scholarly journals Antibiocorrosive Hybrid Materials with High Durability

2021 ◽  
Vol 15 (4) ◽  
pp. 500-511
Author(s):  
Khatuna Barbakadze ◽  
◽  
Witold Brostow ◽  
Nathalie Hnatchuk ◽  
Giorgi Lekishvili ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
Biologically Active ◽  
Glass Transitions ◽  
Scratch Testing ◽  
Wear Rates ◽  
High Durability ◽  
Scanning Electron Micrography ◽  
Low Wear ◽  
Epoxy Groups ◽  
Scanning Electron

We have developed novel antibiocorrosive multifunctional hybrid materials based on functionalizedperfluoroalkylmethacrylate copolymerswith epoxy groups in main chainsand selected biologically active compounds.The hybrids are transparent, showgood adhesion to various surfaces (plastic, wood),high viscoelastic recovery in scratch testing,low wear rates and glass transitions above 323 K. No phase separation is seen in scanning electron micrography. Enhanced mechanical strength and good abrasion resistance are advantages for uses of our protective and antibiocorrosive coatings in various applications including protection of cultural heritage.

Investigation Into the Wear Films Formed on Certain Superalloys Between 20 and 600°C During Rotation in an Unlubricated Bearing

2009 ◽  
Author(s):  
P. D. Wood ◽  
H. E. Evans ◽  
C. B. Ponton
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive ◽  
Poor Adherence ◽  
Tribological Behaviour ◽  
X Ray ◽  
Wear Rates ◽  
Stellite 6 ◽  
Low Wear ◽  
Scanning Electron

The tribological behaviour of Stellite 6, Tribaloy 700 and Tribaloy 400C have been studied during self-mated unlubricated rotational sliding between 20 to 600°C, at 3ms−1 for 1 hour using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). Testing was conducted using a specially designed wear rig in which bearings and shafts of the materials were machined and tested within a furnace. Tribaloy 700 exhibited high bearing wear rates for all temperatures. Tribaloy 400C and Stellite 6 bearing wear rates generally decreased with temperature until very low wear rates were recorded at 600°C. The bearing wear rates appeared to be related to the formation of wear resistant oxide films often known as ‘glazes’. Adherent ‘glazes’ formed on Tribaloy 400C and Stellite 6 at 450°C and 600°C. However, ‘glazes’ formed on Tribaloy 700 showed poor adherence to the substrate causing high wear rates.

Wear Behavior of TiB2/GNPs and B4C/GNPs Reinforced AA6061 Matrix Composites

2021 ◽  
Vol 143 (11) ◽  
Author(s):  
Safa Polat ◽  
Yavuz Sun ◽  
Engin C¸evik
Keyword(s):  
Wear Behavior ◽  
Sem Analysis ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Pressure Infiltration ◽  
X Ray ◽  
Wear Rates ◽  
Graphene Nanoparticles ◽  
Infiltration Method ◽  
Scanning Electron

Abstract In this study, it was aimed to investigate the effects of reinforcements used for improving the thermal properties of AA6061 alloy on wear resistance. For this purpose, AA6061 matrix composites were produced by pressure infiltration method using ceramic microparticles (TiB2 and B4C) and graphene nanoparticles (GNPs). The produced composites were first characterized by porosity measurement, X-ray diffraction (XRD), and scanning electron microscopy (SEM) analysis. Then, the wear behavior was examined under three different loads (20–40–60 N) with the reciprocating ball on the flat method in a dry environment. Specific wear-rates were calculated according to the Archard principle by measuring the depth and width of the traces after tests with a profilometer. Wearing mechanisms were determined with the help of optical and microstructure images. According to the obtained results, it was found that B4C + GNPs reinforced samples were more resistant to abrasion at low loads, but TiB2 + GNPs reinforced samples were higher at higher loads.

Cinematographical study of cell migration in the opened gastrula of Ambystoma mexicanum

Development ◽  
1978 ◽  
Vol 44 (1) ◽  
pp. 71-80
Author(s):  
H. Y. Kubota ◽  
A. J. Durston
Keyword(s):  
Cell Migration ◽  
Cell Body ◽  
Time Lapse ◽  
Ambystoma Mexicanum ◽  
Scanning Electron Micrographs ◽  
Neighbouring Cell ◽  
Posterior Process ◽  
Scanning Electron Micrography ◽  
Marginal Cells ◽  
Scanning Electron

The migration of inner marginal cells was studied in the Ambystoma gastrula, using scanning electron micrography and time-lapse cinemicrography. Scanning electron micrographs of gastrulae which were fixed while intact revealed that the migrating cells have flattened lamellipodia at their anterior end and a rounded cell body, which can sometimes be seen to be attached to a neighbouring cell by a slender posterior process. Films of opened gastrulae showed actively moving cells, with the same features described above. Details of their movements are reported and discussed in relation to the mechanism of gastrulation.

Fretting Behavior of Coated and Treated Titanium Alloy Using an Open-Loop System

2005 ◽  
Author(s):  
G. R. Yantio Njankeu ◽  
J.-Y. Paris ◽  
J. Denape ◽  
L. Pichon ◽  
J.-P. Rivie`re
Keyword(s):  
Titanium Alloy ◽  
Relative Motion ◽  
High Frequency ◽  
Open Loop ◽  
Loop System ◽  
Test Apparatus ◽  
Open Loop System ◽  
Wear Rates ◽  
Low Wear

Titanium alloys are well known to present poor sliding behaviour and high wear values. Various coatings and treatments have been tested to prevent such an occurrence under fretting conditions at high frequency of displacement (100 Hz). An original test apparatus, using an open-loop system instead of a classical imposed displacement simulator, has been performed to directly display the phenomenon of seizure, defined as the stopping of the relative motion between the contacting elements. A classification of the tested coatings has been proposed on the basis of their capacity to maintain full or partial sliding conditions, to present low wear rates and to prevent seizure.

scholarly journals A Novel Two-Axis Load Sensor Designed for in Situ Scratch Testing inside Scanning Electron Microscopes

Sensors ◽  
2013 ◽  
Vol 13 (2) ◽  
pp. 2552-2565 ◽  
Author(s):  
Hu Huang ◽  
Hongwei Zhao ◽  
Boda Wu ◽  
Shunguang Wan ◽  
Chengli Shi
Keyword(s):  
Scratch Testing ◽  
Load Sensor ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Epoxidation of Palm Oil Catalyzed by Titanium-Grafted Silica Catalyst

2013 ◽  
Vol 812 ◽  
pp. 30-37 ◽  
Author(s):  
Syed Ismail Sharifah Nafisah ◽  
Ahmad Faiza Mohd ◽  
Mohamed Rahmah ◽  
Yhaya Firdaus ◽  
Fauzi Roslinda ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Palm Oil ◽  
Batch Reactor ◽  
Sol Gel ◽  
Silica Content ◽  
Nmr Spectrum ◽  
Epoxidized Palm Oil ◽  
Epoxidation Reaction ◽  
Epoxy Groups ◽  
Scanning Electron

Epoxidation reaction is an important reaction in organic synthesis because the formed epoxides are intermediates that can be converted to a variety of products. Catalytic palm oil epoxidation using titanium-grafted silica, hydrogen peroxide, and peroxoformic acid was carried out at 60 °C in a fixed batch reactor. Titanium-grafted silica with different percentages of silica content was prepared through sol-gel hydrolysis and was utilized in epoxidation of palm oil. Titanium-grafted silica particles and Epoxidized palm oil were characterized by techniques such as Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscope (FESEM) and Nuclear Magnetic Resonance (NMR). The TiOSi bonds were detected at 960 cm-1in Ti-Si 0.5 and exhibited highest yield of epoxidized palm oil (EPO) in the epoxidation process which is 84% conversion of unsaturation in palm oil to epoxy groups. New peaks observed in the range of δ 2.4 ppm to 3.6 ppm in the NMR spectrum of EPO belong to protons of the epoxy cyclic ring group, CH-O-CH confirming successful epoxidation of palm oil using the prepared catalyst.

Preparation and Tribological Property of Plasma Sprayed Adaptive Ni-Mo-Al-Ag-BN Composite Coating

2017 ◽  
Vol 739 ◽  
pp. 30-35
Author(s):  
Jian Liang Li ◽  
Hang Li ◽  
Dang Sheng Xiong ◽  
Yu Juan Ji ◽  
Yong Kun Qin
Keyword(s):  
High Temperature ◽  
Composite Coating ◽  
Tribological Property ◽  
Lubrication Mechanism ◽  
Wear Rates ◽  
Mechanism Model ◽  
Wide Range ◽  
Plasma Sprayed ◽  
Scanning Electron ◽  
Lubrication Mechanisms

In this paper an adaptive Ni-Mo-Al-Ag-BN composite coating was deposited by plasmaspraying. Its tribological property from 20°C-600°C were evaluated by using high temperature tribometer. Scanning electron microscopy and Raman spectroscopy were used to characterize the coating and corresponding wear tracks to determine the lubrication mechanisms. The result shows that the friction coefficient of the Ni-Mo-Al–Ag-BN composite coating from 200°C to 400°C is about 0.4 and declines very slightly at 600°C . The wear rates of the coating is 2.0×10-4mm3/N*m at 600°C and the downward trend is obvious compared with 400°C. Silver provide lubrication below 400 °C. Ag2MoO4 were formed with the temperature raised, and acted as high-temperature lubricants above 400 °C. Ni-Mo-Al–Ag-BN composite coating established a new lubrication mechanism model at 600°C . It can be concluded that the plasma sprayed Ni-Mo-Al - Ag - BN composite coating can keep good tribological property at wide range of temperature.

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