S162012 Adhesion and Friction Force Measurement of Ultra-thin Liquid Lubricant on Magnetic Disks by Pin-on-Disk test

2012 ◽  
Vol 2012 (0) ◽  
pp. _S162012-1-_S162012-4
Author(s):  
Hiroshi TANI ◽  
Toshiya MITSUTOME ◽  
Yusuke TSUJIGUCHI ◽  
Masayuki KANDA ◽  
Norio TAGAWA
Keyword(s):  
Friction Force ◽  
Force Measurement ◽  
Magnetic Disks ◽  
Liquid Lubricant ◽  
Pin On Disk ◽  
Disk Test

Effect of TiO2 Addition of Oxidizing Catalytic Activity of an Al2O3 Slider for Magnetic Disks

1994 ◽  
Vol 116 (2) ◽  
pp. 275-279 ◽  
Author(s):  
Shinsuke Higuchi ◽  
Takeshi Miyazaki ◽  
Yasutaka Suzuki ◽  
Hideaki Tanaka ◽  
Iwao Matsuyama
Keyword(s):  
Catalytic Activity ◽  
Grain Boundary ◽  
Test System ◽  
High Catalytic Activity ◽  
Carbon Overcoat ◽  
Magnetic Disks ◽  
Tio2 Addition ◽  
Pin On Disk ◽  
Tio2 Phase ◽  
Disk Test

Oxidizing catalytic activity of a slider is a factor which could affect wear of magnetic disks with a carbon overcoat. Al2O3 composites containing 2–50 mol% TiO2 were produced, which had different oxidizing catalytic activities but nearly the same hardness and thermal conductivity. Activation energy (Ec) for carbon oxidation when it is mixed with the composite was measured to get the oxidizing catalytic activity, and it was found that Ec changed from about 70 kJ/mol for Al2O3 to about 110 kJ/mol for Al2O3 containing 9.1–16.7 mol% TiO2. TiO2 addition increased and decreased Ec. The former was due to segregation of the Ti-Al-O phase at the Al2O3 grain boundary, which could inhibit the catalysis at the Al2O3 grain boundary. The latter was due to the unreacted TiO2 phase, which by itself has high catalytic activity. TiO2-Al2O3 sliders having different Ec were examined in sliding wear against a magnetic disk with a carbon overcoat using a pin-on-disk test system. It was found that wear rate of the carbon overcoat was lower when the slider had a larger Ec, i.e., lower catalytic activity. It was also found that wear particles of the carbon overcoat were likely to be larger with lower catalytic activity.

Comparisons of Friction Characteristics of a Lightly Loaded Pin Sliding Over Magnetic Disks Coated With Polar and Non-Polar PFPE Lubricants

2005 ◽  
Author(s):  
Yinbo He ◽  
Yasunaga Mitsuya ◽  
Hedong Zhang ◽  
Kenji Fukuzawa
Keyword(s):  
Friction Force ◽  
Gradual Increase ◽  
Rotating Disk ◽  
Disk Surface ◽  
Lubricant Film ◽  
Magnetic Disks ◽  
Friction Tester ◽  
Pin On Disk ◽  
End Group ◽  
Pfpe Lubricants

This paper deals with the measurement of friction force exerted on molecularly thin lubricant film surfaces using a specially arranged pin-on-disk type friction tester. The measurements were carried out by sliding a 1.5-mm-diameter glass ball slider on a rotating disk surface with small loading force. Polar and non-polar PFPE lubricants were dip-coated on magnetic disks covered with diamond-like-carbon (DLC) film. Lubricant film thickness was varied to constitute multiple layered film structures on the DLC surface. To clarify the stratified effect of thin lubricant film on friction, a lightly loading force and a slow rotational speed were selected. The tested results showed that the friction force on non-polar lubricant surfaces increase slightly for mono-layer and multi-layer cases, while the friction force on polar lubricants show steady and gradual increase with increasing loading force. We conclude that friction force at small loading force is dependent intimately on the thickness, molecular weight and end-group functionality.

Predicting the wear coefficient and friction coefficient in dry point contact using continuum damage mechanics

2018 ◽  
Vol 233 (3) ◽  
pp. 447-455 ◽  
Author(s):  
Sahar Ghatrehsamani ◽  
Saleh Akbarzadeh
Keyword(s):  
Friction Coefficient ◽  
Damage Mechanics ◽  
Point Contact ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Wear Coefficient ◽  
Mechanics Model ◽  
Pin On Disk ◽  
Disk Test ◽  
The Continuum

Wear coefficient and friction coefficient are two of the key parameters in the performance of any tribo-system. The main purpose of the present research is to use continuum damage mechanics to predict wear coefficient. Thus, a contact model is utilized that can be used to obtain the friction coefficient between the contacting surfaces. By applying this model to the continuum damage mechanics model, the wear coefficient between dry surfaces is predicted. One of the advantages of using this model is that the wear coefficient can be numerically predicted unlike other methods which highly rely on experimental data. In order to verify the results predicted by this model, tests were performed using pin-on-disk test rig for several ST37 samples. The results indicated that the wear coefficient increases with increasing the friction coefficient.

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.

Investigation of wear on the upper edges of webs of thin-film coated single-screw extruders processing pure polymers

2021 ◽  
Vol 63 (2) ◽  
pp. 143-150
Author(s):  
Torben Buttler ◽  
Jens Hamje ◽  
Rolf Reiter ◽  
Volker Wesling
Keyword(s):  
Wear Behavior ◽  
Cold Work ◽  
Polymer Processing ◽  
Chromium Nitride ◽  
Metallographic Examination ◽  
Test Speed ◽  
Single Screw Extruders ◽  
Pin On Disk ◽  
Screw Extruders ◽  
Disk Test

Abstract During polymer extrusion there are a variety of situations in which the screwthread of the extrusion screw has an unlubricated metal-to-metal contact with the barrel wall. At the same time the screw coating is subjected to the highest loads. The combination of a secondary hardening cold work steel 1.2379 and a chromium nitride coating deposited by ARC-PVD, which is frequently used in polymer processing, is characterized and investigated. The characterization is done by metallographic examination, SEM and CLSM. The tests were performed on a pin-on-disk and a pin-roll test rig. Different roughness levels were tested on the pin-on-disk test, where massive differences in wear behavior were found. A hybrid surface structure is proposed to optimize the tribosystem. On the pin-on-disk test stand, rollers made of the same material pairing were tested. The test speed was varied to highlight differences and similarities between the tribological systems. A wear minimization of 50 % was achieved and the similarities between the tribological systems were highlighted. In addition, the investigations led to the development of a new model thesis which provides a reason for the development of stippling on the screw when processing polycarbonate.

Development of Piston Friction Force Measurement System

2002 ◽  
Vol 26 (8) ◽  
pp. 1608-1614
Author(s):  
Gyeong-Pyo Ha ◽  
Jung-Su Kim ◽  
Myeong-Rae Jo ◽  
Dae-Yun O
Keyword(s):  
Friction Force ◽  
Measurement System ◽  
Force Measurement ◽  
Force Measurement System

MEMS-Based Micro Probe Incorporating Electrostatic Actuator Towards Friction Force Microscopy With Accurate Gap Control

2018 ◽  
Author(s):  
Kenji Fukuzawa ◽  
Mikito Takahashi ◽  
Yusuke Hori ◽  
Shintaro Itoh ◽  
Hedong Zhang
Keyword(s):  
Friction Force ◽  
Force Measurement ◽  
Electrostatic Force ◽  
Sample Surface ◽  
Gap Size ◽  
Electrostatic Actuator ◽  
Friction Force Microscopy ◽  
Force Microscopy ◽  
Gap Control ◽  
Lubrication Properties

Lubrication in nanometer-sliding gaps has attracted much interest along with the advance of processing technology. To clarify the lubrication phenomena in nanometer gaps, force measurement under accurate control of the gap between the sliding probe and sample surface is needed because the lubrication properties significantly depend on the gap size. In this paper, we aimed at realizing friction force microscopes that is capable of accurate control of sliding gap. A probe with an actuator that utilizes electrostatic force was proposed and its feasibility was demonstrated.

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