scholarly journals Microstructure and properties of nano-laminated Y3Si2C2 ceramics fabricated via in situ reaction by spark plasma sintering

2021 ◽  
Vol 10 (3) ◽  
pp. 578-586
Author(s):  
Lin-Kun Shi ◽  
Xiaobing Zhou ◽  
Jian-Qing Dai ◽  
Ke Chen ◽  
Zhengren Huang ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Atomic Scale ◽  
Max Phase ◽  
X Ray Diffraction ◽  
Selected Area Electron Diffraction ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma ◽  
Diffraction Patterns

AbstractA nano-laminated Y3Si2C2 ceramic material was successfully synthesized via an in situ reaction between YH2 and SiC using spark plasma sintering technology. A MAX phase-like ternary layered structure of Y3Si2C2 was observed at the atomic-scale by high resolution transmission electron microscopy. The lattice parameters calculated from both X-ray diffraction and selected area electron diffraction patterns are in good agreement with the reported theoretical results. The nano-laminated fracture of kink boundaries, delamination, and slipping were observed at the tip of the Vickers indents. The elastic modulus and Vickers hardness of Y3Si2C2 ceramics (with 5.5 wt% Y2O3) sintered at 1500 °C were 156 and 6.4 GPa, respectively. The corresponding values of thermal and electrical conductivity were 13.7 W·m-1·K-1 and 6.3×105 S·m-1, respectively.

scholarly journals Microstructure and properties of nano-laminated Y3Si2C2 ceramics fabricated via in situ reaction by spark plasma sintering

2020 ◽  
Author(s):  
Lin-Kun Shi ◽  
Xiaobing Zhou ◽  
Jian-Qing Dai ◽  
Ke Chen ◽  
Zhengren Huang ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Atomic Scale ◽  
Max Phase ◽  
X Ray Diffraction ◽  
Selected Area Electron Diffraction ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma ◽  
Diffraction Patterns

Abstract A new nano-laminated Y3Si2C2 ceramic material, for the first time, was successfully synthesized via in situ reaction between YH2 and SiC by spark plasma sintering. A MAX phase-like ternary layered structure of Y3Si2C2 was observed at the atomic-scale by high resolution transmission electron microscopy. The lattice parameters calculated from both X-ray diffraction and selected area electron diffraction patterns are in good agreement with the reported theoretical results. The nano-laminated fracture of kink boundaries, delamination, and slipping was observed at the tip of the Vickers indent. The values of elastic modulus and Vickers hardness of the Y3Si2C2 ceramics sintered at 1500 °C were 156 and 6.4 GPa, respectively. The corresponding values of thermal and electrical conductivity were 13.7 W m-1 k-1 and 6.3 × 105 S m-1, respectively.

Spark Plasma Sintering of PbTe Thermoelectric Bulk Materials With Small Grains

2008 ◽  
Author(s):  
Chia-Hung Kuo ◽  
Chii-Shyang Hwang ◽  
Jie-Ren Ku ◽  
Ming-Shan Jeng ◽  
Fang-Hei Tsau
Keyword(s):  
Electron Microscopy ◽  
Spark Plasma Sintering ◽  
X Ray Diffraction ◽  
Bulk Materials ◽  
Combination Process ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma ◽  
Diffraction Patterns ◽  
Microscopy Images

PbTe is a conventional thermoelectric material for thermoelectric generator at intermediate temperature. Small grain size effect has been reported to improve PbTe ZT values (figure of merit). We report a combination process of attrition milling and spark plasma sintering (SPS) for preparing PbTe bulk materials with small grain sizes. The PbTe powders were milled by attrition under 600 rpm for 6–96 h and followed by SPS process under the sintering temperature of 573–773 K, the heating rate of 100 K/min, and the sintering pressure of 50 MPa. The powders and bulk materials as-prepared were then studied by X-ray diffraction patterns, scanning electron microscopy images, and transmission electron microscopy images. Transport properties of polycrystalline PbTe bulks were evaluated through temperature dependent thermal conductivity measurements.

scholarly journals Microstructure and Electrical Property of Ex-Situ and In-Situ Copper Titanium Carbide Nanocomposites

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 735
Author(s):  
Nguyen Hoang Viet ◽  
Nguyen Thi Hoang Oanh
Keyword(s):  
Electrical Conductivity ◽  
Electron Microscope ◽  
Applied Pressure ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma

In this study, ex-situ Cu-TiC nanocomposites of 1, 3 and 5 vol. % TiC and in-situ Cu-TiH2-C nanocomposites (corresponding to 5 vol. % TiC) were prepared using ball milling and spark plasma sintering methods. Powder mixtures were milled for 4 h at 400 rpm. As-milled Cu-TiC composite powders were consolidated under an applied pressure of 70 MPa. The phase composition, and microstructure of the composite samples were characterized by X-ray diffraction, and scanning electron microscope and transmission electron microscope techniques, respectively. With the increasing TiC content from 1 to 5 vol. %, the hardness of the ex-situ composites when sintered at 600 °C changed between 161.4 and 178.5 HV and the electrical conductivity decreased from 52.1 to 47.6% IACS. In-situ Cu-TiH2-C nanocomposite sintered at 950 °C had higher hardness and electrical conductivity than ex-situ Cu-TiC composite due to having a homogenous distribution of nano reinforcement particles and dense structure.

Synthesis of Physically Functionalized Carbon Nanotube Reinforced Al-Si Nanocomposite by Spark Plasma Sintering

2014 ◽  
Vol 783-786 ◽  
pp. 1542-1547
Author(s):  
Anway Maiti ◽  
Ram S. Maurya ◽  
Tapas Laha
Keyword(s):  
Carbon Nanotube ◽  
Spark Plasma Sintering ◽  
High Energy ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Tem Analysis ◽  
Activity Effect ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma

Multiwalled carbon nanotube (MWCNT) reinforced Al-Si (11 wt%) alloy based nanocomposites were synthesized by spark plasma sintering using high energy ball milled nanocrystalline Al-Si powders mixed with physically functionalized MWCNTs. Improvement in MWCNT dispersion and associated improvement in densification of the nanocomposites were confirmed. The microhardness and elastic modulus of the nanocomposites measured by nanoindentation exhibited appreciable improvement. Grain size measurement by X ray diffraction and transmission electron microscopy confirmed achievement of nanocrystalline grains in Al-Si powder after ball milling, as well as in the consolidated nanocomposites. TEM analysis was performed to reveal the dislocation activity, effect of presence of primary Si and distribution of MWCNTs in the nanocomposites.

Microstructural Characterization of In Situ TiB Whiskers in Ti MMCs Fabricated by SPS

2007 ◽  
Vol 336-338 ◽  
pp. 1310-1312
Author(s):  
Hai Bo Feng ◽  
De Chang Jia ◽  
Yu Zhou ◽  
Qing Chang Meng
Keyword(s):  
Electron Microscopy ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Microstructural Characterization ◽  
Average Diameter ◽  
Matrix Composites ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma

The in situ TiB whisker reinforced titanium matrix composites were prepared by mechanical alloying followed by spark plasma sintering. X-ray diffraction, scanning electron microscopy and transmission electron microscopy were used to characterize the microstructure of the TiB whiskers. The effect of sintering temperature on morphologies of in situ TiB whiskers was evaluated. With the increase of spark plasma sintering temperature, the average diameter of in situ TiB whiskers increased. The in situ TiB whiskers exhibited a hexagonal shape with (100), (101) and (10 1 ) planes at the transverse section and a growth orientation of [010]TiB direction.

scholarly journals Study of the Influence of Sintering Atmosphere and Mechanical Activation on the Synthesis of Bulk Ti2AlN MAX Phase Obtained by Spark Plasma Sintering

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4574
Author(s):  
Christopher Salvo ◽  
Ernesto Chicardi ◽  
Cristina García-Garrido ◽  
Rosalía Poyato ◽  
José A. Jiménez ◽  
...  
Keyword(s):  
Mechanical Activation ◽  
Spark Plasma Sintering ◽  
Powder Mixture ◽  
Max Phase ◽  
Activation Process ◽  
X Ray Diffraction ◽  
Sintering Atmosphere ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma

The influence of the mechanical activation process and sintering atmosphere on the microstructure and mechanical properties of bulk Ti2AlN has been investigated. The mixture of Ti and AlN powders was prepared in a 1:2 molar ratio, and a part of this powder mixture was subjected to a mechanical activation process under an argon atmosphere for 10 h using agate jars and balls as milling media. Then, the sintering and production of the Ti2AlN MAX phase were carried out by Spark Plasma Sintering under 30 MPa with vacuum or nitrogen atmospheres and at 1200 °C for 10 min. The crystal structure and microstructure of consolidated samples were characterized by X-Ray Diffraction, Scanning Electron Microscopy, and Energy Dispersive X-Ray Spectroscopy. The X-ray diffraction patterns were fitted using the Rietveld refinement for phase quantification and determined their most critical microstructural parameters. It was determined that by using nitrogen as a sintering atmosphere, Ti4AlN3 MAX phase and TiN were increased at the expense of the Ti2AlN. In the samples prepared from the activated powders, secondary phases like Ti5Si3 and Al2O3 were formed. However, the higher densification level presented in the sample produced by using both nitrogen atmosphere and MAP powder mixture is remarkable. Moreover, the high-purity Ti2AlN zone of the MAX-1200 presented a hardness of 4.3 GPa, and the rest of the samples exhibited slightly smaller hardness values (4.1, 4.0, and 4.2 GPa, respectively) which are matched with the higher porosity observed on the SEM images.

Microstructure and Mechanical Property of Fe-Al2O3 Nanocomposites Synthesized by Reactive Milling Followed by Spark Plasma Sintering

2012 ◽  
Vol 710 ◽  
pp. 291-296 ◽  
Author(s):  
K.R. Ravi ◽  
A. Murugesan ◽  
V. Udhayabanu ◽  
R. Subramanian ◽  
B.S Murty
Keyword(s):  
Spark Plasma Sintering ◽  
Grain Structure ◽  
Reactive Milling ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Microscopy Investigation ◽  
Electron Microscopy Investigation ◽  
Micron Size ◽  
Spark Plasma

The in-situ Fe based nanocomposite containing Al2O3 particle is synthesized by reactive milling of Fe2O3-Al-Fe powder mixture in toluene medium followed by consolidation of powders using Spark Plasma Sintering process. Transmission electron microscopy investigation of consolidated Fe-Al2O3 nanocomposites has shown heterogenous grain structure of Fe consisting of nano, submicron and micron size grains together with nanometer Al2O3 particles. The hardness of Fe-Al2O3 nanocomposites consolidated at 800°C is 795 MPa.

Oxidation of Nb/Nb5Si3 In Situ Composites Fabricated via Spark Plasma Sintering with Al Addition

2013 ◽  
Vol 376 ◽  
pp. 49-53 ◽  
Author(s):  
Wen Yuan Long ◽  
Xiang Yan Zou ◽  
Wei Dong Wang ◽  
Jun Ping Yao
Keyword(s):  
Oxidation Resistance ◽  
Spark Plasma Sintering ◽  
Raw Materials ◽  
Oxidation Behaviour ◽  
X Ray Diffraction ◽  
In Situ Composites ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Al Addition

Dense Nb/Nb5Si3composites were fabricated via spark plasma sintering technology using Nb, Si, and Al elemental powders as raw materials. The microstructures of the synthesised composites were analysed through scanning electron microscopy, X-ray diffraction, and electron probe microanalysis. The results show that the composites consisted of residual Nb particle phase and Nb5Si3phase. The microstructure of the Nb/ Nb5Si3in situ composites was evidently affected by Al addition, which prompted the formation of the Al3Nb10Si3phase. The oxidation resistance of the Nb/Nb5Si3in situ composites significantly improved with the increase in Al addition. Pesting oxidation behaviour was exhibited at 800°C by the Nb-20Si composites when exposed to air for 4h. This pest oxidation behaviour is not exhibited by the Nb-20Si-10Al and Nb-20Si-15Al composites after exposure to air for ~10h. The composite exhibits the best oxidation resistance at 15at% Al.

scholarly journals Ordered Domains and Microwave Properties of Sub-micron Structured Ba(Zn1/3Ta2/3)O3 Ceramics Obtained by Spark Plasma Sintering

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 638
Author(s):  
Fei Liu ◽  
Shaojun Liu ◽  
Xuejiao Cui ◽  
Lijin Cheng ◽  
Hao Li ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Annealing Temperature ◽  
Microwave Dielectric Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Dielectric ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma ◽  
Dielectric Ceramics

The degree of Zn2+ and Ta5+ ions ordering could play an important role in the dielectric loss in Ba(Zn1/3Ta2/3)O3 (BZT) ceramics. However, the influence of the grain size of Ba(B′1/3B″2/3)O3 ceramics with nano or sub-micron grains on the ordering domains structure is still not clear. In the present paper, highly dense (~98%) BZT microwave dielectric ceramics with homogeneous sub-micron structure (~330 nm) were prepared through spark plasma sintering (SPS). High resolution transmission electron microscopy combined with X-ray diffraction (XRD)clearly showed that the B-site ordering structure of sintered BZT samples by SPS becomes the B-site long-range 1:2 ordering as annealing proceeds. In contrast, the short-range 1:2 ordering in non-annealed counterparts was also present, which was not detectable by XRD. The size of B-site ordering domains enlarged with annealing temperature. The sub-micron structure of sintered BZT ceramics by SPS remained stable at up to 1400 C; however, the size of B-site 1:2 ordering domain was more than five times larger, which led to a significant increase of the quality factor (Q·f) to 37,700 GHz from 15,000 GHz.

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