Effect of CO2 Laser on Glazed Zircon Surface Complemented by ZrO2 Oxide

2021 ◽  
Vol 39 (1B) ◽  
pp. 252-261
Author(s):  
Zahraa A. Salman ◽  
Kadhim A. Hubeatir ◽  
Shihab A. Zaidan
Keyword(s):  
Co2 Laser ◽  
Tetragonal Zirconia ◽  
Ceramic Substrate ◽  
Zro2 Nanoparticles ◽  
Force Microscopy ◽  
Atomic Force ◽  
Continuous Co2 Laser ◽  
Cad Cam ◽  
Indicator Power ◽  
Dental Zirconia Ceramics

In this paper, the effect of CO2 laser on glaze-dental Zirconia ceramics after adding ZrO2 nanoparticles to glaze is introduced, and its improvement methods are studied. Specimens have been prepared using CAD/CAM dental machines and sintered at 1530o-C. Then the surface was glazed with VITA glaze plus (5% and 10%) Nano ZrO2. A 15W continuous CO2 laser was used as the indicator power to irradiate the glaze layer. The main phase of the ceramic substrate is tetragonal Zirconia, and the alumina content in the corundum phase is a certain percentage. The appearance of the varnish on the ceramic substrate changes the X-ray diffraction pattern through the appearance of new phases, which changes the crystallite size and the percentage of lattice strain. The range of grain size measured by atomic force microscopy was 88.46 nm to 62.18nm. In addition, the surface roughness was changed due to the appearance of crystal cores and grain growth. In addition, the addition of ZrO2 and laser irradiation changed the residual stress on the surface, which was reflected in the hardness value increased from 575 kg/mm2 to 1215 kg/mm2 after the laser treatment with the addition of 5% ZrO2. Generally, in terms of the structure and hardness of the surface of the glaze layer, the addition of 5% ZrO2 is better than 10%. SEM tests also showed no cracks in the central part of the treated area. These characteristics increase hardness.

scholarly journals Aging Behavior of Commercial and Synthesized Dental Y-TZP Ceramics

2015 ◽  
Vol 820 ◽  
pp. 297-302 ◽  
Author(s):  
Anelyse Arata ◽  
Tiago Moreira Bastos Campos ◽  
João Paulo Barros Machado ◽  
Walter Kenji Yoshito ◽  
Valter Ussui ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Monoclinic Phase ◽  
Rietveld Method ◽  
Tetragonal Zirconia ◽  
Degradation Process ◽  
Hydrothermal Aging ◽  
Force Microscopy ◽  
Atomic Force ◽  
Oral Environment ◽  
Experimental Group

Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) is used for dental prosthodontics, however, it can present accelerated tetragonal to monoclinic phase transformation in oral environment. The aim of this study was to compare the behavior of a Y-TZP synthesized in laboratory by the coprecipitation method to a commercial Y-TZP, after hydrothermal aging in pressurized reactor (150°C/ 35 hours). The discs were sintered at 1520°C for two hours. The kinetics curve of phase transformation was determined through the data collect by XRD diffractograms treated by the Rietveld method. The experimental and commercial control groups did not present monoclinic phase. After 35 hours of aging, the experimental group presented 69% of monoclinic phase compared to 67% for the commercial group. Scanning electron microscopy and atomic force microscopy images suggested that the commercial group presented heterogeneity of grain size and that the experimental group was more homogeneous. All groups presented superficial degradation process.

Microstructured Bioactive Interfaces using Piezoelectric Ink Jet Technology

2006 ◽  
Vol 950 ◽  
Author(s):  
Anand Doraiswamy ◽  
Cerasela Z. Dinu ◽  
Jan Sumerel ◽  
Douglas B. Chrisey ◽  
Roger J. Narayan
Keyword(s):  
Tissue Engineering ◽  
Atomic Force Microscopy ◽  
Infrared Spectroscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cell Culturing ◽  
Ink Jet ◽  
Cad Cam ◽  
Spectroscopy Studies ◽  
Non Destructive

ABSTRACTWe have demonstrated microscale patterning of biotin and streptaividin proteins using an athermal rapid prototyping process based on piezoelectric inkjet technology. A MEMS-based piezoelectric actuator was used to dispense picoliter quantities of fluid through micron-sized nozzles. Atomic force microscopy and Fourier infrared spectroscopy studies were performed on CAD/CAM deposited proteins that were prepared using several firing voltages. Our results indicate that piezoelectric inkjet deposition is a powerful non-contact, non-destructive process for developing high-throughput biological microarrays for use in biosensing, cell culturing, and tissue engineering.

Nanoindentation of yttria-doped zirconia: Effect of crystallographic structure on deformation mechanisms

2009 ◽  
Vol 24 (3) ◽  
pp. 719-727 ◽  
Author(s):  
Y. Gaillard ◽  
M. Anglada ◽  
E. Jiménez-Piqué
Keyword(s):  
Phase Transformation ◽  
Tetragonal Zirconia ◽  
Dislocation Nucleation ◽  
Deformation Mechanisms ◽  
Crystallographic Structure ◽  
Force Microscopy ◽  
Atomic Force ◽  
Tetragonal Crystals ◽  
Indenter Shape ◽  
Critical Contact

This article presents a nanoindentation study of polycrystalline and single crystals of yttria-doped zirconia with both tetragonal and cubic phases. Analysis of the deformation mechanisms is performed by both atomic force microscopy (AFM) and micro-Raman spectroscopy. Phase transformation from tetragonal to monoclinic phase is clearly distinguished on tetragonal crystals, whereas in cubic crystals the plastic deformation seems to be controlled by dislocation nucleation and interactions. AFM observations in tetragonal zirconia grains have shown that both grain size and autocatalytic transformation strongly influence the size of the transformed zone. Furthermore, the martensitic phase transformation seems to be also strongly dependent of the indenter shape. Experimental results suggest that a critical contact pressure is necessary to induce the phase transformation.

Cryogenic atomic force microscopy

1991 ◽  
Vol 49 ◽  
pp. 54-55
Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke
Keyword(s):  
Room Temperature ◽  
Rapid Freezing ◽  
Cryogenic Temperatures ◽  
Soft Or ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Flexible Molecules ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

AFM study of the dynamics of α-alumina surface faceting during high-temperature processing

1995 ◽  
Vol 53 ◽  
pp. 334-335 ◽  
Author(s):  
Michael W. Bench ◽  
Jason R. Heffelfinger ◽  
C. Barry Carter
Keyword(s):  
High Temperature ◽  
Thin Foil ◽  
Sem Analysis ◽  
Conductive Coatings ◽  
Force Microscopy ◽  
Minimal Sample ◽  
Atomic Force ◽  
Formation And Evolution ◽  
High Temperature Processing ◽  
Nominal Surface

To gain a better understanding of the surface faceting that occurs in α-alumina during high temperature processing, atomic force microscopy (AFM) studies have been performed to follow the formation and evolution of the facets. AFM was chosen because it allows for analysis of topographical details down to the atomic level with minimal sample preparation. This is in contrast to SEM analysis, which typically requires the application of conductive coatings that can alter the surface between subsequent heat treatments. Similar experiments have been performed in the TEM; however, due to thin foil and hole edge effects the results may not be representative of the behavior of bulk surfaces.The AFM studies were performed on a Digital Instruments Nanoscope III using microfabricated Si3N4 cantilevers. All images were recorded in air with a nominal applied force of 10-15 nN. The alumina samples were prepared from pre-polished single crystals with (0001), , and nominal surface orientations.

Scanning tunneling microscopy and atomic force microscopy: New tools for biology

1989 ◽  
Vol 47 ◽  
pp. 778-779
Author(s):  
CE Bracker ◽  
P. K. Hansma
Keyword(s):  
Physical Property ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Small Scale ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
New Family ◽  
Small Probe ◽  
Atomic Force ◽  
Transmission Electron

A new family of scanning probe microscopes has emerged that is opening new horizons for investigating the fine structure of matter. The earliest and best known of these instruments is the scanning tunneling microscope (STM). First published in 1982, the STM earned the 1986 Nobel Prize in Physics for two of its inventors, G. Binnig and H. Rohrer. They shared the prize with E. Ruska for his work that had led to the development of the transmission electron microscope half a century earlier. It seems appropriate that the award embodied this particular blend of the old and the new because it demonstrated to the world a long overdue respect for the enormous contributions electron microscopy has made to the understanding of matter, and at the same time it signalled the dawn of a new age in microscopy. What we are seeing is a revolution in microscopy and a redefinition of the concept of a microscope.Several kinds of scanning probe microscopes now exist, and the number is increasing. What they share in common is a small probe that is scanned over the surface of a specimen and measures a physical property on a very small scale, at or near the surface. Scanning probes can measure temperature, magnetic fields, tunneling currents, voltage, force, and ion currents, among others.

Morphology and development of flow-pattern defect with extended nonagitated Secco etching

1994 ◽  
Vol 52 ◽  
pp. 868-869
Author(s):  
Y. Pan
Keyword(s):  
Flow Pattern ◽  
Silicon Crystal ◽  
Gate Oxide ◽  
Crystal Growth Rate ◽  
Etch Depth ◽  
Force Microscopy ◽  
Etch Pit ◽  
Float Zone ◽  
Atomic Force ◽  
Multiple Step

The D defect, which causes the degradation of gate oxide integrities (GOI), can be revealed by Secco etching as flow pattern defect (FPD) in both float zone (FZ) and Czochralski (Cz) silicon crystal or as crystal originated particles (COP) by a multiple-step SC-1 cleaning process. By decreasing the crystal growth rate or high temperature annealing, the FPD density can be reduced, while the D defectsize increased. During the etching, the FPD surface density and etch pit size (FPD #1) increased withthe etch depth, while the wedge shaped contours do not change their positions and curvatures (FIG.l).In this paper, with atomic force microscopy (AFM), a simple model for FPD morphology by non-crystallographic preferential etching, such as Secco etching, was established.One sample wafer (FPD #2) was Secco etched with surface removed by 4 μm (FIG.2). The cross section view shows the FPD has a circular saucer pit and the wedge contours are actually the side surfaces of a terrace structure with very small slopes. Note that the scale in z direction is purposely enhanced in the AFM images. The pit dimensions are listed in TABLE 1.

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.

Development of the UHV-STM

1990 ◽  
Vol 48 (1) ◽  
pp. 322-323
Author(s):  
M. Iwatsuki ◽  
S. Kitamura ◽  
A. Mogami
Keyword(s):  
Surface Science ◽  
Real Space ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Great Promise ◽  
Force Microscopy ◽  
Atomic Force ◽  
Stm Image ◽  
Surface Construction ◽  
Very High

Since Binnig, Rohrer and associates observed real-space topographic images of Si(111)-7×7 and invented the scanning tunneling microscope (STM),1) the STM has been accepted as a powerful surface science instrument.Recently, many application areas for the STM have been opened up, such as atomic force microscopy (AFM), magnetic force microscopy (MFM) and others. So, the STM technology holds a great promise for the future.The great advantages of the STM are its high spatial resolution in the lateral and vertical directions on the atomic scale. However, the STM has difficulty in identifying atomic images in a desired area because it uses piezoelectric (PZT) elements as a scanner.On the other hand, the demand to observe specimens under UHV condition has grown, along with the advent of the STM technology. The requirment of UHV-STM is especially very high in to study of surface construction of semiconductors and superconducting materials on the atomic scale. In order to improve the STM image quality by keeping the specimen and tip surfaces clean, we have built a new UHV-STM (JSTM-4000XV) system which is provided with other surface analysis capability.

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