Wear of thermoplastics determined by multiple scratching

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
M. Dolores Bermúdez ◽  
Witold Brostow ◽  
Francisco J. Carrión-Vilches ◽  
Juan J. Cervantes ◽  
Dorota Pietkiewicz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Resistance ◽  
Scanning Probe Microscopy ◽  
Polyamide 6 ◽  
Constant Load ◽  
Scanning Probe ◽  
Styrene Acrylonitrile ◽  
Scratch Tests ◽  
Scanning Electron

AbstractWe studied wear resistance in sliding by multiple scratching along the same groove for a variety of thermoplastics: polystyrene, styrene-acrylonitrile, polyamide 6 and polysulfone. Constant-load experiments were carried out with a micro scratch tester for several loads between 2.5 and 15 N; each time 15 scratches were performed. Except for polystyrene, all materials show an asymptotic residual depth as a function of the number of scratch tests performed. In contrast to other materials, polystyrene exhibits brittleness and debris formation. Scanning electron microscopy and scanning probe microscopy were used to characterize the deformation and wear mechanisms and were connected to the wear data obtained by multiple scratching. At 15 N we found a viscoelastic recovery for polystyrene of 27.8% while for polyamide 6 the corresponding value is 80.2%.

Scratch velocity and wear resistance

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
M. Dolores Bermúdez ◽  
Witold Brostow ◽  
Francisco J. Carrión-Vilches ◽  
Juan J. Cervantes ◽  
Gowrisankar Damarla ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Scanning Probe Microscopy ◽  
Sliding Wear ◽  
Polyamide 6 ◽  
Scanning Probe ◽  
Low Velocity ◽  
Contact Heating ◽  
Surface Damages ◽  
Styrene Acrylonitrile ◽  
Microscopy Images

AbstractUsing a micro-scratch tester we have determined the influence of scratch velocity on the sliding wear resistance of several thermoplastics: polystyrene (PS), styrene-acrylonitrile, polyamide 6, polyethersulfone and polysulfone. Variable velocities (from 1 to 15 mm/min) were applied under two different load configurations: progressively increasing loads from 0.03 to 30 N and multiple scratching under constant loads from 2.5 to 10 N. Penetration and residual depth were measured along a 5 mm length. In the case of PS the scanning electron microscopy images of the progressive load scratch reveal a transition from shear yielding to crazing at low velocity. In multiple scratching tests the residual depths obtained at 1 mm/min are substantially higher than those at 15 mm/min for all thermoplastics tested. This result is explained by contact heating at higher speeds resulting in increased chain relaxation capability and thus more viscoelastic recovery. Scanning probe microscopy was used in order to observe surface damages. Except for PS, all other materials at all velocities exhibit asymptotic behaviour of the residual depth as a function of the number of tests.

scholarly journals Scanning Techniques for Nanobioconjugates of Carbon Nanotubes

Scanning ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-19
Author(s):  
Kazuo Umemura ◽  
Shizuma Sato
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Scanning Probe Microscopy ◽  
Drug Delivery Systems ◽  
Living Cells ◽  
Review Article ◽  
Scanning Probe ◽  
Biological Applications ◽  
Scanning Electron

Nanobioconjugates using carbon nanotubes (CNTs) are attractive and promising hybrid materials. Various biological applications using the CNT nanobioconjugates, for example, drug delivery systems and nanobiosensors, have been proposed by many authors. Scanning techniques such as scanning electron microscopy (SEM) and scanning probe microscopy (SPM) have advantages to characterize the CNT nanobioconjugates under various conditions, for example, isolated conjugates, conjugates in thin films, and conjugates in living cells. In this review article, almost 300 papers are categorized based on types of CNT applications, and various scanning data are introduced to illuminate merits of scanning techniques.

Tribological Behavior of PTFE Nanocomposites Reinforced with PBA Grafted Alumina Nanoparticles

2012 ◽  
Vol 184-185 ◽  
pp. 1380-1383
Author(s):  
Yong Ping Niu ◽  
Xiang Yan Li ◽  
Jun Kai Zhang ◽  
Ming Han ◽  
Yong Zhen Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Tribological Behavior ◽  
Compression Molding ◽  
Alumina Nanoparticles ◽  
Low Friction ◽  
Grafted Nanoparticles ◽  
Scanning Electron

Polybutyl acrylate (PBA) grafted alumina nanoparticles were synthesized. Polytetrafluoroethylene (PTFE) nanocomposites reinforced with PBA grafted nanoparticles were prepared by compression molding. The effects of PBA grafted nanoparticles on the tribological behavior of the PTFE nanocomposites were investigated on a tribometer. The abrasion mechanisms of the PTFE nanocomposites were investigated by scanning electron microscopy (SEM) of the abraded surfaces. The results show that the addition of PBA grafted nanoparticles maintains low friction coefficient and improves the wear resistance of the PTFE nanocomposites.

scholarly journals Microstructure and properties of boronizing layer of Fe-based powder metallurgy compacts prepared by boronizing and sintering simultaneously

2009 ◽  
Vol 41 (2) ◽  
pp. 199-207 ◽  
Author(s):  
X. Dong ◽  
J. Hu ◽  
Z. Huang ◽  
H. Wang ◽  
R. Gao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Resistance ◽  
Wear Testing ◽  
Processing Temperature ◽  
X Ray Diffraction ◽  
Surface Microhardness ◽  
X Ray ◽  
Substrate Hardness ◽  
Scanning Electron

In this study, the boronized layers were formed on the surfaces of specimens with a composition of Fe-2 wt. % Cu-0.4 wt. % C by sintering and boronizing simultaneously, using a pack boronizing method. The processes were performed in the temperature range of 1050 - 1150 oC at a holding time of 4 hours in 97 % N2 and 3 % H2 atmosphere. Scanning electron microscopy examinations showed that the boronized layers formed on the surface of boronized and sintered specimens have a denticular morphology. The thicknesses of the boronized layers varied from 63 to 208 ?m depending on the processing temperature. The structures of the boronized layers were Fe2B and FeB confirmed by X-ray diffraction analysis. The microhardness values of boronized layers ranged from 1360 to 2066 HV0.3 much higher than that of substrate hardness which was about 186 HV0.3. Wear testing results showed that the wear resistance of the boronized and sintered specimens was significantly improved, resulting from increased surface microhardness.

Microstructure and Properties of Boronized Layer Produced by Borosulphurizing Method

2012 ◽  
Vol 562-564 ◽  
pp. 204-207
Author(s):  
Dong Wang ◽  
Hui Qin Li ◽  
Han Yu Zhao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Resistance ◽  
Carbon Steel ◽  
Optical Microscope ◽  
Boride Layer ◽  
Microstructure And Properties ◽  
Scanning Electron ◽  
Microhardness Tester

In this study, 45 carbon steel was boronized and borosulphurized at 950°C for 2, 3， 4, 5, 6 and 8 h, respectively. The samples were characterized by scanning electron microscopy, optical microscope, microhardness tester and ring-on-block wear tester. It is found that the surface of borosulphurized samples was dense, compact and relatively smooth; Although the boride layers produced by boro- sulphurizing at 950°C showed a lower microhardness value compared with that produced by boronizing, the wear resistance of the borosulphurized carbon steel is higher than that of boronized sample due to formation of FeS phase in the boride layer.

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