Documents disponibles écrits par cet auteur

Comparison of interfacial forces during post-chemical-mechanical-polishing cleaning / Dedy Ng in Transactions of the ASME . Journal of tribology, Vol. 130 n°2 (Mars/Avril 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 130 n°2 (Mars/Avril 2008) . - 5 p. Titre : Comparison of interfacial forces during post-chemical-mechanical-polishing cleaning Type de document : texte imprimé Auteurs : Dedy Ng, Auteur ; Hong Liang, Auteur Année de publication : 2008 Article en page(s) : 5 p. Note générale : Tribology Langues : Anglais (eng) Résumé : This research investigates the interfacial forces involved in tribological interactions while removing nanosized particles during post-chemical-mechanical polishing cleaning. Surface and interfacial forces are discussed to understand the particle adhesion and subsequent removal through physical and chemical interactions. Approaches include theoretical analysis combined with experimental study. The theoretical analysis was focused on the forces that exist between particles and a substrate. Surface interaction consideration includes applied pressure, frictional force, and hydrodynamic drag. The polishing experiments were carried out on silicon wafers with SiO2 slurry. Cleaning experiments were performed in de-ionized water using a polyvinyl acetal brush to remove particles from a hydrophilic-silicon surface. The fluid-drag force was found to affect the lubricating behavior of cleaning through changing material properties. Values of interfacial forces and their effects on cleaning were discussed along with a lubricating model system. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=1468024 [article] Comparison of interfacial forces during post-chemical-mechanical-polishing cleaning [texte imprimé] / Dedy Ng, Auteur ; Hong Liang, Auteur . - 2008 . - 5 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 130 n°2 (Mars/Avril 2008) . - 5 p. Résumé : This research investigates the interfacial forces involved in tribological interactions while removing nanosized particles during post-chemical-mechanical polishing cleaning. Surface and interfacial forces are discussed to understand the particle adhesion and subsequent removal through physical and chemical interactions. Approaches include theoretical analysis combined with experimental study. The theoretical analysis was focused on the forces that exist between particles and a substrate. Surface interaction consideration includes applied pressure, frictional force, and hydrodynamic drag. The polishing experiments were carried out on silicon wafers with SiO2 slurry. Cleaning experiments were performed in de-ionized water using a polyvinyl acetal brush to remove particles from a hydrophilic-silicon surface. The fluid-drag force was found to affect the lubricating behavior of cleaning through changing material properties. Values of interfacial forces and their effects on cleaning were discussed along with a lubricating model system. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=1468024

Formation and characterization of tribofilms / Prasenjit Kar in Transactions of the ASME . Journal of tribology, Vol. 130 N° 4 (Octobre 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 130 N° 4 (Octobre 2008) . - 6 p. Titre : Formation and characterization of tribofilms Type de document : texte imprimé Auteurs : Prasenjit Kar, Auteur ; Pranay Asthana, Auteur ; Hong Liang, Auteur Année de publication : 2015 Article en page(s) : 6 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Particulate  matter  Lubricants  Tribological  films  Mineral  oil  Steel  Petroleum  Wear  Temperature Résumé : Fundamentals of tribofilm formation and their properties were studied. In order to understand the effects of lubricants on tribofilms, four base oils were investigated. Lubricants include castor oil, polyethylene glycol, mineral oil, and margarine. These oils were chosen based on their molecular structure, polarity, utility, and biodegradability. Experiments were conducted using a ball-on-disk tribometer to form tribofilms. Surface characterization was carried out using a stylus profilometer, a scanning electron microscope, and a transmission electron microscope. Results showed that oils with high polarity such as castor oil enhanced the formation of a transfer layer on the steel surface, whereas nonpolar oils such as mineral oil failed to do so. Oils with high polarity act as effective base oils to prevent metal hardening and bond debris particles to the metal surface. Oils with nonpolar components, on the other hand, generate abrasive nanoparticles during rubbing. Experiments with margarine at elevated temperature resulted in the formation of a hard and thick tribofilm. An adsorption model is illustrated to highlight the effects of lubricant molecules. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=1468136 [article] Formation and characterization of tribofilms [texte imprimé] / Prasenjit Kar, Auteur ; Pranay Asthana, Auteur ; Hong Liang, Auteur . - 2015 . - 6 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 130 N° 4 (Octobre 2008) . - 6 p. Mots-clés : Particulate  matter  Lubricants  Tribological  films  Mineral  oil  Steel  Petroleum  Wear  Temperature Résumé : Fundamentals of tribofilm formation and their properties were studied. In order to understand the effects of lubricants on tribofilms, four base oils were investigated. Lubricants include castor oil, polyethylene glycol, mineral oil, and margarine. These oils were chosen based on their molecular structure, polarity, utility, and biodegradability. Experiments were conducted using a ball-on-disk tribometer to form tribofilms. Surface characterization was carried out using a stylus profilometer, a scanning electron microscope, and a transmission electron microscope. Results showed that oils with high polarity such as castor oil enhanced the formation of a transfer layer on the steel surface, whereas nonpolar oils such as mineral oil failed to do so. Oils with high polarity act as effective base oils to prevent metal hardening and bond debris particles to the metal surface. Oils with nonpolar components, on the other hand, generate abrasive nanoparticles during rubbing. Experiments with margarine at elevated temperature resulted in the formation of a hard and thick tribofilm. An adsorption model is illustrated to highlight the effects of lubricant molecules. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=1468136

Wear mode comparison of high-performance inconel alloys / Grant R. Fox in Transactions of the ASME . Journal of tribology, Vol. 132 N° 2 (Avril 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 132 N° 2 (Avril 2010) . - 06 p. Titre : Wear mode comparison of high-performance inconel alloys Type de document : texte imprimé Auteurs : Grant R. Fox, Auteur ; Hong Liang, Auteur Année de publication : 2011 Article en page(s) : 06 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Abrasion  Adhesion  Chromium  alloys  Iron  alloys  Molybdenum  alloys  Nickel  alloys  Niobium  alloys  Oxidation  Sliding  friction Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Inconel alloys have been used as engineering materials in high temperature and high stress applications due to their excellent mechanical properties. Tribological performances of these alloys, however, have not been conducted extensively. This is because in tribological applications, these materials have not often been utilized in friction and wear-related applications, resulting in a deficiency in the characterization of their tribomechanical properties. In the present research, we investigate the mechanisms of tribological performance of two different Inconel alloys in terms of contact pressures and sliding speeds. We studied their frictional behavior. The wear data were plotted against the pressure×velocity (PV parameter) in order to investigate the changes of surface properties and wear behaviors of the same under the influence of mechanical energy input. It was interesting to find that the wear mechanisms were influenced by the process of tribotesting. There are three competing wear mechanisms found, abrasion, adhesion, and oxidation. Each of those dominates the tribological performance under different conditions. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Wear mode comparison of high-performance inconel alloys [texte imprimé] / Grant R. Fox, Auteur ; Hong Liang, Auteur . - 2011 . - 06 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 132 N° 2 (Avril 2010) . - 06 p. Mots-clés : Abrasion  Adhesion  Chromium  alloys  Iron  alloys  Molybdenum  alloys  Nickel  alloys  Niobium  alloys  Oxidation  Sliding  friction Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Inconel alloys have been used as engineering materials in high temperature and high stress applications due to their excellent mechanical properties. Tribological performances of these alloys, however, have not been conducted extensively. This is because in tribological applications, these materials have not often been utilized in friction and wear-related applications, resulting in a deficiency in the characterization of their tribomechanical properties. In the present research, we investigate the mechanisms of tribological performance of two different Inconel alloys in terms of contact pressures and sliding speeds. We studied their frictional behavior. The wear data were plotted against the pressure×velocity (PV parameter) in order to investigate the changes of surface properties and wear behaviors of the same under the influence of mechanical energy input. It was interesting to find that the wear mechanisms were influenced by the process of tribotesting. There are three competing wear mechanisms found, abrasion, adhesion, and oxidation. Each of those dominates the tribological performance under different conditions. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]