Evaluations of tribological characteristics of PFPE lubricants on DLC surfaces of magnetic disks

2007 ◽  
Vol 27 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Y. He ◽  
Y. Fujikawa ◽  
H. Zhang ◽  
K. Fukuzawa ◽  
Y. Mitsuya
Keyword(s):  
Tribological Characteristics ◽  
Magnetic Disks ◽  
Pfpe Lubricants

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.

scholarly journals HDI tribology characteristics of PFPE lubricants with different main-chains on magnetic disks

2020 ◽  
Vol 2020 (0) ◽  
pp. S16101
Author(s):  
Hiroshi TANI ◽  
Tsuyoshi SHIMIZU ◽  
Ryosuke SAGATA ◽  
Renguo LU ◽  
Shinji KOGANEZAWA ◽  
...  
Keyword(s):  
Magnetic Disks ◽  
Pfpe Lubricants

Tribological Characteristics of Newly Synthesized Multi-Functional PFPE Lubricants

2005 ◽  
Author(s):  
Hiroshi Chiba ◽  
Yukiko Oshikubo ◽  
Keiji Watanabe ◽  
Takeshi Tokairin ◽  
Eishin Yamakawa
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Fluid ◽  
Tribological Characteristics ◽  
Hydroxyl Groups ◽  
Parent Molecule ◽  
Polar Groups ◽  
Pfpe Lubricant ◽  
End Groups ◽  
Nmr Methods ◽  
Pfpe Lubricants

We have successfully synthesized a multi-functional PFPE lubricant in which extra polar groups exist in the middle of molecule. This was achieved by combining several PFPE molecules that contain hydroxyl end groups. The multifunctional molecule was fractionated using supercritical fluid of carbon dioxide then identified using NMR methods, which showed that average three to five hydroxyl groups are contained in one molecule depending on each fraction. This paper presents lubricant spreading properties and first monolayer thickness determined by means of half-dip coat method. It was found that resulting first monolayer thickness shows does not increase significantly; rather it was almost the same as that of the parent molecule.

A machine for real-time estimation of the tribological characteristics of materials

2020 ◽  
Vol 86 (4) ◽  
pp. 61-65
Author(s):  
M. V. Abramchuk ◽  
R. V. Pechenko ◽  
K. A. Nuzhdin ◽  
V. M. Musalimov
Keyword(s):  
Real Time ◽  
Time Estimation ◽  
Tribological Characteristics ◽  
Continuous Processing ◽  
Friction Machine ◽  
Dynamic Friction Coefficient ◽  
Displacement Sensors ◽  
Frictional Interaction ◽  
Real Time Estimation ◽  
Automated Quality Control

A reciprocating friction machine Tribal-T intended for automated quality control of the rubbing surfaces of tribopairs is described. The distinctive feature of the machine consists in implementation of the forced relative motion due to the frictional interaction of the rubbing surfaces fixed on the drive and conjugate platforms. Continuous processing of the signals from displacement sensors is carried out under conditions of continuous recording of mutual displacements of loaded tribopairs using classical approaches of the theory of automatic control to identify the tribological characteristics. The machine provides consistent visual real time monitoring of the parameters. The MATLAB based computer technologies are actively used in data processing. The calculated tribological characteristics of materials, i.e., the dynamic friction coefficient, damping coefficient and measure of the surface roughness, are presented. The tests revealed that a Tribal-T reciprocating friction machine is effective for real-time study of the aforementioned tribological characteristics of materials and can be used for monitoring of the condition of tribo-nodes of machines and mechanisms.

scholarly journals Tribological Aspects, Optimization and Analysis of Cu-B-CrC Composites Fabricated by Powder Metallurgy

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4217
Author(s):  
Üsame Ali Usca ◽  
Mahir Uzun ◽  
Mustafa Kuntoğlu ◽  
Serhat Şap ◽  
Khaled Giasin ◽  
...  
Keyword(s):  
Weight Loss ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Applied Load ◽  
Practical Significance ◽  
Tribological Characteristics ◽  
M 10 ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Four Levels

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

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