scholarly journals Effects of Gd211 Particles Characteristic in the Precursor Pellets on the Levitation Force of Single-Domain GdBCO Bulks Prepared by the Gd + 011 TSIG Method

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xiaochun Yuan ◽  
Wanmin Yang
Keyword(s):  
Sintering Temperature ◽  
Levitation Force ◽  
Solid Phase ◽  
Single Domain ◽  
Particle Sizes ◽  
The Novel ◽  
Bulk Superconductors ◽  
Lower Porosity ◽  
Different Temperatures ◽  
Average Size

In this paper, single-domain GdBCO bulks have been fabricated by a new Gd + 011 TSIG method with precursor solid phase pellets (PSPPs) of different Gd211 particle sizes and distributions, prepared by solid state reaction with well-mixed (Gd2O3 + BaCuO2) pellets at different temperatures. The novel results indicated that (1) the average size of Gd211 particles in PSPP is monotonically increasing with increasing the sintering temperature up to 1200°C. (2) With increasing the sintering temperature from 950 to 1200°C, the porous ratio and the density of the PSPP are, respectively, monotonically decreasing and increasing. Furthermore when the sintering temperature is less than 1000°C, the porous ratio is higher and the density is lower than the values of the pressed pellets. (3) With increasing the sintering temperature, the average size of Gd211 particles in the GdBCO bulk first decreases and then increases. In addition, the smallest Gd211 particles are obtained in the sample sintered at 1050°C. (4) The maximum levitation force is obtained in the sample sintered at 1150°C with a relatively larger size of Gd211 particles and lower porosity. This result is significant when fabricating high-quality GdBCO bulk superconductors by controlling the porosity, Gd211 particle size, and their distribution characteristic.

Influence of ZnO doping on the properties of single domain YBCO bulks fabricated by RE+011 TSIG process

2017 ◽  
Vol 31 (25) ◽  
pp. 1745018
Author(s):  
W. M. Yang ◽  
X. C. Yuan ◽  
Y. X. Guo
Keyword(s):  
Lattice Distortion ◽  
Levitation Force ◽  
Solid Phase ◽  
Single Domain ◽  
Pinning Force ◽  
Ybco Bulk ◽  
Trapped Field ◽  
Bulk Superconductors ◽  
Flux Pinning Force ◽  
Zno Doping

Single domain YBCO bulk superconductors with different additions of ZnO have been successfully fabricated by RE[Formula: see text]011 TSIG process with a new solid phase of [(100-[Formula: see text])(Y2O[Formula: see text]BaCuO2)+[Formula: see text]ZnO] and a new liquid phase of (Y2O3+6CuO+10BaCuO2). The effects of ZnO additions on the growth morphology, microstructure, critical temperature ([Formula: see text]), the levitation force and trapped field of the YBCO bulks have been investigated. It is found that within the range of ZnO additions [Formula: see text]=0–1.0 wt.%, all the samples are of the typical characteristic of single-domain YBCO bulk; the [Formula: see text] of the samples decreases from 92 K to 80 K when the ZnO addition [Formula: see text] increases from [Formula: see text]=0 wt.% to [Formula: see text]=1.0 wt.%; the levitation force and trapped field of the samples firstly increase and then decrease with increase of ZnO additions after going through a maximum, which is closely related with the ZnO addition and the resulting flux pinning force caused by lattice distortion due to the substitution of Zn[Formula: see text] for Cu[Formula: see text] site in the YBCO crystal; the largest levitation force 36.8 N (77 K, 0.5 T) and trapped field 0.416 T (77 K, 0.5 T) of the samples are obtained when [Formula: see text]=0.1 wt.%, respectively. This result is significantly important and helpful for us to improve the properties of YBCO bulk superconductors.

Effect of Reaction between Fe and Carbide Particles on Mechanical Properties of Fe-Base Composite

2008 ◽  
Vol 55-57 ◽  
pp. 357-360 ◽  
Author(s):  
S. Chakthin ◽  
Nuchthana Poolthong ◽  
Ruangdaj Tongsri
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Carbide Particle ◽  
Sintering Temperature ◽  
Particle Sizes ◽  
Different Temperatures ◽  
Base Composite ◽  
Sic Composites ◽  
Carbide Particles ◽  
Sic Particle

Sintered Fe-5 wt. % carbide (SiC or TiC) composites have been prepared via a powder metallurgy (P/M) route. Two carbide particle sizes, < 20 µm and 20-32 µm, were mixed with Fe powder. The powder mixtures were compacted and sintered at 3 different temperatures, 1100, 1150 and 1200 °C. Microstructures of sintered Fe-5 wt. % SiC composites showed evidence of SiC decomposition. The decomposed Si and C atoms diffused into Fe particles resulting in formation of solid solution of Si and C in Fe during sintering. During cooling, the solid solution of C in Fe decomposed to pearlite structure (ferrite and cementite (Fe3C) lamellar structure). Microstructures of sintered Fe-5 wt. % TiC composites showed no evidence of TiC decomposition at the investigated sintering temperatures. Because of the reaction between SiC and Fe, tensile strength and hardness of the sintered Fe-SiC composites were higher than those of the sintered Fe. Experimental results showed that strength and hardness of the sintered Fe-SiC composites increased with increasing sintering temperature and with decreasing SiC particle size. In contrast, mechanical properties of the sintered Fe-TiC composites were inferior to those of the sintered Fe. The reason of poor mechanical properties may be attributed to poor bonding between Fe and TiC particles.

The effect of the grain alignment on the levitation force in single domain YBa2Cu3Oy bulk superconductors

1999 ◽  
Vol 319 (3-4) ◽  
pp. 164-168 ◽  
Author(s):  
W.M Yang ◽  
Y Feng ◽  
L Zhou ◽  
P.X Zhang ◽  
M.Z Wu ◽  
...  
Keyword(s):  
Levitation Force ◽  
Single Domain ◽  
Grain Alignment ◽  
Bulk Superconductors

Particle Size Dependent Structural and Magnetic Properties of CoCrFeO4 Nanoparticles

2012 ◽  
Vol 486 ◽  
pp. 129-133
Author(s):  
R. Mane Dhanraj ◽  
H. Kadam Ram ◽  
T. Alone Suresh ◽  
E. Shirsath Sagar
Keyword(s):  
Particle Size ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Combustion Method ◽  
Blocking Temperature ◽  
Particle Sizes ◽  
Particle Size Range ◽  
Size Dependent ◽  
Auto Combustion ◽  
Different Temperatures

Nanoparticles of CoCrFeO4ferrite in the particle size range of 9 - 38 nm have been prepared by a sol-gel auto combustion method. Synthesized powders were annealed at four different temperatures viz. 400 °C, 600 °C, 800 °C and 1000 °C. Particle sizes are determined by X-ray analysis and TEM. The size of the nanoparticles increase linearly with sintering temperature and time, most probably due to coalescence that increases as sintering temperature increases. The saturation magnetization increases from 62 to 81 emu/g and coercivity initially increases up to 814 Oe and then decreases to 366 Oe with increase in particle size and sintering temperature. The typical blocking temperature increases from 135 to 165 K with increasing particle size.

Dry Sliding Wear Studies of Copper-Based Powder Metallurgy Brake Materials

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Glenn Kwabena Gyimah ◽  
Ping Huang ◽  
Dong Chen
Keyword(s):  
Sintering Temperature ◽  
Wear Behavior ◽  
Friction Material ◽  
Dry Sliding Wear ◽  
Temperature Sensitive ◽  
The Novel ◽  
Different Temperatures ◽  
The Coefficient Of Friction ◽  
Novel Material ◽  
Mechanical And Tribological Characteristics

The paper focuses on a novel friction material on Cu-based powder metal material. Several elements, such as Al, SiO2, Fe, graphite, Sn, Mn, and MoS2 were added to the Cu and were developed by PM techniques. The aim of the experiment was to study the effect of increasing Sintering temperature on mechanical and tribological characteristics of the novel train brake pads. The materials prepared were sintered at three different temperatures (850 °C, 900 °C, and 950 °C). A high pressure pad-on-disk braking tester was developed to test the wear behavior of these materials without lubrication. Wear was measured by microscopic examination of the pad after the tribometer test. The tests showed that the coefficient of friction, wear rate and wear number were improved immensely by high temperature sintering. This means that, the level of the sintering temperature has significant effect on the performance of the braking material. Thereby, the tribological and the mechanical properties of the novel material were found to be temperature sensitive.

Sintering and Dielectric Properties of SrTiO3-based Ceramics

2012 ◽  
Vol 1397 ◽  
Author(s):  
Juan Li ◽  
Dengren Jin ◽  
Lixin Zhou ◽  
Jinrong Cheng
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Precursor Solution ◽  
Particle Sizes ◽  
Low Dielectric ◽  
Different Temperatures ◽  
High Dielectric ◽  
Room Temperature Dielectric Constant

ABSTRACTHigh dielectric tunability, low dielectric loss tangent and appropriate level of dielectric constant are the basic requirements for applications as electrically tunable dielectric microwave devices. In our experiments, the SrTiO3 green compacts made of the powder mixtures with various particle sizes were infiltrated with a BaTiO3 precursor solution and sintered at different temperatures between 1280 and 1350 ºC for 2 hours and 1350 ºC for 6 hours. The sintering, microstructural and dielectric properties were investigated. Results showed that the relative density of SrTiO3 ceramics could reached 93% when sintered at 1280 ºC for 2 hours. When sintered for 6 hours at 1350 °C, the room temperature dielectric constant of SrTiO3 reaches 900 at a frequency of 1MHz. It has only weak temperature dependence between 100 and 500K. The reason of the low sintering temperature for the dense SrTiO3 ceramics and the effects of sintering scheme on the dielectric properties from 100 K to 500 K are discussed in this paper.

scholarly journals Influence of Artificially Macroscopical Drilling on the Crystal Growth Orientation of Single Domain SmBCO Bulk Superconductor

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 150
Author(s):  
Miao Wang ◽  
Yuguang Liu ◽  
Xiaomei Wang ◽  
Hang Xian ◽  
Wan-min Yang
Keyword(s):  
High Temperature ◽  
Solid Phase ◽  
Single Domain ◽  
Superconducting Properties ◽  
Bulk Superconductor ◽  
Growth Orientation ◽  
Bulk Superconductors ◽  
Boundary Orientation ◽  
Tangent Direction ◽  
Orientation Growth

A large drilled single domain SmBa2Cu3O7−δ (SmBCO) bulk superconductor with a diameter of 32 mm and different hole sizes was successfully fabricated using the modified top-seeded infiltration and growth (TSIG) process. The morphology, superconducting properties, and grain boundary orientation growth of the drilled SmBCO samples were investigated. It was found that not only are the properties of the drilled sample equivalent to those of normal SmBCO bulk superconductors, but also the NdBCO seed crystal can be well controlled because of the increase in the specific surface area in the solid phase pellet. In addition, the growth orientation along the tangent direction of the holes was first noticed in the drilled single domain SmBCO bulk superconductor. This conclusion is highly important for the accurate control of the growth temperature of high temperature bulk superconductors.

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