Fe-Si-Al Alloys Prepared by a Spark Plasma Sintering Technique

2015 ◽  
Vol 827 ◽  
pp. 300-305 ◽  
Author(s):  
Toto Sudiro ◽  
Kemas Ahmad Zaini Thosin ◽  
Didik Aryanto ◽  
Agus Sukarto Wismogroho ◽  
Kazuya Kurokawa

Fe-Si alloys with various concentration of Al (0, 1, 3 and 5 % by mass) were synthesized by a spark plasma sintering technique. The specimens were prepared in an evacuated chamber of less than 4 Pa and under compressive stress of 40 MPa. During spark discharge, the heating rate was fixed at 10°C/min. After the SPS process was completed, the specimen surfaces were ground with silicon carbide papers. The metallographic characterization was performed by mean of X-ray diffraction (XRD) and scanning electron microscope (SEM) equipped with energy dispersive X-ray (EDX) spectroscopy. According to sintering curves, all samples seem to have a similar sintering behavior. The densification of specimens was completed in the temperature range of about 1020-1050°C. Microstructure and phase characterization revealed that the alloys were mainly composed of FeSi2 and FeSi phases containing oxide inclusions. The SEM images indicated that the fraction of FeSi phase and oxide inclusions appears to decrease with increase in Al concentration in the Fe-Si alloy.

2016 ◽  
Vol 881 ◽  
pp. 307-312
Author(s):  
Luis Antonio C. Ybarra ◽  
Afonso Chimanski ◽  
Sergio Gama ◽  
Ricardo A.G. da Silva ◽  
Izabel Fernanda Machado ◽  
...  

Tungsten carbide (WC) based composites are usually produced with cobalt, but this binder has the inconvenience of shortage, unstable price and potential carcinogenicity. The objective of this study was to develop WC composite with intermetallic Fe3Al matrix. Powders of WC, iron and aluminum, with composition WC-10 wt% Fe3Al, and 0.5 wt% zinc stearate were milled in a vibration mill for 6 h and sintered in a SPS (spark plasma sintering) furnace at 1150 °C for 8 min under pressure of 30 MPa. Measured density and microstructure analysis showed that the composite had significant densification during the (low-temperature, short time) sintering, and X-ray diffraction analysis showed the formation of intermetallic Fe3Al. Analysis by Vickers indentation resulted in hardness of 11.2 GPa and fracture toughness of 24.6 MPa.m1/2, showing the feasibility of producing dense WC-Fe3Al composite with high mechanical properties using the SPS technique.


2010 ◽  
Vol 654-656 ◽  
pp. 819-822
Author(s):  
Genki Kikuchi ◽  
Hiroshi Izui ◽  
Yuya Takahashi ◽  
Shota Fujino

In this study, we focused on the sintering performance of Ti-4.5Al-3V-2Mo-2Fe (SP-700) and mechanical properties of SP-700 reinforced with titanium boride (TiB/SP-700) fabricated by spark plasma sintering (SPS). TiB whiskers formed in titanium by a solid-state reaction of titanium and TiB2 particles were analyzed with scanning electron microscopy and X-ray diffraction. The TiB/SP-700 was sintered at temperatures of 1073, 1173, and 1273 K and a pressure of 70 MPa for 10, 30, and 50 min. The volume fraction of TiB ranged from 1.7 vol.% to 19.9 vol.%. Tensile tests of TiB/SP-700 were conducted at room temperature, and the effect of TiB volume fraction on the tensile properties was investigated.


2021 ◽  
Vol 1016 ◽  
pp. 1790-1796
Author(s):  
Maxim Syrtanov ◽  
Egor Kashkarov ◽  
Tatyana Murashkina ◽  
Nahum Travitzky

This paper describes the influence of sintering temperature on phase composition and microstructure of paper-derived Ti3AlC2 composites fabricated by spark plasma sintering. The composites were sintered at 100 MPa pressure in the temperature range of 1150-1350 °C. Phase composition and microstructure were analyzed by X-ray diffraction and scanning electron microscopy, respectively. The multiphase structure was observed in the sintered composites consisting of Ti3AlC2, Ti2AlC, TiC and Al2O3 phases. The decomposition of the Ti3AlC2 phase into Ti2AlC and TiC carbide phases was observed with temperature rise. The total content of Ti3AlC2 and Ti2AlC phases was reduced from 84.5 vol.% (1150 °C) to 69.5 vol.% (1350 °C). The density of composites affected by both the content of TiC phase and changes in porosity.


2016 ◽  
Vol 704 ◽  
pp. 183-189
Author(s):  
Yong Jun Su ◽  
Yi Feng Zheng ◽  
De Liang Zhang ◽  
Fan Tao Kong

TiAl alloy with a composition of Ti-43Al-5V-4Nb-Y (at.%) was prepared by spark plasma sintering (SPS). The TiAl powders were sintered between 650°C and 1300°C for 5 min under different loads. With the increasing of the temperature, the diffusion of the elements can be observed. Full compaction is achieved in a short period of time and the overall processing duration does not exceed 30 min. A fully lamellar structure was seen in the TiAl alloy after heat treatment. The microstructures of the samples were determined by X-ray diffraction and scanning electron microscopy. Their mechanical properties were evaluated by tensile tests performed at room temperature


2005 ◽  
Vol 475-479 ◽  
pp. 2895-2898
Author(s):  
Hideki Oginuma ◽  
Katsuyoshi Kondoh ◽  
Takashi Yamaguchi ◽  
Eiji Yuasa

In this study, the solid-state reaction to form Mg2Si bulky materials via spark plasma sintering (SPS) process was discussed. Elemental powder mixture of Mg-33.33mol%Si was refined and consolidated as green compacts by repeated plastic working (RPW) SPS was performed to synthesize and sinter magnesium silicide at 1100K from the RPWed compact. The only peaks of Mg2Si, not Mg and Si, were detected by X-ray diffraction analysis. Mg2Si bulky intermetallic began to shrink above 800K during SPS process, and its densification significantly occurred. The density of SPSed Mg2Si bulk material is about 100% of the theoretically relative one.


2004 ◽  
Vol 18 (01) ◽  
pp. 87-93 ◽  
Author(s):  
ZHIMIN WANG ◽  
YIDONG WU ◽  
YUANJIN HE

Crystals of MnSi 1.73 were prepared by Spark Plasma Sintering (SPS) technique, analyzed by X-ray diffraction (XRD), and invested by metalogragh and scanning electron microscopy (SEM). The growth processes of the samples were studied. It was found that the Mn–Si powders partly formed MnSi 1.73 crystals at 912–937 K under the mechanical pressure of 20 MPa in low vacuum (about 5.0 Pa), and fully formed MnSi 1.73 crystals after sintered at 1173 K for 15 minutes under 40 MPa.


2017 ◽  
Vol 32 (S1) ◽  
pp. S221-S224 ◽  
Author(s):  
Frantisek Lukac ◽  
Tomas Chraska ◽  
Orsolya Molnarova ◽  
Premysl Malek ◽  
Jakub Cinert

Precipitation of secondary intermetallic phases in aluminium alloy Al7075 sintered by spark plasma sintering method from powders milled at room and cryogenic temperature was studied by X-ray powder diffraction. Deformation energy stored during cryogenic milling influences the precipitation in Al7075 alloy. High temperature X-ray diffraction experiment revealed the potential for further precipitation strengthening of samples prepared by spark plasma sintering of milled powders. It was established that the correction of absorption edge of metal Kβ-line filter used for laboratory sources greatly enhances the precision of quantitative Rietveld analysis as well as the determination of precipitates’ crystallite sizes.


2014 ◽  
Vol 783-786 ◽  
pp. 1087-1092
Author(s):  
Karen D. Robles-Arellano ◽  
Lukas Bichler

Development of creep-resistant 8mol% Yttria-stabilized Zirconia (YSZ) ceramic has received much interest due to its potential use in fuel cells and thermal barrier coatings. In this research, Spark Plasma Sintering was used to develop a high-density 10 mol% La203 + YSZ composite. Compressive creep testing was performed at 1300 oC at 45 – 78 MPa load. The mechanism of plastic deformation of the composite was studied using Scanning Electron Microscopy and X-Ray Diffraction. The results suggest that lattice diffusion and grain boundary sliding were the active creep mechanisms.


2012 ◽  
Vol 1485 ◽  
pp. 9-20 ◽  
Author(s):  
Braeden M. Clark ◽  
James P. Kelly ◽  
Olivia A. Graeve

ABSTRACTThe sintering of tantalum carbide nanopowders by spark plasma sintering (SPS) is investigated. The washing procedure for the powders is modified from previous work to eliminate excess lithium in the powders that is left over from the synthesis process. The sintering behavior of the nanopowders is investigated by X-ray diffraction and scanning electron microscopy by studying specimens that were sintered to different temperatures. To improve the homogeneity of the microstructure of the specimens, milling procedures were implemented. Vaporization during sintering is observed, and the usefulness of carbon additions and systematic decreases in temperature to curb this behavior was explored. Future experiments to achieve full density and to maintain a nanostructure of the specimens include sintering with higher pressures, lower temperatures, and longer dwell times. Additives for maintaining a nanostructure and developing suitable high-temperature properties are also discussed.


2006 ◽  
Vol 6 (11) ◽  
pp. 3429-3432
Author(s):  
Chung-Hyo Lee ◽  
Seong-Hee Lee ◽  
Sung-Yong Chun ◽  
Sang-Jin Lee

A mixture of pure Mg and Si powders with an atomic ratio 2:1 has been subjected to mechanical alloying (MA) at room temperature to prepare the Mg2Si thermoelectric material. Mg2Si intermetallic compound with a grain size of 50 nm can be obtained by MA of Mg66.7Si33.3 powders for 60 hours and subsequently annealed at 620 °C. Consolidation of the MA powders was performed in a spark plasma sintering (SPS) machine using graphite dies up to 800–900 °C under 50 MPa. The shrinkage of consolidated samples during SPS was significant at about 250 °C and 620 °C. X-ray diffraction data shows that the SPS compact from 60 h MA powders consolidated up to 800 °C consists of only nanocrystalline Mg2Si compound with a grain size of 100 nm.


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