Effect of disk surface asperity on statistic characteristics of air bearing films at the head/disk interface

2016 ◽  
Author(s):  
Bao-Jun Shi ◽  
Zhao-Quan Zhang ◽  
Jia-Dong Ji ◽  
Zhong-Lei Wang
Keyword(s):  
Disk Surface ◽  
Air Bearing ◽  
Head Disk Interface ◽  
Surface Asperity ◽  
Disk Interface

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.

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.

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.

Numerical Investigation of Thermal Effects on a HAMR Head-Disk Interface

2014 ◽  
Author(s):  
Kyaw Sett Myo ◽  
Weidong Zhou ◽  
Xiaoyang Huang ◽  
Shengkai Yu
Keyword(s):  
Temperature Field ◽  
Laser Beam ◽  
Numerical Investigation ◽  
Thermal Effects ◽  
Hard Disk ◽  
Disk Surface ◽  
Recording Media ◽  
Head Disk Interface ◽  
Disk Interface ◽  
High Density Recording

Heat-assisted magnetic recording (HAMR) is one of prospective high density recording technologies in current hard disk industry. It requires heating a spot on the recording media with the laser beam to overcome the superpara-magnetic limit. The heat produced by laser beam causes the temperature field on the hard disk surface to be highly non-uniform, which may lead to unexpectedly severe lubricant loss, or even the failure of the whole HAMR system. In the meantime, the heat loss caused by the optical delivery system may cause unwanted thermal protrusion on the slider body, which may affect slider’s flying stability in the end.

Stability and Dynamics of Non-Linear Slider Behaviour Due to Disk Waviness in the Presence of Intermolecular and Electrostatic Forces

2005 ◽  
Author(s):  
Vineet Gupta ◽  
David B. Bogy
Keyword(s):  
Resonance Frequency ◽  
Equations Of Motion ◽  
Disk Surface ◽  
Air Bearing ◽  
Electrostatic Forces ◽  
Disk Interface ◽  
Non Linear ◽  
Bearing Stiffness ◽  
Stiffness And Damping ◽  
Nonlinear Nature

In this paper we present a theoretical investigation of the stability and the dynamics of the non-linear behavior of a slider at very low head media spacing. A single DOF head disk interface (HDI) model, with constant air bearing stiffness and damping has been used to study the effect of disk waviness on the nonlinear slider dynamics in the presence of intermolecular and electrostatic forces. A variational approach based on the principle of least action was used to derive the equations of motion of the slider. Further, a stability criteria was derived that helped to better understand the instabilities that appear in slider when the slider is flying in close proximity to the disk surface. Due to extremely nonlinear nature of the interaction between the slider and the disk, we observed some strange features of the motion of the slider. In particular the effects of the nonlinear interaction force, air bearing stiffness and damping on the instabilities of the periodic motions of the slider are discussed in detail. We found that the branch associated to the disk waviness frequencies larger than the resonance frequency is always stable and the branch associated to the disk waviness frequencies smaller than the resonance frequency exhibits two stable domains and one unstable domain. This analysis was further extended to include the nonlinear nature of air bearing stiffness and damping as well as contact at the HDI.

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