scholarly journals A Review on the Study of the Generation of (Nano)particles Aerosols during the Mechanical Solicitation of Materials

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Neeraj Shandilya ◽  
Olivier Le Bihan ◽  
Martin Morgeneyer
Keyword(s):  
Broad Spectrum ◽  
Wear Mechanisms ◽  
Interdisciplinary Studies ◽  
Nano Particles ◽  
Wear Particles ◽  
Potential Health ◽  
Particle Generation ◽  
Modeling Techniques ◽  
Material Sciences ◽  
Stress Application

This paper focuses on presenting the forefront of the interdisciplinary studies conceived towards the generation of the wear particles aerosol when materials are subjected to mechanical stresses. Various wear mechanisms and instrumentation involved during stress application and aerosolization of wear particles, as well as particles characterization, measurement, and modeling techniques are presented through the investigation of a series of contextual works which are emphasized on the identification of these aspects. The review is motivated from the fact that understanding mechanisms involved in wear-induced particle generation, both at nano- and at microscale, is important for many applications that involve surfaces sliding over each other due to various potential health aspects. An attempt has been made to explain how the information based on this broad spectrum of subjects discovered in this contribution can be used and improved in order to produce a more resilient, rational, and versatile knowledge base which has been found lacking in the present literature during its survey. The area of study is highly multidisciplinary since it involves aerosol, particle, and material sciences.

The Influence of Temperature on Failure Development in Steels Under Transition to Seizure

1996 ◽  
Vol 118 (3) ◽  
pp. 527-531 ◽  
Author(s):  
L. Rapoport
Keyword(s):  
Wear Mechanisms ◽  
Skin Effect ◽  
Oxide Films ◽  
Disk Surface ◽  
Wear Particles ◽  
Temperature Model ◽  
Mechanical Instability ◽  
Infinite Body ◽  
Temperature Instability ◽  
Adhesion Interaction

Seizure phenomena in pin-on-disk tests have been studied for “soft” and “hard” steel specimens. Differences in competing and dominant wear mechanisms under steady state friction have been preserved for “soft” and “hard” specimens in the region of transition to seizure or galling. Severe wear was observed for “soft” specimens under all loads tested, while adhesion and splitting off of wear particle conglomerates (microseizure) were identified for “hard” specimens. The contact temperature, calculated in accordance with the temperature model of plastically deformed contact spots (Kuhlmann-Wilsdorf), has appeared to be low for “soft” specimens and not sufficient for adhesion interaction. The effect of oxide films on the friction of “hard” specimens has been estimated in accordance with the temperature model for a coated semi-infinite body (Tian and Kennedy). The insulated oxide films on the surface of “hard” specimens create the “skin effect” and lead, therefore, to raising the temperature up to the temperature of adhesion interaction. Temperature instability of hard surfaces has been demonstrated to result from the “skin effect” and from a disturbance in equilibrium of formation and failure of oxide films. It has been shown that for “soft” specimens the prime cause of transition to seizure was the mechanical interlocking between the wear particles and the soft disk surface combined with mechanical instability, while for “hard” specimens the cause was temperature instability. A more realistic temperature model of the contact has been considered, which takes into account some competing wear mechanisms (oxidational wear, ploughing, delamination) and the effect of wear particles.

A Study of Airborne Wear Particles Generated From a Sliding Contact

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Ulf Olofsson ◽  
Lars Olander ◽  
Anders Jansson
Keyword(s):  
Ultrafine Particles ◽  
Fine Particles ◽  
Urban Environments ◽  
Airborne Particles ◽  
Wear Particles ◽  
Coarse Particles ◽  
Sliding Velocity ◽  
Airborne Particle ◽  
Particle Generation ◽  
Pin On Disk

Recently, much attention has been paid to the influence of airborne particles in the atmosphere on human health. Sliding contacts are a significant source of airborne particles in urban environments. In this study airborne particles generated from a sliding steel-on-steel combination are studied using a pin-on-disk tribometer equipped with airborne-particle counting instrumentation. The instrumentation measured particles in size intervals from 0.01μm to 32μm. The result shows three particle size regimes with distinct number peaks: ultrafine particles with a size distribution peak around 0.08μm, fine particles with a peak around 0.35μm, and coarse particles with a peak around 2 or 4μm. Both the particle generation rate and the wear rate increase with increasing sliding velocity and contact pressure.

scholarly journals Rapid Analyses of Polyetheretherketone Wear Characteristics by Accelerated Wear Testing with Microfabricated Surfaces for Artificial Joint Systems

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Chen-Ying Su ◽  
Chien-Wei Kuo ◽  
Hsu-Wei Fang
Keyword(s):  
Wear Particle ◽  
Wear Testing ◽  
Testing System ◽  
Artificial Joint ◽  
Wear Particles ◽  
Particle Generation ◽  
Biological Responses ◽  
Major Factors ◽  
Joint Arthroplasties

Wear particle-induced biological responses are the major factors resulting in the loosening and then failure of total joint arthroplasties. It is feasible to improve the lubrication and reduce the wear of artificial joint system. Polyetheretherketone (PEEK) is considered as a potential bearing material due to its mechanical characteristics of resistance to fatigue strain. The PEEK wear particles have been indicated to be involved in biological responses in vitro, and further studies regarding the wear phenomena and wear particle generation are needed. In this study, we have established an accelerated wear testing system with microfabricated surfaces. Various contact pressures and lubricants have been utilized in the accelerated wear tests. Our results showed that increasing contact pressure resulted in an increase of wear particle sizes and wear rate, and the size of PEEK wear particles can be controlled by the feature size of microfabricated surfaces. These results provided the information rapidly about factors that affect the morphology and amount of PEEK wear particles and can be applied in the future for application of PEEK on the biological articulation system.

scholarly journals On the role of N-methylmorpholine-N-oxide (NMMO) in the generation of elemental transition metal precipitates in cellulosic materials

Cellulose ◽  
2021 ◽  
Author(s):  
Thomas Rosenau ◽  
Antje Potthast ◽  
Hubert Hettegger ◽  
Markus Bacher ◽  
Martina Opietnik ◽  
...  
Keyword(s):  
Transition Metal ◽  
Chloride Ions ◽  
Nano Particles ◽  
Reaction Conditions ◽  
Cellulosic Materials ◽  
Chemical Systems ◽  
Particle Generation ◽  
Transition Metal Salts ◽  
Metal Nano Particles

AbstractSeveral literature reports describe the role of aqueous solutions of N-methylmorpholine-N-oxide monohydrate (NMMO) as a suitable medium for the generation of transition metal (nano)particles in or on cellulosic materials and further elaborate its role as a co-reactant of the transition metal salts that are reduced to the elemental metal. However, this would assign NMMO the role of a reductant, which is in contradiction of its obvious oxidative nature. In the present study, the exemplary cases of silver, gold, and platinum salts as the precursors of the respective metal (nano)particles in aqueous NMMO/cellulose mixtures were investigated. Naturally, NMMO did not act as a reducing agent in any case—this role was taken over by the frequently used NMMO stabilizer propyl gallate, or by cellulose itself, into which carbonyl and carboxyl groups were introduced. Also, hypochlorite—produced intermediately from chloride ions and subsequently undergoing disproportionation into chloride and chlorate—or transient N-methylene(morpholinium) ions generated from NMMO, which are in turn oxidized to formyl morpholide, can act as the corresponding reductants while the metal ions are reduced, depending on the reaction conditions. Apart from providing interesting mechanistic insights, the study points to the importance of a precise description of the composition of the chemical systems used, as well as the importance of seemingly inert auxiliaries, which turned out to be essential co-reactants in the metal (nano)particle generation. Graphic abstract

Nano-Scale Fatigue Wear of Carbon Nitride Coatings: Part II—Wear Mechanisms

2003 ◽  
Vol 125 (2) ◽  
pp. 437-444 ◽  
Author(s):  
Dong F. Wang ◽  
Koji Kato
Keyword(s):  
Wear Mechanisms ◽  
Carbon Nitride ◽  
Low Cycle Fatigue ◽  
Surface Flow ◽  
Theoretical Expression ◽  
Asperity Contact ◽  
Wear Particles ◽  
Critical Number ◽  
Fatigue Wear ◽  
Nitride Coatings

This is the second part of two companion papers, the first of which reported the empirical data on wear properties in carbon nitride coatings by a spherical diamond counter-face in repeated sliding contacts through in situ examination, with an emphasis on the effect of friction cycles and normal load. The second part will concentrate on wear mechanisms for the transition from “No observable wear particles” to “Wear particle generation.” The relationship between the critical number of friction cycles, Nc, and the representative plastic strain, Δεp, at asperity contact region was confirmed to follow the Manson-Coffin equation with two empirical constants, β and C. The observed generation of wear particles in carbon nitride coatings is therefore concluded to be a low cycle fatigue wear by surface flow and surface delamination in the ploughing mode. For further predicting lifespan, a simplified theoretical expression, combining the Manson-Coffin equation with the analytical solution of a proposed elastic perfectly-plastic indentation model, gives the relation between the critical number of friction cycles, Nc, and the coating thickness h, with respect to the contact pressure P, and the radius R of the asperity on the tip of the diamond pin.

In Vitro Dissolution of Amorphous Calcium Phosphate (ACP) Increased the Wear Particle Generation of Plasma-Sprayed HA Coatings

2007 ◽  
Vol 330-332 ◽  
pp. 561-564
Author(s):  
Wei Dong Tong ◽  
Pan Jian Li
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Morphological Changes ◽  
Wear Particle ◽  
In Vitro Dissolution ◽  
Wear Particles ◽  
Particle Generation ◽  
Ha Coating ◽  
Plasma Sprayed

Hydroxyapatite (HA) coated total hip joint device has caused concerns of generating wear particles after long-term implantation. We designed a pin-on-disk (POD) test to examine the morphological changes and wear particle generation of plasma sprayed HA coating in vitro. HA coatings were immersed in supplemented α-calf bovine serum for 48 hours. Serum soaked HA coating exhibited significant amount of weight loss due to dissolution of amorphous calcium phosphate (ACP). POD test demonstrated the serum soaked HA coatings presented many micronsized particles on the surface while the as-received HA coatings maintained good integrity. The generation of wear particles of the serum soaked HA coatings is related to the reduction of the cohesion/adhesion of HA coatings due to the preferential dissolution of ACP.

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