The effect of milling speed on the structural properties of mechanically alloyed Fe–45%Ni powders

Gheisari, Kh.; Javadpour, Sirus; Oh, Joo Tien; Ghaffari, Mohammad Ali

doi:10.1016/j.jallcom.2008.04.074

Cited by 96 publications

(36 citation statements)

References 18 publications

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“…It seems that increasing the milling speed above a critical value, provides enough energy to introduce the required volume contraction to the powder in order to start the brookite-to-rutile phase transformation. 23 The reconstructive anatase-to-rutile phase transformation involves an overall volume contraction of $8%, while the brookite-torutile phase transition is accompanied by a $3.4% volume contraction. 24 This implies that the brookite-to-rutile phase transformation has a lower barrier energy rather than anataseto-rutile one.…”

Section: Characterization Of Materialsmentioning

confidence: 99%

The role of brookite in mechanical activation of anatase-to-rutile transformation of nanocrystalline TiO2: An XRD and Raman spectroscopy investigation

2011

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The mechanism of phase transformation in nanocrystalline TiO 2 powders at ambient temperature during high energy ball milling and the role of brookite phase in anatase-to-rutile phase transformation were investigated by the use of Rietveld analysis of X-ray diffraction patterns and Raman spectroscopy methods. The milling process was performed on a fully anatase phase nanocrystalline TiO 2 powder via a high energy planetary ball mill with different ball-to-powder weight ratios followed by annealing of the as-milled samples. Some transformation from anatase-to-brookite was observed in all as-milled powders by high resolution transmission electron microscopy. It was proposed that brookite occurs at the {112} twin surfaces of anatase phase and therefore promotes anatase-to-rutile phase transformation. Based on the XRD and Raman results, it was proposed that brookite appears as an essential intermediate phase in mechanically induced anatase-to-rutile phase transformation which facilitates the phase transformation at ambient temperatures and also at higher temperatures during the post-annealing step.

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Section: Characterization Of Materialsmentioning

confidence: 99%

The role of brookite in mechanical activation of anatase-to-rutile transformation of nanocrystalline TiO2: An XRD and Raman spectroscopy investigation

2011

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“…In addition, the refinement of crystallite size leads to short-circuit diffusion and the existence of crystal defects results in increased solubility of elements in the crystal lattice. Therefore, facilitating the diffusion mechanism leads to an increase in the amount of the NiFe 2 O 4 phase through increased rotation speed [22]. Since crystallite size and lattice strain are the factors that affect peak broadening, we calculated their values using the modified Debye-Scherrer equation as reported in Table 2.…”

Section: Evaluation Of the Effect Of Rotation Speed On The Crystallitmentioning

confidence: 99%

Parametric optimization of NiFe2O4 nanoparticles synthesized by mechanical alloying

Hajalilou

Hashim

Ebrahimi‐Kahrizsangi

et al. 2014

Materials Science-Poland

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In this study, the Taguchi robust design method is used for optimizing ball milling parameters including milling time, rotation speed and ball to powder weight ratio in the planetary ball milling of nanostructured nickel ferrite powder. In fact, the current work deals with NiFe 2 O 4 nanoparticles mechanochemically synthesized from NiO and Fe 2 O 3 powders. The Taguchi robust design technique of system optimization with the L9 orthogonal array is performed to verify the best experimental levels and contribution percentages (% ρ) of each parameter. Particle size measurement using SEM gives the average particle size value in the range of 59 -67 nm. X-ray diffraction using Cu Kα radiation is also carried out to identify the formation of NiFe 2 O 4 single phase. The XRD results suggest that NiFe 2 O 4 with a crystallite size of about 12 nm is present in 30 h activated specimens. Furthermore, based on the results of the Taguchi approach the greatest effect on particle size (42.10 %) is found to be due to rotation speed followed by milling time (37.08 %) while ball to powder weight ratio exhibits the least influence.

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“…Moreover, it presents the ability to synthesise products with controlled porosity and microstructure [20]. Mechanical milling (MM) is an efficient technique to refine powder particles, which is beneficial for improving the densification and mechanical properties of the PM alloys in the subsequent sintering process [21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Effect of Sintering Time on the Densification, Microstructure, Weight Loss and Tensile Properties of a Powder Metallurgical Fe-Mn-Si Alloy

Hodgson

Chang

et al. 2017

Metals

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This work investigated the isothermal holding time dependence of the densification, microstructure, weight loss, and tensile properties of Fe-Mn-Si powder compacts. Elemental Fe, Mn, and Si powder mixtures with a nominal composition of Fe-28Mn-3Si (in weight percent) were ball milled for 5 h and subsequently pressed under a uniaxial pressure of 400 MPa. The compacted Fe-Mn-Si powder mixtures were sintered at 1200 • C for 0, 1, 2, and 3 h, respectively. In general, the density, weight loss, and tensile properties increased with the increase of the isothermal holding time. A significant increase in density, weight loss, and tensile properties occurred in the compacts being isothermally held for 1 h, as compared to those with no isothermal holding. However, further extension of the isothermal holding time (2 and 3 h) only played a limited role in promoting the sintered density and tensile properties. The weight loss of the sintered compacts was mainly caused by the sublimation of Mn in the Mn depletion region on the surface layer of the sintered Fe-Mn-Si compacts. The length of the Mn depletion region increased with the isothermal holding time. A single α-Fe phase was detected on the surface of all of the sintered compacts, and the locations beyond the Mn depletion region were comprised of a dual dominant γ-austenite and minor ε-martensite.

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The effect of milling speed on the structural properties of mechanically alloyed Fe–45%Ni powders

Cited by 96 publications

References 18 publications

The role of brookite in mechanical activation of anatase-to-rutile transformation of nanocrystalline TiO2: An XRD and Raman spectroscopy investigation

The role of brookite in mechanical activation of anatase-to-rutile transformation of nanocrystalline TiO2: An XRD and Raman spectroscopy investigation

Parametric optimization of NiFe2O4 nanoparticles synthesized by mechanical alloying

Effect of Sintering Time on the Densification, Microstructure, Weight Loss and Tensile Properties of a Powder Metallurgical Fe-Mn-Si Alloy

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