Characterization of Ni3(Si,Ti) intermetalic alloys synthesized by powder metallurgical method

2013 ◽  
Vol 1516 ◽  
pp. 121-126
Author(s):  
Yuki Miura ◽  
Yasuyuki Kaneno ◽  
Takayuki Takasugi ◽  
Atsushi Kakituji
Keyword(s):  
Chemical Composition ◽  
Single Phase ◽  
Sintering Temperature ◽  
High Hardness ◽  
Powder Metallurgy Method ◽  
Sintered Alloy ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sintered Alloys

ABSTRACTA Ni3(Si,Ti) intermetalic alloy was synthesized by the powder metallurgy method using elemental powders. The raw powder mixtures with various compositions were sintered by a spark plasma sintering apparatus and then homogenized at high temperatures. Microstructure, hardness, tensile properties and density of the sintered alloys were investigated as functions of the chemical composition and sintering temperature. It was found that a highly-densified Ni3(Si,Ti) sintered alloy was obtained by choosing proper chemical composition and sintering temperature. Also, the Ni3(Si,Ti) sintered alloy with an L12 single-phase microstructure exhibited high hardness and tensile strength.

scholarly journals Fabrication and Characterization of Quinary High Entropy-Ultra-High Temperature Diborides

Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 108-120
Author(s):  
Simone Barbarossa ◽  
Roberto Orrù ◽  
Valeria Cannillo ◽  
Antonio Iacomini ◽  
Sebastiano Garroni ◽  
...  
Keyword(s):  
High Temperature ◽  
Single Phase ◽  
Nominal Composition ◽  
High Entropy ◽  
Chemical Complexity ◽  
Alternative Processing ◽  
Plasma Sintering ◽  
High Temperature Synthesis ◽  
Spark Plasma

Due to their inherent chemical complexity and their refractory nature, the obtainment of highly dense and single-phase high entropy (HE) diborides represents a very hard target to achieve. In this framework, homogeneous (Hf0.2Nb0.2Ta0.2Mo0.2Ti0.2)B2, (Hf0.2Zr0.2Ta0.2Mo0.2Ti0.2)B2, and (Hf0.2Zr0.2Nb0.2Mo0.2Ti0.2)B2 ceramics with high relative densities (97.4, 96.5, and 98.2%, respectively) were successfully produced by spark plasma sintering (SPS) using powders prepared by self-propagating high-temperature synthesis (SHS). Although the latter technique did not lead to the complete conversion of initial precursors into the prescribed HE phases, such a goal was fully reached after SPS (1950 °C/20 min/20 MPa). The three HE products showed similar and, in some cases, even better mechanical properties compared to ceramics with the same nominal composition attained using alternative processing methods. Superior Vickers hardness and elastic modulus values were found for the (Hf0.2Nb0.2Ta0.2Mo0.2Ti0.2)B2 and the (Hf0.2Zr0.2Ta0.2Mo0.2Ti0.2)B2 systems, i.e., 28.1 GPa/538.5 GPa and 28.08 GPa/498.1 GPa, respectively, in spite of the correspondingly higher residual porosities (1.2 and 2.2 vol.%, respectively). In contrast, the third ceramic, not containing tantalum, displayed lower values of these two properties (25.1 GPa/404.5 GPa). However, the corresponding fracture toughness (8.84 MPa m1/2) was relatively higher. This fact can be likely ascribed to the smaller residual porosity (0.3 vol.%) of the sintered material.

scholarly journals Development of calcium stabilized nitrogen rich α-sialon ceramics along the Si3N4:1/2Ca3N2:3AlN line using spark plasma sintering

2020 ◽  
Vol 9 (5) ◽  
pp. 606-616
Author(s):  
B. A. Ahmed ◽  
T. Laoui ◽  
A. S. Hakeem
Keyword(s):  
Spark Plasma Sintering ◽  
Single Phase ◽  
Sintering Temperature ◽  
Compositional Analysis ◽  
Physical And Mechanical Properties ◽  
Alkaline Metal ◽  
Maximum Hardness ◽  
Plasma Sintering ◽  
Alkaline Metal Cation ◽  
Spark Plasma

Abstract Calcium stabilized nitrogen rich sialon ceramics having a general formula of CaxSi12-2xAl2xN16 with x value (x is the solubility of cation Ca in α-sialon structure) in the range of 0.2–2.2 for compositions lying along the Si3N4:1/2Ca3N2:3AlN line were synthesized using nano/submicron size starting powder precursors and spark plasma sintering (SPS) technique. The development of calcium stabilized nitrogen rich sialon ceramics at a significantly low sintering temperature of 1500 °C (typically reported a temperature of 1700 °C or greater) remains to be the highlight of the present study. The SPS processed sialons were characterized for their microstructure, phase and compositional analysis, and physical and mechanical properties. Furthermore, a correlation was developed between the lattice parameters and the content (x) of the alkaline metal cation in the α-sialon phase. Well-densified single-phase nitrogen rich α-sialon ceramics were achieved in the range of 0.53(3) ⩽ x ⩽ 1.27(3). A nitrogen rich α-sialon sample possessing a maximum hardness of 22.4 GPa and fracture toughness of 6.1 MPa·m1/2 was developed.

Spark Plasma Sintering and Characterization of WC-Co-cBN Composites

2014 ◽  
Vol 616 ◽  
pp. 194-198 ◽  
Author(s):  
Jian Feng Zhang ◽  
Rong Tu ◽  
Takashi Goto
Keyword(s):  
Fracture Toughness ◽  
Phase Transformation ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Moderate Pressure ◽  
Plasma Sintering ◽  
Spark Plasma

WC-Co-cBN composites were consolidated by SPS at 1373 to 1673 K under a moderate pressure of 100 MPa. The addition of cBN increased the starting and finishing temperature of shrinkage and decreased the relative density of WC-Co. The relative density of WC-(10-20 vol%) cBN composites was about 97-100% at 1573 K and decreased with increasing the sintering temperature to 1673 K due to the phase transformation of cBN to hBN. The highest hardness and fracture toughness of WC-Co-20 vol% cBN composite sintered at 1573 K were 23.2 GPa and 8.0 MP m1/2, respectively.

scholarly journals Development of calcium stabilized nitrogen rich alpha-sialon ceramics along the Si3N4:1/2Ca3N2:3AlN line using spark plasma sintering

2020 ◽  
Author(s):  
Bilal Anjum Ahmed ◽  
Abbas Saeed Hakeem ◽  
Tahar Laoui
Keyword(s):  
Spark Plasma Sintering ◽  
Single Phase ◽  
Sintering Temperature ◽  
Compositional Analysis ◽  
Physical And Mechanical Properties ◽  
Alkaline Metal ◽  
Maximum Hardness ◽  
Plasma Sintering ◽  
Alkaline Metal Cation ◽  
Spark Plasma

Abstract Calcium stabilized nitrogen rich sialon ceramics having a general formula of CaxSi12-2xAl2xN16 with x value in the range of 0.2-2.2 for compositions lying along the Si3N4:1/2Ca3N2:3AlN line were synthesized using nano/submicron size starting powder precursors and spark plasma sintering (SPS) technique. The development of calcium stabilized nitrogen rich sialon ceramics at a significantly low sintering temperature of 1500°C (typically reported a temperature of 1700°C or greater) remains to be the highlight of the present study. The SPS processed sialons were characterized for their microstructure, phase and compositional analysis, physical and mechanical properties. Furthermore, a correlation was developed between the lattice parameters and the content (x) of the alkaline metal cation in the alpha-sialon phase. Well densified single-phase nitrogen rich alpha-sialon ceramics were achieved in the range of 0.53(3) ≤ x ≤ 1.27(3). A nitrogen rich alpha-sialon sample possessing a maximum hardness of 22.4 GPa and fracture toughness of 6.1 MPa.m1/2 was developed.

scholarly journals Spark Plasma Sintering Behavior of Nb-Mo-Si Alloy Powders Fabricated by Hydrogenation-Dehydrogenation Method

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3549 ◽  
Author(s):  
Sung Lee ◽  
Ki Park ◽  
Jang-Won Kang ◽  
Yanghoo Kim ◽  
Hyun-Su Kang ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Sintering Behavior ◽  
Powder Metallurgy Method ◽  
Composite Powders ◽  
Plasma Sintering ◽  
Formation Behavior ◽  
Spark Plasma ◽  
Two Phases ◽  
Nb5si3 Phase

In this study, the sintering behaviors of Nb-6Mo-20Si-3Cr (at percentage) in situ composite powders were studied. The Nb alloy powder was fabricated by a hydrogenation-dehydrogenation method, and both the alloy ingot and powders consisted of two phases: An Nb metal phase and the α-Nb5Si3 phase. Consolidation of the alloy powders was performed at 1500, 1600, and 1700 °C using spark plasma sintering, and the microstructures and phases formed at various sintering temperatures were analyzed. Micropores were observed in the compact sintered at 1500 °C due to the lack of complete densification at that temperature. The densification was completed at 1600 °C and the microstructure was slightly coarsened at 1700 °C compared to the microstructure of the compact sintered at 1600 °C. The microstructures prepared by the powder metallurgy method were finer than the microstructure of the ingot prepared by the casting method. The phase formation behavior varied according to the sintering temperature. Specifically, the α-Nb5Si3 phase, which is a stable structure of the Nb5Si3 phase at a low temperature, was transformed to the β-Nb5Si3 phase (which is stable at a high temperature) with an increasing sintering temperature.

Fabrication Processes and Properties of Highly Pure MgAlON Materials

2007 ◽  
Vol 561-565 ◽  
pp. 543-546 ◽  
Author(s):  
Qing Huang ◽  
Yong Huang ◽  
Chang An Wang ◽  
Hou Xing Zhang
Keyword(s):  
Spark Plasma Sintering ◽  
Open Porosity ◽  
Single Phase ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Hot Press ◽  
Plasma Sintering ◽  
Short Period ◽  
Spark Plasma ◽  
Hot Press Sintering

In this paper, the MgAlON ceramic was fabricated by Spark Plasma Sintering (SPS) and hot press sintering respectively. The results showed that highly pure and single-phase MgAlON could be fabricated at lower sintering temperature in a short period through SPS process, compared with the conventional Hot Press sintering (HP) process. The bending strength of MgAlON specimens prepared by SPS process was higher than 500MPa while bending strength of HP specimens was much lower. The open porosity was almost eliminated in SPS MgAlON specimens. Spark Plasma Sintered MgAlON had a single phase of MgAlON while Hot Press Sintered MgAlON had major MgAlON and minor AlN and Al2O3.

Characterization of Metal-Like Carbides-Graphene Composite Prepared by SPS Method

2015 ◽  
Vol 655 ◽  
pp. 87-91 ◽  
Author(s):  
Piotr Wyzga ◽  
Lucyna Jaworska ◽  
Piotr Putyra ◽  
Marcin Podsiadlo ◽  
Jolanta Cyboron
Keyword(s):  
Niobium Carbide ◽  
Zirconium Carbide ◽  
High Hardness ◽  
Carbide Powder ◽  
Self Diffusion ◽  
Graphene Composite ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
20 Nm

High hardness, good thermal and electrical conductivity make carbides technologically important materials. The high melting temperature and low coefficients of self-diffusion make it difficult to obtain full dense material. In this paper the results of Spark Plasma Sintering (SPS) of transition metal carbides: NbC, TaC, TiC, ZrC, VC with the addition of graphene 10-20 nm x 14 microns in an amount of 2.5 mass % are presented. Powders were mixed in isopropyl alcohol in a planetary ball mill for 1h. The sintering processes was carried out at 2200°C at two different times: 5 and 30 min. Microstructure of the samples was analyzed using scanning electron microscopy. The measurements of density, Young's modulus hardness and electrical properties were carried out, also. The best properties were obtained for titanium carbide powder, sintered for 30 min. The most significant density increase of the sintered carbide–graphene composite by about 5.3% (depending on increasing sintering duration) was obtained for niobium carbide, while the smallest densities change for zirconium carbide.

Effect of Dopant on N-Type Bi2Te2.7Se0.3 Thermoelectric Materials Fabricated by Spark Plasma Sintering

2008 ◽  
Vol 368-372 ◽  
pp. 544-546
Author(s):  
Dong Choul Cho ◽  
Jae Seol Lee ◽  
Chul Ho Lim ◽  
Chi Hwan Lee
Keyword(s):  
Thermal Conductivity ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Sintered Sample ◽  
Dopant Content ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type ◽  
Type Conduction

The n-type Bi2Te2.7Se0.3 compounds were fabricated to investigate the characterization of spark plasma sintering with various SbI3 dopant contents. The Bi2Te2.7Se0.3 compounds with SbI3 dopant content is exhibited n-type conduction characterization, but the Bi2Te2.7Se0.3 compounds without SbI3 dopant content is exhibited p-type conduction characterization. The maximum Seebeck coeficient represented with 0.05wt.% SbI3 dopant content. The Seebeck coefficient of the sintered sample with increasing sintering temperature is increased from -158 to -182 μV/K. The electrical resistivity and thermal conductivity with 0.05wt.% SbI3 dopant content were 1.0 m and 1.33 W/mK, respectively.

scholarly journals Development of calcium stabilized nitrogen rich alpha-sialon ceramics along the Si3N4-1/2Ca3N2:3AlN line using spark plasma sintering

2020 ◽  
Author(s):  
Bilal Anjum Ahmed ◽  
Abbas Saeed Hakeem ◽  
Tahar Laoui
Keyword(s):  
Spark Plasma Sintering ◽  
Single Phase ◽  
Sintering Temperature ◽  
Compositional Analysis ◽  
Physical And Mechanical Properties ◽  
Alkaline Metal ◽  
Maximum Hardness ◽  
Plasma Sintering ◽  
Alkaline Metal Cation ◽  
Spark Plasma

Abstract Calcium stabilized nitrogen rich sialon ceramics having a general formula of CaxSi12-2xAl2xN16 with x value in the range of 0.2-2.2 for compositions lying along the Si3N4-1/2Ca3N2:3AlN line were synthesized using nano/submicron size starting powder precursors and spark plasma sintering (SPS) technique. The development of calcium stabilized nitrogen rich sialon ceramics at a significantly low sintering temperature of 1500oC (typically reported temperature of 1700oC or greater) remains to be the highlight of the present study. The SPS processed sialons were characterized for their microstructure, phase and compositional analysis, physical and mechanical properties. Furthermore, a correlation was developed between the lattice parameters and the content (x) of alkaline metal cation in the alpha-sialon phase. Well densified single-phase nitrogen rich alpha-sialon ceramics were achieved in the range of 0.4 < x < 1.6. A nitrogen rich alpha-sialon sample possessing a maximum hardness of 22.4 GPa and fracture toughness of 6.1 MPa.m1/2 was developed.

Structural and magnetic characterization of spark plasma sintered Fe-50Co alloys

2012 ◽  
Vol 1516 ◽  
pp. 201-207 ◽  
Author(s):  
Mahesh Kumar Mani ◽  
Giuseppe Viola ◽  
Mike J Reece ◽  
Jeremy P Hall ◽  
Sam L Evans
Keyword(s):  
Sintering Temperature ◽  
Average Particle Size ◽  
Average Particle ◽  
Mechanical Pressure ◽  
Plasma Sintering ◽  
Saturation Induction ◽  
Porous Microstructure ◽  
Density Values ◽  
Spark Plasma

ABSTRACTFe-50 wt% Co alloy powders with average particle size of 10 μm were compacted by spark plasma sintering (SPS) at 700, 800, 900 and 950oC by applying 40, 80, 100 MPa uniaxial pressures for 2, 5, 10 minutes. The densities of the samples were found to increase with temperature from 700 to 900oC for constant sintering pressure and time and to decrease for the material sintered at 950oC. The effects of sintering time on density were more significant in samples sintered at 700oC and 800oC than those densified at 900oC. The consequences of small increases in mechanical pressure during sintering on density values were significant for samples sintered at 700oC. The coercivity (Hc) of the compacts decreased significantly with increasing sintering temperature, and with increasing dwell time at sintering temperatures lower than 700oC. The sample sintered at 950oC, which contains the largest grains among the prepared samples and porous microstructure, exhibited the minimum coercivity. Unlike Hc, the remanence (Br) and saturation induction (Bsat) values were more strongly affected by the specimen density than by grain size. Br and Bsat values were found to vary linearly with sintering temperature and pressure owing to increasing density. An increase in soaking time at 800 and 900 oC, although enabling higher density, exhibited contradicting effects on Bsat values. The SPS parameters to obtain maximum density and optimum magnetic properties for Fe-50% Co alloy were found to be 900oC, 80 MPa and 2-5 minutes.

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