Study of the Sintering of Mixtures Al2O3-Nb2O5 and Y2O3-Nb2O5

2012 ◽  
Vol 727-728 ◽  
pp. 799-803 ◽  
Author(s):  
Ricardo F. Cabral ◽  
Marcelo Henrique Prado da Silva ◽  
Jose B. de Campos ◽  
Eduardo Sousa Lima
Keyword(s):  
Weight Loss ◽  
Mass Loss ◽  
Mole Fraction ◽  
Ball Mill ◽  
Rietveld Method ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Milling

Al2O3-Nb2O5 has been widely explored as one of the most used material for sintering mixing in the literature, due to its excellent hardness properties, used in armor. In this study, Al2O3-Nb2O5 and Y2O3-Nb2O5 powders were prepared, with 50% in mole fraction of each oxide. The mixtures were subjected to high energy milling in an eccentric ball mill for 3 h, dried and sieved in a sieve vibrator. The green bodies were compacted at 70 MPa and sintered from 1250 to 1650 °C for 3 h, at 100 °C steps. The materials were characterized by quantitative X-Ray diffraction (XRD) using Rietveld method and by mass loss. The Al2O3-Nb2O5 mixtures experienced a weight loss of 84% at sintering temperatures of 1550 and 1650 °C.

Synthesis of Layered Ti2Al(N0.5C0.5) by a Combination of High Energy Milling and Hot Press Sintering

2011 ◽  
Vol 52-54 ◽  
pp. 846-849 ◽  
Author(s):  
Jian Feng Zhu ◽  
Na Han ◽  
Kun Wang ◽  
Fen Wang
Keyword(s):  
Ball Mill ◽  
Compositional Analysis ◽  
High Energy ◽  
Hot Press ◽  
X Ray Diffraction ◽  
Nitrogen Gas ◽  
X Ray ◽  
High Energy Milling ◽  
Hot Press Sintering ◽  
Scanning Electron

Elemental mixture of Ti, Al and C was high energy milled in a planetary ball mill under high-purity nitrogen gas protection and then hot pressed. The fully dense bulk layered ternary Ti2AlN0.5C0.5 with sub-micron grain size was successfully obtained. The phase formation and transformation in high energy milling and subsequently hot press sintering were studied in detail by using X-ray diffraction (XRD). Scanning electron microscopy (SEM) linked with energy dispersive spectroscopy (EDS) was used for the structural and compositional analysis. The formation mechanism was also discussed.

scholarly journals X-Ray Powder Diffraction Studies of Mechanically Milled Cobalt

2012 ◽  
Vol 626 ◽  
pp. 913-917
Author(s):  
W.S. Yeo ◽  
Z. Nur Amirah ◽  
H.S.C. Metselaar ◽  
T.H. Ong
Keyword(s):  
Grain Size ◽  
Phase Transformation ◽  
Surface Energy ◽  
Phase Formation ◽  
Rietveld Method ◽  
High Energy ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Structure Defects ◽  
X Ray

The allotropic phase transformation of cobalt powder prepared by high-energy ball milling was investigated as a function of milling time. Measurement of crystallite size and micro-strain in the powder systems milled for different times were conducted by X-ray diffractometry. The X-ray diffraction (XRD) peaks were analyzed using the Pearson VII profile function in conjunction with Rietveld method. X-ray diffraction line broadening revealed that allotropic transformation between face-centred-cubic phase (fcc) and hexagonal close-packed phase (hcp) in cobalt is grain size dependent and also on the accumulation of structure defects. The results showed that the phase formation of cobalt depends on the mill intensity that influences of both the grain size and the accumulation of structure defects. However, this theory alone is not adequate to explain the effects in this work. It was found that the total surface energy (Ω) theory satisfactorily explains the phase transformation behavior of cobalt. The smaller value of surface energy (Ω) of the fcc crystal than the hcp phase when size decreases may alter the qualitative aspects of the phase formation.

Phase Amorphization during High-Energy Milling of Mixtures of Zirconia with Yttria or Ceria Powders

2005 ◽  
Vol 498-499 ◽  
pp. 331-336 ◽  
Author(s):  
R. Muccillo ◽  
L. Franchi ◽  
J.T. Santos ◽  
I.C. Cosentino ◽  
E.N.S. Muccillo
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Barium Carbonate ◽  
High Energy ◽  
Milling Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Milling ◽  
Transmission Electron ◽  
Strontium Ferrites

Strontium ferrites powders were obtained by high energy milling process after calcinations of iron oxide and barium carbonate. Phase formations and crystallite size was determined using X-ray diffraction. Morphology, particle size and agglomeration stages were analyzed using scanning and transmission electron microscopy. Results show particles in the range of 14 to 40 nanometers, large agglomerates and crystalline phases formation.

Nanocrystalline Intermetallic Mg2Ni Produced in a Batch Scale Mill

2006 ◽  
Vol 509 ◽  
pp. 141-146
Author(s):  
E. Martínez-Franco ◽  
Thomas Klassen ◽  
Rüdiger Bormann ◽  
D. Jaramillo-Vigueras
Keyword(s):  
Ball Mill ◽  
Energy Dispersive Spectrometry ◽  
Particle Morphology ◽  
High Energy ◽  
X Ray Diffraction ◽  
Batch Production ◽  
Production Scale ◽  
X Ray ◽  
Powder Mass ◽  
Scanning Electron

Nanocrystalline intermetallic Mg2Ni is successfully produced on a batch production scale from elemental powder blends by mechanical alloying using a high-energy rotor ball mill (Simoloyer). Different ball-to-powder mass ratios are used in order to provide results for scaling to industrial production. Transformation of elemental Mg-Ni powders into the Mg2Ni intermetallic is observed by x-ray diffraction. Particle morphology during milling is observed by scanning electron microscopy. A relatively low Fe contamination is estimated by energy dispersive spectrometry.

Synthesis of Nanocrystalline Fe25Al57.5Ni17.5 by Mechanical Alloying

2012 ◽  
Vol 476-478 ◽  
pp. 1318-1321
Author(s):  
Qi Zhi Cao ◽  
Jing Zhang
Keyword(s):  
Thermal Analysis ◽  
Solid Solution ◽  
Differential Thermal Analysis ◽  
Mechanical Alloying ◽  
Ball Mill ◽  
Structural Changes ◽  
Early Stage ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray

Nanostructured Fe25Al57.5Ni17.5intermetallics was prepared directly by mechanical alloying (MA) in a high-energy planetary ball-mill. The phase transformations and structural changes occurring in the studied material during mechanical alloying were investigated by X-ray diffraction (XRD). Thermal behavior of the milled powders was examined by differential thermal analysis (DTA). Disordered Al(Fe,Ni) solid solution was formed at the early stage. After 50 h of milling, Al(Fe,Ni) solid solution transformed into Al3Ni2，AlFe3，AlFe0.23Ni0.77 phase. The power annealed at temperature 500 results in forming of intermetallics AlFe3 and FeNi3 after 5h milling. The nanocrystalline intermetallic compound was obtained after 500h milling.

scholarly journals The influence of compaction pressure on the density and electrical properties of cordierite-based ceramics

2015 ◽  
Vol 47 (1) ◽  
pp. 15-22 ◽  
Author(s):  
N. Obradovic ◽  
N. Djordjevic ◽  
A. Peles ◽  
S. Filipovic ◽  
M. Mitric ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Ball Mill ◽  
Compaction Pressure ◽  
High Energy ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Air Atmosphere ◽  
High Energy Ball Mill ◽  
Energy Ball

Due to its characteristics, cordierite, 2MgO?2Al2O3?5SiO2, is a high-temperature ceramic material of a great scientific interest. Mechanical activation of the starting mixtures containing 5.00 mass% TiO2 was performed in a high-energy ball mill for 10 minutes. The compaction pressure varied from 0.5 to 6tcm-2 (49-588 MPa). The sintering process was performed at 1350?C for four hours in the air atmosphere. The phase composition of the activated and sintered samples was analyzed using X-ray diffraction. Scanning electron microscopy was used to analyze the microstructure of both compacted and sintered samples. The authors have investigated the influence of compaction pressure on the sintered samples and their electrical properties.

scholarly journals Mechanochemical synthesis of Co3C carbide with carbon nanotubes

2019 ◽  
Vol 20 (1) ◽  
pp. 13-17
Author(s):  
O. I. Nakonechna ◽  
M. M. Dashevski ◽  
A. M. Kurylyuk ◽  
N. M. Bilyavyna
Keyword(s):  
Crystal Structure ◽  
Carbon Nanotubes ◽  
Ball Mill ◽  
Diffraction Method ◽  
High Energy ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Reliability Factor ◽  
X Ray ◽  
Reaction Milling

Nanoscaled (about 15 nm of size) metastable carbide Co3C was synthesized in a high-energy planetary ball mill by mechanical alloying of a mixture of powder cobalt (75 at. %) and multiwalled carbon nanotubes (CNT, 25 at. %). Phase transformation takes place at reaction milling according to the reaction hcp-Co + CNT ® Co3C (reaction time is 120 - 220 min). The crystal structure of the Co3C carbide formed in the milling products was studied by X-ray diffraction method. It has revealed that the Co3C phase crystallizes in a Fe3C-type structure with a = 0.4982(3) nm, b = 0.6715(6) nm, c = 0.4457(7) nm, Pnma space group. The reliability factor RB is equal to 0.065 for 48 reflections presented at diffraction pattern. It is found that the crystal structure of the Co3C carbide obtained by reaction milling of the Co-CNT charge is significantly internally deformed (distortion degree of the CCo6 octahedron is 3.67 %) and contains the reduced interatomic Co-C distances (up to 0.188 nm). It was shown that the use of carbon nanotubes instead of graphite substantially reduces the duration of the Co3C carbide synthesis.

Sintering of Al4C3 Using Aluminum Scrap and Commercial Graphite

2014 ◽  
Vol 802 ◽  
pp. 66-71
Author(s):  
Rodrigo Estevam Coelho ◽  
D.B. Silvany ◽  
M.D.C. Sobral ◽  
M.C.A. Silva
Keyword(s):  
Ball Mill ◽  
Graphite Powder ◽  
High Energy ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Aluminum Scrap ◽  
X Ray ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Scanning Electron

In this works, aluminum scraps powders were mixed with commercial graphite and mechanically alloyed in a high-energy ball mill and subsequently powders sintering. The initial grinding of aluminum scraps for 2 hours and then mixed with commercial graphite powder at a proportion of (y)Al-(x)C (wt%) (x = 1, 5 e 10, 25). The mixture of aluminum and graphite powders was processed for a time at 5 hours of milling. The samples were sintered at a temperature of 750°C and 1000°C. Samples were analyzed by scanning electron microscopy and X-ray diffraction. The results of this study were to find important parameters of composition and sintering, because the increase in concentration of carbon in the aluminum indicates that the material may have different applications.

Effect of the Calcination Time of Fish Bones in the Synthesis of Hydroxyapatite

2005 ◽  
Vol 498-499 ◽  
pp. 600-605 ◽  
Author(s):  
W.M. Lima ◽  
W.R. Weinand ◽  
O.A.A. dos Santos ◽  
A. Paesano ◽  
F.H.M. Ortega
Keyword(s):  
Ball Mill ◽  
High Energy ◽  
X Ray Diffraction ◽  
Calcination Time ◽  
X Ray ◽  
Fish Bones ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Combination Of Methods ◽  
Scanning Electron

In this work, a combination of methods for HAp synthesis is investigated. Fish bones were calcined at 900oC between 4h and 12h, followed by milling in a high-energy ball mill, by 2h and 4h at 300rpm. The obtained material was characterized by using techniques such as laser granulometry, X-ray diffraction, scanning electron microscopy (SEM) and atomic absorption spectroscopy. The performed analysis permitted us to obtain the Ca/P ratio, the morphology and the phase structure of hydroxyapatite particles powder.

Sign in / Sign up

Export Citation Format

Share Document