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Rodríguez, José Antonio; Gallardo, José M.; Herrera, E. J.

doi:10.1023/a:1018653607670

Cited by 59 publications

(32 citation statements)

References 2 publications

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“…According to other studies, the ball-milling process can also change the shape of particles or powders, especially using high-energy ball milling. [10][11][12] However, this study shows that the shape of particles or powders can be changed using low-energy ball milling. The initial stages of fabrication of a composite involve deformation and fracturing of soft metal and ceramic powders as those powders are mixed and sintered.…”

Section: Growth Mechanism and Microstructurementioning

confidence: 99%

“…The impact energy from the ball-milling process transforms the shape of powders in the composite. The high energy input by the high-energy ball milling process produces mechanical alloys or flakey powders, [10][11][12] while the low energy input by low-energy ball milling can be used to make simple mixtures of different types of powders. Moreover, ductile powders such as metal powders can be transformed by this low impact energy process.…”

Section: Introductionmentioning

confidence: 99%

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Investigation of Mechanical Properties and Elongated Ni Grain Growth in an Al2O3-Ni Composite during Low-Energy Ball Milling

et al. 2011

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A composite of 40 mass% Al 2 O 3 -60 mass% Ni was fabricated using powder metallurgy. The composite consisted of Ni powders dispersed in an Al 2 O 3 matrix. The morphology of the Ni powders in the composite was monitored during a low-energy ball-milling process over about 10 h. The shape of the Ni particles changed from spherical to elongated shape using this milling method. The aspect ratio of the elongated Ni grains was measured, and 16% of the total Ni grains in the composite were found to have an aspect ratio higher than 3.0. To investigate changes in mechanical properties due to the elongated Ni powders, strength and hardness were measured. The composite having elongated Ni powders with an aspect ratio higher than 3.0 showed improved strength and hardness compared to the composite containing non-milled particles. Lowenergy milling of composites is thus an effective way to control the microstructure of particles in order to improve the mechanical properties of the final composite. Because of its low production cost and simplicity, this method could potentially be used in the production of various reinforced composites.

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Section: Growth Mechanism and Microstructurementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Investigation of Mechanical Properties and Elongated Ni Grain Growth in an Al2O3-Ni Composite during Low-Energy Ball Milling

et al. 2011

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“…The high thermal stability against grain growth observed in this alloy (grain size increased only by a factor~1.5 after VHP) could be attributed to the presence of Al 2 Cu precipitates and dispersoids of Al 4 C 3 and Al 2 O 3 (Figure 3(a)), which are expected to hinder the grain boundary movement through Zener pinning. [12] Compression tests are done on VHP samples, and the results are shown in Figure 4. The coarse-grained pure Al samples exhibit low YS and substantial work hardening thereafter.…”

mentioning

confidence: 99%

“…Oxygen and carbon are introduced into ball-milled Al alloys during powder processing. [12] These can react with Al to form fine oxide and carbide particles, but may be difficult to observe. [12] The main role of these dispersoids is in stabilizing the grain size through Zener pinning.…”

mentioning

confidence: 99%

Microstructure and Mechanical Properties of Nanostructured Al-4Cu Alloy Produced by Mechanical Alloying and Vacuum Hot Pressing

Shanmugasundaram

Heilmaier

Murty

et al. 2009

Metall Mater Trans A

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Bulk nanostructured Al-4 wt pct Cu alloy with high compression strength (879 MPa) was produced by mechanical alloying followed by vacuum hot pressing (VHP). The hot-pressed compacts were nanostructured with a grain size of 50 nm and were densified to more than 99 pct of the theoretical density. Contributions from different strengthening mechanisms were estimated using simplified models and were compared with the experiment.Ultrafine-grained (UFG) and nanocrystalline (nc) materials are increasingly being studied due to their improved mechanical properties. Bulk UFG or nc metals and alloys are commonly produced by methods based on severe plastic deformation (SPD). These SPD techniques, such as high energy ball milling, [1] equal channel angular pressing, [2] and high pressure torsion, [3] introduce very large plastic strains leading to grain refinement in coarse-grained powder or bulk materials. High energy ball milling can also be used to produce homogeneous supersaturated solid solutions from elemental powder blends. [4] The nc powders produced by high energy ball milling are usually consolidated into bulk by hot pressing, spark plasma sintering, and hot isostatic pressing followed by hot extrusion. [5,6] The Al-Cu alloys are important due to their high strength, which is achieved through precipitation strengthening. Recent work has shown that in precipitation-hardened UFG alloys, simultaneous improvement in strength and ductility could be achieved through SPD followed by annealing and aging. [7] There is very limited literature on the microstructure and mechanical properties of nanostructured Al-Cu alloys. Fogagnolo et al. studied solid solution formation in an Al-4.5 pct Cu alloy during milling and characterized the thermal stability during subsequent heat treatment. [8] The present work aims to synthesize nc Al-4 wt pct Cu binary alloy from elemental Al and Cu powder blend by high energy ball milling and to study the mechanical properties on bulk samples obtained via consolidation of the nc powders.Al-4 wt pct Cu alloy was prepared by mechanical alloying from high-purity (99.9 pct) elemental Al and Cu powders using a Retsch PM400 (RETSCH PM 400, Haan, Germany) high-energy planetary ball mill at 200 rpm and a ball-to-powder weight ratio of 14:1 using a hardened steel vessel and balls (10-mm diameter). Stearic acid (1 wt pct) was added as the process control agent. The loading and unloading of the powders were done in a glove box in argon atmosphere. Samples were taken at regular intervals during milling and analyzed using X-ray diffraction (XRD) with Cu K a radiation. From the XRD peak profile, instrumental broadening and K a2 components were subtracted and then the grain size (crystallite size) and lattice strain were estimated using the Williamson and Hall method. [9] Lattice parameters of Al were calculated from four peaks using the Cohen method. [10] The Cu concentration in solid solution was determined from the values of the lattice parameter using Vegard's law. Hardness variation as a function of milling ...

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“…1) On the other hand, the demand of porous material is gradually emerging due to technological advancement of many applications such as energy conversion and storage, environment friendly catalysis, sensors, drug delivery, medical diagnosis, cell makers and photonics 2,3) as it offers an enhanced interaction between the atoms, ions and molecules, turning it to deliver superior properties. Therefore, the synthesis of nano-and porous Al powder is of great interest, and a lot of techniques such as pulsed wire evaporation (PWE) 4,5) and mechanical alloying [6][7][8] have been previously employed to manufacture Al nanopowders along with nanocrystalline and amorphous composites [9][10][11] through powder metallurgy route for tailoring their structures with desired properties.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Agglomerated Coarse Al Powders Comprising Nanoparticles by Low Energy Ball Milling Process

et al. 2011

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Agglomerated coarse Al powders consisting of nanoparticles were synthesized by low energy ball milling process, and subsequently their structures were characterized in terms of agglomeration size, shape, and porosity depending on various milling time, ball size, and ball to powder weight ratio in order to optimize the process parameters. A higher milling time caused a decrease in the agglomeration size and their shape tends to become spherical while reducing the pore sizes. The agglomeration size was also reduced as the ball to powder weight ratio increased and the ball size decreased. The partial cold welding of the nanoparticles at lower milling time and fully cold welding of the nanoparticles at higher milling time were correspondingly responsible to produce larger and smaller agglomerations, respectively.

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Cited by 59 publications

References 2 publications

Investigation of Mechanical Properties and Elongated Ni Grain Growth in an Al<SUB>2</SUB>O<SUB>3</SUB>-Ni Composite during Low-Energy Ball Milling

Investigation of Mechanical Properties and Elongated Ni Grain Growth in an Al<SUB>2</SUB>O<SUB>3</SUB>-Ni Composite during Low-Energy Ball Milling

Microstructure and Mechanical Properties of Nanostructured Al-4Cu Alloy Produced by Mechanical Alloying and Vacuum Hot Pressing

Synthesis and Characterization of Agglomerated Coarse Al Powders Comprising Nanoparticles by Low Energy Ball Milling Process

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