scholarly journals The Al2O3-3D-ceramics' structure changing when sintering

Author(s):  
S. P. Bogdanov ◽  
M. M. Sychev ◽  
L. A. Lebedev

It was proposed to regard the ceramic products with periodic topology as the systems having the multilevel organized structures. The development of the structure was studied at different scales levels after the sintering at 1700 °С for the corundum ceramics prepared by 3D-printing. The peculiarities of the geometry change were shown for the 3d-printed layered structure, for the material's grain structure and for the crystal lattice parameters of the α-Al2O3grains.Ill. 5. Ref.8.

2014 ◽  
Vol 70 (a1) ◽  
pp. C1560-C1560
Author(s):  
Fumiko Kimura ◽  
Wataru Oshima ◽  
Hiroko Matsumoto ◽  
Hidehiro Uekusa ◽  
Kazuaki Aburaya ◽  
...  

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.


2007 ◽  
Vol 33 (1) ◽  
pp. 86-88 ◽  
Author(s):  
N. Z. Gasanov ◽  
E. M. Kerimova ◽  
A. I. Gasanov ◽  
Yu. G. Asadov

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 549-565
Author(s):  
Tomasz Blachowicz ◽  
Guido Ehrmann ◽  
Andrea Ehrmann

Abstract 3D printing belongs to the emerging technologies of our time. Describing diverse specific techniques, 3D printing enables rapid production of individual objects and creating shapes that would not be produced with other techniques. One of the drawbacks of typical 3D printing processes, however, is the layered structure of the created parts. This is especially problematic in the production of optical elements, which in most cases necessitate highly even surfaces. To meet this challenge, advanced 3D printing techniques as well as other sophisticated solutions can be applied. Here, we give an overview of 3D printed optical elements, such as lenses, mirrors, and waveguides, with a focus on freeform optics and other elements for which 3D printing is especially well suited.


2017 ◽  
Vol 96 ◽  
pp. 00006
Author(s):  
Artem Obkhodsky ◽  
Alexander Popov ◽  
Alexey Zolotarev ◽  
Sergey Kuznetsov ◽  
Victor Sachkov

2010 ◽  
Vol 32 (4) ◽  
pp. 231-235 ◽  
Author(s):  
O. O. Kurakevych ◽  
T. Chauveau ◽  
V. L. Solozhenko

1980 ◽  
Vol 61 (1) ◽  
pp. K87-K90 ◽  
Author(s):  
H. Bartholin ◽  
A. Waintal ◽  
G. Parisot ◽  
F. Kervella ◽  
J. P. Senateur

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