Effect of Slider Burnish on Disk Damage During Dynamic Load/Unload

1998 ◽  
Vol 120 (2) ◽  
pp. 332-338 ◽  
Author(s):  
M. Suk ◽  
D. Gillis
Keyword(s):  
Contact Stress ◽  
Disk Surface ◽  
Hertzian Contact ◽  
Radius Of Curvature ◽  
Air Bearing ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Disk Interface ◽  
Current Design ◽  
Hertzian Contact Stress

Two of the most difficult issues to resolve in current design of head/disk interface in magnetic recording devices are stiction and durability problems. One method of overcoming these problems is by implementing a technology known as load/unload, where the system is designed so that the slider never touches the disk surface. One potential problem with this type of system is slider/disk contact induced disk defects. The objective of this paper is to show that the likelihood of disk scratches caused by head/disk contacts during the load/unload process can be significantly decreased by rounding the edges of the air-bearing surface. Using the resistance method, we observe that head/disk contacts burnish the corners of the slider and thereby decrease exponentially with load/unload cycles. A well burnished slider rarely causes any disk damage thus resulting in an interface with significantly higher reliability. A simple Hertzian contact stress analysis indicates that the contact stress at the head/disk interface can be greatly decreased by increasing the radius of curvature of the air-bearing surface edges.

Pumping Effect of Slider Air Bearing Surface for Non-Langmuir Adsorption

2010 ◽  
Author(s):  
Bo Zhang ◽  
Akira Nakajima
Keyword(s):  
Disk Surface ◽  
Air Bearing ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Adsorption Model ◽  
Adsorbed Film ◽  
Disk Interface ◽  
Langmuir Adsorption ◽  
Langmuir Adsorption Model ◽  
Slider Air Bearing

Numerical analysis of the adsorbed film thickness at the air bearing surface is conducted using the non-Langmuir adsorption model. It is found that the adsorbed film at the air bearing surface becomes significant when the viscosity of adsorbed film is higher than about 1 Pa s. The adsorbed contaminant will accumulate at the rear end of the slider, and it is possible that the accumulated liquid-like contaminant may form a liquid tail which will directly contact with the disk surface, resulting in a crush of the head/disk interface.

scholarly journals Parametric Investigations at the Head-Disk Interface of Thermal Fly-Height Control Sliders in Contact

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Sripathi V. Canchi ◽  
David B. Bogy ◽  
Run-Han Wang ◽  
Aravind N. Murthy
Keyword(s):  
Hard Disk Drives ◽  
Air Bearing ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Surface Design ◽  
Disk Interface ◽  
Height Control ◽  
Experimental Findings ◽  
And Control ◽  
Fly Height

Accurate touchdown power detection is a prerequisite for read-write head-to-disk spacing calibration and control in current hard disk drives, which use the thermal fly-height control slider technology. The slider air bearing surface and head gimbal assembly design have a significant influence on the touchdown behavior, and this paper reports experimental findings to help understand the touchdown process. The dominant modes/frequencies of excitation at touchdown can be significantly different leading to very different touchdown signatures. The pressure under the slider at touchdown and hence the thermal fly-height control efficiency as well as the propensity for lubricant pickup show correlation with touchdown behavior which may be used as metrics for designing sliders with good touchdown behavior. Experiments are devised to measure friction at the head-disk interface of a thermal fly-height control slider actuated into contact. Parametric investigations on the effect of disk roughness, disk lubricant parameters, and air bearing surface design on the friction at the head-disk interface and slider burnishing/wear are conducted and reported.

Boundary Effect on Particle Motion in the Head Disk Interface

2007 ◽  
Author(s):  
Nan Liu ◽  
David B. Bogy
Keyword(s):  
Drag Force ◽  
Particle Motion ◽  
Boundary Effect ◽  
Hard Disk Drives ◽  
Areal Density ◽  
Air Bearing ◽  
Disk Drives ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Disk Interface

Simulation of particle motion in the Head Disk Interface (HDI) helps to understand the contamination process on a slider, which is critical for achieving higher areal density of hard disk drives. In this study, the boundary effect—the presence of the slider and disk—on particle motion in the HDI is investigated. A correction factor to account for this effect is incorporated into the drag force formula for particles in a flow. A contamination criterion is provided to determine when a particle will contaminate a slider. The contamination profile on a specific Air Bearing Surface is obtained, which compares well with experiments.

Air-bearing surface chemical modification for low-friction head–disk interface

2006 ◽  
Vol 13 (8-10) ◽  
pp. 811-816 ◽  
Author(s):  
Yuki Shimizu ◽  
Junguo Xu ◽  
Shozo Saegusa ◽  
Noritsugu Umehara
Keyword(s):  
Chemical Modification ◽  
Air Bearing ◽  
Surface Chemical ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Low Friction ◽  
Disk Interface ◽  
Surface Chemical Modification

Contact ABS Design Concepts

2002 ◽  
Author(s):  
Junguo Xu ◽  
Hidekazu Kohira ◽  
Shozo Saegusa
Keyword(s):  
Frequency Shift ◽  
Friction Force ◽  
Flying Height ◽  
Air Bearing ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Disk Interface ◽  
Design Concepts ◽  
Smooth Disk

The design of a head-disk interface for an ultra-low flying height was studied from the viewpoint of contact vibration. It is known that a super-smooth disk is necessary for a slider to fly at an ultra-low flying height; however, such a disk increases the friction force, which potentially increases the vibration of the slider. To solve this problem, the head-disk interface must be optimized to reduce this increased vibration. We found that the use of micro-texture on the air bearing surface can prevent contact vibration. Combining trimming with the use of a micro-texture was most effective in reducing contact vibration. A frequency-shift-damping slider was also found to damp vibration effectively.

Fluorine-ion-implanted air-bearing surface for low-friction head–disk interface

2009 ◽  
Vol 16 (1-2) ◽  
pp. 293-299 ◽  
Author(s):  
Yuki Shimizu ◽  
Noritsugu Umehara ◽  
Junguo Xu
Keyword(s):  
Air Bearing ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Low Friction ◽  
Disk Interface ◽  
Ion Implanted

Slider Overcoats for Enhanced Interface Durability in Magnetic Recording Applications

1995 ◽  
Vol 117 (1) ◽  
pp. 86-93 ◽  
Author(s):  
S. K. Ganapathi ◽  
Timothy A. Riener
Keyword(s):  
Magnetic Recording ◽  
Friction And Wear ◽  
Disk Drive ◽  
Disk Surface ◽  
Electrical Performance ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Component Level ◽  
Disk Interface ◽  
Significant Performance

The effects on tribological performance of air bearing surface overcoats on magnetic recording sliders are presented. Both component level and disk drive level testing indicate that significant performance enhancements are afforded by the overcoat, and that both stiction/friction and wear of the head/disk interface are reduced, thus increasing interface durability. The degradation in electrical performance of the heads due to the presence of the overcoat is shown to be consistent with that predicted by the Wallace equation. In addition, it is shown that the performance enhancements of the overcoat are achieved only in the presence of lubricant on the disk surface, suggesting that the overcoat lubricant interaction may be more benign than the interaction of the lubricant with the slider material.

Air-Bearing Design Towards Super Stable Head-Disk Interface

2006 ◽  
Author(s):  
Bo Liu ◽  
MingSheng Zhang ◽  
Yijun Man ◽  
Shengkai Yu ◽  
Gonzaga Leonard ◽  
...  
Keyword(s):  
Air Bearing ◽  
Head Disk Interface ◽  
Disk Interface ◽  
Bearing Design

Numerical Investigation of Bouncing Vibrations of a Partial Contact Slider

2007 ◽  
Author(s):  
Du Chen ◽  
David D. Bogy
Keyword(s):  
Hard Disk Drives ◽  
Disk Surface ◽  
Air Bearing ◽  
Nonlinear Dynamic Model ◽  
Frequency Spectra ◽  
Disk Interface ◽  
Partial Contact ◽  
Adhesion Contact ◽  
Contact Situation ◽  
Contact Slider

A nonlinear dynamic model is developed to analyze the bouncing vibration of a partial contact air bearing slider, which is designed for the areal recording density in hard disk drives of 1 Tbit/in2 or even higher. In this model the air bearing with contact is modeled using the generalized Reynolds equation modified with the Fukui-Kaneko slip correction and a new second order slip correction for the contact situation [1]. The adhesion, contact and friction between the slider and the disk are also considered in the model. It is found that the disk surface roughness, which moves into the head disk interface (HDI) as the disk rotates, excites the bouncing vibrations of the partial contact slider. The frequency spectra of the slider’s bouncing vibration have high frequency components that correspond to the slider-disk contact.

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