Effect of Milling Parameters on the TiB and TiB2 Formation in Ti-50at%B and Ti-66at%B Powders

2008 ◽  
Vol 591-593 ◽  
pp. 135-140 ◽  
Author(s):  
Gilbert Silva ◽  
Erika Coaglia Trindade Ramos ◽  
Alfeu Saraiva Ramos
Keyword(s):  
Energy Condition ◽  
Weight Ratio ◽  
Dsc Analysis ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Powder Mixtures ◽  
X Ray ◽  
Milling Parameters ◽  
Equilibrium Structures ◽  
Rotary Speed

This work discusses on the effect of milling parameters on the TiB and TiB2 formation in Ti-50at%B and Ti-66at%B powders, respectively. Both powder mixtures were processed in a planetary ball Fritsch P-5 ball mill under Ar atmosphere, varying the milling parameters: rotary speed (150 and 200 rpm), size of balls (10 and 19mm diameter) and ball-to-powder weight ratio (2:1 and 10:1). In order to obtain the equilibrium structures the milled powders were heated at 1200oC for 1h. Samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermal analysis (DSC). XRD results indicated that extended Ti(B) solid solutions were formed during ball milling of Ti-50at%B and Ti-66at%B powders. After milling for 170h it was noted the TiB and TiB2 formation in Ti-50B and Ti-66B powders processed under higher-energy condition. DSC analysis revealed that the TiB2 formation was completed during heating of mechanically alloyed Ti-66at%B powders only. After heating at 1200oC for 1h, a large amount of TiB and TiB2 was found in Ti-B powders milled under higher energy condition.

Phase Transformation in Mechanically Alloyed and Hot-Pressed Ti-2Nb-22Si-11B and Ti-6Nb-22Si-11B Powder Mixtures

2014 ◽  
Vol 802 ◽  
pp. 9-13 ◽  
Author(s):  
Andrezza Campos Zanardo ◽  
Neide Aparecida Mariano ◽  
Luciano Braga Alkmin ◽  
Alex Matos da Silva Costa ◽  
Carlos Angelo Nunes ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Hot Pressing ◽  
Energy Dispersive Spectrometry ◽  
Weight Ratio ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Powder Mixtures ◽  
Eds Analysis ◽  
Rotary Speed

This work aims to discuss on the phase transformation in mechanically alloyed and hot-pressed Ti-2Nb-22Si-11B and Ti-6Nb-22Si-11B powder mixtures. The milling process was conducted in a planetary ball milling using stainless steel vials (225 mL) and balls (19 mm diameter), rotary speed of 300 rpm, and a ball-to-powder weight ratio of 10:1. Hot pressing of mechanically alloyed Ti-Nb-Si-B powders was performed under vacuum at 1100°C for 1h. The as-milled and hot-pressed Ti-Nb-Si-B samples were evaluated by X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry. XRD results of milled Ti-Nb-Si-B powders indicated that the peaks of Nb and Si were reduced for longer milling times, suggesting that Nb and Si atoms were dissolved into the Ti lattice to form extended solid solutions. Iron contamination close to 6 at% was detected by EDS analysis. Hot pressing produced dense and homogeneous samples containing a small amount of Ti6Si2B.

Phase Transformation in Mechanically Alloyed and Hot-Pressed Nb-4Si-8B and Nb-8Si-16B Alloys

2014 ◽  
Vol 802 ◽  
pp. 14-19
Author(s):  
Carlos Edilson Chiaradia ◽  
Luciano Braga Alkmin ◽  
Carlos Ângelo Nunes ◽  
Vinícius André Rodrigues Henriques ◽  
Gilda Maria Cortez Pereira ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Energy Dispersive Spectrometry ◽  
Weight Ratio ◽  
Wet Milling ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
X Ray ◽  
Equilibrium Structures ◽  
Steel Balls ◽  
Milled Powders

The work reports on the phase transformation in mechanically alloyed and hot-pressed Nb-4Si-8B and Nb-8Si-16B (at-%) alloys. Elemental powder mixtures were processed in a planetary ball mill under argon atmosphere using 300 rpm, stainless steel balls (19 mm diameter) and vials (225 mL), and a ball-to-powder weight ratio of 10:1. After dry milling for 7h, wet milling with isopropyl alcohol for more 20 min was adopted to increase the recovering of previously cold-welded Nb-4Si-8B powders. To obtain the equilibrium structures the as-milled powders were hot-pressed under vacuum at 1200oC for 1 h. The as-milled powders and hot-pressed samples were characterized by X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry. XRD results revealed the presence of metastable phases in as-milled Nb-Si-B powders. The hot pressing has produced dense Nb-Si-B samples, which were formed by the Nbss, Nb3B2and Fe2Nb phases beside of other unknown Si-rich phase.

Phase Transformations in Mechanically Alloyed and Sintered Ti-XMg-22Si-11B (X = 2 and 7 at.-%at) Powders

2017 ◽  
Vol 899 ◽  
pp. 3-8
Author(s):  
Luiz Otávio Vicentin Maruya ◽  
Bruno Bacci Fernandes ◽  
Mario Ueda ◽  
Alfeu Saraiva Ramos
Keyword(s):  
Ball Milling ◽  
Energy Dispersive Spectrometry ◽  
Weight Ratio ◽  
High Energy ◽  
X Ray Diffraction ◽  
Amorphous Halo ◽  
Mechanically Alloyed ◽  
X Ray ◽  
Equilibrium Structures ◽  
Energy Ball

This work reports on effect of magnesium addition on the Ti6Si2B stability in Ti-xMg-22Si-11B (x = 2 and 6 at.-%) alloys prepared by high-energy ball milling and subsequent sintering. Ball milling was conducted under Ar atmosphere in stainless steel vials and balls, 300 rpm, and a ball-to-powder weight ratio of 10:1. Following, the powders milled for 10 h were axially compacted in order to obtain cylinder samples with 6 mm diameter. To obtain the equilibrium structures the green samples were sintered at 1100°C for 4 h under Ar atmosphere. X-ray diffraction, scanning electron microscopy and energy dispersive spectrometry were used to characterize the as-milled powders and sintered samples. Extended Ti solid solution were found in the Ti-2Mg-22Si-11B and Ti-7-Mg-Si-B powders milled for 20 min and 60 min, respectively, whereas an amorphous halo was produced on Ti-2Mg-22Si-11B powders milled for 420 min. The increase of Mg amount in the starting powder mixture has inhibited the Ti6Si2B formation in the mechanically alloyed and sintered Ti-7Mg-22Si-11B alloy.

Mechanically Driven Dissolution of Sn in Near-Equiatomic Bcc FeCo

2012 ◽  
Vol 194 ◽  
pp. 187-193 ◽  
Author(s):  
J.M. Loureiro ◽  
Benilde F.O. Costa ◽  
Gerard Le Caër ◽  
Bernard Malaman
Keyword(s):  
Magnetic Field ◽  
Solid Solutions ◽  
Room Temperature ◽  
Hyperfine Magnetic Field ◽  
Ternary Alloys ◽  
119Sn Mössbauer Spectroscopy ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Powder Mixtures ◽  
X Ray

Ternary alloys, (Fe50−x/2Co50−x/2)Snx(x ≤ 33 at.%), are prepared by mechanical alloying from powder mixtures of the three elements. As-milled alloys are studied by X-ray diffraction and 57Fe and 119Sn Mössbauer spectroscopy. The solubility of Sn in near-equiatomic bcc FeCo is increased from ~0.5 at. % at equilibrium to ~20 at.% in the used milling conditions. The average 119Sn hyperfine magnetic field at room temperature is larger, for any x, than the corresponding fields in mechanically alloyed Fe-Sn solid solutions.

High-Energy Ball Milling and Sintering of Ti-2Ta-22Si-11B and Ti-6Ta-22Si-11B Powders Mixtures

2014 ◽  
Vol 802 ◽  
pp. 20-24 ◽  
Author(s):  
Lucas Moreira Ferreira ◽  
Luciano Braga Alkmin ◽  
Érika C.T. Ramos ◽  
Carlos Angelo Nunes ◽  
Alfeu Saraiva Ramos
Keyword(s):  
Ball Milling ◽  
Weight Ratio ◽  
High Energy ◽  
Milling Process ◽  
Wet Milling ◽  
X Ray Diffraction ◽  
Heat Treated ◽  
Equilibrium Structures ◽  
Rotary Speed ◽  
Steel Balls

The milling process of elemental Ti-2Ta-22Si-11B and Ti-6Ta-22Si-11B (at-%) powder mixtures were performed in a planetary Fritsch P-5 ball mill using stainless steel vials (225 mL) and hardened steel balls (19 mm diameter). Ball-to-powder weight ratio of 10:1 and a rotary speed of 300 rpm were adopted, varying the milling time. Wet milling (isopropyl alcohol) for 20 more minutes was used to increase the yield powder in to the vial. Following the Ti-Ta-Si-B powders milled for 600 min were heat-treated at 1100°C for 1 h in order to obtain the equilibrium structures. The milled powders and heat-treated samples were characterized by X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry. Supersaturated Ti solid solutions were formed during ball milling of Ti-Ta-Si-B powders while that the Ti5Si3 phase was formed after milling for 620 min of the Ta-richer powder mixture only. The particles sizes were initially increased during the initial milling times, and the wet milling provided the yield powder into the vials. A large amount of pores was found in both the sintered samples which presented the formation of the TiSS,(ss-solid solution) Ti6Si2B and TiB.

scholarly journals Direct Synthesis of (K0.5Na0.5)NbO3Powders by Mechanochemical Method

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Nguyen Duc Van
Keyword(s):  
Milling Time ◽  
Direct Synthesis ◽  
Weight Ratio ◽  
Intermediate Species ◽  
X Ray Diffraction ◽  
Mechanochemical Method ◽  
X Ray ◽  
Milling Parameters ◽  
First Time ◽  
Carbonato Complex

The synthesis and structural properties of lead-free piezoelectric (K0.5Na0.5)NbO3powders prepared by mechanochemical method using Nb2O5, K2CO3, and Na2CO3as starting materials were reported. X-ray diffraction, infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy were used to characterize the prepared samples. Results showed that, for the first time, by selecting the milling speed of 600 rpm and the ball-to-powder weight ratio of 35 : 1 as milling parameters, pure (K0.5Na0.5)NbO3crystalline phase was obtained directly in the as-milled samples after 5 h of milling time. The existence of a carbonato complex betweenCO32−and Nb5+ions as an intermediate species of the formation of (K0.5Na0.5)NbO3was also found.

Phase Formation, Stability and Superconducting Properties of Mechanically Alloyed Yttrium-Nickel-Borocarbides

1998 ◽  
Vol 547 ◽  
Author(s):  
L. Ledig ◽  
D. Hough ◽  
C.-G. Oertel ◽  
J. Eckert ◽  
W. Skrotzki
Keyword(s):  
Amorphous Phase ◽  
Amorphous State ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
X Ray ◽  
Milling Parameters ◽  
Transmission Electron ◽  
Nanocrystalline And Amorphous ◽  
Nickel Borocarbides

AbstractThe solid state reaction of YNi2B2C by mechanical alloying of elemental powders has been investigated by X-ray diffraction, transmission electron microscopy and susceptibility measurements. Depending on the ball milling parameters either nanocrystalline YNi2B2C or an amorphous phase can be produced. Crystallization of the amorphous phase by annealing at 893 K produces YNi2B2C as major and Ni2B as minor intermetallic compound. Superconductivity is only observed in the annealed state. However, the transition temperature is much lower than in arc-melted samples. This is discussed with respect to the nanocrystalline and amorphous state as well as deviations from stoichiometry produced by impurities introduced during milling.

The Transformation of Co-Rich Alloys Produced by Mechanical Alloying

2006 ◽  
Vol 509 ◽  
pp. 135-140
Author(s):  
Francisco Cruz-Gandarilla ◽  
R. Gayosso-Armenta ◽  
J. Gerardo Cabañas-Moreno ◽  
Heberto Balmori-Ramírez
Keyword(s):  
Single Phase ◽  
Intermetallic Phase ◽  
High Energy ◽  
Inert Atmosphere ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Powder Mixtures ◽  
X Ray ◽  
Heat Treated ◽  
Energy Ball

Elemental powder mixtures of Co and Ti were subjected to high-energy ball milling in order to produce mechanically alloyed powders with nominal compositions Co64Ti36, Co67Ti33, Co70Ti30, Co73Ti27, Co76Ti24 and Co85Ti15. The mechanically alloyed powders were treated during 30 minutes in inert atmosphere at temperatures in the range 300 – 700 °C. Both the as-milled powders as well as those subjected to heat treatments have been characterized by x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray spectrometry and differential thermal analysis. As-milled products consist mostly of agglomerated powders with a size between 10 and 80 µm which give an amorphous-like diffraction pattern, except for the Co85Ti15 sample whose pattern presents the characteristic peaks of the Co3Ti intermetallic phase. The transformation of the asmilled powders occurs at temperatures in the range of about 530 – 670 °C with clearly observed exothermic events. The Co3Ti phase is found in all heat treated samples, together with fcc-Co (in Co76Ti24 and Co85Ti15) or the hexagonal Co2Ti intermetallic phase (in Co64Ti36, Co67Ti33 and Co70Ti30); the Co73Ti27 sample was essentially single-phase Co3Ti after heating to 700 °C. Our results suggest the occurrence of crystallization of an amorphous phase in two overlapping stages during heating of the mechanically alloyed powders.

Effect of Ni Addition on Formation of Nanocrystalline Phase during Mechanical Alloying of (Fe Al)-40(60) at.% Ni and (Fe Al3)-10(30) at.% Ni Powders

2013 ◽  
Vol 275-277 ◽  
pp. 1814-1817
Author(s):  
Zhang Jing ◽  
Qi Zhi Cao ◽  
Guo Hua Huang ◽  
Jin Li Huang
Keyword(s):  
Solid Solutions ◽  
Early Stage ◽  
Structural Evolution ◽  
Nanocrystalline Phase ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Powder Mixtures ◽  
X Ray ◽  
Ni Content ◽  
Ni Addition

Al-Fe-Ni ternary powder mixtures containing (FeAl)-40(60) at.% Ni and (FeAl3)-10(30) at.% Ni were mechanically alloyed by a high-energry planetary ball mill. The structural evolution of the powders during milling was studied by X-ray diffraction technique (XRD). During milling of (FeAl)-40(60) at.% Ni system, Al and Fe solid solutions formed at the early stage change to FeAl, AlNi3 and FeNi3 intermetallic compounds. However, the Al and Fe solid solutions observed at the early stage transform into Al3Ni2, AlFe3 and AlFe0.23Ni0.77 intermetallic compound at last. The experimental results showed that the last milling products were decided by the proportion of atom between Al and Fe in the powder and the Ni content in the power had not affected to the last products.

Mechanical Alloying and Sintering of Ni-Sn and Ni-Mg Powder Mixtures

2017 ◽  
Vol 899 ◽  
pp. 493-498
Author(s):  
Gabriel Henrique da Cruz Faria ◽  
Ricardo Boueri Magalhães ◽  
Andrezza Campos Zanardo ◽  
Erika Coaglia Trindade Ramos ◽  
Antonio Augusto Araújo Pinto da Silva ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Alloy Composition ◽  
Cold Welding ◽  
X Ray Diffraction ◽  
Two Phase ◽  
Powder Mixtures ◽  
X Ray ◽  
Milling Parameters ◽  
Structural Evaluation ◽  
Scanning Electron

Various intermetallics can be synthetized by mechanical alloying depending on alloy composition, type of mill, and milling parameters. This work discusses on the phase transformations during ball milling and subsequent sintering of Ni-Sn and Ni-Mg powder mixtures. The structural evaluation of as-milled and sintered samples was conducted by X-ray diffraction and scanning electron microscopy. Metastable phases were formed during milling of the Ni-Sn and Ni-Mg powder mixtures. The Ni3Sn and Ni3Sn2 compounds were produced after sintering from the as-milled Ni-25Sn and Ni-40Sn powders, respectively. Two-phase Ni2Mg+NiMg2 alloy was found after sintering of as-milled Ni-66Mg powders because the nominal Mg amount in starting powders was reduced due to its preferential cold welding during milling and/or evaporation during sintering.

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