HDI-03 AN ANALYSIS OF THE DIMPLE/GIMBAL CONTACT IN A HARD DISK DRIVE SUSPENSION(Head/Disk Interface and Tribology I,Technical Program of Oral Presentations)

To achieve a higher storage density in a hard disk drive, the fly height of the air bearing slider, as part of the magnetic spacing, has to be minimized. At an ultralow fly height, the intermittent–continuous contact at the head–disk interface (HDI) is unavoidable and directly affects the mechanical and magnetic performance of the hard disk drive, and is of great interest. The HDI wear has a nonlinear and time-varying nature due to the change of contact force and roughness. To predict the HDI wear evolution, an iterative model of Coupled Head And Disk (CHAD) wear, is developed based on the contact mechanics. In this model, a composite transient wear coefficient is adopted and multiple phases of the wear evolution are established. A comprehensive contact stiffness is derived to characterize the contact at the HDI. The abrasive and adhesive wear is calculated based on the extended Archard’s wear law. The plastic and elastic contact areas are calculated with a three-dimensional (3D) sliding contact model. Based on the CHAD wear model, for the first time, the coupling between head and disk wear evolutions is thoroughly investigated. Accelerated wear tests have also been performed to verify the disk wear effect on the slider wear. A wear coefficient drop with time is observed during the tests and it is attributed to a wear mechanism shift from abrasive to adhesive wear. A shift in the type of contact from plastic to elastic accounts for the wear mechanism change.

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Effect of Non-Operational Shock on Interaction Between Suspension Lift-Tab and Load/Unload Ramp

World Tribology Congress III, Volume 1 ◽

10.1115/wtc2005-63558 ◽

2005 ◽

Author(s):

Aravind N. Murthy ◽

Eric M. Jayson ◽

Frank E. Talke

Keyword(s):

Hard Disk Drive ◽

Failure Modes ◽

Hard Disk Drives ◽

Hard Disk ◽

Areal Density ◽

Disk Drive ◽

Disk Drives ◽

Head Disk Interface ◽

Disk Interface ◽

Operational Shock

Most hard disk drives manufactured in the last few years have Load/Unload (L/UL) technology. As opposed to the Contact Start/Stop (CSS) technology, L/UL technology has the advantage of improved areal density because of more disk space availability and better shock performance. The latter characteristic has significant benefits during the non-operational state of the hard disk drive since head/disk interactions are eliminated and the head is parked on a ramp adjacent to the disk. However, even if head/disk interactions are absent, other failure modes may occur such as lift-tab damage and dimple separation leading to flexure damage. A number of investigations have been made to study the response of the head disk interface with respect to shock when the head is parked on the disk ([1], [2]). In this paper, we address the effect of non-operational shock for L/UL disk drives.

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Humidity effects on lubricant transfer in the head-disk interface of a hard disk drive

Journal of Applied Physics ◽

10.1063/1.3061704 ◽

2009 ◽

Vol 105 (7) ◽

pp. 07B704 ◽

Cited By ~ 10

Author(s):

Sang Hoon Kim ◽

Qing Dai ◽

Bruno Marchon ◽

Karl Flechsig

Keyword(s):

Hard Disk Drive ◽

Hard Disk ◽

Disk Drive ◽

Head Disk Interface ◽

Lubricant Transfer ◽

Disk Interface ◽

Humidity Effects

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Wear Analysis of Head-Disk Interface During Contact

ASME/STLE 2004 International Joint Tribology Conference, Parts A and B ◽

10.1115/trib2004-64050 ◽

2004 ◽

Author(s):

Wei Peng ◽

James Kiely ◽

Yiao-Tee Hsia

Keyword(s):

Hard Disk Drive ◽

Wear Mechanism ◽

Adhesive Wear ◽

Contact Stiffness ◽

Hard Disk ◽

Disk Drive ◽

Head Disk Interface ◽

Wear Coefficient ◽

Disk Interface ◽

Fly Height

To achieve a higher storage density in a hard disk drive, the fly height of the air bearing slider, as part of the magnetic spacing, has to be minimized. At an ultra-low fly height, the intermittent / continuous contact at the head–disk interface (HDI) is unavoidable and directly affects the mechanical and magnetic performance of the hard disk drive, and is of great interest. The HDI wear has a non-linear and time-varying nature due to the change of contact force and roughness. To predict the HDI wear evolution, an iterative model of Coupled Head And Disk (CHAD) wear, is developed based on the contact mechanics. In this model, a composite transient wear coefficient is adopted and multiple phases of the wear evolution are established. A comprehensive contact stiffness is derived to characterize the contact at the HDI. The abrasive and adhesive wear is calculated based on the extended Archard’s wear law. The plastic and elastic contact areas are calculated with a 3-D sliding contact model. Based on the CHAD wear model, for the first time, the coupling between head and disk wear evolutions is thoroughly investigated. Accelerated wear tests have also been performed to verify the disk wear effect on the slider wear. A wear coefficient drop with time is observed during the tests and it is attributed to a wear mechanism shift from abrasive to adhesive wear. A shift in the type of contact from plastic to elastic accounts for the wear mechanism change.

Download Full-text