Effect of the additives of ultrafine (highly dispersed) powders on the phase formation during the sintering process of the charges of ?-sialons

1990 ◽  
Vol 29 (10) ◽  
pp. 799-803
Author(s):  
V. A. Gunchenko ◽  
M. S. Koval'chenko ◽  
G. V. Trunov ◽  
T. N. Miller ◽  
Ya. P. Grabis
Keyword(s):  
Phase Formation ◽  
Sintering Process ◽  
Highly Dispersed

Effect of WC Addition on Phase Formation and Microstructure of TiC-Ni Composites

2008 ◽  
Vol 55-57 ◽  
pp. 353-356
Author(s):  
Nawarat Wora-uaychai ◽  
Nuchthana Poolthong ◽  
Ruangdaj Tongsri
Keyword(s):  
Liquid Phase ◽  
Tungsten Carbide ◽  
Phase Formation ◽  
Liquid Phase Sintering ◽  
Precipitation Process ◽  
Solid Solution Phase ◽  
Binder Phase ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray

In this research, titanium carbide-nickel (TiC-Ni) composites, with tungsten carbide addition, were fabricated by using a powder metallurgy technique. The TiC-Ni mixtures containing between 0-15 wt. % tungsten carbide (WC), were compacted and then sintered at 1300°C and 1400°C, respectively. The phase formation and microstructure of the WC-added TiC-Ni composites have been investigated by X-ray diffraction and scanning electron microscopy techniques. Mechanical properties of these composites were assessed by an indentation technique. The X-ray diffraction patterns showed no evidence of tungsten rich phases in the sintered WC-added cermets. This indicates that during the sintering process, tungsten carbide particles were dissolved in metallic binder phase (Ni phase) via dissolution/re-precipitation process during liquid phase sintering. The liquid phase formed during sintering process could improve sinterability of TiC-based cermets i.e., it could lower sintering temperatures. The TiC-Ni composites typically exhibited a core-rim structure. The cores consisted of undissolved TiC particles enveloped by rims of (Ti, W)C solid solution phase. Hardness of TiC-Ni composites increased with WC content. Sintering temperature also had a slight effect on hardness values.

Aspects of the phase-formation processes in highly dispersed BaTiO3-based materials

1991 ◽  
Vol 30 (12) ◽  
pp. 1005-1006
Author(s):  
V. I. Lapshin ◽  
E. L. Fokina ◽  
I. A. Kozlovskaya
Keyword(s):  
Phase Formation ◽  
Formation Processes ◽  
Highly Dispersed

The effect of B2O3 impurity in the original B powder on the phase formation of MgB2 during the sintering process

2011 ◽  
Vol 471 (23-24) ◽  
pp. 1660-1663 ◽  
Author(s):  
Ying Tang ◽  
Xiangjie Kong ◽  
LiDe Fang ◽  
Hongtao Wang
Keyword(s):  
Phase Formation ◽  
Sintering Process

scholarly journals Effect of MnO2 Dopant on Properties of Na+-β/β"-Al2O3 Solid Electrolyte Prepared by a Synthesizing-cum-sintering Process

2021 ◽  
Vol 27 (1) ◽  
pp. 68-76
Author(s):  
Dae-Han LEE ◽  
Jin-Sik KIM ◽  
Young-Hyuk KIM ◽  
Sung-Ki LIM
Keyword(s):  
Ionic Conductivity ◽  
Solid Electrolyte ◽  
Phase Formation ◽  
Growth Promotion ◽  
Synthesis Temperature ◽  
Negative Influence ◽  
Ion Concentration ◽  
Sintering Process ◽  
Conventional Solid State Reaction ◽  
Β Phase

In order to simplify the complexity of the conventional solid-state reaction process, Na+-β/β″-Al2O3 as a fast Na+-ionic conductive solid electrolyte was fabricated using a synthesizing-cum-sintering process combined with the double-zeta method, which is able to distribute a small amount of Li2O more homogeneously in the Na2O-Al2O3-Li2O system. Additionally, in order to enhance the ionic conductivity, MnO2 was used as a dopant to increase the Na+-ion concentration on the conduction plane in the Na+-β/β″-Al2O3 crystal structure. The relative sintered density increased with the synthesis temperature, ultimately reaching 99.7 % after synthesis at 1400 °C. The phase formation showed an overall β″-phase fraction over 90 %. The addition of MnO2 had a positive effect on the phase formation, but a negative influence on the relative density resulting from the grain growth promotion effect. The highest ionic conductivity was observed at 1.74 × 10-1 S/cm (350 °C) for the sample sintered at 1600 °C with 0.5 wt.% MnO2.

Dielectric properties of (SWCNTs)x GdBa2CuO7−δ superconductor nanocomposites

2017 ◽  
Vol 31 (31) ◽  
pp. 1750290 ◽  
Author(s):  
M. Anas ◽  
S. Ebrahim ◽  
I. G. Eldeen ◽  
R. Awad ◽  
A. I. Abou-Aly
Keyword(s):  
Dielectric Properties ◽  
Phase Formation ◽  
Dielectric Response ◽  
Single Walled Carbon Nanotubes ◽  
Superconducting Phase ◽  
Sintering Process ◽  
Superconducting Properties ◽  
Solid State Reaction Technique ◽  
Micro Cracks ◽  
Walled Carbon Nanotubes

Gd-123 superconducting phase was prepared by solid-state reaction technique. Single-walled carbon nanotubes (SWCNTs) were added in Gd-123 superconducting matrix with different concentrations during the final sintering process to obtain (SWCNTs)[Formula: see text] GdBa2Cu3O[Formula: see text] (x = 0.0–0.1 wt.%) nanoparticles–superconductor composite. The influence of SWCNTs addition on the phase formation, structural, morphological, superconducting and dielectric properties of Gd-123 phase was investigated. It was found that SWCNTs addition enhance the phase formation and does not change the crystal structure of the host Gd-123 superconducting phase. The superconducting properties of Gd-123 samples were improved after the addition of SWCNTs up to x = 0.06 wt.% due to the enhancement in intergrain connectivity by healing up of micro-cracks and reduction of defects, while these properties were retarded with further increase in x. The dielectric response of (SWCNTs)[Formula: see text] Gd-123 superconducting phase with x = 0.0, 0.01, 0.04, 0.05, 0.06 and 0.1 wt.% was measured from 100 KHz to 5 MHz at 77 K. The results reveal that for both real ([Formula: see text]) and imaginary ([Formula: see text]) parts of dielectric constant, the frequency of dispersion increased by increasing SWCNTs amount up to 0.06 wt.%, then this frequency shifted to lower values for x [Formula: see text] 0.06 wt.%. The results were discussed according to the presence and interference of both interfacial and dipolar polarizations.

scholarly journals Effect of Magnetite on Mineral Phase Formation in Sintering Process

2021 ◽  
Vol 107 (6) ◽  
pp. 456-462
Author(s):  
Ziming Wang ◽  
Takayuki Maeda ◽  
Ko-ichiro Ohno ◽  
Kazuya Kunitomo
Keyword(s):  
Phase Formation ◽  
Sintering Process ◽  
Mineral Phase

scholarly journals The Mechanism of the Effect of Al2O3 Content on the Liquid Phase Fluidity of Iron Ore Fines

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 931 ◽  
Author(s):  
Heping Li ◽  
Shengli Wu ◽  
Zhibin Hong ◽  
Weili Zhang ◽  
Heng Zhou ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Mineral Composition ◽  
Phase Formation ◽  
Iron Ore ◽  
Al2o3 Content ◽  
Calcium Ferrite ◽  
Sintering Process ◽  
Liquidity Index ◽  
Iron Ore Fines

The sintering process is significantly important for the ironmaking in China because of the large amount of sinter consumed. Al2O3 is an important element determining the quality and quantity of sinter. However, different conclusions have been made regarding the effects of Al2O3 on the amount and fluidity of the liquid phase formed in the sinter phase. Therefore, it is necessary to examine the effects of Al2O3 content on the amount and fluidity of the liquid phase. The present work investigated the effects of different Al2O3 contents of iron ore fines on the liquid phase formation, mineral composition, and consolidation strength. The results showed that a small amount of Al2O3 increased the amount of calcium ferrite, making the liquid phase formation easier. As the Al2O3 content in iron ore fines increased, the liquidity index decreased continuously, while the fluidity and the consolidation strength of the sintered body were directly related to the content squared. The quality of the sinter is optimal when the Al2O3 content of the iron ore fines is about 2 wt % (the SiO2 content is 4 wt %).

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