scholarly journals Tribological Properties of Mo-Si-B Alloys Doped with La2O3 and Tested at 293–1173 K

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2011 ◽  
Author(s):  
Wenhu Li ◽  
Taotao Ai ◽  
Hongfeng Dong ◽  
Guojun Zhang
Keyword(s):  
High Temperature ◽  
Tribological Properties ◽  
Laser Scanning ◽  
Wear Behavior ◽  
Surface Oxidation ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Low Friction ◽  
Friction Coefficients ◽  
Wear Rates

According to the stoichiometric ratios of Mo-10Si-7B, Mo-12Si-8.5B, Mo-14Si-9.8B, and Mo-25Si-8.5B, some new Mo-Si-B alloys doped with 0.3 wt % lanthanum (III) oxide (La2O3) were prepared via liquid-liquid (L-L) doping, mechanical alloying (MA), and hot-pressing (HP) sintering technology. The phase-composition and microstructure were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The worn surfaces of the plate specimens were studied by confocal laser scanning microscopy (CLSM). Then, the tribological properties of Mo-Si-B alloy doped with sliding plate specimens of 0.3 wt % La2O3 were investigated against the Si3N4 ball specimens. The friction coefficients of Mo-Si-B alloys decreased and the wear rates of the alloys increased with test load. The high-temperature friction and wear behavior of Mo-Si-B alloy are related to the surface-oxidation and contact-deformation of the alloy at a high temperature. The low friction coefficients and the reduced wear rates are thought to be due to the formation of low friction MoO3 films. MoO3 changed the contact state of the friction pairs and behaved as lubricating films.

Real time and in situ observation of graphene growth on liquid metal surfaces via a carbon segregation method using high-temperature confocal laser scanning microscopy

RSC Advances ◽  
2016 ◽  
Vol 6 (103) ◽  
pp. 101235-101241 ◽  
Author(s):  
Pengcheng Yan ◽  
Yeon Joo Jeong ◽  
Mohammad F. Islam ◽  
P. Chris Pistorius
Keyword(s):  
High Temperature ◽  
Liquid Metal ◽  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
In Situ Observation ◽  
Laser Scanning Confocal Microscope

Determination of graphene formation and growth using direct,in situimaging with high-temperature laser scanning confocal microscope.

Self-Lubricating Behavior of ZrO2(Y2O3)-Mo-CaF2-Graphite Composite

2013 ◽  
Vol 815 ◽  
pp. 584-587 ◽  
Author(s):  
Ling Qian Kong ◽  
Qin Ling Bi ◽  
Sheng Yu Zhu ◽  
Wei Min Liu
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
High Temperatures ◽  
Tribological Properties ◽  
Hot Pressing ◽  
Tribological Behavior ◽  
Low Friction ◽  
Friction Coefficients ◽  
Graphite Composite ◽  
Worn Surface

t is of great importance to find ways to lubricate ZrO2ceramic. In this paper, a kind of ZrO2 matrix high temperature self-lubricating compositewith addition of CaF2 and graphite as lubricants was prepared by hot-pressing. It was found that the tribological properties of ZrO2(Y2O3)-CaF2-graphiteshow a good tribological behavior both at low temperature and high temperatures. The low friction coefficients of ZrO2 (Y2O3)-Mo-CaF2-graphite at high temperatures were due to the perfect lubricity of CaMoO4 which was formed on the worn surface at high temperatures.

High-Temperature Tribological Properties of ReB2-Based Ceramic/Si3N4 Sliding Pairs

2021 ◽  
Vol 1016 ◽  
pp. 978-983
Author(s):  
Takashi Murakami ◽  
Tsuguyori Ohana
Keyword(s):  
High Temperature ◽  
Tribological Properties ◽  
Low Friction ◽  
Friction Coefficients

Our group prepared an ReB2-based ceramic with a composition of Re-74.5at% B to investigate its microstructure, high-temperature microvickers hardness, and high-temperature tribological properties in air. The microvickers hardness of the ReB2-based ceramic was higher than 2600 at temperatures below 1073 K. The friction coefficients of ReB2-based ceramic/Si3N4 sliding pairs were stable and low (≃ 0.15) at 1073 K. We concluded that the low friction coefficients of the sliding pairs resulted from the formation of low-friction hexagonal BN and B2O3 films. The friction coefficients of the ReB2-based ceramic/Si3N4 sliding pairs were also low at 298 K (≃ 0.3 to 0.4) and 1273 K (≃ 0.1), but were unstable and high ( 0.6) at 673 K.

3-D imaging of cells using a confocal laser scanning microscope and digital image processing

1988 ◽  
Vol 46 ◽  
pp. 96-97
Author(s):  
Thomas M. Jovin ◽  
Michel Robert-Nicoud ◽  
Donna J. Arndt-Jovin ◽  
Thorsten Schormann
Keyword(s):  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Scanning Microscope ◽  
Laser Scanning Microscope ◽  
Biochemical Processes ◽  
Adjacent Structures

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.

Vacuoles Induced in Mammalian Cells by Helicobacter Cytotoxin are Acidic Organelles

1990 ◽  
Vol 48 (3) ◽  
pp. 168-169
Author(s):  
M. H. Chestnut ◽  
C. E. Catrenich
Keyword(s):  
Acridine Orange ◽  
Mammalian Cells ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Ulcer Disease ◽  
Gastroduodenal Disease ◽  
H Pylori

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.

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