Obtaining of the Ir-Al Nanocrystalline Powders by Mechanical Alloying

2011 ◽  
Vol 672 ◽  
pp. 171-174
Author(s):  
Ionel Chicinaş ◽  
P. Cârlan ◽  
Florin Popa ◽  
Virgiliu Călin Prică ◽  
Lidia Adriana Sorcoi

The Ir-Al powder in the 1:1 atomic ratio was obtained by high energy mechanical alloying in a Pulverisette 4 Fritch planetary mill. The final product was obtained after 28 h of milling in argon atmosphere. Alloy formation was investigated by X-ray diffraction. After 4 h of milling the new structure of IrAl compound is found in the diffraction patterns. The obtained powders are nanocrystalline with a mean crystallite size of 11 nm after 28 h of milling. The particle morphology and the chemical homogeneity were studied using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDX). It was found that the obtained compound present large particles composed by smaller one.

2016 ◽  
Vol 38 ◽  
pp. 114-123
Author(s):  
A. El Mohri ◽  
A. Guittoum ◽  
K. Taibi ◽  
M. Azzaz

The mechanical alloying (MA) of elemental powder mixtures of Fe90Mg10 (atomic ratio of 79.67:20.33) was performed in an argon atmosphere using a planetary ball mill process. The alloy formation and the different physical properties were investigated as a function of milling time, t (in the 0–54h range) by means of the X-ray diffraction (XRD) technique, scanning electron microscopy (SEM), and Mössbauer spectroscopy (MS). The formation of the solid solution α-Fe (Mg) started after 4 h of milling. The Mg peaks are completely missing. XRD results also indicated that when the milling time increases, the lattice parameter increases, whereas the grain size decreases and the mean level of microstrains increase. The powder particle morphology was observed by SEM at different stages of milling. The Mössbauer spectra were fitted with two sextets corresponding to the crystalline body centered cubic (bcc) Fe phase and a second sextet which represents supersaturated solid solutions of Mg in (α-Fe). The appearance and the increase in intensity of the second sextet 17, 66 % at (12 h) to 50 % (54 h) with t corresponding to the dissolved Mg in the (α-Fe). This may indicate that the interfacial region effect increases with milling time due to the grain size reduction and to the disordered state of the interfacial region.


2016 ◽  
Vol 1133 ◽  
pp. 75-79 ◽  
Author(s):  
Emee Marina Salleh ◽  
Sivakumar Ramakrishnan ◽  
Zuhailawati Hussain

The aim of this work was to study the effect of milling time on binary magnesium-titanium (Mg-Ti) alloy synthesized by mechanical alloying. A powder mixture of Mg and Ti with the composition of Mg-15wt%Ti was milled in a planetary mill under argon atmosphere using a stainless steel container and balls. Milling process was carried out at 400 rpm for various milling time of 2, 5, 10, 15 and 30 hours. 3% n-heptane solution was added prior to milling process to avoid excessive cold welding of the powder. Then, as-milled powder was compacted under 400 MPa and sintered in a tube furnace at 500 °C in argon flow. The refinement analysis of the x-ray diffraction patterns shows the presence of Mg-Ti solid solution when Mg-Ti powder was mechanically milled for 15 hours and further. Enhancements of Mg-Ti phase formation with a reduction in Mg crystallite size were observed with the increase in milling time. A prolonged milling time has increased the density and hardness of the sintered Mg-Ti alloy.


2011 ◽  
Vol 672 ◽  
pp. 149-152 ◽  
Author(s):  
Traian Florin Marinca ◽  
Ionel Chicinaş ◽  
Virgiliu Călin Prică ◽  
Florin Popa ◽  
Bogdan Viorel Neamţu

The nanocrystalline zinc ferrite (ZnFe2O4) powder was synthesized by high energy reactive ball milling (RM) in a planetary mill. As starting materials a mixture of commercial zinc oxide (ZnO) powder and iron oxide (Fe2O3) powder was used. The starting mixture was milled for different periods of time, up to 30 h. The milled powders were annealed for 4 h at 350 oC in order to eliminate the internal stress and to finish the solid state reaction of ferrite formation. Zinc ferrite formation was investigated by X-ray diffraction. The obtained powder has a mean crystallite size of 12 nm after 20 h of milling. Using scanning electron microscopy (SEM) the particle morphology was studied. Particles size range of the powders was also determined using a laser particle size analyser.


2007 ◽  
Vol 353-358 ◽  
pp. 1625-1628 ◽  
Author(s):  
Gen Shun Ji ◽  
Qin Ma ◽  
Tie Ming Guo ◽  
Qi Zhou ◽  
Jian Gang Jia ◽  
...  

The high energy ball milling of Ni-50 atom % Si elemental powder mixtures was carried out using a planetary mill. X-ray diffraction (XRD) was used to identify the phase evolutions during the high energy ball milling period. The microstructure morphology of the powders milled different time was determined by field emission scanning electron microscope (FESEM). The beginning time of mechanical alloying was determined by back scattered electrons (BSE) images. The XRD patterns showed that the nickel peaks intensity and the silicon peaks intensity obviously decreased with milling time increased to 1 hour. BSE images revealed that nickel and silicon powders were not blended uniformly for 1 hour of milling. It was found that NiSi formed as the milling time increased to 5 hours, simultaneously, the nickel peaks and the silicon peaks almost disappeared. That means the obvious mechanical alloying started from 5 hours of milling. BSE images agreed with the result analyzed from XRD patterns. With the milling time further increased from 10 to 75 hours, the NiSi peaks decreased gradually, at the same time, the Ni2Si peaks appeared and then increased gradually.


2015 ◽  
Vol 13 ◽  
pp. 109-113 ◽  
Author(s):  
Cristina Daniela Stanciu ◽  
Florin Popa ◽  
Ionel Chicinaş ◽  
Olivier Isnard

Fe-Si alloy with a large Si content of 6.5 wt. % is obtained in nanocrystalline state by mechanical alloying of elemental iron and silicon powders. The mechanical alloying process was carried out using a high energy ball mill in argon atmosphere. Samples were collected after 0.5, 1, 2, 4, 6 and 8 hours of ball milling. The X-ray diffraction (XRD) studies indicate that after 4 hours of milling the Fe-Si alloy is formed. The powder magnetisation decreases upon increasing the milling time up to 4 hours as a consequence of the Fe-Si alloy formation. Upon heating, the DSC studies show the Fe3Si compound formation in the samples milled for milling times lower than 6 hours. Also, the Curie temperature of the alloy was evidenced.


2011 ◽  
Vol 672 ◽  
pp. 68-71
Author(s):  
Ionel Chicinaş ◽  
Viorel Pop ◽  
Florin Popa ◽  
Virgiliu Călin Prică ◽  
Traian Florin Marinca ◽  
...  

The Hipernik alloy (50Ni50Fe wt. %) was obtained by mechanical alloying. The milling was performed in argon atmosphere, with a ball/powder mass ration of 8:1 for times ranging from 2 up to 20h. The alloy formation was studied by X-ray diffraction. The obtained structure is face cantered cubic, indicating the extension of the γ domain for the Ni-Fe alloys by mechanical alloying. The mean crystallite size was calculated with the Williamson – Hall method. Using scanning electron microscopy (SEM) the morphology and the chemical homogeneity of the powders was analysed. The technological properties of the powders as particle size distribution and flowability are determined as a function of the milling time. The magnetic behaviour of the samples was studied by magnetic measurements under high magnetic fields.


2014 ◽  
Vol 216 ◽  
pp. 283-287 ◽  
Author(s):  
Cristina Daniela Stanciu ◽  
Traian Florin Marinca ◽  
Florin Popa ◽  
Ionel Chicinaş ◽  
Olivier Isnard

Fe-Si alloy with a Si content of 10 wt. % was obtained in nanocrystalline state by mechanical alloying of elemental iron and silicon powders. The mechanical alloying process was carried out in a high energy ball mill (Fritsch, Pulverisette 4) in argon atmosphere. The X-ray diffraction (XRD) studies indicated that after 4 hours of milling the Fe-Si alloy is formed. The mean crystallites size decreases down to 7 nm after 8 hours of milling. The particles morphology investigated by scanning electron microscopy (SEM) showed an evolution during milling process from two different kinds of particles to a one kind of particles with irregular shape. The magnetisation of powders decreases upon increasing the milling time up to 4 hours as a consequence of the Fe-Si alloy formation.


Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1841
Author(s):  
Edgar Pio ◽  
Ariosto Medina ◽  
Carola Martínez ◽  
Felipe Manuel Castro Cerda ◽  
Claudio Aguilar

Four titanium alloys (Ti-Ta, Ti-Ta-Sn, Ti-Ta-Mn, and Ti-Nb-Sn) were synthesized by mechanical alloying (MA) in a planetary mill in different times between 2 h and 100 h. The microstructure characterization was made by X-ray diffraction (XRD), in which the Rietveld method was applied to analyze the diffraction patterns. The study demonstrated that after short milling times between 2 h and 30 h, the fraction of hexagonal close-packed (hcp) phase decreases; at the same time, the formation of body-centered cubic (bcc) and face-centered cubic (fcc) Ti phases are promoted. Additionally, after 30 h of MA, the full transformation of hcp-Ti was observed, and the bcc-Ti to fcc-Ti phase transformation took place until 50 h. The results suggest that the addition of Ta and Sn promotes the fcc-Ti phase formation, obtaining 100% of this phase at 50 h onwards, whereas Nb and Mn show the opposite effect.


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1225
Author(s):  
Cristina García-Garrido ◽  
Ranier Sepúlveda Sepúlveda Ferrer ◽  
Christopher Salvo ◽  
Lucía García-Domínguez ◽  
Luis Pérez-Pozo ◽  
...  

In this work, a blend of Ti, Nb, and Mn powders, with a nominal composition of 15 wt.% of Mn, and balanced Ti and Nb wt.%, was selected to be mechanically alloyed by the following two alternative high-energy milling devices: a vibratory 8000D mixer/mill® and a PM400 Retsch® planetary ball mill. Two ball-to-powder ratio (BPR) conditions (10:1 and 20:1) were applied, to study the evolution of the synthesized phases under each of the two mechanical alloying conditions. The main findings observed include the following: (1) the sequence conversion evolved from raw elements to a transitory bcc-TiNbMn alloy, and subsequently to an fcc-TiNb15Mn alloy, independent of the milling conditions; (2) the total full conversion to the fcc-TiNb15Mn alloy was only reached by the planetary mill at a minimum of 12 h of milling time, for either of the BPR employed; (3) the planetary mill produced a non-negligible Fe contamination from the milling media, when the highest BPR and milling time were applied; and (4) the final fcc-TiNb15Mn alloy synthesized presents a nanocrystalline nature and a partial degree of amorphization.


1998 ◽  
Vol 13 (5) ◽  
pp. 1171-1176 ◽  
Author(s):  
S-H. Yip ◽  
D. Guay ◽  
S. Jin ◽  
E. Ghali ◽  
A. Van Neste ◽  
...  

The structural and electrochemical properties of the Ti–Ru–Fe–O system have been studied over the whole ternary metal compositional range, keeping constant the oxygen content at 30 at.%. The phase diagram was explored systematically by varying the composition of the material along one of the following axes: (i) constant Ru content of 16 at. %; (ii) constant Ti/Ru ratio of 2; (iii) constant Ti/Fe ratio of 1.6. For O/Ti ratios equal or below unity, the most prominent peaks observed in the x-ray diffraction patterns belong to a B2 structure. For O/Ti ratio larger than unity, stable titanium oxide phases are formed, which coexist with a cubic Fe-like or hcp-Ru like phases depending on the Fe/Ru ratio. Powder compositions with stoichiometry close to Ti2RuFeO2 are of interest due to good electrocatalytic properties, long-term stability, and low Ru content.


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