Mathematical Model for Continuous Tube Rolling and the Effect of Technological Factors on Surface Defect Formation

2020 ◽  
Vol 2020 (13) ◽  
pp. 1632-1636
Author(s):  
V. A. Toporov ◽  
P. A. Ibragimov ◽  
O. A. Panasenko ◽  
D. Sh. Nukhov ◽  
A. O. Khalezov
2021 ◽  
Vol 316 ◽  
pp. 928-935
Author(s):  
Alexander Shapoval ◽  
Iurii Savchenko ◽  
Oleg Markov

Developed a mathematical model, which makes it possible to optimize, from the point of view of defect formation, the parameters of stress concentration in a deformable elastic body of the materials being processed, destruction is considered as a method for creating defects at a submicroscopic level in various media. Getting expressions of conformal reflection of single circle on an arbitrary area, using a conformal reflection and transformation of Laplace, it is possible to design behavior of a tensely deformed state of solid at the arbitrary loading.


2019 ◽  
Vol 6 (6) ◽  
pp. 1740-1753 ◽  
Author(s):  
Tong Li ◽  
Zelin Shen ◽  
Yiling Shu ◽  
Xuguang Li ◽  
Chuanjia Jiang ◽  
...  

Exposed crystal facets of TiO2 nanomaterials significantly affect the surface defect formation of the materials during thermal treatment.


2001 ◽  
Vol 40 (Part 2, No. 10A) ◽  
pp. L1051-L1053
Author(s):  
Taisuke Furukawa ◽  
Takumi Nakahata ◽  
Shigemitsu Maruno ◽  
Junji Tanimura ◽  
Yasunori Tokuda ◽  
...  

Author(s):  
J. Hulliger

AbstractDipolar but achiral organic molecules may undergo orientational disorder in the bulk but particularly at the surface of a seed crystal. In cases where the activation energy for reversal of the dipoles in the bulk is much larger than that for reversal at the growing crystal faces, thermodynamic arguments predict that orientational disorder occurring at surface attachment sites can produce metastable but macroscopically large growth sectors, featuring different polar properties than the seed. If the process of nucleation produces a non-pyroelectric symmetry group, then orientational disorder at the surface may give rise to pyroelectric properties during subsequent growth. Similarly, for seeds belonging to a pyroelectric group, orientational disorder can reduce the initial pyroelectric effect. According to this new surface-related mechanism of intrinsic defect formation, acentric and achiral molecules are likely to form real-structures which show a pyroelectric effect, although from a crystallographic point of view, such crystals may be described topologically by e.g. a centric structure. These present views are applied to the space group


RSC Advances ◽  
2015 ◽  
Vol 5 (86) ◽  
pp. 70032-70050 ◽  
Author(s):  
Lei Zhang ◽  
Guoqun Zhao ◽  
Guiwei Dong ◽  
Shuai Li ◽  
Guilong Wang

A multiphase model was established to simulate the bubble morphological evolution in MFIM, and a new phenomenon of surface collapse and pits with the gradient depth was discovered.


1998 ◽  
Vol 507 ◽  
Author(s):  
J Robertson ◽  
M J Powell

ABSTRACTThe growth of a-Si:H and the resulting weak bond and defect formation mechanism is analysed in terms of the adsorbed Sill3 model of growth. It is found that this model describes the surface processes well, but it needs further development to correctly describe the temperature dependence of the formation of defects and weak bonds, since the surface defect density decreases monotonically with temperature and does not show a minimum near 250C. We show that the experimentally observed increase in hydrogen content, weak bond and defect density at lower deposition temperatures can be accounted for by a hydrogen evolution reaction from H2* sites.


1990 ◽  
Vol 8 (4) ◽  
pp. 3157-3162 ◽  
Author(s):  
C. W. Chen ◽  
D. M. Makowiecki ◽  
C. S. Alford ◽  
M. A. McKernan ◽  
P. B. Ramsey

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