Effect of van der Waals forces on molecularly thin lubricant in the magnetic storage head-disk interface

2005 ◽  
Vol 98 (12) ◽  
pp. 124906 ◽  
Author(s):  
Ray R. Dagastine ◽  
Lee R. White ◽  
Paul M. Jones ◽  
Yiao-Tee Hsia
Keyword(s):  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Magnetic Storage ◽  
Head Disk Interface ◽  
Disk Interface ◽  
Molecularly Thin Lubricant

van der Waals force calculation between laminated media, pertinent to the magnetic storage head-disk interface

2005 ◽  
Vol 97 (10) ◽  
pp. 104503 ◽  
Author(s):  
Lee R. White ◽  
Raymond R. Dagastine ◽  
Paul M. Jones ◽  
Yiao-Tee Hsia
Keyword(s):  
Van Der Waals ◽  
Van Der Waals Force ◽  
Magnetic Storage ◽  
Head Disk Interface ◽  
Disk Interface ◽  
Force Calculation

Effect of media overcoat on van der Waals interaction at the head–disk interface

2005 ◽  
Vol 97 (12) ◽  
pp. 126106 ◽  
Author(s):  
Raymond R. Dagastine ◽  
Lee R. White ◽  
Paul M. Jones ◽  
Yiao-Tee Hsia
Keyword(s):  
Van Der Waals ◽  
Van Der Waals Interaction ◽  
Head Disk Interface ◽  
Disk Interface

Simulation of Contact at Head and Multilayer Disk Interface Under Quasi-Static Condition

2016 ◽  
Author(s):  
Ao Hongrui ◽  
Han Zhiying ◽  
Zhang Kai ◽  
Jiang Hongyuan
Keyword(s):  
Normal Load ◽  
Static Condition ◽  
Flying Height ◽  
Lubricant Layer ◽  
Magnetic Storage ◽  
Multilayer Thin Film ◽  
Head Disk Interface ◽  
Principal Stresses ◽  
Disk Interface ◽  
Von Mises

The reduction of head-media separation (HMS) results in a decreased flying height. Consequently, the contact probability between the slider and the lubricant layer or hard overcoat surface on the disks will increase greatly. Therefore, investigating the contact stress of the disk is vital for improving the reliability of the head disk interface. In this study, a rigid hemisphere sliding over a multilayer thin film half-space is implemented to simulate the contact between the recording slider and the magnetic storage multilayer disk under the quasi-static condition. The effects of different parameters such as normal load, friction coefficient and radius of slider on the von Mises, shear and principal stresses in the multilayer system are analyzed by using finite element method (FEM).

Optimization of molecularly thin lubricant to improve bearing capacity at the head-disk interface

2014 ◽  
Vol 21 (7) ◽  
pp. 1501-1511 ◽  
Author(s):  
Shahla Chowdhury ◽  
Antonis I. Vakis ◽  
Andreas A. Polycarpou
Keyword(s):  
Bearing Capacity ◽  
Head Disk Interface ◽  
Disk Interface ◽  
Molecularly Thin Lubricant

Molecularly Thin Lubricant Layer Contact Model Accounting for Interfacial Slip

2010 ◽  
Author(s):  
Antonis I. Vakis ◽  
Melih Eriten ◽  
Andreas A. Polycarpou
Keyword(s):  
Lubricant Layer ◽  
Rigid Sphere ◽  
Magnetic Storage ◽  
Interfacial Slip ◽  
Lateral Velocity ◽  
Disk Interface ◽  
Flat Substrate ◽  
High Shear Rates ◽  
Layer Contact ◽  
Molecularly Thin Lubricant

A model is presented that accounts for contact with a molecularly thin lubricant layer confined between a rigid sphere and flat substrate. The sphere is moving at a high lateral velocity inducing high shear rates and a significant increase of lubricant viscosity. Interfacial slip is modeled based on experimental and molecular dynamics data and includes effects of lubricant morphology and chemistry. The model is used to interpret experimental measurements of viscosity and slip and express them as functions of shear rate. These data can then be used in a typical head-disk interface in magnetic storage.

Analytical and Experimental Elastic-Plastic Impact Analysis of a Magnetic Storage Head-Disk Interface

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Raja R. Katta ◽  
Andreas A. Polycarpou ◽  
Jorge V. Hanchi ◽  
Mallika Roy
Keyword(s):  
Thin Film ◽  
Impact Analysis ◽  
Hard Disk Drives ◽  
Rigid Sphere ◽  
Magnetic Storage ◽  
Impact Model ◽  
Head Disk Interface ◽  
Disk Interface ◽  
Elastic Plastic ◽  
The Impact

As the use of hard disk drives in mobile applications increases, the susceptibility of disk damage due to high velocity slider-disk impact presents a serious challenge. The impact could result in extremely high contact stresses, leading to the failure of the head-disk interface. An elastic-plastic contact-mechanics-based impact model was developed and implemented to study the impact between a slider corner and a disk. The impact model is based on the contact of a rigid sphere on a deformable half-space. The effect of slider corner radii and impact velocities on the contact parameters was initially investigated for a homogeneous disk substrate. To examine the effects of thin-film layers on the disk, the model was extended to a realistic layered disk, where the actual layered mechanical properties were directly measured. At high impact velocities and/or small slider corner radii, the impact was found to be dominated by the substrate and the effect of layers was negligible. At low impact velocities and/or large slider corner radii, the effect of nanometer thick layers could be clearly seen, as these layers are stiffer than the substrate protecting the disk from potential damage at lighter loads. Realistic dynamic impact experiments involving a slider and a spinning thin-film disk were performed using an operational shock tester. The impact damage was characterized in terms of residual penetration depth caused by the impact force of the shock and the impact velocity of the slider. However, the results were inconclusive in correlating with the impact model. To better control the experimental parameters, quasistatic nanoindentation experiments were performed on actual thin-film media and were successfully compared with the model predictions.

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