Microstructure and Mechanical Properties of Gas Atomized Aluminum Alloy Powder Compact Densified by Pulsed Current Pressure Sintering Process

Nagae, T.; Yokota, Masaru; Nosé, M.; Tomida, Shogo; Otera, Katsumasa; Kamiya, Takashi; Saji, Shigeoki

doi:10.2320/matertrans.43.537

Cited by 14 publications

(7 citation statements)

References 13 publications

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“…Sintering occurs at these points and the interior of the powder particles is nearly unaffected and retains the microstructure formed during atomization. Spark discharge is limited to contact points where it can break up the oxide layers present at the powder particle surface and contributes thus to a very low porosity of the sintered material [ 4 ]. A further advantage of SPS is a short time of exposition to elevated temperatures which helps to limit undesirable processes like grain growth.…”

Section: Introductionmentioning

confidence: 99%

Spark Plasma Sintering of a Gas Atomized Al7075 Alloy: Microstructure and Properties

et al. 2016

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The powder of an Al7075 alloy was prepared by gas atomization. A combination of cellular, columnar, and equiaxed dendritic-like morphology was observed in individual powder particles with continuous layers of intermetallic phases along boundaries. The cells are separated predominantly by high-angle boundaries, the areas with dendritic-like morphology usually have a similar crystallographic orientation. Spark plasma sintering resulted in a fully dense material with a microstructure similar to that of the powder material. The continuous layers of intermetallic phases are replaced by individual particles located along internal boundaries, coarse particles are formed at the surface of original powder particles. Microhardness measurements revealed both artificial and natural ageing behavior similar to that observed in ingot metallurgy material. The minimum microhardness of 81 HV, observed in the sample annealed at 300 °C, reflects the presence of coarse particles. The peak microhardness of 160 HV was observed in the sample annealed at 500 °C and then aged at room temperature. Compression tests confirmed high strength combined with sufficient plasticity. Annealing even at 500 °C does not significantly influence the distribution of grain sizes—about 45% of the area is occupied by grains with the size below 10 µm.

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Section: Introductionmentioning

confidence: 99%

Spark Plasma Sintering of a Gas Atomized Al7075 Alloy: Microstructure and Properties

et al. 2016

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“…First of all no differences were detected in applying the pressure using mode I or II and the data represent the samples obtained in mode II. This is very important because it has been shown [5,7] that mode II gives a stronger neck growth and higher ductility compared to mode I. On the sintered parts it was difficult to perform reliable microhardness measurements due to the low load.…”

Section: Resultsmentioning

confidence: 99%

Microstructure and Mechanical Properties of Nanostructured Aluminum Consolidated by SPS

Zadra

Casari

Molinari

2007

MSF

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Nanostructured aluminum powders were obtained by means of planetary ball milling with methanol as the Process Control Agent (PCA). The behavior, during milling, was considered measuring the microhardness and grain size at different milling times. Bulk near-full density samples were sintered using the Spark Plasma Sintering technology with different schedules: temperature of 500°C and 550°C, pressure of 30 MPa and 60 MPa and different modes of applying the pressure were changed in order to understand the behavior during sintering. The samples sintered at 500°C showed a density of about 2.4-2.61 g/cm3 while for that sintered at 550°C it was 2.65-2.67 g/cm3 depending on the applied pressure. All the samples retained their nanostructure with an increase of the grain size from about 46 up to 70-90 nm. Using X-ray diffraction and metallography the formation of Al4C3 carbides was detected for samples sintered at highest temperatures.

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“…11 Other authors showed that using this kind of schedules minimises the quantity of gas entrapped into the powder returning in higher sustainable plasticity. 12…”

Section: Effect Of Pressurementioning

confidence: 99%

Spark plasma sintering of pure aluminium powder: mechanical properties and fracture analysis

Zadra¹,

Casari²,

Girardini³

et al. 2007

Powder Metallurgy

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The objective of the present study was to investigate the spark plasma sintering technology when a pure coarse aluminium powder is used. In order to understand the process, different conditions of temperature, current flow through the sample, pressure and delay at which the pressure is applied were investigated to clarify the role of the pulsed electric current. It has been shown that the presence of the current flow and applying the sintering pressure with a certain delay in respect to the beginning of the cycle promote better sintering and mechanical properties. With a heating rate of 100 K min 21 , a sintering temperature of 525uC, dwell time of 1 min and pressure of 60 MPa, the mechanical properties and the fracture morphology are very similar to those of pure annealed wrought aluminium.

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Microstructure and Mechanical Properties of Gas Atomized Aluminum Alloy Powder Compact Densified by Pulsed Current Pressure Sintering Process

Cited by 14 publications

References 13 publications

Spark Plasma Sintering of a Gas Atomized Al7075 Alloy: Microstructure and Properties

Spark Plasma Sintering of a Gas Atomized Al7075 Alloy: Microstructure and Properties

Microstructure and Mechanical Properties of Nanostructured Aluminum Consolidated by SPS

Spark plasma sintering of pure aluminium powder: mechanical properties and fracture analysis

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