Bulk Fe-Al-C Nanoalloys Made by Mechanically Alloying with Subsequent Spark Plasma Sintering and Their Mechanical Properties

2005 ◽  
Vol 101-102 ◽  
pp. 103-110 ◽  
Author(s):  
Yoritoshi Minamino ◽  
Yuichiro Koizumi ◽  
Nobuhiro Tsuji ◽  
Naoko Hirohata ◽  
Kiyoshi Mizuuchi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Compression Tests ◽  
Good Thermal Stability ◽  
Environmental Embrittlement ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Superior Mechanical Properties ◽  
Bulk Nanocrystalline ◽  
Rupture Strain

Three kinds of bulk nanocrystalline Fe-24at%Al-Xat%C (X=1,2,4) alloy were produced from Fe and Al powders with addition of methanol by MA with subsequent SPS at 1273K under 64MPa. Their microstructure and mechanical properties were investigated. The compacts have the relative densities of 99.97% (1at%C) to 99.6% (4at%C). The structure of compacts with 1at%C is composed of Fe3Al grains of 1.5µm in diameter and nano k-carbides (Fe3AlC0.5) precipitates, while those of compacts with 2 and 4at%C are composed of nanocrystalline Fe3Al of about 80nm in diameter, nano k-carbides and a-grains of about 1µm in diameter. These structures have the good thermal stability, maintaining the nanostructure even at 973K. The mechanical properties of these compacts were measured by compression tests at R.T. to 973K. The compacts with 1at%C and 2at%C of this work perform the superior mechanical properties (e.g. yield strength of 2.15GPa and rupture strain of 0.14 for compact with 2at%C at R.T.) when compared with the ordinary Fe3Al casting (e.g. 380MPa and 0.12). They also exhibit no environmental embrittlement, which is one of fatal problems for the ordinary Fe3Al mateials.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Nanocrystalline Aluminum 5083 Alloy

2015 ◽  
Vol 782 ◽  
pp. 113-118
Author(s):  
Ying Mei Teng ◽  
Zhao Hui Zhang ◽  
Zi Zhou Yuan
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Compressive Strength ◽  
Sintering Temperature ◽  
Initial Pressure ◽  
Fine Grain ◽  
Microstructure And Mechanical Properties ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Bulk Nanocrystalline

The bulk nanocrystalline (NC) aluminum (Al) 5083 was synthesized by spark plasma sintering (SPS) technique with low initial pressure of 1 MPa, high holding pressure of 300 MPa and holding time of 4 min at different sintering temperatures, using surface passivated nanopowders. The effect of sintering temperature on microstructure and mechanical properties of the bulk NC Al 5083 were investigated. Results indicate that the density, grain size, the hardness and the compressive strength of the bulk NC Al 5083 increase with an increase in sintering temperature. The mechanical properties of the material are greatly improved due to the fine grain size. The bulk NC Al 5083 sintered at 723 K has the highest micro-hardness of 2.37 GPa and the best compressive strength of 845 MPa.

Thermal Stability and Mechanical Properties of Nanocrystalline L12 Al3Hf and (Al+12.5 at.%Zn)3Hf Prepared by MA and SPS

2004 ◽  
Vol 449-452 ◽  
pp. 809-812 ◽  
Author(s):  
Chang Won Kang ◽  
Hee Sup Jang ◽  
Seon Jin Kim
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Fracture Toughness ◽  
Phase Transformation ◽  
Grain Growth ◽  
Annealing Temperature ◽  
Annealing Temperatures ◽  
Grain Sizes ◽  
Plasma Sintering ◽  
Spark Plasma

Thermal stability and mechanical properties of L12 Al3Hf and (Al+12.5 at.%Zn))3Hf synthesized by mechanical alloying(MA) and spark plasma sintering(SPS) were investigated. Nanocrystalline L12 phase was produced after MA for 8 and 10 hrs in Al3Hf and (Al+12.5 at.%Zn))3Hf powders, respectively. The grain sizes were reduced to about 10 nm in both systems after MA for 20 hrs. After SPS, L12 phase was maintained only in Zn added system. In (Al+12.5 at.%Zn))3Hf, L12 to D023 phase transformation was started at about 850°C and finished at about 1150°C Microhardness was decreased with increasing the annealing temperature while fracture toughness was increased due to the grain growth. Fracture toughness of (Al+12.5 at.%Zn))3Hf was greater than that of Al3Hf in all annealing temperatures. Fracture toughness of (Al+12.5 at.%Zn))3Hf after annealing at 1200°C was about 5.38 MPam1/2.

scholarly journals Effect of Short Attritor-Milling of Magnesium Alloy Powder Prior to Spark Plasma Sintering

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3973
Author(s):  
Peter Minárik ◽  
Mária Zemková ◽  
Michal Knapek ◽  
Stanislav Šašek ◽  
Jan Dittrich ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Spark Plasma Sintering ◽  
Alloy Powder ◽  
Mechanical Performance ◽  
Milled Powder ◽  
Plasma Sintering ◽  
Attritor Milling ◽  
Spark Plasma ◽  
Superior Mechanical Properties

The spark plasma sintering (SPS) technique was employed to prepare compacts from (i) gas-atomized and (ii) attritor-milled AE42 magnesium powder. Short attritor-milling was used mainly to disrupt the MgO shell covering the powder particles and, in turn, to enhance consolidation during sintering. Compacts prepared by SPS from the milled powder featured finer microstructures than compacts consolidated from gas-atomized powder (i.e., without milling), regardless of the sintering temperatures in the range of 400–550 °C. Furthermore, the grain growth associated with the increase in the sintering temperature in these samples was less pronounced than in the samples prepared from gas-atomized particles. Consequently, the mechanical properties were significantly enhanced in the material made of milled powder. Apart from grain refinement, the improvements in mechanical performance were attributed to the synergic effect of the irregular shape of the milled particles and better consolidation due to effectively disrupted MgO shells, thus suppressing the crack formation and propagation during loading. These results suggest that relatively short milling of magnesium alloy powder can be effectively used to achieve superior mechanical properties during consolidation by SPS even at relatively low temperatures.

High-strength Al87Ni8La5 bulk alloy produced by spark plasma sintering of gas atomized powders

2009 ◽  
Vol 24 (9) ◽  
pp. 2909-2916 ◽  
Author(s):  
Sergio Scudino ◽  
Kumar B. Surreddi ◽  
Hoang V. Nguyen ◽  
Gang Liu ◽  
Thomas Gemming ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spark Plasma Sintering ◽  
Room Temperature ◽  
Bulk Material ◽  
High Strength ◽  
Compression Tests ◽  
Bulk Alloy ◽  
Plasma Sintering ◽  
Spark Plasma

In situ devitrification and consolidation of gas atomized Al87Ni8La5 glassy powders into highly dense bulk specimens was carried out by spark plasma sintering. Room temperature compression tests of the consolidated bulk material reveal remarkable mechanical properties, namely, high compression strength of 930 MPa combined with plastic strain exceeding 25%. These findings demonstrate that the combined devitrification and consolidation of glassy precursors by spark plasma sintering is a suitable method for the production of Al-based materials characterized by high strength and considerable plastic deformation.

Thermal Stability and Properties of Cu-TiB2 Nanocomposites Prepared by Combustion Synthesis and Spark-Plasma Sintering

2007 ◽  
Vol 534-536 ◽  
pp. 1517-1520
Author(s):  
Dae Hwan Kwon ◽  
Thuy Dang Nguyen ◽  
Dina V. Dudina ◽  
Jong Won Kum ◽  
Pyuck Pa Choi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ball Milling ◽  
Copper Matrix ◽  
High Energy ◽  
Good Thermal Stability ◽  
Plasma Sintering ◽  
High Temperature Synthesis ◽  
Spark Plasma ◽  
Nanocomposite Powders ◽  
Tib2 Particles

In the present work, Cu-TiB2 nanocomposite powders were synthesized by combining high-energy ball-milling of Cu-Ti-B mixtures and subsequent self-propagating high temperature synthesis (SHS). Cu-40wt.%TiB2 powders were produced by SHS reaction and ball-milled. The milled SHS powder was mixed with Cu powders by ball milling to produce Cu-2.5wt.%TiB2 composites. TiB2 particles less than 250nm were formed in the copper matrix after SHS-reaction. The releative density, electrical conductivity and hardness of specimens sintered at 650-750°C were nearly 98%, 83%IACS and 71HRB, respectively. After heat treatment at 850 to 950°C for 2 hours under Ar atmosphere, hardness was descedned by 15%. Our Cu-TiB2 composite showed good thermal stability at eleveated temperature.

scholarly journals Effect of graphite nanoplatelets on spark plasma sintered and conventionally sintered aluminum-based nanocomposites developed by powder metallurgy

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Pankaj Shrivastava ◽  
Syed Nasimul Alam ◽  
Taraknath Maity ◽  
Krishanu Biswas
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Graphite Nanoplatelets ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Sintered Aluminum ◽  
Conventional Sintering ◽  
Spark Plasma ◽  
Superior Mechanical Properties

Abstract In this work, aluminum (Al)-based nanocomposites reinforced with graphite nanoplatelets (GnPs) have been fabricated by conventional sintering as well as spark plasma sintering (SPS) techniques, and their microstructure and mechanical properties have been studied. The powder metallurgy (PM) route has been adopted to fabricate the various Al–GnP nanocomposites. Characterization of the powder mixtures and the nanocomposites has been carried out through different characterization techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. Compressive strength, Young's modulus, density, and Vickers microhardness of the various nanocomposites have also been determined. The HRTEM results show the formation of nonstoichiometric Al4C3 nanoparticles – during both conventional sintering and SPS – at the interface of the Al grains and GnP, which worsen the mechanical properties of the nanocomposites. SPSed nanocomposites show superior mechanical properties due to higher densification, finer grain size, and homogeneous nanofiller dispersion in the Al matrix, compared to the conventionally sintered Al–GnP nanocomposites.

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