Low-Temperature (<300°C) Phosphate Ceramics from Reactive Aluminas

1989 ◽  
Vol 179 ◽  
Author(s):  
M. R. Silsbee ◽  
R. A. Steinke ◽  
D. M. Roy ◽  
D. K. Agrawal ◽  
R. Roy
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Low Temperatures ◽  
Ceramic Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Characterization Techniques ◽  
Exciting Potential

AbstractReactive aluminas, including rapidly calcined gibbsites, offer exciting potential for forming ceramic materials at low temperatures. New x-ray amorphous aluminas will react with water at room temperatures to form compacts with 10–50 MPa tensile strengths, via viscous slurries. The cementious behavior of these materials has been examined. The results of TGA, x-ray diffraction, SEM, mechanical properties, and other characterization techniques, as applied to these systems, will be discussed.

scholarly journals The Stability of Icosahedral Cd-Yb

2003 ◽  
Vol 805 ◽  
Author(s):  
Günter Krauss ◽  
Sofia Deloudi ◽  
Andrea Steiner ◽  
Walter Steurer ◽  
Amy R. Ross ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ambient Temperature ◽  
Mechanical Stress ◽  
Single Crystals ◽  
High Temperatures ◽  
Low Temperatures ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability

ABSTRACTThe stability of single-crystalline icosahedral Cd-Yb was investigated using X-ray diffraction methods in the temperature range 20 K ≤ T ≤ 900 K at ambient pressure and from ambient temperature to 873 K at about 9 GPa. Single-crystals remain stable at low temperatures and in the investigated HP-HT-regime. At high temperatures and ambient pressure, the quasicrystal decomposes. The application of mechanical stress at low temperatures yields to the same decomposition, the formation of Cd. A reaction of icosahedral Cd-Yb with traces of oxygen or water causing the decomposition seems reasonable, but a low-temperature instability of this binary quasi-crystal cannot be ruled out totally.

X-Ray Diffraction Studies on Shock Modified Y Ba2 Cu3 O7 Superconductors

1988 ◽  
Vol 32 ◽  
pp. 429-436
Author(s):  
Lynn E. Lowry ◽  
Daniel D. Lawson ◽  
Wayne M. Phillips
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Shock Compression ◽  
Ceramic Materials ◽  
Copper Matrix ◽  
Fabrication Technique ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Induced Defects

Y.Ba2Cu3O7, a high TC superconductor powder, was shock compacted and explosively welded inside a copper matrix using the explosive fabrication methods described by Murr, Hare and Eror. The shock compression fabrication technique provides the ability to process the superconductor powders into useable structures that will minimize environmental degradation and will not negatively affect the physical or mechanical properties. Additionally, the introduction of shock induced defects are known to increase solid-state reactivity in ceramic materials. For this reason, shock compression fabrication of the superconductor/copper system offers the possibility of enhancing the superconducting properties of the YBa2Cu3O7 powders.

The Effects of Austempering Temperature and Time on Mechanical Properties of Ductile Cast Iron Grade FCD450

2020 ◽  
Vol 856 ◽  
pp. 92-98
Author(s):  
Janthira Chantarach ◽  
Rungsinee Canyook
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Low Temperature ◽  
Impact Toughness ◽  
Ductile Cast Iron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Austempering Temperature ◽  
Iron Grade

The purpose of the study was to inspect microstructure, mechanical properties and impact toughness of ductile cast iron grade FCD450 produced by austempering process. The study focused on austempering parameter, which effected impact toughness of material at low temperature. The FCD450 was initially temperature austenized at 885°C (1625˚F) for 2 hours. Austempering was carried out at three different temperatures of 271°C (520˚F), 313°C (560˚F) and 357°C (675˚F). The austempering temperature were varied at 1.5, 2.5 and 3.5 hours. X-ray diffraction was showed that the austempered ductile cast iron (ADI) microstructure consists of austenite and ferrite. The results showed that when austempered at 357°C (675˚F) for 2.5 hours has highest hardness and impact energy at low temperature. The dimple ductile fracture of ADI fracture surfaces was revealed by scanning electron microscope (SEM).

Techniques of SrAl12O19 Platelets Formation in ZTA

2015 ◽  
Vol 788 ◽  
pp. 246-251
Author(s):  
Natalya Belousova ◽  
Sergey Veselov ◽  
Nina Cherkasova ◽  
Aleksey Lazarev ◽  
Ruslan Kuzmin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Ceramic Material ◽  
Ceramic Materials ◽  
Mechanical Tests ◽  
Initial Material ◽  
X Ray Diffraction ◽  
Sintered Ceramic ◽  
X Ray ◽  
Platelet Formation

A possibility of the SrAl12O19platelet formation in the Al2O3– ZrO2ceramic using SrCO3or Sr3Al2O6is evaluated. An impact of two techniques of platelet synthesis on mechanical properties of the material is investigated. Defects revealed in the sintered ceramic material are analyzed. Recommendations on the best method of the SrAl12O19phase formation in ceramic materials are given based on the structural and X-ray diffraction analyses as well as on mechanical tests. It is shown that an addition of 3 wt% SrAl12O19into the ZTA ceramic results in an increase in fracture toughness by up to 30 % in comparison with the initial material.

Kinetically asymmetric charge and discharge behavior of LiNi0.5Mn1.5O4 at low temperature observed by in situ X-ray diffraction

2014 ◽  
Vol 2 (37) ◽  
pp. 15414-15419 ◽  
Author(s):  
Ikuma Takahashi ◽  
Haruno Murayama ◽  
Kenji Sato ◽  
Takahiro Naka ◽  
Koji Kitada ◽  
...  
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Discharge Behavior

Thermodynamically reversible LiNi0.5Mn1.5O4 electrodes kinetically behave asymmetrically during charging and discharging at low temperatures.

Use of Angang Slag for the Production of Glass-Ceramic Materials

2008 ◽  
Vol 368-372 ◽  
pp. 1426-1428
Author(s):  
Hong Xia Lu ◽  
Tie Cui Hou ◽  
Zhang Wei ◽  
Li Jian Li ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
Clay Brick ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Ceramic Materials ◽  
Furnace Slag

The characteristic of Angang blast furnace slag was studied by X-ray fluorescence spectrometry, DSC, X-ray diffraction and SEM. SiO2-Al2O3-CaO system glass-ceramics have been obtained successfully from slag with other additives. The properties of slag-based glass-ceramics were analyzed in this paper. It has been found that nucleation temperature is in the range of 600~700 °C, and crystallization temperature is in the range of 850~950 °C. The crystals phase is 2 CaO⋅ Al2O3⋅ SiO2. The chemical and mechanical properties of slag-based glass-ceramics are superior to the properties of clay brick.

Low Temperature Studies Of Rare Gases Adsorbed On Molecular Sieve Materials

1991 ◽  
Vol 233 ◽  
Author(s):  
Graham F. Mccann ◽  
I. Gameson ◽  
W.J. Steado ◽  
T. Rayment ◽  
P.J. Barrie ◽  
...  
Keyword(s):  
Low Temperature ◽  
Phase Transformations ◽  
Adsorption Isotherms ◽  
Low Temperatures ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Variable Temperature ◽  
Rare Gases ◽  
X Ray Diffraction ◽  
X Ray

ABSTRACTX-ray diffraction (XRD) and adsorption isotherms have long been traditional methods of characterising molecular sieves. By combining these techniques at low temperatures with variable temperature 129-Xe N.M.R. we now have a fuller understanding of the behaviour of sorbed layers inside these materials. In particular we have observed phase transformations of Xe in a polyhydroxyaluminium-pillared montmorillonite molecular sieve and have developed a model consistent with the data. In addition, using XRD, an interpillar distance of ca. 30Å was calculated. We present the first detailed low temperature studies of 129-Xe N.M.R. on these systems.

Low temperature amorphization and superconductivity in FeSe single crystals at high pressures

2010 ◽  
Vol 25 (2) ◽  
pp. 396-400 ◽  
Author(s):  
Andrew K. Stemshorn ◽  
Georgiy Tsoi ◽  
Yogesh K. Vohra ◽  
Stanislav Sinogeiken ◽  
Phillip M. Wu ◽  
...  
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Single Crystals ◽  
Amorphous Phase ◽  
Tetragonal Phase ◽  
Electrical Resistance ◽  
Low Temperatures ◽  
High Pressures ◽  
X Ray Diffraction ◽  
X Ray

In this study, we report low temperature x-ray diffraction studies combined with electrical resistance measurements on single crystals of iron-based layered superconductor FeSe to a temperature of 10 K and a pressure of 44 GPa. The low temperature high pressure x-ray diffraction studies were performed using a synchrotron source and superconductivity at high pressure was studied using designer diamond anvils. At ambient temperature, the FeSe sample shows a phase transformation from a PbO-type tetragonal phase to a NiAs-type hexagonal phase at 10 ± 2 GPa. On cooling, a structural distortion from a PbO-type tetragonal phase to an orthorhombic Cmma phase is observed below 100 K. At a low temperature of 10 K, compression of the orthorhombic Cmma phase results in a gradual transformation to an amorphous phase above 15 GPa. The transformation to the amorphous phase is completed by 40 GPa at 10 K. A loss of superconductivity is observed in the amorphous phase and a dramatic change in the temperature behavior of electrical resistance indicates formation of a semiconducting state at high pressures and low temperatures. The formation of the amorphous phase is attributed to a kinetic hindrance to the growth of a hexagonal NiAs phase under high pressures and low temperatures.

Growth and Structure of Tungsten Carbide-Transition Metal Superlattices

1987 ◽  
Vol 103 ◽  
Author(s):  
T. D. Moustakas ◽  
J. Y. Koo ◽  
A. Ozekcin
Keyword(s):  
Low Temperature ◽  
Tungsten Carbide ◽  
Ceramic Materials ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Lattice Imaging ◽  
X Ray ◽  
First Time ◽  
Nanoscale Range ◽  
Low Temperature Process

ABSTRACTSuperlattices between ceramic materials, such as tungsten carbide, and transition metals have been synthesized for the first time. The growth and structure of these superlattices were investigated by low angle X-ray diffraction and TEM lattice imaging and microdiffraction. The data show that the low temperature process of forming these two dimensional composites leads to unique crystal structures and morphology in the nanoscale range.

Study on Self-Reinforcement of High-Density Polyethylene Extruded with Vibration in Low Temperature

2011 ◽  
Vol 337 ◽  
pp. 368-371
Author(s):  
Xue Mei Qin ◽  
Bao Shan Shi ◽  
Bing Li
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
High Density Polyethylene ◽  
Crystal Morphology ◽  
High Density ◽  
Axial Vibration ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron Microcopy

The effect of vibration on the microstructure and mechanical properties of high-density polyethylene (HDPE) sheets, obtained through vibration plasticating extruder in low temperature, were studied systematically. Property Tests show that the tensile strength and the Vika temperature were much improved under the reciprocating axial vibration in low temperature. Differential scanning calorimetry , scanning electron microcopy and wide angle X-ray diffraction were executed to analyze the microstructure of the samples. The results indicate that the vibration extrudate in low temperature has higher crystallinity, perfect crystallite, and new crystal morphology formed , which account for enhancement of the mechanical properties and Vika temperature of sheets, compared to conventional static extrudate.

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