Nano-asperity contact analysis and surface optimization for magnetic head slider/disk contact

Wear ◽  
1996 ◽  
Vol 202 (1) ◽  
pp. 83-98 ◽  
Author(s):  
Chin Y. Poon ◽  
Bharat Bhushan
Keyword(s):  
Contact Analysis ◽  
Asperity Contact ◽  
Magnetic Head ◽  
Head Slider ◽  
Disk Contact ◽  
Surface Optimization

Optimum Design of Magnetic Head Slider Under Static and Dynamic Operation Conditions of Hard Disk Drive

1999 ◽  
Author(s):  
Yasuhisa Hattori ◽  
Hiromu Hashimoto ◽  
Masayuki Ochiai
Keyword(s):  
Objective Function ◽  
Hard Disk Drive ◽  
Optimum Design ◽  
Hard Disk ◽  
Disk Drive ◽  
Magnetic Head ◽  
Head Slider ◽  
Dynamic Operation ◽  
Operation Conditions ◽  
Design Variables

Abstract The aim of this paper is to develop the general methodology for the optimum design of magnetic head slider for improving the spacing characteristics between head slider and disk surfaces under the static and dynamic operation conditions of hard disk drive and to present an application of the methodology to IBM 3380-type slider design. In the optimum design, the objective function is defined as the weighted sum of minimum spacing, maximum difference of spacing due to variation of radial location of head and maximum amplitude ratio of slider motion. Slider rail width, taper length, taper angle, suspension position and preload are selected as the design variables. Before the optimization of magnetic head slider, the effects of these five design variables on the objective function are examined by the parametric study, and then the optimum design variables are determined by applying the hybrid optimization technique combining the direct search method and the successive quadratic programming (SQP). From the results obtained, the effectiveness of optimum design on the spacing characteristics of magnetic head slider is clarified.

Contact Analysis of a Smooth Ball on an Anisotropic Rough Surface

1994 ◽  
Vol 116 (4) ◽  
pp. 850-859 ◽  
Author(s):  
C. Y. Poon ◽  
R. S. Sayles
Keyword(s):  
Surface Roughness ◽  
Rough Surface ◽  
Stochastic Approach ◽  
Contact Analysis ◽  
Asperity Contact ◽  
Correlation Lengths ◽  
Real Contact ◽  
Rough Surface Contact ◽  
Contact Pressures ◽  
Contact Spots

The effects of surface roughness and waviness upon the real contact areas, gaps between contact spots, and asperity contact pressures were studied. The distribution of real areas, gaps, and contact pressures are presented for different surface roughness, σ and correlation lengths, β*. The load-area relationship is compared to Bush’s model of strongly anisotropic rough surface contact using a stochastic approach.

Dynamic characteristics of a magnetic head slider

1985 ◽  
Vol 21 (5) ◽  
pp. 1509-1511 ◽  
Author(s):  
Y. Mizoshita ◽  
K. Aruga ◽  
T. Yamada
Keyword(s):  
Dynamic Characteristics ◽  
Magnetic Head ◽  
Head Slider

Air flow around a magnetic-head-slider suspension and its effect on slider flying-height fluctuation

1990 ◽  
Vol 26 (5) ◽  
pp. 2430-2432 ◽  
Author(s):  
Y. Yamaguchi ◽  
A. Ahasan Talukder ◽  
T. Shibuya ◽  
M. Tokuyama
Keyword(s):  
Air Flow ◽  
Flying Height ◽  
Magnetic Head ◽  
Head Slider

Influence of Surface Roughness Lay Directionality on Scuffing Failure of Lubricated Point Contacts

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
S. Li
Keyword(s):  
Frictional Heat ◽  
Bulk Temperature ◽  
Asperity Contact ◽  
Load Range ◽  
Rolling Velocity ◽  
Sliding Direction ◽  
Disk Contact ◽  
Continuous Surface ◽  
Scuffing Failure ◽  
Resistance Performance

The influence of roughness lay directionality on scuffing failure is studied considering different roughness lay direction combinations of the contacting surfaces of a ball-on-disk contact. Using a recently developed scuffing model Li et al., (2013, “A Model to Predict Scuffing Failures of a Ball-On-Disk Contact,” Tribol. Int., 60, pp. 233–245)., the bulk temperature and flash temperature are predicted for each roughness lay combination within the load range from 0.76 GPa to 2.47 GPa in a step-wise manner under the rolling velocity of 10 m/s and slide-to-roll ratio of −0.5 to show substantial impacts of roughness lay directionality on scuffing resistance performance (SRP). It is found (i) the lay direction combination that results into contacts of asperities with small contact radii leads to increased local contact pressures and frictional heat flux, reducing SRP; (ii) the continuous asperity contact along the sliding direction leads to continuous surface temperature rise and lowers SRP; and (iii) the lubricant side leakage caused by the pressure gradient in the direction normal to the sliding direction leads to reduced SRP. With these main mechanisms in effect, the SRP of a contact decreases as the deviation between the roughness texture orientations of the two surfaces increases. The surfaces with their roughness lay directions both perpendicular to the sliding direction exhibits best SRP. The surfaces with one roughness lay direction positioned in line with the direction of sliding and the other positioned perpendicular to the sliding direction shows worst SRP.

Air flow around magnetic-head-slider suspension and its effect on slider flying-height fluctuation

1990 ◽  
Author(s):  
Y. Yamaguchi ◽  
A.A. Talukder ◽  
T. Shibuya ◽  
M. Tokuyama
Keyword(s):  
Air Flow ◽  
Flying Height ◽  
Magnetic Head ◽  
Head Slider

Magnetic Head-Media Interface Temperatures: Part 2—Application to Magnetic Tapes

1987 ◽  
Vol 109 (2) ◽  
pp. 252-256 ◽  
Author(s):  
B. Bhushan
Keyword(s):  
Analytical Model ◽  
Magnetic Particles ◽  
Temperature Drop ◽  
Interface Temperature ◽  
Thermal Gradients ◽  
Asperity Contact ◽  
Sliding Surface ◽  
Magnetic Head ◽  
Head Surface ◽  
Radiometric Technique

An analytical model has been used to predict the interface temperature of a typical magnetic head-tape contact and of isolated (exposed) magnetic particles in contact with the head. Average and maximum interface temperatures for the assumed head-tape interface are about 7° and 10° C, respectively. If the exposed magnetic particles contact the head surface, the average and maximum temperture rises could be about 600° and 900° C, respectively. The duration of an asperity contact is about 2 to 4 μs and the thermal gradients perpendicular to the sliding surface are very large (a temperature drop of 90 percent in a depth of less than the radius of an asperity contact or a few micrometers). The predicted temperatures are compared with the temperatures previously measured using an infrared radiometric technique.

Numerical Simulations of Slider Interaction With Multiple Asperity Using Hertzian Contact Model

1995 ◽  
Vol 117 (4) ◽  
pp. 575-579 ◽  
Author(s):  
Ellis Cha ◽  
D. B. Bogy
Keyword(s):  
Disk Drive ◽  
Contact Model ◽  
Hertzian Contact ◽  
Flying Height ◽  
Radius Of Curvature ◽  
Asperity Contact ◽  
Disk Contact ◽  
Suspension Dynamics ◽  
Magnetic Hard Disk ◽  
Hertzian Contact Model

A numerical simulation of slider-disk contact in a magnetic hard disk drive is studied using the Hertzian contact model. The slider-disk contact is caused by flying height fluctuation due to disk runout for very low flying sliders. The rough disk topography is generated numerically by combining a sinusoidal waviness and a Gaussian roughness. For each asperity contact, the radius of curvature is calculated from the disk topography, and the radius is used to calculate the contact force using the Hertzian contact model. The slider’s response to a single asperity calculated using the Hertzian contact model agrees well with the result obtained using the impulse-momentum based contact model. The simulation results of slider-disk contact including suspension dynamics are calculated with and without friction for a “nano-slider.”

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