Contact Force and Frictional Heating due to “Large” Particles in the Head Disk Interface

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Xinjiang Shen ◽  
David B. Bogy
Keyword(s):  
Friction Coefficient ◽  
Contact Force ◽  
Contact Region ◽  
Frictional Heating ◽  
Frictional Coefficient ◽  
Movement Pattern ◽  
Contact Forces ◽  
Head Disk Interface ◽  
Disk Interface ◽  
Large Particles

Particles in the head disk interface may cause large contact forces acting on the slider as well as thermal asperities in the read/write signal. This is especially true for the close spacing required for 1Tbit∕in.2. In this paper, a three-body contact model is employed to study the effects of a particle entrapped between a slider and a disk. A criterion for determining a particle’s movement pattern is proposed. The study of particles in the head disk interface shows that large particles are likely to slide between the slider and disk interface, and the particles going through the trailing pad of an air bearing slider cause severe contact forces on the slider and generate large heat sources. The frictional heating study shows that the temperature around the magnetoresistive head increases to about 5°C for a single 200nm particle passing through the trailing pad of the slider. The effects of the particle size, disk material, and friction coefficient are also studied. It is found that the disk and slider materials and the frictional coefficient between the materials largely affect the contact force acting on the slider by an entrapped particle as well as the temperature rise at its contact region. It is also found that the friction coefficient largely affects a particle’s movement pattern in the head disk interface.

Soft Particle-Induced Magnetic Erasure Without Physical Damage to the Media

2007 ◽  
Vol 129 (4) ◽  
pp. 729-734 ◽  
Author(s):  
M. Roy ◽  
J. L. Brand
Keyword(s):  
Frictional Heating ◽  
Mechanical Damage ◽  
Soft Particle ◽  
Head Disk Interface ◽  
Physical Damage ◽  
Component Level ◽  
Disk Interface ◽  
Permanent Loss ◽  
The Media ◽  
The Impact

With ever increasing areal density, interactions of particles with a head-disk interface become an ever more important factor impacting the drive reliability. Although particles trapped between the head and the disk could induce mechanical damage to the media resulting in permanent loss of data, data loss has also been observed without any obvious signs of physical damage to the media. We devised a component-level test to study this mode of data erasure on both glass and aluminium media. Our data indicate that the frictional heating associated with contact force between the particle and the disk could lead to permanent loss of data. In addition, we performed investigations to study the impact of air bearing design features, load/unload mechanism, and particle number density on the head disk interface.

A Study of Subambient Pressure Tri-Pad Sliders Using Acoustic Emission

1998 ◽  
Vol 120 (1) ◽  
pp. 54-59 ◽  
Author(s):  
A. G. Khurshudov ◽  
F. E. Talke
Keyword(s):  
Acoustic Emission ◽  
Contact Force ◽  
Contact Forces ◽  
Constant Speed ◽  
Flying Height ◽  
Contact Behavior ◽  
Disk Interface

Acoustic emission is used to study the contact behavior of subambient pressure tri-pad sliders during start/stop and constant speed operation. The contact force at the slider/disk interface is determined as a function of velocity and the dependence of contact force on flying height is investigated. The results indicate that contact forces for typical subambient pressure tri-pad sliders are on the order of a few mN.

Frictional heating effect on thermal protrusion in head disk interface

2014 ◽  
Vol 20 (8-9) ◽  
pp. 1565-1570 ◽  
Author(s):  
Jianhua Li ◽  
Junguo Xu ◽  
Masaru Furukawa
Keyword(s):  
Frictional Heating ◽  
Heating Effect ◽  
Head Disk Interface ◽  
Disk Interface ◽  
Thermal Protrusion

Simulation of Dynamic Behavior of Slider at Head/Disk Interface of Hard Disk Drives

2012 ◽  
Vol 151 ◽  
pp. 189-192
Author(s):  
Yi Chen ◽  
Hong Rui Ao ◽  
Hong Yuan Jiang
Keyword(s):  
Contact Force ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Equation Of Motion ◽  
Hertzian Contact ◽  
Contact Method ◽  
Disk Drives ◽  
Head Disk Interface ◽  
Dynamics Model ◽  
Disk Interface

The effect of contact between the sliders and disks on the flying characteristics of sliders in hard disk drives was modeled and analyzed. The differential equation of motion for slider was constructed based on slider/disk dynamics model with consideration of contact force. The contact was simplified as an elastic contact style and described by Hertzian contact method. The slider responses were simulated by using SimMechanics software. The results indicate that slider acts as periodic vibration under the contact force.

scholarly journals Sliding Interaction for Coated Asperity with Power-Law Hardening Elastic-Plastic Coatings

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2388
Author(s):  
Bin Zhao ◽  
Hanzhang Xu ◽  
Xiqun Lu
Keyword(s):  
Friction Coefficient ◽  
Yield Strength ◽  
Young’S Modulus ◽  
Contact Force ◽  
Young's Modulus ◽  
Contact Forces ◽  
Geometrical Parameters ◽  
Asperity Contact ◽  
Strength Ratio ◽  
Modulus Ratio

Sliding between asperities occurs inevitably in the friction pair, which affects the efficiency and reliability in both lubricated and non-lubricated conditions. In this work, the contact parameters in the coated asperity sliding process are studied, and the universal expressions of the average contact force and the friction coefficient are obtained. The effect of the interference between asperities, the material and geometrical parameters including the Young’s modulus ratio and yield strength ratio of the coating and substrate, and the hardening exponent and thickness of the coating on the average contact forces and friction coefficient is considered. It shows both normal and tangential contact forces increase with the increasing interference, increasing Young’s modulus ratio, decreasing yield strength ratio, and decreasing coating thickness; while the trend is different for the effect of the hardening exponent of the coating. The normal force increases and the tangential force decreases as the hardening exponent increases. Based on this, the influence of these parameters on the effective friction coefficient is obtained further. It reveals that the friction coefficient increases as the interference and Young’s modulus ratio enlarge and decreases as the yield strength ratio, the coating’s hardening exponent, and thickness increase. The universal expressions for the contact force and friction coefficient in the sliding process are obtained. This work might give some useful results to help choose the optimum coatings for specific substrates to reduce friction in cases where the asperity contact exists, especially in the focused field of the journal bearing in the marine engine under poor lubrication conditions.

Interactions Between Dynamic Normal and Frictional Forces During Unlubricated Sliding

1983 ◽  
Vol 105 (2) ◽  
pp. 221-229 ◽  
Author(s):  
A. Soom ◽  
C. Kim
Keyword(s):  
Friction Coefficient ◽  
Frictional Force ◽  
Contact Region ◽  
Contact Forces ◽  
Force Fluctuations ◽  
Surface Irregularities ◽  
Frictional Forces ◽  
Steel Surfaces ◽  
Pin On Disk ◽  
Inertia Forces

The results of measurements showing large normal and frictional force oscillations during unlubricated smooth sliding between steel surfaces are presented. The measurements were made on a pin-on-disk type apparatus instrumented with piezoelectric force and acceleration transducers. Spectral analysis of the contact forces (including inertia forces) up to frequencies of 2 kHz indicate that the fluctuations have their major components in this frequency range. The force oscillations are primarily associated with normal and tangential contact vibrations which are excited by surface irregularities being swept through the contact region during sliding. Transfer function analyses between the normal and frictional forces show the frictional force fluctuations to be in phase with the normal force fluctuations, but related in magnitude by a ratio larger than the concurrently-measured (average) kinetic friction coefficient. This larger oscillatory (or AC) friction coefficient is indicative of fluctuations in the instantaneous coefficient of friction which are shown to occur in synchronism with the contact force oscillations.

Abrasive wear response of Al-Si–SiCp composite: Effect of friction heat and friction coefficient

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Raj Kumar Singh ◽  
Amit Telang ◽  
Satyabrata Das
Keyword(s):  
Heat Treatment ◽  
Friction Coefficient ◽  
Abrasive Wear ◽  
Applied Load ◽  
Frictional Heating ◽  
Matrix Alloy ◽  
Composite Effect ◽  
Friction Heat ◽  
Wear Response ◽  
Abrasive Size

Abstract The effects of friction heat and friction coefficient on the abrasive wear response of Al-7.5Si–SiCp composite against low-cost hypereutectic (Al-17.5Si) alloy were investigated as functions of the abrasive size and applied load in both as-cast and after heat-treatment conditions. Experiments were performed on pin-on-disc apparatus at 38 –80 μm abrasive size, 5 – 20 N applied load, 100 –400 m abrading (sliding) distances and 1 m s–1 constant sliding speed. The frictional heating of as-cast and heat-treated composite was superior compared to the matrix alloy and hypereutectic alloy, whereas the trend reversed for the friction coefficient. The frictional heating and friction coefficient of the materials increased with the abrasive size and applied load in both as-cast and after heat-treatment. The worn surface and wear debris particles were examined by using field emission scanning electron microscopy to understand the wear mechanism.

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