Transparent Pin Wear Test on Thin-Film Magnetic Disk

1995 ◽  
Vol 117 (2) ◽  
pp. 297-301 ◽  
Author(s):  
Youichi Kawakubo ◽  
Yotsuo Yahisa
Keyword(s):  
Thin Film ◽  
Wear Debris ◽  
Wear Test ◽  
Video Camera ◽  
Video Monitoring ◽  
Friction Measurement ◽  
Magnetic Disks ◽  
Bulk Hardness ◽  
Pin On Disk ◽  
Wear Tests

Pin-on-disk wear tests on thin-film magnetic disks were performed using transparent materials. Quartz glass (QG), transparent zirconia (TZ), sapphire (SA), and synthesized diamond (DI) were used as pin materials. In addition to friction, sliding condition and pin wear were continuously monitored with video camera. Simultaneous friction measurement and video monitoring showed that friction dropped when wear debris intruded between pin and disk surfaces. Pin wear, from the measured diameter of wear scar on spherical pins, increased in the order of DI, SA, QG, and TZ. This order of pin wear does not coincide with that of the pin bulk hardness. Disk lifetime increased in the order of TZ, QG, SA, and DI, and the smaller the pin wear, the longer the disk lifetime.

Head Wear in Contact Recording Systems

2003 ◽  
Author(s):  
Youichi Kawakubo ◽  
Shinichi Kobatake ◽  
Shunichi Miyazawa ◽  
Shinichi Nakazawa
Keyword(s):  
Thin Film ◽  
Wear Debris ◽  
Hard Disk Drives ◽  
Disk Surface ◽  
Disk Drives ◽  
Magnetic Disks ◽  
Disk Lubricant ◽  
Pin On Disk ◽  
Contact Recording ◽  
Wear Tests

The possibility of disk failure, a common failure mode conventional HDDs, was studied in conditions supposed contact recording systems. For this purpose, transparent pin-on-disk wear tests were performed on thin-film magnetic disks with sliding load less than 5 mN. We found that visible wear scar did not appear on disk surfaces. Wear debris were found be buried on the disk surfaces. This showed that the reduction of head wear and vibration are two main problems to be solve for future hard disk drives. We then studied effects of disk lubricant and tape burnishing of disk surface on pin wear. The results showed the higher the molecular weight of lubricants, the lower the pin wear, and tape burnishing reduced pin wear.

Reduction of Head Wear on Thin-Film Magnetic Disks

2002 ◽  
Author(s):  
Youich Kawakubo ◽  
Shunichi Miyazawa ◽  
Kenjirou Nagata ◽  
Shinichi Kobatake
Keyword(s):  
Thin Film ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Surface ◽  
Disk Drives ◽  
Magnetic Disks ◽  
Surface Flattening ◽  
Magnetic Disk ◽  
Pin On Disk ◽  
Wear Tests

It is necessary to reduce head wear to develop future hard disk drives. For this purpose, we have been studying transparent pin-on-disk wear tests on thin-film magnetic disks. We reported that pin wear on thin-film magnetic disk showed running-in effects. The reason of the running-in was considered to be a result of disk surface flattening. This means that if we could introduce an efficient burnishing technique, we could reduce head wear in operation. We then introduced a burnishing technique using a hemispherical diamond slider and compared pin wear on disk surfaces with and without burnishing. The results showed that the pin wear was reduced by the introduction of the burnishing technique. We consider that burnishing with hard round slider is another way of reducing head wear on future disk surfaces.

A Comparative Study of the Results Obtained through Different Types of Wear Tests

2012 ◽  
Vol 730-732 ◽  
pp. 951-956
Author(s):  
Ana García ◽  
Laura Ferreiro ◽  
Angel Varela ◽  
José Luís Mier ◽  
Carolina Camba ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Comparative Study ◽  
Wear Test ◽  
Operating Conditions ◽  
Test Standards ◽  
Different Types ◽  
Dry Sand ◽  
Pin On Disk ◽  
Wear Tests

Wear is one of the most worrying problems in industry; it affects many production sectors. Therefore, the wear resistance of materials must be assessed in order to predict their response and anticipate possible failures. Maintenance could then be scheduled accordingly. Due to the large number of situations where wear is important, one of the main complications in tribology is that it is difficult to replicate in a laboratory the precise conditions of service. Thus, there is a need to choose between different kinds of tests to simulate actual conditions. However, this aim is difficult to achieve, as variables and conditions of service are numerous. In this situation, it is neither practical nor possible to have as many test devices in the laboratory as real possibilities. It is necessary to find a test that can be extrapolated to many possible situations. An important question is if the results obtained with different configurations simulated in the laboratory are good equivalents or, on the contrary, the choice of method has an influence and to what extent the latter case is true. In addition, it should be noted that wear test standards mention how difficult it is to reproduce results and how they are influenced by operating conditions In this paper, three wear tests methods are studied- the pin-on-disk, dry sand/rubber wheel test and wet sand/rubber wheel- in order to find a relationship between the results obtained by them. Furthermore, different techniques are analysed to establish, if possible, which ones are more likely to achieve more reliable results.

Tribological Characteristics of Thin-Film Disks With and Without Mobile Lubricant

2009 ◽  
Author(s):  
Youichi Kawakubo ◽  
Takahiro Hayakawa ◽  
Yusuke Sugawara ◽  
Koji Ikeda ◽  
Osamu Kitamura
Keyword(s):  
Thin Film ◽  
Hard Disk Drives ◽  
Disk Surface ◽  
Tribological Characteristics ◽  
Disk Drives ◽  
Slow Speed ◽  
Force Increase ◽  
Low Load ◽  
Pin On Disk ◽  
Wear Tests

Lubricant on thin-film magnetic disks is divided into two parts. One is bonded lubricant that is fixed on disk surface and remains on disk surface after solvent rinsing. The other is mobile lubricant that can move on disk surface and is removed by solvent rinsing. It has been believed that mobile lubricant is imperative to design reliable hard disk drives. However, mobile lubricant would also be a cause of high friction between heads and disks. We started our studies on disks without mobile lubricant to find the possibility of disks with only bonded lubricant. In this paper, tribological characteristics of disks with and without mobile lubricant at the same lubricant thickness were compared using our transparent pin-on-disk wear tests. The results showed that pin wear was smaller on disks without mobile lubricant than those on disks with mobile lubricant in low load or slow speed conditions. The reason of this was considered to be the contact force increase by meniscus force due to lubricant bridge.

scholarly journals Tribological investigation of multilayer CrN/CrCN/TaN films deposited by close field unbalanced magnettron sputtering

2019 ◽  
Vol 58 (1) ◽  
pp. 271-279 ◽  
Author(s):  
Erkan Bahce ◽  
Nese Cakir
Keyword(s):  
Wear Test ◽  
High Hardness ◽  
Scratch Test ◽  
Adhesion Properties ◽  
Cocrmo Alloy ◽  
Unbalanced Magnetron Sputtering ◽  
Unbalanced Magnetron ◽  
Pin On Disc ◽  
Pin On Disk ◽  
Wear Tests

AbstractCrN/CrCN/TaN multilayer films were deposited onto the CoCrMo alloy substrates at different number layers as two, four and 8 layers by close-field unbalanced magnetron sputtering method. Microstructure and the tribo-logical properties of the films were characterized by XRD, SEM, pin-on-disk wear test, scratch test, micro hardness. CrN/CrCN/TaN multilayer coatings exhibited good adhesion properties on the CoCrMo alloy substrate. A very high hardness value of 60 GPa was obtained for 8 multilayered coating. As a result of the pin-on-disc wear tests, it was found that the tribological properties of the CoCrMo alloy were enhanced by coating its surface with this architecture by using close-field unbalanced magnetron system with used parameters.

On data dispersion in pin-on-disk wear tests

Wear ◽  
2002 ◽  
Vol 252 (11-12) ◽  
pp. 1001-1006 ◽  
Author(s):  
S Guicciardi ◽  
C Melandri ◽  
F Lucchini ◽  
G de Portu
Keyword(s):  
Pin On Disk ◽  
Wear Tests

Nanoscale Mechanical Properties of In-Situ Tribofilms Generated from ZDDP and F-ZDDP with and without Antioxidants

2007 ◽  
Vol 7 (12) ◽  
pp. 4378-4390 ◽  
Author(s):  
Anuradha Somayaji ◽  
Ramoun Mourhatch ◽  
Pranesh B. Aswath
Keyword(s):  
Electron Microscopy ◽  
Wear Debris ◽  
Surface Region ◽  
Nucleation And Growth ◽  
Near Surface ◽  
Transmission Electron ◽  
Dialkyl Dithiophosphates ◽  
Wear Tests ◽  
Diphenyl Amine

Tribofilms with thickness ranging from 100–200 nm were developed in-situ during wear tests using a zinc dialkyl dithiophosphates (ZDDP) and fluorinated ZDDP (F-ZDDP). The influence of the antioxidant alkylated diphenyl amine on the formation and properties of these tribofilm is examined. Results indicate that the thickness of the tribofilms formed when F-ZDDP is used is always thicker than the tribofilm formed with ZDDP. In addition, in the presence of antioxidants the tribofilm thickness is increased. The hardness of these tribofilms in the absence of the antioxidants is significantly higher at the near surface region (0–30 nm) when compared to the films formed in the presence of antioxidant. Nanoscratch tests conducted to examine the abrasion resistance of the tribofilms also indicate that the tribofilms formed by F-ZDDP are more resistant to scratch compared to films formed by ZDDP. In the presence of antioxidant, tribofilms formed by F-ZDDP are significantly thicker while both films behave in a similar fashion in nanoscratch tests. Transmission electron microscopy of the wear debris formed during the tests were examined and results indicate the nucleation and growth of nanoparticles of Fe3O4 with an approximate size of 5–10 nm embedded within an otherwise amorphous tribofilm.

Tribological implications of solvents in dip-coating lubrication of thin film magnetic disks

1996 ◽  
Vol 32 (5) ◽  
pp. 3699-3701 ◽  
Author(s):  
C. Gao ◽  
Y.C. Lee ◽  
J. Chao ◽  
M. Russak
Keyword(s):  
Thin Film ◽  
Dip Coating ◽  
Magnetic Disks

Friction-Heating Maps and Their Applications

MRS Bulletin ◽  
1991 ◽  
Vol 16 (10) ◽  
pp. 41-48 ◽  
Author(s):  
H.S. Kong ◽  
M.F. Ashby
Keyword(s):  
Normal Force ◽  
Frictional Heat ◽  
Unified Approach ◽  
Magnetic Disks ◽  
Heat Flows ◽  
Bulk Heating ◽  
Friction Heating ◽  
Image Position ◽  
Pin On Disk ◽  
Nominal Contact Area

Friction is often a nuisance, but it can be useful too. Brakes, clutches, and tires rely on it, of course, though the inevitable fractional heat remains a problem. Other applications use frictional heat: friction cutting and welding, skiing, skating, and curling. The damage to magnetic disks caused by head-disk contact and the striking of matches are also examples.This article illustrates a framework where the thermal aspects of friction can be analyzed in an informative way. It uses a unified approach to the calculation of flash and bulk heating, and a helpful diagram—the frictional temperature map—to display the results. The method is approximate, but the approximations have been carefully chosen and calibrated to give precision adequate to most tasks, and the gain in simplicity is great.The symbols used in this article are defined in Table I.When two contacting solids 1 and 2, pressed together by a normal force F, slide at a relative velocity ν and with coefficient of friction ü, heat is generated at the surface where they meet. The heat generated, q, per unit of nominal contact area, An, per second isThe heat flows into the two solids, partitioned between them in a way that depends on their geometry and thermal properties. Figure 1 shows one geometry commonly used for laboratory tests: the pin-on-disk configuration. The pin is identified by the subscript 1, the disk by subscript 2. Solid 1 can have properties which differ from those of solid 2.

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