Solid Solution (AlN) x (SiC)1–x (x ≈ 0.7) by SHS under High Pressure of Nitrogen Gas

Author(s):  
I. P. Borovinskaya ◽  
T. G. Akopdzhanyan ◽  
E. A. Chemagina ◽  
N. V. Sachkova
Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 766
Author(s):  
Boris Straumal ◽  
Askar Kilmametov ◽  
Anna Korneva ◽  
Pawel Zięba ◽  
Yuri Zavorotnev ◽  
...  

Cu–14 wt% Sn alloy was annealed at temperatures of 320 and 500 °C. The concentration of tin cinit in the copper-based matrix increased with annealing temperature. The annealed samples were subjected to high-pressure torsion (HPT) at 6 GPa, 5 turns, 1 rpa. HPT led to the refinement of Cu grains. The shape of the colonies of α + ε phases changed only slightly. The HPT-driven enrichment of the Cu-based solid solution with Sn atoms cHPT–cinit decreased with increasing cinit. The performed theoretical analysis explained this behavior of the HPT-driven enrichment.


2021 ◽  
pp. 130386
Author(s):  
Anna Korneva ◽  
Askar Kilmametov ◽  
Yuri Zavorotnev ◽  
Leonid Metlov ◽  
Olga Popova ◽  
...  

2018 ◽  
Vol 74 (7) ◽  
pp. 1010-1012 ◽  
Author(s):  
Emil Stoyanov ◽  
Kurt Leinenweber ◽  
Thomas L. Groy ◽  
Abds-Sami Malik

Single crystals of a GeO2–TiO2 solid solution with the corresponding composition Ge0.57Ti0.43O2 (germanium titanium tetraoxide) were obtained by devitrification of germania-titania glass at high pressure and temperature. The new compound crystallizes in the rutile structure type (space group P42/mnm), where Ge and Ti share the same position M (site symmetry m.mm), with occupancy values of 0.57 (3) and 0.43 (3), respectively, and one O-atom position (m.2m). The M site is in a sixfold O-atom coordination and, as in the original TiO2 rutile structure, an elongation of the O—M—O bonds along the c-axis direction of the coordination polyhedron and deviation of the angles from 90° lead to a decrease in the coordination symmetry from octahedral to tetragonal. The Ge and Ti atoms are fully disordered in the structure, which indicates that the rutile structure is surprisingly pliant given the differing sizes of the two cations.


2002 ◽  
Vol 49 (4) ◽  
pp. 270-278
Author(s):  
Nobuaki Asada ◽  
Yoshiharu Yamamoto ◽  
Tadashi Igarashi ◽  
Yoshihiko Doi ◽  
Koji Hayashi

1989 ◽  
Vol 8 (2) ◽  
pp. 173-178 ◽  
Author(s):  
J Chevrier ◽  
J. C Lasjaunias ◽  
F Zougmore ◽  
J. J Capponi

Author(s):  
Chris Alexander ◽  
Salem Talbi ◽  
Richard Kania ◽  
Jon Rickert

Abstract A study was conducted to evaluate two composite repair technologies used to reinforce severe corrosion and thru-wall leaking defects in thin-walled pipe materials; conditions where the welding of conventional Type B steel sleeves cannot be conducted. This program involved the reinforcement of simulated 85% corrosion defects in 6.625-inch × 0.157-inch, Grade X52 pipe materials subjected to cyclic pressure and burst testing. The test matrix also included repaired pipe samples with thru-wall defects that were pressurized using nitrogen gas and buried for 90 days. The program was comprehensive in that it evaluated the following elements involving a total of 81 reinforced corrosion defects. • Corrosion features with a depth of 85% of the pipe’s nominal wall thickness in thin-walled pipe material (i.e., 0.157 inches, or 4 mm). • Thru-wall defects having a diameter of 0.125 inches (3 mm). • Repairs made with leaking defects having 100 psig (690 kPa) internal pressure. • Strain gage measurement made in non-leaking 85% corrosion defects; it should be noted that the remaining “15%” ligament was 0.024 inches (0.6 mm); to the author’s knowledge, no high-pressure testing has ever been conducted on such a thin remaining wall. • Long-term 90-day test that included pressurization with nitrogen gas, followed by relatively aggressive pressure cycling up to 80% SMYS followed by burst testing. This is the first comprehensive study conducted by a major transmission pipeline operator evaluating the performance of competing composite technologies used to reinforce severe corrosion features with thru-wall defects. The reinforcement of leaks has not been accepted by regulatory bodies such as the Canadian Energy Regulator (CER), or the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA). A goal of the current study is to validate composite repair technologies as a precursor to regulatory approval. The results of this study indicate that viable composite repair technologies exist with capabilities to reinforce leaks in pipelines that experience operating conditions typical for gas transmission systems (i.e., minimal pressure cycling).


2020 ◽  
Vol 310 ◽  
pp. 6-13
Author(s):  
Vadim V. Efremov ◽  
Mikhail N. Palatnikov ◽  
Yuriy V. Radyush ◽  
Olga B. Shcherbina

Ferroelectric ceramic solid solutions LixNa1-xTayNb1-yO3 (х = 0.17; у = 0 – 0.5) with the perovskite structure have been obtained by the thermobaric synthesis method. Particularities of their microstructure, elastic properties, electrical conductivity and permittivity have been researched. It has been established that an increase in the thermobaric synthesis temperature leads to a decrease in the Young’s modulus value. Specific static conductivity values have been determined; charge carrier activation enthalpies На have been calculated. The Curie temperature of the samples has been determined to decrease with an increase in tantalum content. A Ferroelectric ceramic solid solution Li0.17Na0.83Ta0.1Nb0.9O3 was shown to undergo four structure phase transitions in the temperature range 300-820 К. A Li0.17Na0.83Ta0.1Nb0.9O3 has been shown to be a high temperature superionic. Possible mechanisms of the detected phenomena are discussed.


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