Transparent Polycrystalline Alumina Ceramic with Sub-Micrometre Microstructure by Means of Electrophoretic Deposition

2006 ◽  
Vol 37 (4) ◽  
pp. 293-297 ◽  
Author(s):  
A. Braun ◽  
G. Falk ◽  
R. Clasen
Keyword(s):  
Electrophoretic Deposition ◽  
Alumina Ceramic ◽  
Polycrystalline Alumina

Creep in a polycrystalline alumina ceramic of increased purity

Refractories ◽  
1969 ◽  
Vol 10 (9-10) ◽  
pp. 643-646
Author(s):  
V. S. Bakunov ◽  
D. N. Poluboyarinov ◽  
R. Ya. Popil'skii ◽  
N. N. Ustyuzhanina
Keyword(s):  
Alumina Ceramic ◽  
Polycrystalline Alumina

scholarly journals CO2 laser for dental alumina ceramic framework welding

2019 ◽  
Vol 22 (4) ◽  
pp. 520-527
Author(s):  
Ricardo Sgura ◽  
André Guaraci DeVito Moraes ◽  
Stephane Silva Reis ◽  
Adriana Rios Mafra Ferrari ◽  
Marcello Rubens Barsi Andreeta ◽  
...  
Keyword(s):  
Fusion Zone ◽  
Co2 Laser ◽  
Alumina Ceramic ◽  
X Ray Diffraction ◽  
Shape Distortion ◽  
Polycrystalline Alumina ◽  
All Ceramic ◽  
Growth System ◽  
Ceramic Blocks ◽  
Laser Heated

Objective: Despite the increase of all-ceramic prosthesis in dental practice there is no evidence of the possibility of welding these structures if necessary. The objective of this study was to use CO2 laser (?=10.6µm) as a welding agent to fuse dental polycrystalline alumina ceramic. Methods: Ceramic blocks of pre-sintered alumina were sectioned into 20 bars (10.0 x 1.5 x 1.5mm) and sintered to the final cross?section dimension of 1.2 x 1.2mm. The bars were adapted to an LHPG (Laser Heated Pedestal Growth) system device where the bars could be fixed in pairs and have their ends irradiated with CO2 laser to fusion. The ring-shaped laser beam (300 µm thickness) was directed with the aid of mirrors to reach samples’ ends. The laser was continuously applied (40W nominal power, 5 seconds). After welding, the samples were analyzed in stereomicroscope and SEM. A diffraction analysis was carried out with one sample. Results: The ceramic bars were successfully fused, but some of them showed some shape distortion in the fusion zone. The aspect of the fused alumina differed in color and translucency from the original sintered material. SEM evidenced the presence of porosity and voids in the center of the fusion zone. X-ray diffraction pointed to a reduction in crystallite size by two to four times in the welded region of samples. Conclusions: This study points to CO2 laser as a possible welding agent to polycrystalline alumina dental ceramic. Porosity observed in the molten zone gives cause for concern regarding weld resistance.

Polycrystalline alumina ceramic fabrication using digital stereolithographic light process

2021 ◽  
Author(s):  
Hsing-I Hsiang ◽  
Chao-Yi Lee ◽  
Chih-Cheng Chen ◽  
Jun Wang ◽  
Dingyuan Tang ◽  
...  
Keyword(s):  
Alumina Ceramic ◽  
Polycrystalline Alumina

Control of crystalline texture in polycrystalline alumina ceramics by electrophoretic deposition in a strong magnetic field

2004 ◽  
Vol 19 (5) ◽  
pp. 1487-1491 ◽  
Author(s):  
T. Uchikoshi ◽  
T.S. Suzuki ◽  
H. Okuyama ◽  
Y. Sakka
Keyword(s):  
Magnetic Field ◽  
Strong Magnetic Field ◽  
Electric Fields ◽  
Electrophoretic Deposition ◽  
Alumina Powder ◽  
Layer By Layer ◽  
Alumina Ceramics ◽  
X Ray Diffraction ◽  
Polycrystalline Alumina ◽  
Seed Particles

Highly crystalline-textured pure dense alumina ceramics were fabricated from spherical alumina powder without any seed particles and sintering additives by electrophoretic deposition (EPD) in a strong magnetic field of 10 T. The crystalline texture was confirmed by x-ray diffraction (XRD) for alumina ceramics deposited at 10 T followed by sintering at 1873 K. The angle between the directions of the magnetic and electric fields (φB-E) was altered to control the dominant crystal faces of the α-alumina monoliths. The average orientation angles estimated from the XRD diagram of the samples prepared at φB-E = 0°, 45°, and 90° were 16.52°, 45.15°, and 84.90°, respectively. Alumina/alumina laminar composites with different crystalline-oriented layers were also fabricated by alternately changing the φB-E layer by layer during EPD in a 10 T magnetic field. It was demonstrated that by using this technique, it is possible to control the crystalline orientation by changing the angle of E versus B during the EPD.

Sign in / Sign up

Export Citation Format

Share Document