Effects of Ball Milling on the Sintering Process and Superconducting Properties of $(\hbox{MgB}_{2})_{0.96}\hbox{Ni}_{0.04}$ Bulks

2012 ◽  
Vol 22 (4) ◽  
pp. 6800405-6800405 ◽  
Author(s):  
Qi Cai ◽  
Zongqing Ma ◽  
Yongchang Liu ◽  
Qian Zhao ◽  
Zhiming Gao
Keyword(s):  
Ball Milling ◽  
Sintering Process ◽  
Superconducting Properties

Effects of High-Energy Ball Milling Time on the Sintering Process of FeSe Superconductors

2016 ◽  
Vol 848 ◽  
pp. 657-663 ◽  
Author(s):  
Sheng Nan Zhang ◽  
Xiao Bo Ma ◽  
Ji Xing Liu ◽  
Jian Qing Feng ◽  
Cheng Shan Li ◽  
...  
Keyword(s):  
Phase Composition ◽  
Ball Milling ◽  
Optimal Parameter ◽  
High Energy ◽  
Superconducting Phase ◽  
High Energy Ball Milling ◽  
Superconducting Transition ◽  
Sintering Process ◽  
Energy Ball ◽  
Precursor Powders

FeSe superconducting bulks were prepared with high energy ball milling (HEBM) aided sintering process, within which process, tetragonal β-FeSe superconducting phase could be formed directly with one step sintering process, and the formation of hexagonal δ-FeSe non-superconducting phase was effectively avoided. The influences of HEBM time on the sintering process of FeSe bulks were systematically investigated. With different HEBM time, the phase composition and morphology of precursor powders changed correspondingly, which thus influenced the final phase composition and superconducting properties of FeSe superconducting bulks. Due to the formation of FeSe bulks with larger tetragonal phase content and higher superconducting transition temperature, HEBM time of 6.0 h was recognized as the optimal parameter. Shorter HEBM time could lead to the insufficient decrease of particle size and low density. While longer HEBM time caused the formation of amorphous hexagonal δ-FeSe, which crystallized during sintering process. Thus no more tetragonal FeSe could be obtained. The FeSe superconducting bulk with the critical temperature Tc(onset) of 8.0 K was obtained with the HEBM time of 6 h, and sintering temperature of 700 oC for 12 h.

Microstructure and superconducting properties of Bi-2223/Ag tapes fabricated in the pressing–melting–sintering process

2010 ◽  
Vol 470 (20) ◽  
pp. 1388-1391 ◽  
Author(s):  
X.Y. Lu ◽  
D. Yi ◽  
H. Chen ◽  
A. Nagata ◽  
K. Sugawara
Keyword(s):  
Sintering Process ◽  
Superconducting Properties

Sintering of Textured YBa2Cu307-x Under Intensive 60Co Gamma Irradiation

1994 ◽  
Vol 354 ◽  
Author(s):  
Elvira M. Ibragimova ◽  
Eldar M. Gasanov ◽  
Makhmud Kalanov ◽  
Marquis A. Kirk ◽  
Ken C. Goretta
Keyword(s):  
Gamma Irradiation ◽  
Dose Rate ◽  
Subsurface Layer ◽  
Gamma Dose ◽  
Ordered Structure ◽  
Sintering Process ◽  
Superconducting Properties ◽  
Oxygen Sublattice ◽  
60Co Gamma ◽  
Sem Analyses

AbstractA study of structural and superconducting characteristics of YBa2Cu307-x ceramics sintered after and in the course of gamma-irradiation is reported. Using X-difraction and SEM analyses and transport measurements, it has been shown that mainly the subsurface layer of crystallites and intergrain contacts are affected by the irradiation by means of sorption/desorption of oxygen and ordering/disordering in oxygen sublattice, which depends on gamma dose rate and dose. The irradiation provides the sintering process with an additional superthermal energy to form the orthorhombic well-ordered structure and to obtain dense ceramics possessing strong intergrain contacts and improved and stable superconducting properties

Processing of Composite Cathode and YSZ Coatings for Solid Oxide Fuel Cells

Materials ◽  
2004 ◽  
Author(s):  
Zhigang Xu ◽  
Devdas Pai ◽  
Jag Sankar
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Ball Milling ◽  
Composite Cathode ◽  
Yttria Stabilized Zirconia ◽  
Lanthanum Manganite ◽  
Sintering Process ◽  
Stabilized Zirconia ◽  
Composite Cathodes ◽  
Ysz Coating ◽  
Effect Of The Composition

In our research, composite cathodes of strontium-doped lanthanum manganite (LSM) and yttria-stabilized zirconia (YSZ) were produced by using slurry casting and sintering procedures. The slurry was prepared using ball milling. The time of ball milling was studied in terms of particle size and homogeneity of the powder in the slurry. The effect of the composition of the slurry on the microstructure was studied to obtain cathodes with desired porosity. The sintering process was also optimized to compromise the porosity, grain size, and strength of the cathodes. The YSZ coating was implemented using electrophoretic deposition in liquid phase. Different charging methods of the YSZ powder in the suspension was used and their results were compared. The microstructures of cathodes and YSZ coatings were characterized using scanning electron microscope (SEM).

Two-Steps Sintering of Alumina-Zirconia Ceramics

2010 ◽  
Vol 660-661 ◽  
pp. 819-825
Author(s):  
Milena K. Manosso ◽  
Elíria Maria Jesus Agnolon Pallone ◽  
Adilson Luiz Chinelatto ◽  
Adriana Scoton Antonio Chinelatto
Keyword(s):  
Grain Size ◽  
Ball Milling ◽  
Grain Growth ◽  
Sintering Process ◽  
Ceramic Powders ◽  
Zirconia Ceramics ◽  
Linear Rate ◽  
Commercial Alumina ◽  
Mean Grain Size ◽  
Cold Pressed

Sintering in two-steps has been applied with success for densification of nanometric ceramic powders without grain growth. Another mechanism that alters the sintering process is the presence of rigid inclusions in the ceramic. In this work it was studied the effect of two-steps sintering and the presence of zirconia inclusions (5% in volume) in the microstructure of a commercial alumina. For this, the powders of alumina and zirconia were desaglomerated in a ball milling and uniaxially pressed at 80 MPa to form cylindrical compacts and isostatically cold pressed at 200 MPa. Temperatures of the steps were chosen starting from the curves of linear rate shrinkage in function of the temperature. The samples were characterized for apparent density, scanning electronic microscopic and mean grain size. The results showed that two-steps sintering and the zirconia inclusions were efficient to control the densification and grain size of alumina.

Effect of MgO content on the formation and superconducting properties of (Bi,Pb)-2223 phase in the partial-melting and sintering process

2001 ◽  
Vol 357-360 ◽  
pp. 828-831 ◽  
Author(s):  
X.Y. Lu ◽  
A. Nagata ◽  
D. Kamio ◽  
K. Sugawara ◽  
S. Kamada ◽  
...  
Keyword(s):  
Partial Melting ◽  
Sintering Process ◽  
Superconducting Properties

The Effect of Ball Milling Process on Sintering and Densification Enhancement of W-Bronze Composites

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Kahtan Sadiq Mohammed ◽  
Azmi Rahmat ◽  
Khairel Rafezi Ahmad
Keyword(s):  
Surface Morphology ◽  
Ball Milling ◽  
Milling Process ◽  
Theoretical Density ◽  
Second Step ◽  
Sintering Process ◽  
Ball Milling Process ◽  
Bronze Matrix ◽  
Milled Powders

Τhe miscibility of W in Sn and Cu is extremely poor. The wettability of W by those two elements is limited. To tackle this problem, two step ball milling process of the W–bronze elemental powders was proposed in this study. The softness of Sn in the first step was exploited to modify the surface morphology of the W particles. In the second step Cu was added to the ball milled mixture. To achieve this goal, two different sets of W50wt. %–pre mix bronze compacts of ball milled and of as received powders were utilized. Sintering process was performed at 1150°C. The two–step ball milled powders yielded sintered compacts of fine polygonal and homogeneous W network skeletal dispersed in bronze matrix. Sintered compacts of about 95% theoretical density were produced by this technique.

Effects of Ball Milling Time on the Microwave Properties of Mg4Nb2O9 Ceramics by the Solid-State Process

2012 ◽  
Vol 499 ◽  
pp. 165-169
Author(s):  
Hai Tao Wu ◽  
Yi Shan Jiang ◽  
Ying Zi Wang ◽  
Ya Ming Chen ◽  
Yun Long Yue
Keyword(s):  
Solid State ◽  
Ball Milling ◽  
Milling Time ◽  
Secondary Phase ◽  
Microwave Properties ◽  
Orthorhombic Symmetry ◽  
Sintering Process ◽  
Solid State Method ◽  
State Process ◽  
Ball Milling Time

Corundum-type magnesium niobate (Mg4Nb2O9) ceramics were synthesized by the conventional solid-state method, the effect of ball milling time on microwave properties was studied in detail. Xrd results showed that the major phase was identified as the ordered corundum structure Mg4Nb2O9with minor secondary phase of orthorhombic-symmetry Mg5Nb4O15. The morphology was obviously affected by ball milling times at sintering process, and then the relationships between the morphology and microwave properties were discussed. The results indicated that ball milling times at sintering process could obviously affect the microstructure and microwave properties of Mg4Nb2O9ceramics. When ball milling time was 10h, the Mg4Nb2O9ceramics were prepared with the conditions of calcination at 1100°C for 2h and sintered at 1350°C for 6h, and the optimal microwave properties were εr~13, Q·ƒ~120,000GHz and ƒ~-60ppm/°C.

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