Toward a Mechanical Wear Equation

1983 ◽  
Vol 105 (2) ◽  
pp. 212-219 ◽  
Author(s):  
J. Halling
Keyword(s):  
Film Thickness ◽  
Simple Form ◽  
Material Properties ◽  
Wear Mechanisms ◽  
Wear Behavior ◽  
Linear Wear ◽  
Surface Films ◽  
Wear Particles ◽  
Asperity Distribution

It is first shown that the simple form of linear wear/load relation of the adhesive and abrasive wear laws arises from the nature of the asperity distribution. Without recourse to specific wear mechanisms, simple concepts for material properties, size of wear particles, and the production of wear particles are introduced. This procedure leads to an increasing appreciation of those factors which might be embraced by the specific wear constant. Of particular interest is the role of ductility in wear behavior. Finally, these ideas are extended to deal with the wear of surface films where it is seen that the film thickness is of paramount importance. Some experimental evidence for the concepts used is also provided.

Surface Films on Zircaloy-2 Samples Cracked in Neutral Aqueous NaCl by Stress Corrosion

1973 ◽  
Vol 31 ◽  
pp. 46-47
Author(s):  
R.A. Ploc
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Film Thickness ◽  
Stress Corrosion ◽  
Zirconium Dioxide ◽  
Surface Film ◽  
Surface Films ◽  
Continuous Layer ◽  
Transmission Electron ◽  
Product Film

Samples of low-nickel Zircaloy-2 (material MLI-788-see(1)), when anodically polarized in neutral 5 wt% NaCl solutions, were found to be susceptible to pitting and stress corrosion cracking. The SEM revealed that pitting of stressed samples was occurring below a 2000Å thick surface film which behaved differently from normal zirconium dioxide in that it did not display interference colours. Since the initial film thickness was approximately 65Å, attempts were made to examine the product film by transmission electron microscopy to deduce composition and how the corrosion environment could penetrate the continuous layer.

The role of gas flow distributions on CO2 mineralization within monolithic cemented composites: coupled CFD-factorial design approach

2021 ◽  
Author(s):  
Iman Mehdipour ◽  
Gabriel Falzone ◽  
Dale Prentice ◽  
Narayanan Neithalath ◽  
Dante Simonetti ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Factorial Design ◽  
Material Properties ◽  
Gas Flow ◽  
Design Approach ◽  
Processing Conditions ◽  
Gas Processing ◽  
Co2 Mineralization

Optimizing the spatial distribution of contacting gas and the gas processing conditions enhances CO2 mineralization reactions and material properties of carbonate-cementitious monoliths.

Friction and Wear Behavior of Silicon Carbonitride Processed From the Polymer-Derived Ceramic Route

2005 ◽  
Author(s):  
Tsali Cross ◽  
Somuri Prasad ◽  
Rishi Raj
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Silicon Carbonitride ◽  
Linear Wear ◽  
Polymer Derived Ceramic ◽  
Organometallic Precursors ◽  
Future Work ◽  
Contact Pressures

Polymer derived ceramics (PDC’s) are processed from liquid organometallic precursors by cross-linking the polymers into infusible solids, followed by controlled pyrolysis. No previous work regarding their tribology has been reported. Further, the synthesis of PDC’s as thin films, and the role that the nanostructure plays on the mechanical properties has not been reported. The objective of this research was to evaluate the fundamental tribological behavior of polymer derived SiCN in both bulk and thin film form. Friction and wear evaluations were made on bulk materials and thin films using a Si3N4 ballon-disk linear wear tester at various contact pressures and in different environments that contained various amounts of humidity. The micro/nanostructure was characterized by FTIR, microRaman, and scanning electron microscopy. Bulk SiCN gave a low friction coefficient and good wear resistance in humid environments but showed significant fracture and gouging in dry environments at higher contact pressures. Although there is ambiguity regarding the tribology of the thin films there seems to be a dependence upon the nitrogen content within the materials derived from the polymeric stage. The future work will focus on optimizing processing conditions of thin films and investigating the role that nitrogen plays in both bulk and thin film SiCN materials.

The Role of Topology and Tissue Mechanics in Remora Attachment

2014 ◽  
Vol 1648 ◽  
Author(s):  
Michael Culler ◽  
Keri A. Ledford ◽  
Jason H. Nadler
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Tissue Mechanics ◽  
Unit Cell ◽  
Surface Topology ◽  
Finite Element Models ◽  
Cell Geometry ◽  
Critical Step ◽  
Tissue Material

ABSTRACTRemora fish are capable of fast, reversible and reliable adhesion to a wide variety of both natural and artificial marine hosts through a uniquely evolved dorsal pad. This adhesion is partially attributed to suction, which requires a robust seal between the pad interior and the ambient environment. Understanding the behavior of remora adhesion based on measurable surface parameters and material properties is a critical step when creating artificial, bio-inspired devices. In this work, structural and fluid finite element models (FEM) based on a simplified “unit cell” geometry were developed to predict the behavior of the seal with respect to host/remora surface topology and tissue material properties.

scholarly journals Hematite photoelectrodes for water splitting: evaluation of the role of film thickness by impedance spectroscopy

2014 ◽  
Vol 16 (31) ◽  
pp. 16515 ◽  
Author(s):  
Tânia Lopes ◽  
Luísa Andrade ◽  
Florian Le Formal ◽  
Michael Gratzel ◽  
Kevin Sivula ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Film Thickness ◽  
Water Splitting

CERAMICS BASED ON ORGANOSILICON POLYMERS-PRECURSORS: MICROSTRUCTURE AND PROPERTIES (review). Part 2

2021 ◽  
pp. 22-32
Author(s):  
A.M. Shestakov ◽  
Keyword(s):  
Electron Microscopy ◽  
Nmr Spectroscopy ◽  
Material Properties ◽  
Structural Organization ◽  
Ceramic Materials ◽  
Special Role ◽  
Correct Interpretation ◽  
Instrumental Methods ◽  
Organosilicon Polymers

Shows the scientific approaches of various authors to the study of the microstructure of ceramics, the purpose of which is to elucidate its structural organization at the micro- and nanoscale, as well as the influence of the microstructure on the complex of material properties. Various instrumental methods for studying ceramics (NMR spectroscopy, electron microscopy, х-ray structural analysis, etc.) are considered, the permissible capabilities of research methods and analysis of the results obtained with their correct interpretation are shown. The special role of theoretical modeling in understanding the structure of the considered ceramic materials is noted.

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.

Sign in / Sign up

Export Citation Format

Share Document