Author: Farage Ahmed SherrimaPublisher:
ISBN:
Category :
Languages : en
Pages : 242
Book Description
Static and Dynamic Behavior of Magnetic Thin-film Heads
Author: Farage Ahmed SherrimaPublisher:
ISBN:
Category :
Languages : en
Pages : 242
Book Description
Static and Dynamic Behavior of Magnetic Thin-film Heads
Author: Farage Ahmed SherrimaPublisher:
ISBN:
Category : Magnetic recorders and recording
Languages : en
Pages : 132
Book Description
Dynamic and Quasi-static Contact and Scratch Analysis of Micro-nanoscale Thin Solid Films with Application to Magnetic Storage Hard Disk Drives
Author: Raja Ramakanth KattaPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
With current demand for decreased size of micro/nanoscale systems, coupled with increased mobility, critical understanding of the ensuing contact or impact related behavior of thin solid films used in these systems is of paramount importance for improved design and reliability. In modern micro/nanodevice technologies significant emphasis has to be placed on the design of thin-films which can provide the required contact and scratch resistance. To aid this endeavor, scientific studies of the contact and scratch processes in these systems, both static and dynamic are needed to provide the tools necessary to help the advancement of these technologies. One such problem is the impact contact or quasi-static contact and scratch of the slider and disk in magnetic storage hard disk drives (HDD). Similar contact problems are encountered during the operation of other micromechanical systems like RF-MEMS switches where surface damage is observed after cyclic contact. One of the most critical elements of multilayer contact analysis is proper determination of the nanomechanical properties of each thin-film on the multilayer system. In the first part of this work the method of determining the mechanical properties using the Oliver and Pharr (O-P) nanoindentation technique is described. For nanometer sized thin-films where the O-P technique gives incorrect results, an improved method is used. Later a dimensional analysis-based method to obtain the mechanical properties from the nanoindentation data is implemented for magnetic storage films. A direct comparison of the properties obtained from conventional O-P nanoindentation technique to this new technique is presented. In the second part of this work, the effect of dynamic contact or impact on multilayer thin films specific to magnetic storage hard disk drives is presented. Since there are no impact models available for multilayer thin films in the literature, a new contact mechanics-based (CM) semi-analytical model of a rigid sphere (representing a slider corner) impacting an elastic-plastic (E-P) multilayer thin-film half-space was proposed for the first time to examine the potential damage to a magnetic storage head disk interface (HDI). A dynamic 3D finite element analysis (FEA) model was also developed to examine the impact damage in more detail and validate the impact model. To characterize the plastic deformation and frictional energy losses associated with the impact damage, a comprehensive oblique elastic impact coefficient of restitution (COR) model was proposed for elastic-plastic impacts for the first time and validated using FEA. A method to decouple the oblique impact parameters into normal impact COR and tangential impact COR was formulated. Since, in microsystems, the geometry of the impacting bodies is not limited to spherical bodies, a new contact mechanics-based (CM) model of a rigid cylinder with a finite length impacting an elastic-plastic homogeneous disk was also proposed and includes a novel method of estimating the residual depth after impact. Based on elastic unloading, an improved coefficient of restitution model was also proposed. This new impact model was applied to study a practical case of a cylindrical feature on the slider of a magnetic storage hard disk drive impacting the disk to predict various critical impact contact parameters. The CM model was validated using a plane strain FEA-based model and it was found that a cylindrical feature with longer length results in a substantial alleviation of impact damage. The final part of this work involved the investigation of the performance of thin-film multilayers while under the influence of much milder quasi-static contact scratch. A 2D plane strain FEA model of a rigid cylinder sliding over a multilayered thin-film half space was developed. The effects of different contact parameters such as applied normal load, friction coefficient and radius of curvature of the cylinder on the critical stresses in the multilayer system were analyzed. Later, for direct experimental comparison a full-blown 3D quasi-static FEA-based nanoscratch model of the multilayer thin-film system was also developed. The FEA scratch results were compared to nanoscratch experiments performed on actual magnetic disks. Consequently, the 3D FEA scratch model was used to quantitatively correlate the subsurface plastic deformation to the magnetic erasures typically found in HDDs due to scratch for the very first time.
Dissertation Abstracts International
Author: Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 652
Book Description
Static and Dynamic Properties of Ferroelectric Thin-film Memories
Author: Hendrik M. DuikerPublisher:
ISBN:
Category : Ferroelectric devices
Languages : en
Pages : 190
Book Description
Advanced Tribology
Author: Jianbin LuoPublisher: Springer Science & Business Media
ISBN: 3642036538
Category : Technology & Engineering
Languages : en
Pages : 1040
Book Description
"Advanced Tribology" is the proceedings of the 5th China International Symposium on Tribology (held every four years) and the 1st International Tribology Symposium of IFToMM, held in Beijing 24th-27th September 2008. It contains seven parts: lubrication; friction and wear; micro/nano-tribology; tribology of coatings, surface and interface; biotribology; tribo-chemistry; industry tribology. The book reflects the recent progress in the fields such as lubrication, friction and wear, coatings, and precision manufacture etc. in the world. The book is intended for researchers, engineers and graduate students in the field of tribology, lubrication, mechanical production and industrial design. The editors Jianbin Luo, Yonggang Meng, Tianmin Shao and Qian Zhao are all the professors at the State Key Lab of Tribology, Tsinghua University, Beijing.
Proceedings of the International Conference on Magnetism
Author: Computational Analyses of Magnetization Dynamics in Thin Film Write Heads
Author: Gene Michael SandlerPublisher:
ISBN:
Category : Magnetic recorders and recording
Languages : en
Pages : 466
Book Description
Advances in Information Storage Systems
Author: Bharat BhushanPublisher: World Scientific
ISBN: 9812815902
Category : Technology & Engineering
Languages : en
Pages : 381
Book Description
This volume covers friction-induced vibration, the influence of actuator-bearing grease composition, wear measurements for proximity recording heads, characteristics of a suspension assembly, design and analysis of the HDD Servo System, reluctance torque reduction, etc. It is organized into three parts: Mechanics and Tribology for Data Storage Systems; Dynamics and Controls for Data Storage Systems; and Electric Motors for Data Storage Systems.
Author: