SOME FACTORS EFFECT ON ZERO-RESISTANCE TEMPERATURE OF SUPERCONDUCTR Y1Ba2Cu3O9−x

1987 ◽  
Vol 01 (02) ◽  
pp. 267-272 ◽  
Author(s):  
Liquan Chen ◽  
Zhili Xiao ◽  
Yuzhen Huang ◽  
Zhenhong Mai ◽  
Xi Chu ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Heating Rate ◽  
Oxygen Pressure ◽  
Sintering Temperature ◽  
Sintering Time ◽  
Zero Resistance ◽  
Temperature Heating

Some factors which might effect on Tco during the sintering procedure have been studied. These factors include the sintering time, sintering temperature, heating rate, cooling rate, oxygen pressure, annealing in different atmosphere and multiple sintering as well. The attention has also paid to the influence of Al3+ which might be introduced by using Al2O3 crucible.

scholarly journals Optimization of Sintering Process of Alumina Ceramics Using Response Surface Methodology

2021 ◽  
Vol 13 (12) ◽  
pp. 6739
Author(s):  
Darko Landek ◽  
Lidija Ćurković ◽  
Ivana Gabelica ◽  
Mihone Kerolli Mustafa ◽  
Irena Žmak
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Heating Rate ◽  
Sintering Temperature ◽  
Nonlinear Models ◽  
Slip Casting ◽  
Holding Time ◽  
Alumina Ceramics ◽  
Aqueous Suspensions ◽  
Temperature Heating

In this work, alumina (Al2O3) ceramics were prepared using an environmentally friendly slip casting method. To this end, highly concentrated (70 wt.%) aqueous suspensions of alumina (Al2O3) were prepared with different amounts of the ammonium salt of a polycarboxylic acid, Dolapix CE 64, as an electrosteric dispersant. The stability of highly concentrated Al2O3 aqueous suspensions was monitored by viscosity measurements. Green bodies (ceramics before sintering) were obtained by pouring the stable Al2O3 aqueous suspensions into dry porous plaster molds. The obtained Al2O3 ceramic green bodies were sintered in the electric furnace. Analysis of the effect of three sintering parameters (sintering temperature, heating rate and holding time) on the density of alumina ceramics was performed using the response surface methodology (RSM), based on experimental data obtained according to Box–Behnken experimental design, using the software Design-Expert. From the statistical analysis, linear and nonlinear models with added first-order interaction were developed for prediction and optimization of density-dependent variables: sintering temperature, heating rate and holding time.

scholarly journals Dilation of Ti-6Al-4V/HA Composite Tensile Parts

2002 ◽  
Vol 11 (2) ◽  
pp. 096369350201100
Author(s):  
E. S. Thian ◽  
N. H. Loh ◽  
K. A. Khor ◽  
S. B. Tor
Keyword(s):  
Heating Rate ◽  
Sintering Temperature ◽  
Holding Time ◽  
Test Results ◽  
Basic Information ◽  
Sintering Process ◽  
Densification Rate ◽  
In Situ Test ◽  
Temperature Heating

Prior to the actual sintering process, a dilatometry study is performed to provide basic information and guidelines. This paper studies the effects of three sintering factors: sintering temperature, heating rate and holding time, on the densification rate of Ti-6Al-4V/HA composite parts. According to the in-situ test results, suitable values for the sintering factors can then be established.

THE SUPERCONDUCTING STUDY OF TlBaCaCu2Oy

1988 ◽  
Vol 02 (09) ◽  
pp. 1095-1101
Author(s):  
JIE YAN ◽  
XIAOMING YANG ◽  
GUANGWEN PEI ◽  
ZHENYU MEN ◽  
DEYING SONG
Keyword(s):  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Sintering Atmosphere ◽  
X Ray ◽  
Cell Parameters ◽  
Sintering Time ◽  
Zero Resistance ◽  
Annealing Rate ◽  
The Stability

The relation of the superconductivity of TlBaCaCu 2 O y to the sintering temperature, sintering time, annealing rate and sintering atmosphere was studied. It was shown that the zero-resistance temperature of the superconductors of the type was up to 118K and the stability was to some extent quite good. Through X-ray diffraction analysis, the TlBaCaCu 2 O y was found to possess two kinds of tetragonal structures. The T co =118 K sample has the unit cell parameters of a=5.446(2)Å, c=35.698(2)Å; while for T co =93.5 K , one has the parameters of a=5.469(2)Å, c=30.051(2)Å, the substitution of Tl, Ba, Ca , by many other elements show that only TlBaMgCu 2 O y and TlMg 2 Cu 2 O y are superconductors and others are insulators.

Step-Sintering of Fe-(1-3)%Mn-0.8%C Steels

2020 ◽  
Vol 405 ◽  
pp. 373-378
Author(s):  
Monika Tenerowicz-Żaba ◽  
Maciej Sułowski
Keyword(s):  
Tensile Strength ◽  
Phase Transformation ◽  
Cooling Rate ◽  
Heating Rate ◽  
Microstructure Evolution ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Tensile Tests ◽  
Transformation Temperatures ◽  
Metallographic Observation

The aim of the study was to examine how the microstructure changes during heating of Fe-Mn-C system (step-sintering). Mixtures of powders containing 1 – 3 % Mn and 0.8 % C were prepared in Turbula TC2 mixer for 30 minutes. Before step-sintering, the dilatometric investigations were carried out, which allowed to obtain phase transformation temperatures of Fe-(1-3)Mn%-0.8%C system. Following dilatometric investigations, 4 steps – temperatures were determined dependently of isothermal sintering temperature. The commonly used industry temperatures – 1120 °C and 1250 °C – were set as target temperatures. For each of them, 4 heat steps were carried out. The procedure of investigations was as follows: samples were heated to the step temperature with heating rate 60 K/min, then isothermally sintered at step temperature for 5 min, and finally cooled to the room temperature with cooling rate ~ 66 K/min. Fe-Mn-C samples were mechanically (tensile) tested. After tensile tests, metallographic observations of the samples were performed. Based on the results obtained, the tensile strength was increasing with the increasing of the step temperature. The metallographic observation showed the microstructure evolution – with increasing the step temperature, decreasing of porosity was observed.

Spark plasma sintering and characterization of bulk nanostructured fully stabilized zirconia: Part I. Densification studies

2004 ◽  
Vol 19 (11) ◽  
pp. 3255-3262 ◽  
Author(s):  
U. Anselmi-Tamburini ◽  
J.E. Garay ◽  
Z.A. Munir ◽  
A. Tacca ◽  
F. Maglia ◽  
...  
Keyword(s):  
Crystallite Size ◽  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Significant Influence ◽  
Sintering Temperature ◽  
Stabilized Zirconia ◽  
Sintering Time ◽  
Final Density ◽  
Plasma Sintering ◽  
Spark Plasma

The sintering of nanosize powders of fully stabilized zirconia was investigated using the spark plasma sintering (SPS) method. The influence of sintering temperature, heating rate, direct current pulse pattern, sintering time, and sintering pressure on the final density and grain size of the product was investigated. The dependence of densification on temperature showed a maximum at 1200 °C, resulting with nearly fully dense zirconia with a crystallite size of about 100 nm. Heating rate (50∼300 °C min−1) and sintering time (5–16 min) had no significant influence on the final density and the crystallite size. Pulsing patterns ranging from 2:2 to 48:2 (on:off) had no influence on the density or the crystallite size. However, the applied pressure had a significant influence on the final density but no apparent effect on crystallite size for a sintering temperature of 1200 °C and a hold time of 5 min.

Taguchi Method for the Determination of Optimised Sintering Parameters of Titanium Alloy Foams

2011 ◽  
Vol 264-265 ◽  
pp. 1731-1736 ◽  
Author(s):  
Sufizar Ahmad ◽  
Norhamidi Muhamad ◽  
Andanastuti Muchtar ◽  
Jaafar Sahari ◽  
Khairur Rijal Jamaludin ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Taguchi Method ◽  
Heating Rate ◽  
Alloy Powder ◽  
Sintering Temperature ◽  
Time Profile ◽  
Vacuum Furnace ◽  
Titanium Foam ◽  
Temperature Heating

Sintering is a key step in the preparation of metal foams. The present work focuses on the sintering effects on the properties of titanium foam prepared using the slurry technique. Sintering affects the density as well as the mechanical properties of the sintered parts. To achieve a high density of the titanium alloy foam, the effects of various parameters including temperature, time profile and composition have to be characterized and optimized. This paper reports the use of the Taguchi method in characterizing and optimizing the sintering process parameters of titanium alloys. The effect of four sintering factors: composition, sintering temperature, heating rate and soaking time to the density has been studied. The titanium slurry was prepared by mixing titanium alloy powder, polyethylene glycol (PEG), methylcellulose and water. Polyurethane (PU) foam was then impregnated into the slurry and dried at room temperature. This was later sintered in a high temperature vacuum furnace. The various factors were assigned to an L9 orthogonal array. From the Analysis of Variance (ANOVA), the sintering temperature was found to give the highest percentage of contribution (34.73) followed by the composition of the titanium alloy powder (26.41) and the heating rate (0.64). The optimum density for the sintered titanium alloy foam was 1.4873±0.918 gcm-1. Confirmatory experiments have produced results that lay within the 90% confidence interval.

scholarly journals Synthesis and Na+ Ion Conductivity of Stoichiometric Na3Zr2Si2PO12 by Liquid-Phase Sintering with NaPO3 Glass

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3790
Author(s):  
Yongzheng Ji ◽  
Tsuyoshi Honma ◽  
Takayuki Komatsu
Keyword(s):  
Solid State ◽  
Liquid Phase ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Ion Conductivity ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Sintering Time ◽  
Lower Activation

Sodium super ionic conductor (NASICON)-type Na3Zr2Si2PO12 (NZSP) with the advantages of the high ionic conductivity, stability and safety is one of the most famous solid-state electrolytes. NZSP, however, requires the high sintering temperature about 1200 °C and long sintering time in the conventional solid-state reaction (SSR) method. In this study, the liquid-phase sintering (LPS) method was applied to synthesize NZSP with the use of NaPO3 glass with a low glass transition temperature of 292 °C. The formation of NZSP was confirmed by X-ray diffraction analyses in the samples obtained by the LPS method for the mixture of Na2ZrSi2O7, ZrO2, and NaPO3 glass. The sample sintered at 1000 °C for 10 h exhibited a higher Na+ ion conductivity of 1.81 mS/cm at 100 °C and a lower activation energy of 0.18 eV compared with the samples prepared by the SSR method. It is proposed that a new LPE method is effective for the synthesis of NZSP and the NaPO3 glass has a great contribution to the Na+ diffusion at the grain boundaries.

scholarly journals Microwave Sintering and Microwave Dielectric Properties of (1–x)Ca0.61La0.26TiO3-xNd(Mg0.5Ti0.5)O3 Ceramics

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 438
Author(s):  
Shuwei Yang ◽  
Bingliang Liang ◽  
Changhong Liu ◽  
Jin Liu ◽  
Caisheng Fang ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Mobile Communications ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Microwave Dielectric Properties ◽  
Conventional Heating ◽  
Sintering Process ◽  
Microwave Dielectric ◽  
Sintering Time ◽  
Frequency Temperature

The (1–x)Ca0.61La0.26TiO3-xNd(Mg0.5Ti0.5)O3 [(1–x)CLT-xNMT, x = 0.35~0.60] ceramics were prepared via microwave sintering. The effects of sintering temperature and composition on the phase formation, microstructure, and microwave dielectric properties were investigated. The results show that the microwave sintering process requires a lower sintering temperature and shorter sintering time of (1–x)CLT-xNMT ceramics than conventional heating methods. All of the (1–x)CLT-xNMT ceramics possess a single perovskite structure. With the increase of x, the dielectric constant (ε) shows a downward trend; the quality factor (Qf) drops first and then rises significantly; the resonance frequency temperature coefficient (τf) keeps decreasing. With excellent microwave dielectric properties (ε = 51.3, Qf = 13,852 GHz, τf = −1.9 × 10−6/°C), the 0.65CLT-0.35NMT ceramic can be applied to the field of mobile communications.

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