Investigation of Friction Over a Wide Range of Normal Forces

2007 ◽  
Author(s):  
Dirk Drees ◽  
Satish Achanta
Keyword(s):  
Surface Roughness ◽  
Dual Phase Steel ◽  
Normal Force ◽  
Diamond Like Carbon ◽  
Dual Phase ◽  
Normal Forces ◽  
Atomic Force ◽  
Wide Range ◽  
Atomic Interactions ◽  
The Coefficient Of Friction

Friction at different force, length, and time scales is of great interest in tribology. The mechanical, chemical, and physical (atomic) interactions, each operating at their own time length and force scale, makes friction complex. This work is an attempt to improve the understanding of friction at normal forces ranging from nN up to N. This investigation was carried out under reciprocating ball-on-flat sliding conditions on engineering surfaces like diamond-like carbon (DLC) and dual phase steel. The test equipments used for this investigation are an atomic force microscope, a microtribometer, and a macrofretting tester. It was observed that for a hard/hard tribocouple like DLC/Si3N4, the variation in the coefficient of friction is negligible whereas the variation is large when the tribocouple is hard / soft like in dual phase steel / Si3N4. By changing the surface roughness of the material, the dependence of friction on normal force could be altered or manipulated.

Mechanical behavior of DP780 dual phase steel at a wide range of strain rates

2018 ◽  
Vol 5 (9) ◽  
pp. 096519 ◽  
Author(s):  
Shengci Li ◽  
Lan Zhang ◽  
Hongjin Zhao ◽  
Liang Qi ◽  
Yonglin Kang
Keyword(s):  
Mechanical Behavior ◽  
Dual Phase Steel ◽  
Dual Phase ◽  
Strain Rates ◽  
Wide Range

Effect of the Temperature on Diamond-Like Carbon (DLC) Thin Film Based on LIS

2013 ◽  
Vol 421 ◽  
pp. 212-216 ◽  
Author(s):  
Lei Huang ◽  
Jun Tang Yuan ◽  
Zhen Hua Wang ◽  
Bin Bin Yu
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Intensity Ratio ◽  
Failure Load ◽  
Ion Source ◽  
Diamond Like Carbon ◽  
Anode Layer ◽  
Effect Mechanism ◽  
Atomic Force ◽  
Different Temperatures

Diamond-like carbon (DLC) thin films were deposited on YG6 cemented carbide by an anode-layer linear ion source (LIS). The effect of different temperatures (20°C, 80°C, 115°C and 150°C) on DLC thin films was investigatedby using atomic force microscope (AFM), scanning electron microscope (SEM) and Raman spectroscopy. It was found thatthe surface roughness of the film decreased at first and then increased with the increase of the temperature, and reached the trough at 80°C. The intensity ratio (ID/IG) and the adhesion of the film increased at first and then decreased, and both of them reached the peak at 80°C. When the temperature was 80°C, the surface roughness was 6.9nm, the intensity ratio (ID/IG) was1.91 and the critical failure load was 107.23N. The results show that the temperatures have a great effect on the surface morphology and mechanism properties of DLC thin films. Consequently, this paperfurther studied the effect mechanism of different temperatures on DLC thin films based on the experiment.

scholarly journals Energy absorbing properties of a steel profile made of dual phase steel

2018 ◽  
Vol 183 ◽  
pp. 01062
Author(s):  
Wojciech Moćko ◽  
Adam Brodecki
Keyword(s):  
Dual Phase Steel ◽  
Testing Machine ◽  
Dual Phase ◽  
Strain Rates ◽  
Bending Tests ◽  
Three Point Bending ◽  
Numerical Predictions ◽  
Steel Material ◽  
Wide Range ◽  
Energy Absorbing

Three point bending tests were carried out using a drop tower testing machine. Profile were made of 2 mm dual phase steel. Material was characterized at wide range of strain rates to calibrate Rusinek-Klepaczko constitutive model. Finally, experimental results were compared with numerical predictions obtained using finite element method.

scholarly journals Probing of Nanoscale Friction and Mechanical Characteristics of Cotton Fiber’s Surface

Fibers ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 64
Author(s):  
Hosseinali ◽  
Thomasson
Keyword(s):  
Surface Topography ◽  
Mechanical Characteristics ◽  
Normal Force ◽  
Adhesion Force ◽  
Transition Phase ◽  
Contact Mode ◽  
Frictional Properties ◽  
Normal Forces ◽  
Atomic Force ◽  
Two Samples

The surface topography and nanomechanical attributes of two samples of cotton fibers, namely, A and B, were characterized with various operation modes of an Atomic Force Microscope (AFM). The surface topography and friction images of the fibers were obtained in contact mode. The nanomechanical properties images—i.e., adhesion and deformation—were obtained in force tapping mode. The results indicate that the surface nanomechanical and nanoscale frictional properties of the fibers vary significantly between two samples. The plots of friction versus normal force of the fibers’ surface from both samples are fitted to the equation of single-asperity, adhesion-controlled friction. Nevertheless, within the range of the applied normal force, the friction curves of sample A surfaces show a characteristic transition phase. That is, under low normal forces, the friction curves closely conform with the Hertzian component of friction; after the transition takes place at higher normal forces, the friction curves follow Amontons’ law of friction. We demonstrated that the transition phase corresponds to a state at which the cuticle layer molecules are displaced from the fibers’ surface. The average adhesion force of the samples is consistent with the average friction signal strength collected under low normal forces.

SELECTIVE DRY ETCHING OF GaN OVER AlGaN IN BCL3/SF6 MIXTURES

2004 ◽  
Vol 14 (03) ◽  
pp. 756-761 ◽  
Author(s):  
D. BUTTARI ◽  
A. CHINI ◽  
A. CHAKRABORTY ◽  
L. MCCARTHY ◽  
H. XING ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Inductively Coupled Plasma ◽  
Laser Interferometry ◽  
Force Microscopy ◽  
Inductively Coupled ◽  
Icp Etching ◽  
Atomic Force ◽  
Template Process ◽  
Wide Range

Inductively coupled plasma (ICP) etching of GaN with high selectivity over Al .22 Ga .78 N in BCl 3/ SF 6 mixtures has been studied. Selectivity and surface morphology were investigated over a wide range of pressures (3.75–37.5mTorr), RF powers (30–120 W), ICP powers (100–400 W), and SF 6/ BCl 3 ratios (0.1–0.7). Higher pressures, lower dc biases, and higher SF 6/ BCl 3 ratios increased the GaN to AlGaN selectivity. Selectivities up to 25 were measured by laser interferometry. A root mean square (rms) surface roughness of 0.67 nm was measured by atomic force microscopy (AFM) after removal of 0.5 μm from a GaN template (process selectivity: 15, as-grown rms surface roughness: 0.56 nm). A degradation in surface morphology, with the gradual formation of pits, was observed for selectivities above 10.

scholarly journals Optimization Study on Surface Roughness and Tribological Behavior of Recycled Cast Iron Reinforced Bronze MMCs Produced by Hot Pressing

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3364
Author(s):  
Aydın Güneş ◽  
Ömer Sinan Şahin ◽  
Hayrettin Düzcükoğlu ◽  
Emin Salur ◽  
Abdullah Aslan ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Weight Loss ◽  
Cast Iron ◽  
Coefficient Of Friction ◽  
Tribological Behavior ◽  
Operational Parameters ◽  
Optimization Study ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Marine Engineering

Surface roughness reflects the quality of many operational parameters, namely service life, wear characteristics, working performance and tribological behavior of the produced part. Therefore, tribological performance is critical for the components used as tandem parts, especially for the MMCs (Metal Matrix Composites) which are a unique class of materials having extensive application areas such as aerospace, aeronautics, marine engineering and the defense industry. Current work covers the optimization study of production parameters for surface roughness and tribological indicators of newly produced cast iron reinforced bronze MMCs. In this context, two levels of temperature (400 and 450 °C), three levels of pressure (480, 640 and 820 MPa) and seven levels of reinforcement ratios (60/40, 70/30, 80/20, 90/10, 100/0 of GGG40/CuSn10, pure bronze-as received and pure cast iron-as received) are considered. According to the findings obtained by Taguchi’s signal-to-noise ratios, the reinforcement ratio has a dominant effect on surface roughness parameters (Ra and Rz), the coefficient of friction and the weight loss in different levels. In addition, 100/0 reinforced GGG40/CuSn10 gives minimum surface roughness, pure cast iron provides the best weight loss and pure bronze offers the desired coefficient of friction. The results showed the importance of material ingredients on mechanical properties by comparing a wide range of samples from starting the production phase, which provides a perspective for manufacturers to meet the market supply as per human requirements.

scholarly journals Numerical Evaluation of Surface Roughness Influences on Cold Formability of Dual‐Phase Steel

2020 ◽  
Vol 91 (11) ◽  
pp. 2000141
Author(s):  
Peerapon Wechsuwanmanee ◽  
Junhe Lian ◽  
Wenqi Liu ◽  
Sebastian Münstermann
Keyword(s):  
Surface Roughness ◽  
Numerical Evaluation ◽  
Dual Phase Steel ◽  
Dual Phase

Surface roughness measurements of vanadium-contaminated fluidized cracking catalysts by atomic force microscopy

1996 ◽  
Vol 54 ◽  
pp. 866-867
Author(s):  
H. Kinney ◽  
M.L. Occelli ◽  
S.A.C. Gould
Keyword(s):  
Surface Roughness ◽  
Zeolite Y ◽  
Atomic Level ◽  
Microporous Structure ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Roughness Measurements ◽  
Cracking Catalysts

For this study we have used a contact mode atomic force microscope (AFM) to study to topography of fluidized cracking catalysts (FCC), before and after contamination with 5% vanadium. We selected the AFM because of its ability to well characterize the surface roughness of materials down to the atomic level. It is believed that the cracking in the FCCs occurs mainly on the catalysts top 10-15 μm suggesting that the surface corrugation could play a key role in the FCCs microactivity properties. To test this hypothesis, we chose vanadium as a contaminate because this metal is capable of irreversibly destroying the FCC crystallinity as well as it microporous structure. In addition, we wanted to examine the extent to which steaming affects the vanadium contaminated FCC. Using the AFM, we measured the surface roughness of FCCs, before and after contamination and after steaming.We obtained our FCC (GRZ-1) from Davison. The FCC is generated so that it contains and estimated 35% rare earth exchaged zeolite Y, 50% kaolin and 15% binder.

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