Effect of Al and Si Additions on the Synthesis of Spark Plasma Sintered Zr2Al4C5 Creamic

2016 ◽  
Vol 697 ◽  
pp. 530-534 ◽  
Author(s):  
Q.L. Guo ◽  
Jun Jun Pei ◽  
Ji Zhong Gan ◽  
Jun Guo Li ◽  
Lian Meng Zhang

The Zr2Al4C5 ceramic was successfully fabricated by the spark plasma sintering at 1800 °C for 10 min under uniaxial 20 MPa pressure in vacuum using a mixed raw materials of Zr, Al, Si and graphite powders. The X-ray diffraction analysis results showed that the unexpected Zr2Al3C5 phase rather than target compound Zr2Al4C5 formed in the sintered samples. An initial Zr:Al:C molar ratio of 2:4.2:4.8 for raw powders, and even 55 mol.% excess Al, did not lead to a phase transformation from Zr2Al3C5 to Zr2Al4C5. When 4 wt.% Si was induced in the starting powders, the major phase became Zr2Al4C5 and no obvious Zr2Al3C5 was detected in the sintered samples with an initial Zr:Al:C molar ratio of 2:6.2:4.8 (55 mol.% excess Al). The introduction of Si could suppress and even remove additional ZrC, and Si atoms would exclusively occupy the site of Al to make Zr2Al4C5 become a stable solid solution. The scanning electron microscopy observation showed that the as-synthesized Zr2Al4C5 grains had elongated, rod-like and/or plate-like shapes. The mechanical properties of the sintered Zr2Al4C5 ceramic were also investigated, and it showed a hardness of 11.06±0.34 GPa and a fracture toughness of 4.6 ± 0.4 MPa×m1/2.

2009 ◽  
Vol 66 ◽  
pp. 25-28 ◽  
Author(s):  
Song Zhang ◽  
Chuan Bin Wang ◽  
Qiang Shen ◽  
Lian Meng Zhang

A group of boron-carbon ceramic material was in-situ synthesized and densified simultaneously via Spark Plasma Sintering (SPS) technique from carbon and boron element powders with different molar ratio. The phase structures of samples with different B/C molar ratio were characterized by X-ray Diffraction (XRD). The B/C atomic ratio of the sintered materials was calculated from X-ray photoelectron spectroscopy (XPS) measurement data. Meanwhile, the chemical analysis (CA) method had also been taken to verify the B/C atomic ratio. Finally, the experience equation had been obtained to control the B/C atomic ratio of sintered samples.


2007 ◽  
Vol 280-283 ◽  
pp. 767-770 ◽  
Author(s):  
Ming Hao Fang ◽  
Wei Pan ◽  
Zhen Yi Fang ◽  
Sui Lin Shi ◽  
Qiang Xu

Pure Strontium barium niobate, Sr0.5Ba0.5Nb2O6 (SBN50), was synthesized successfully by spark plasma sintering from two mixtures: SrCO3/BaCO3/Nb2O5 mixtures and the mixtures calcined at 800oC. The phase identification of the SBN crystalline grains was evaluated by X-ray diffraction analysis, and the formation mechanism was discussion based on the XRD results at various temperatures. They are different when SrCO3/BaCO3/Nb2O5 powder mixtures and the mixtures calcined at 800oC was chosen as the raw materials.


2012 ◽  
Vol 452-453 ◽  
pp. 12-15
Author(s):  
Kee Do Woo ◽  
Sang Hoon Park ◽  
Ji Young Kim

Ti-6Al-4V ELI (Extra Low Interstitial) alloy have been widely used as alternative bone due to its excellent biocompatibility, although it still has many problems such as high elastic modulus and toxic. Therefore, biomaterial with low elastic modulus and nontoxic has to be developed. In this study, the raw materials which are nontoxic elements such as Nb and Mo were mixed and milled in a mixing machine (24h) and a high energy mechanical ball milling machine (1h, 4h and 8h) respectively. Ti-Nb-Mo-CPP composites were fabricated by spark plasma sintering (SPS) at 1000°C under 70MPa using mixed and milled powders. The effects of CPP contents and milling time on biocompatibility and mechanical property have been investigated. By X-ray diffraction (XRD), chemical reaction during the sintering was occurred and revealed new phases, Ti2O, CaO, CaTiO3, and TixPy. Vickers hardness of composites increases with increase milling time and addition of CPP contents. Biocompatibility of CPP added Ti-Nb-Mo alloys were improved.


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.


2012 ◽  
Vol 727-728 ◽  
pp. 982-987
Author(s):  
E. de Carvalho ◽  
Marcelo Bertolete ◽  
Izabel Fernanda Machado ◽  
E.N.S. Muccillo

Polycrystalline CaCu3Ti4O12 ceramics were prepared by solid state reactions by spark plasma sintering (SPS) technique. In this study, the effects of the dwell temperature on structural, microstructural and dielectric properties of CaCu3Ti4O12 ceramics have been investigated. Powder mixtures were calcined at 900°C for 18 h before SPS consolidation. The dwell temperatures were 850, 900, 915 and 930°C. Sintered pellets were characterized by X-ray diffraction, scanning electron microscopy and impedance spectroscopy. X-ray diffraction patterns show evidences of a single-phase perovskite-type structure. The calculated lattice parameter is 7.40 Å. The hydrostatic density increases slightly with increasing dwell temperature. Scanning electron microscopy observations revealed a heterogeneous microstructure for all samples. The dielectric loss remains constant over a wide temperature range. The obtained permittivity is approximately 103 at 1 kHz. The increase of the dwell temperature is found to produce a brittle ceramic.


2007 ◽  
Vol 336-338 ◽  
pp. 1124-1126
Author(s):  
Xiao Su Cheng ◽  
Ling Ke Zeng ◽  
Xiu Yan Li ◽  
Wen Yan Sheng ◽  
An Ze Shui ◽  
...  

In this paper, microspheres were prepared by using Chinese bauxite as raw materials through centrifugal spray drying method. The microstructure and composition of ceramic microsphere were investigated by X-ray diffraction, scanning electron microscope and X-ray energy spectrum. The particle size was 10~100#m. The XRD analysis reveals that the main crystalline phase of the ceramic microsphere were α-Al2O3 and mullite (3Al2O3•2SiO2). The Al2O3 content (chemical composition) of the microspheres was little more than 70%, and the molar ratio of Al2O3/SiO2 was near to the molar ratio of alumina and silica of mullite.


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