato ◽  
Yoshimasa Hirai ◽  
Takehisa Fukui ◽  
Hatsuhiko Usami
Keyword(s):  
Atomic Force Microscopy ◽  
Tribological Properties ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Modification of Surface and Tribological Properties of DLC Films by Adding Silver Content

2008 ◽  
Author(s):  
H.-S. Zhang ◽  
J. L. Endrino ◽  
A. Anders
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Tribological Properties ◽  
Silver Content ◽  
Diamond Like Carbon ◽  
Dlc Coatings ◽  
Force Microscopy ◽  
Atomic Force ◽  
Plasma Immersion Ion Implantation ◽  
Scratch Tests

The incorporation of silver into the diamond-like carbon (DLC) coatings has shown excellent potential in various applications; therefore the surface and tribological properties of silver-containing DLC thin films deserve to be investigated. In this study we have deposited silver-containing hydrogenated and hydrogen-free DLC coatings by plasma immersion ion implantation and deposition (PIII-D) methods. Atomic force microscopy (AFM) and nano-scratch tests were used to study the surface and tribological properties. The silver incorporation had only slight effects on hydrogenated DLC coatings. However, the incorporation of silver has significant effect on hydrogen-free DLC of smoothing the surface and increasing the surface energy. Those effects have been illustrated and explained in the context of experimental results.

scholarly journals On the frequency dependence of viscoelastic material characterization with intermittent-contact dynamic atomic force microscopy: avoiding mischaracterization across large frequency ranges

2020 ◽  
Vol 11 ◽  
pp. 1409-1418
Author(s):  
Enrique A López-Guerra ◽  
Santiago D Solares
Keyword(s):  
Atomic Force Microscopy ◽  
Mechanical Response ◽  
Viscoelastic Behavior ◽  
Partial Solution ◽  
Electromagnetic Properties ◽  
Multiple Characteristic ◽  
Force Microscopy ◽  
Atomic Force ◽  
Linear Viscoelastic ◽  
Intermittent Contact

Atomic force microscopy (AFM) is a widely use technique to acquire topographical, mechanical, or electromagnetic properties of surfaces, as well as to induce surface modifications at the micrometer and nanometer scale. Viscoelastic materials, examples of which include many polymers and biological materials, are an important class of systems, the mechanical response of which depends on the rate of application of the stresses imparted by the AFM tip. The mechanical response of these materials thus depends strongly on the frequency at which the characterization is performed, so much so that important aspects of behavior may be missed if one chooses an arbitrary characterization frequency regardless of the materials properties. In this paper we present a linear viscoelastic analysis of intermittent-contact, nearly resonant dynamic AFM characterization of such materials, considering the possibility of multiple characteristic times. We describe some of the intricacies observed in their mechanical response and alert the reader about situations where mischaracterization may occur as a result of probing the material at frequency ranges or with probes that preclude observation of its viscoelastic behavior. While we do not offer a solution to the formidable problem of inverting the frequency-dependent viscoelastic behavior of a material from dynamic AFM observables, we suggest that a partial solution is offered by recently developed quasi-static force–distance characterization techniques, which incorporate viscoelastic models with multiple characteristic times and can help inform dynamic AFM characterization.

Structural, Electrical, and Resistance Force Characteristics of Ga-In-Sn Eutectic Alloys

2015 ◽  
Vol 642 ◽  
pp. 162-167
Author(s):  
Y.F. Shen ◽  
Jeng Haur Horng ◽  
C.C. Wen ◽  
Jau Shiung Fang
Keyword(s):  
Atomic Force Microscopy ◽  
Electrical Resistivity ◽  
Electrical Property ◽  
Friction Coefficient ◽  
Normal Force ◽  
Resistance Force ◽  
Eutectic Alloys ◽  
Force Microscopy ◽  
Atomic Force ◽  
Force Characteristics

This work aims at investigating the electrical property and the friction force of Ga-In-Sn eutectic alloys. The performance of the alloys is increasingly needed on conducting lubricant. Resistance force dependence of normal force was examined by atomic force microscopy, and the results showed that Ga65In21Sn14had the highest friction coefficient of 3.07 and Ga80In13Sn7had a lowest friction coefficient of 1.46. Electrical resistivity of the studied eutectic alloy was from 25.9 to 27.7 μΩcm at 25°C. Accordingly, the electrical resistivity as a function of temperature revealed a temperature coefficient of ranging from 12.67 ✕10-3°C-1to 4.94 ✕10-3°C-1. High thermally stable and wetting capability make the studied Ga-In-Sn alloys can potentially be used as a conducting lubricant.

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