The Detection of Flash Temperatures in a Sliding Contact by the Method of Tribo-Induced Thermoluminescence

1991 ◽  
Vol 113 (1) ◽  
pp. 120-127 ◽  
Author(s):  
S. Suzuki ◽  
F. E. Kennedy
Keyword(s):  
Thin Film ◽  
Short Duration ◽  
Contact Spot ◽  
Sliding Contact ◽  
Sliding Contacts ◽  
Magnetic Disk ◽  
Sliding Interface

A method is presented for measuring short duration flash temperatures in sliding contacts. The method uses a photomultiplier to collect photons emitted by a hot contact spot. The method was used to measure flash temperatures at the contact between a spherical sapphire slider and a rapidly moving thin film magnetic disk. It was found that temperature flashes of over 1000° C, lasting less than 2 μs, can occur at the sliding interface.

Depletion of Moleculary Thin Lubricant Under Flying Head in Hard Disk Drives

2007 ◽  
Author(s):  
Kenji Yanagisawa ◽  
Youichi Kawakubo ◽  
Masato Yoshino
Keyword(s):  
Thin Film ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Lubricant Film ◽  
Simulation Program ◽  
Disk Drives ◽  
Lubricant Thickness ◽  
Magnetic Disk ◽  
Lubricant Depletion ◽  
Lubricant Films

In Hard Disk Drives, lubricants are very important materials to reduce head and disk wear. Therefore, it is necessary to know the lubricant depletion under flying heads. Lubricant depletion due to flying heads has been studied experimentally. We developed simulation program to calculate numerically the change in lubricant thickness under a flying head on a thin-film magnetic disk from 10nm thick lubricant film. In recent HDDs, the lubricants thickness has become molecularly thin and polar lubricants have been used. In this paper, we took account of thickness-dependent lubricants diffusion and viscosity in our simulations to calculate a 1.2 nm thick polar lubricant film used in recent HDDs. The simulated results considering the thickness-dependent diffusion and viscosity showed that depletion was small in molecularly thin lubricant films. We considered it necessary to include thickness-dependent diffusion and viscosity in lubricant depletion simulation.

Evaluation of response characteristics of thin film gauge for conductive heat transfer mode

2020 ◽  
pp. 014233122096066
Author(s):  
Tanweer Alam ◽  
Rakesh Kumar
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Flux ◽  
Short Duration ◽  
Temperature Data ◽  
Heat Transfer Analysis ◽  
Transient Temperature ◽  
Conductive Heat ◽  
Sensing Element ◽  
Element Analysis

Heat transfer analysis is the one of the most important designing aspects for many engineering systems. The design prospect in the preview of heat transfer focuses on the prediction of heat flux with the help of measured transient temperature data. Thin film gauges are one of the most predominant method for the heat flux prediction especially for short duration transient temperature measurement. Thin film gauges are usually exposed to the heated environment for the measurement purpose. However, there are some prominent research areas like ablation phenomenon met to spacecraft thermal shields during re-entry to the atmosphere, for which direct exposure of the thin film gauge to the heated environment causes the functional and working difficulties associated with the gauge. In the present study, it is aimed to investigate the suitability of thin film gauge for the conduction-based short duration measurement. An experimental set up is fabricated, which is used to supply the heat load to the hand-made thin film gauge using platinum as sensing element and quartz as a substrate. The transient temperature data is recorded during experiment is further compared with the simulated temperature histories obtained through finite element analysis. The heat flux estimation for both the analysis is made using measured transient temperature data by convolute integral of one- dimensional heat conduction equation. The estimated heat flux value for the experimental and numerical result is found to be in excellent agreement.

scholarly journals Insights into dynamic sliding contacts from conductive atomic force microscopy

2020 ◽  
Vol 2 (9) ◽  
pp. 4117-4124
Author(s):  
Nicholas Chan ◽  
Mohammad R. Vazirisereshk ◽  
Ashlie Martini ◽  
Philip Egberts
Keyword(s):  
Electrical Conductivity ◽  
Atomic Force Microscopy ◽  
Sliding Contact ◽  
Current Transport ◽  
Conductive Atomic Force Microscopy ◽  
Sliding Contacts ◽  
Force Microscopy ◽  
Single Asperity ◽  
Atomic Force ◽  
Sliding Dynamics

Measuring the electrical conductivity serves as a proxy for characterizing the nanoscale contact. In this work, the correlation between sliding dynamics and current transport at single asperity sliding contact is investigated.

Experimental Studies and Molecular Dynamics Simulations of the Sliding Contact of Metallic Glass

2000 ◽  
Vol 644 ◽  
Author(s):  
Xi-Yong Fu ◽  
Michael L. Falk ◽  
David A. Rigney
Keyword(s):  
Molecular Dynamics ◽  
Metallic Glass ◽  
Molecular Dynamics Simulations ◽  
Bulk Metallic Glass ◽  
Amorphous Material ◽  
Experimental Studies ◽  
Sliding Contact ◽  
Atomic Scale ◽  
Sliding Interface ◽  
Dynamics Simulations

AbstractTribological properties of bulk metallic glass Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 were studied experimentally using a pin/disk geometry without lubrication. Experimental observations were compared with 2D molecular dynamics simulations of amorphous material in sliding contact. The friction coefficient and the wear rate of bulk metallic glass (BMG) depend on normal load and test environment. The sliding of annealed BMG re-amorphizes devitrified material. A mechanically mixed layer is generated during sliding; this layer has enhanced oxygen content if the sliding is in air. The MD simulations show that atomic scale mixing occurs across the sliding interface. The growth kinetics of the mixing process scales with the square root of time. In the simulations, a low density region is generated near the sliding interface; it corresponds spatially to the softer layer detected in experiments. Subsurface displacement profiles produced by sliding and by simulation are very similar and are consistent with the flow patterns expected from a simple Navier-Stokes analysis when the stress state involves both compression and shear.

scholarly journals Friction and wear behavior of thin-film ceramic coatings under lubricated sliding contact

2014 ◽  
Vol 569 ◽  
pp. 70-75 ◽  
Author(s):  
Cinta Lorenzo-Martin ◽  
Oyelayo O. Ajayi ◽  
Sol Torrel ◽  
Iqbal Shareef ◽  
George R. Fenske
Keyword(s):  
Thin Film ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Ceramic Coatings ◽  
Sliding Contact ◽  
Friction And Wear Behavior ◽  
Lubricated Sliding

scholarly journals Corrosion of Thin Film Magnetic Disk: Galvanic Effects of the Carbon Overcoat

1989 ◽  
Vol 136 (1) ◽  
pp. 42-46 ◽  
Author(s):  
V. Brusic ◽  
M. Russak ◽  
R. Schad ◽  
G. Frankel ◽  
A. Selius ◽  
...  
Keyword(s):  
Thin Film ◽  
Carbon Overcoat ◽  
Magnetic Disk

A Method for Characterizing Running-In of Sliding Contacts

2016 ◽  
Vol 681 ◽  
pp. 228-233
Author(s):  
R. Ismail ◽  
M. Tauviqirrahman ◽  
J. Jamari ◽  
D.J. Schipper
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pressure Distribution ◽  
Sliding Contact ◽  
Wear Depth ◽  
Contact Pressure Distribution ◽  
Sliding Contacts ◽  
Element Analysis ◽  
Element Simulation ◽  
Proposed Model

Although in terms of conservation wear is undesirable, however, running-in wear is encouraged rather than avoided. Running-in is rather complex and most of the studies related to the change in micro-geometry have been conducted statistically. The purpose of this study was to characterize the running-in of sliding contacts using finite element analysis based on measured micro-geometries. The developed model combines the finite element simulation, Archard’s wear equation and updated geometry to calculate the contact pressure distribution and wear depth. Results show that the proposed model is able to predict the running-in phase of sliding contact system.

scholarly journals Calibration of a silver thin film gauge for short duration convective step heat load

Sadhana ◽  
2016 ◽  
Vol 41 (7) ◽  
pp. 787-794 ◽  
Author(s):  
Shrutidhara Sarma ◽  
Niranjan Sahoo ◽  
Aynur Unal
Keyword(s):  
Thin Film ◽  
Short Duration ◽  
Heat Load ◽  
Silver Thin Film
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