Density and Mechanical Strength of Ferrite for Inertial Gyroscope

2007 ◽  
Vol 546-549 ◽  
pp. 2265-2268
Author(s):  
Zhong Yu ◽  
Zhong Wen Lan ◽  
Ke Sun ◽  
Yu Chen
Keyword(s):  
Grain Size ◽  
Fracture Surface ◽  
Crystal Lattice ◽  
Lattice Constant ◽  
Bending Strength ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zn Ferrite ◽  
Electronic Microscope ◽  
Crystal Lattice Constant

The effects of NiO on density and mechanic strength of Mn-Zn ferrite used for inertial gyroscope were investigated by measurements of crystal lattice constant, Vickers hardness, bending strength. To investigate this further, powder of Mn-Zn ferrite was characterized by x-ray diffraction (XRD) and the fracture surface of Mn-Zn ferrite was checked by scanning electronic microscope (SEM). The investigation revealed that the substitution of Ni2+ modified crystal lattice constant and crystal grain size so that it caused crystal lattice constant of Mn-Zn ferrite to decline and crystal grain size to decrease, therefore it was useful to improve density and mechanic strength of Mn-Zn ferrite by this way. The results show that proper addition of NiO can bring higher density and more perfect mechanic strength of Mn-Zn ferrite used for inertial gyroscope.

Solid-Phase Crystallization of a-Si:H by RTA

2010 ◽  
Vol 44-47 ◽  
pp. 4151-4153 ◽  
Author(s):  
Rui Min Jin ◽  
Ding Zhen Li ◽  
Lan Li Chen ◽  
Xiang Ju Han ◽  
Jing Xiao Lu
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Amorphous Silicon ◽  
Glass Substrate ◽  
Solid Phase ◽  
X Ray Diffraction ◽  
Solid Phase Crystallization ◽  
X Ray ◽  
Average Grain Size ◽  
Electronic Microscope

Amorphous silicon films prepared by PECVD on glass substrate has been crystallized by rapid thermal annealing (RTA) at the same temperature for different time. From X-ray diffraction (XRD) and scanning electronic microscope (SEM), it is found that the grain size is biggest crystallized at 720°C for 8 min, an average grain size of 28nm or so is obtained. The thin film is smoothly and perfect structure.

Facet crystallography by electron diffraction in the SEM

1993 ◽  
Vol 51 ◽  
pp. 774-775
Author(s):  
J.A. Sutliff
Keyword(s):  
Grain Size ◽  
Fracture Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Optical Reflection ◽  
Euhedral Crystal ◽  
Facet Plane ◽  
Engineering Materials ◽  
Diffraction Patterns ◽  
Surface Facet

The study of fracture in engineering materials often involves an analysis of the crystallography of the fracture surface. In particular, the question is often asked, "What, if any, low index plane corresponds to the plane of a particular fracture surface facet?" To determine the crystallographic plane of a surface facet, it is necessary to determine the orientation of the grain and the orientation of the facet plane relative to the grain. For example, if a euhedral crystal of known orientation is fractured, an optical reflection goniometer can be used to measure the angles between a facet and known crystal faces in order to deduce the direction of the facet normal. Laue x-ray diffraction patterns taken from well aligned facets can also be analyzed to determine the orientation of the crystal normal to the facet. In many engineering materials, the facets are small, usually as a result of a small grain size in the material, and it becomes impractical to use these techniques.

Microstructure and Mechanical Properties of TiNiFe Shape Memory Alloys with Different Compositions

2016 ◽  
Vol 849 ◽  
pp. 295-301 ◽  
Author(s):  
Yan Feng Li ◽  
Xue Feng ◽  
Xun Jun Mi ◽  
Xiang Qian Yin ◽  
Xiao Yu Kang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Tensile Test ◽  
Shape Memory ◽  
Lattice Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ni Content ◽  
Microstructure And Mechanical Properties

The microstructure and mechanical properties of TiNiFe alloys with different compositions was investigated by tensile test, X-ray diffraction, EBSD, SEM, and TEM. The results indicated that tensile strength rapidly increased with increasing Ni content. In addition, Ti2(Ni,Fe) particles were observed in the TiNiFe alloys, which affected the mechanical properties. Increasing the content of Ni had little influence on the grain size of TiNiFe alloys. With the replacement of Ni by Fe, the lattice constant of TiNiFe alloys decreased as the Ni content increased.

scholarly journals Preparation of high-entropy carbides by different sintering techniques

2021 ◽  
Vol 56 (19) ◽  
pp. 11237-11247 ◽  
Author(s):  
Johannes Pötschke ◽  
Manisha Dahal ◽  
Mathias Herrmann ◽  
Anne Vornberger ◽  
Björn Matthey ◽  
...  
Keyword(s):  
Grain Size ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Vacuum Sintering ◽  
X Ray ◽  
High Entropy ◽  
Mean Grain Size ◽  
The Mean ◽  
Gas Pressure Sintering ◽  
Hardness Values

AbstractDense (Hf, Ta, Nb, Ti, V)C- and (Ta, Nb, Ti, V, W)C-based high-entropy carbides (HEC) were produced by three different sintering techniques: gas pressure sintering/sinter–HIP at 1900 °C and 100 bar Ar, vacuum sintering at 2250 °C and 0.001 bar as well as SPS/FAST at 2000 °C and 60 MPa pressure. The relative density varied from 97.9 to 100%, with SPS producing 100% dense samples with both compositions. Grain size measurements showed that the substitution of Hf with W leads to an increase in the mean grain size of 5–10 times the size of the (Hf, Ta, Nb, Ti, V,)C samples. Vacuum-sintered samples showed uniform grain size distribution regardless of composition. EDS mapping revealed the formation of a solid solution with no intermetallic phases or element clustering. X-ray diffraction analysis showed the structure of mostly single-phase cubic high-entropy carbides. Hardness measurements revealed that (Hf, Ta, Nb, Ti, V)C samples possess higher hardness values than (Ta, Nb, Ti, V, W)C samples.

scholarly journals X-ray diffraction analysis of kaolin M1 and M2 via the Williamson–Hall and Warren–Averbach methods

2021 ◽  
pp. 174751982098472
Author(s):  
Lalmi Khier ◽  
Lakel Abdelghani ◽  
Belahssen Okba ◽  
Djamel Maouche ◽  
Lakel Said
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Low Temperature ◽  
Diffraction Analysis ◽  
Mechanical Resistance ◽  
X Ray Diffraction ◽  
Integral Breadth ◽  
X Ray ◽  
Mullite Phase

Kaolin M1 and M2 studied by X-ray diffraction focus on the mullite phase, which is the main phase present in both products. The Williamson–Hall and Warren–Averbach methods for determining the crystallite size and microstrains of integral breadth β are calculated by the FullProf program. The integral breadth ( β) is a mixture resulting from the microstrains and size effect, so this should be taken into account during the calculation. The Williamson–Hall chart determines whether the sample is affected by grain size or microstrain. It appears very clearly that the principal phase of the various sintered kaolins, mullite, is free from internal microstrains. It is the case of the mixtures fritted at low temperature (1200 °C) during 1 h and also the case of the mixtures of the type chamotte cooks with 1350 °C during very long times (several weeks). This result is very significant as it gives an element of explanation to a very significant quality of mullite: its mechanical resistance during uses at high temperature remains.

Fabrication of 239/238Pu-Zirconolite Ceramic Pellets by Natural Sintering

2003 ◽  
Vol 807 ◽  
Author(s):  
T. Advocat ◽  
F. Jorion ◽  
T. Marcillat ◽  
G. Leturcq ◽  
X. Deschanels ◽  
...  
Keyword(s):  
Grain Size ◽  
Radioactive Waste ◽  
Nuclear Waste ◽  
Chemical Stability ◽  
Minor Actinides ◽  
Loading Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Physical And Chemical ◽  
Inorganic Matrix

ABSTRACTZirconolite is a potential inorganic matrix that is currently investigated in France, in the framework of the 1991 radioactive waste management law, with a view to provide durable containment of the trivalent and tetravalent minor actinides like neptunium, curium, americium and small quantities of unrecyclable plutonium separated from other nuclear waste. To confirm the actinide loading capacity of the zirconolite calcium site and to study the physical and chemical stability of this type of ceramic when subjected to alpha self-irradiation, zirconolite ceramic pellets were fabricated with 10 wt% plutonium oxide (isotope 239 or 238). The 55 pellets are dense (> 93.3% of the theoretical density on average) and free of cracks. They are characterized by a grain size of between 10 and 20 micrometers. X-ray diffraction analyses confirmed the presence of the zirconolite 2M crystalline structure.

Nanocrystalline Solutions as Precursors to The Spray Deposition of Cdte Thin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Cdte Nanoparticles ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Cdte Thin Films

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.

Effect of Nitridation Magnetic Properties of Nanocrystalline Fe-Co Alloy Powders

2010 ◽  
Vol 654-656 ◽  
pp. 1106-1109
Author(s):  
Ya Qiong He ◽  
Chang Hui Mao ◽  
Jian Yang
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Alloy Powder ◽  
High Energy ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
X Ray ◽  
Transmission Electron ◽  
Nitridation Temperature ◽  
Microstructure And Magnetic Properties

Nanocrystalline Fe-Co alloy powders, which were prepared by high-energy mechanical milling, were nitrided under the mixing gas of NH3/H2 in the temperature range from 380°C to 510°C. X-ray diffraction (XRD) was used to analyze the grain size and reaction during the processing. The magnetic properties of the nitrided powders were measured by Vibrating Sample Magnetometer (VSM). The results show that with the appearance of Fe4N phase after nitride treatment, and the grain-size of FeCo phase decreases with the increase of nitridation temperature between 380°C to 450°C.The saturation magnetization of nitrided alloy powder treated at 480°C is about 18% higher than that of the initial Fe-Co alloy powder, accompanied by the reduction of the coercivity. Transmission electron microscope (TEM) was used, attempting to further analyze the effect of Fe4N phase on microstructure and magnetic properties of the powder mixtures.

Structural and thermodynamic properties of nanocrystalline fcc metals prepared by mechanical attrition

1992 ◽  
Vol 7 (7) ◽  
pp. 1751-1761 ◽  
Author(s):  
J. Eckert ◽  
J.C. Holzer ◽  
C.E. Krill ◽  
W.L. Johnson
Keyword(s):  
Thermal Analysis ◽  
Grain Size ◽  
Melting Point ◽  
Grain Boundary ◽  
Bulk Modulus ◽  
Atomic Level ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fcc Metals ◽  
Mechanical Attrition

Nanocrystalline fcc metals have been synthesized by mechanical attrition. The crystal refinement and the development of the microstructure have been investigated in detail by x-ray diffraction, differential scanning calorimetry, and transmission electron microscopy. The deformation process causes a decrease of the grain size of the fcc metals to 6–22 nm for the different elements. The final grain size scales with the melting point and the bulk modulus of the respective metal: the higher the melting point and the bulk modulus, the smaller the final grain size of the powder. Thus, the ultimate grain size achievable by this technique is determined by the competition between the heavy mechanical deformation introduced during milling and the recovery behavior of the metal. X-ray diffraction and thermal analysis of the nanocrystalline powders reveal that the crystal size refinement is accompanied by an increase in atomic-level strain and in the mechanically stored enthalpy in comparison to the undeformed state. The excess stored enthalpies of 10–40% of the heat of fusion exceed by far the values known for conventional deformation processes. The contributions of the atomic-level strain and the excess enthalpy of the grain boundaries to the stored enthalpies are critically assessed. The kinetics of grain growth in the nanocrystalline fcc metals are investigated by thermal analysis. The activation energy for grain boundary migration is derived from a modified Kissinger analysis, and estimates of the grain boundary enthalpy are given.

The Research about Oxidation Kinetics of Ti60 Alloy and Ni-Co-Cr-Al-Y-Si Coating on Surface

2011 ◽  
Vol 189-193 ◽  
pp. 743-746
Author(s):  
Jian Feng Li ◽  
Li Zhi Guo ◽  
Guo Qing Li
Keyword(s):  
Oxidation Resistance ◽  
X Ray Diffraction ◽  
Surface Appearance ◽  
X Ray ◽  
Good Oxidation Resistance ◽  
Ion Plating ◽  
Alloy Oxidation ◽  
Resistance Performance ◽  
Kinetics Of ◽  
Electronic Microscope

This article summarized depositing craft of the superficial coatings (Ni-Co-Cr-Al-Y-Si) on the Ti60 alloy (Ti-6.5Al-4.2Sn-4Zr-0.6Si) with arc ion plating technology and the oxidation behavior under 600~750 . The X-ray diffraction (XRD) and the scanning electronic microscope (SEM) were used to analyze the surface appearance, the structure and the ingredient conducts of non-coating Ti60 alloy. The contrast shows that the coatings have good protection to Ti60 alloy. The result indicated that the coating has the good oxidation resistance performance under 600°C , 650°C and 750°C . Coated Ti60 alloy oxidation resistance is markly improved. The circulation oxidation dynamics curve basically conforms to the parabola rule.

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