Fabrication of CNT-Reinforced HAp Composites by Spark Plasma Sintering

2007 ◽  
Vol 534-536 ◽  
pp. 893-896 ◽  
Author(s):  
Swapan Kumar Sarkar ◽  
Min Ho Youn ◽  
Ik Hyun Oh ◽  
Byong Taek Lee
Keyword(s):  
Fracture Toughness ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Sintering Process ◽  
Nano Powder ◽  
Pull Out ◽  
Plasma Sintering ◽  
Phosphate Phase ◽  
Spark Plasma ◽  
Calcium Phosphate Phase

Carbon nanotube (CNT) reinforced hydroxyapatite (HAp) composites were fabricated by using the spark plasma sintering process with surfactant modified CNT and HAp nano powder. Without the dependency on sintering temperature, the main crystal phase existed with the HAp phase although a few contents of β-TCP (Tri calcium phosphate) phase were detected. The maximum fracture toughness, (1.27 MPa.m1/2) was obtained in the sample sintered at 1100 oC and on the fracture surface a typical intergranular fracture mode, as well as the pull-out pmhenomenon of CNT, was observed.

scholarly journals Characterization of Multiwalled Carbon Nanotube-Reinforced Hydroxyapatite Composites Consolidated by Spark Plasma Sintering

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Duk-Yeon Kim ◽  
Young-Hwan Han ◽  
Jun Hee Lee ◽  
Inn-Kyu Kang ◽  
Byung-Koog Jang ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Multiwalled Carbon Nanotube ◽  
Multiwalled Carbon ◽  
Pull Out ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Mwnt Content

Pure HA and 1, 3, 5, and 10 vol% multiwalled carbon nanotube- (MWNT-) reinforced hydroxyapatite (HA) were consolidated using a spark plasma sintering (SPS) technique. The relative density of pure HA increased with increasing sintering temperature, but that of the MWNT/HA composite reached almost full density at 900°C, and then decreased with further increases in sintering temperature. The relative density of the MWNT/HA composites increased with increasing MWNT content due to the excellent thermal conductivity of MWNTs. The grain size of MWNT/HA composites decreased with increasing MWNT content and increased with increasing sintering temperature. Pull-out toughening of the MWNTs of the MWNT/HA composites was observed in the fractured surface, which can be used to predict the improvement of the mechanical properties. On the other hand, the existence of undispersed or agglomerate MWNTs in the MWNT/HA composites accompanied large pores. The formation of large pores increased with increasing sintering temperature and MWNT content. The addition of MWNT in HA increased the hardness and fracture toughness by approximately 3~4 times, despite the presence of large pores produced by un-dispersed MWNTs. This provides strong evidence as to why the MWNTs are good candidates as reinforcements for strengthening the ceramic matrix. The MWNT/HA composites did not decompose during SPS sintering. The MWNT-reinforced HA composites were non-toxic and showed a good cell affinity and morphologyin vitrofor 1 day.

Microstructure and Mechanical Properties of Spark-Plasma-Sintered SiC-TiC Composites

2005 ◽  
Vol 287 ◽  
pp. 335-339 ◽  
Author(s):  
Kyeong Sik Cho ◽  
Kwang Soon Lee
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Applied Pressure ◽  
Argon Atmosphere ◽  
Full Density ◽  
Plasma Sintering ◽  
Spark Plasma

Rapid densification of the SiC-10, 20, 30, 40wt% TiC powder with Al, B and C additives was carried out by spark plasma sintering (SPS). In the present SPS process, the heating rate and applied pressure were kept at 100°C/min and at 40 MPa, while the sintering temperature varied from 1600-1800°C in an argon atmosphere. The full density of SiC-TiC composites was achieved at a temperature above 1800°C by spark plasma sintering. The 3C phase of SiC in the composites was transformed to 6H and 4H by increasing the process temperature and the TiC content. By tailoring the microstructure of the spark-plasma-sintered SiC-TiC composites, their toughness could be maintained without a notable reduction in strength. The strength of 720 MPa and the fracture toughness of 6.3 MPa·m1/2 were obtained in the SiC-40wt% TiC composite prepared at 1800°C for 20 min.

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 Effect of High Pressure Spark Plasma Sintering on the Densification of a Nb-Doped TiO2 Nanopowder

Ceramics ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 507-520
Author(s):  
Alexandre Verchère ◽  
Sandrine Cottrino ◽  
Gilbert Fantozzi ◽  
Shashank Mishra ◽  
Thomas Gaudisson ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Applied Pressure ◽  
Sintering Process ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Lower Temperature

Sintering under pressure by means of the spark plasma sintering (SPS) technique is a common route to reduce the sintering temperature and to achieve ceramics with a fine-grained microstructure. In this work, high-density bulk TiO2 was sintered by high pressure SPS. It is shown that by applying high pressure during the SPS process (76 to 400 MPa), densification and phase transition start at lower temperature and are accelerated. Thus, it is possible to dissociate the two densification steps (anatase then rutile) and the transition phase during the sintering cycle. Regardless of the applied pressure, grain growth occurs during the final stage of the sintering process. However, twinning of the grains induced by the phase transition is enhanced under high pressure resulting in a reduction in the crystallite size.

Influence of Technological Conditions on the Properties of PcBN Composites Fabricated by Spark Plasma Sintering

2018 ◽  
Vol 281 ◽  
pp. 420-425
Author(s):  
Yun Peng Ding ◽  
Ming Xuan Zhang ◽  
Qun Luo ◽  
Chen Jiang Dong ◽  
Jiao Jiao Yao ◽  
...  
Keyword(s):  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Cubic Boron Nitride ◽  
Holding Time ◽  
Sintering Process ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Binder Composition ◽  
Better Than

Polycrystalline cubic boron nitride (PcBN) composites were fabricated by spark plasma sintering (SPS). The SiC, Si3N4 and Si/B were used as binder. The effects of SPS sintering process parameters, such as the sintering temperature, holding time, heating rate and binder composition, on the properties of PcBN samples were investigated. PcBN composite with a hardness of 23.12GPa was fabricated efficiently by SPS. The hardness of PcBN sample increased first and then decreased with the increase of sintering temperature. As the holding time was 20 min, the hardness of PcBN sample was the highest. The PcBN performance at the heating rate of 50 °C/min was significantly better than that of 100°C /min. When the binder component of SiC, Si3N4, and Si was 63%:27%:10%, the hardness of PcBN was the highest. With an addition of Si, the PcBN samples had higher hardness than that of B.

Research on Binderless Tungsten Carbide Prepared by Spark Plasma Sintering

2010 ◽  
Vol 37-38 ◽  
pp. 980-984 ◽  
Author(s):  
Xiao Qiang Li ◽  
Zhang Yi Xiao ◽  
Chao Yang ◽  
Sheng Guan Qu
Keyword(s):  
Mechanical Properties ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Rupture Strength ◽  
Sintering Process ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Spark Plasma ◽  
Xrd Patterns ◽  
Average Size

Commerical pure WC powders of 0.2, 0.4, 0.8, 2.0 and 3.0 m in diameter were sintered by spark plasma sintering process at 1300 °C, respectively. By analyzing the XRD patterns of the initial powders and the microstructure of the sintered samples, it is affirmed that the powders with an average size of 0.8 m exhibits the best activity and sintering property. To optimize sintering temperature, the sintering of 0.8 m powders was carried out at 1200-1700 °C. The specimen sintered at 1300 °C has a density of 15.49 g/cm3 and an average grain size of about 0.7 m, and exhibits the most excellent mechanical properties. The corresponding Vickers hardness and transverse rupture strength are 2469 HV and 1656 MPa, respectively.

scholarly journals Preparation and properties of B4C-TiB2 ceramics prepared by spark plasma sintering

2020 ◽  
Author(s):  
Jingzhe Fan ◽  
Weixia Shen ◽  
zhuangfei Zhang ◽  
Chao Fang ◽  
Yuewen Zhang ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Electrical Properties ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Composite Ceramics ◽  
Powder Mixtures ◽  
Mechanical And Electrical Properties ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Ceramic Density

Abstract By doping titanium hydride (TiH2) into boron carbide (B4C), a series of B4C + x wt% TiH2 (x = 0, 5, 10, 15 and 20) composite ceramics were obtained through spark plasma sintering (SPS). The effects of sintering temperature and the amount of TiH2 additive on the microstructure, mechanical and electrical properties of the sintered B4C-TiB2 composite ceramics were investigated. Powder mixtures of B4C with 0−20 wt% TiH2 were heated from 1400 to 1800 °C for 20 minutes under 50 MPa. The results indicated that higher sintering temperatures contributed to greater ceramic density. With increasing TiH2 content, titanium diboride (TiB2) formed between the TiH2 and B4C matrix. This effectively improved Young’s modulus and fracture toughness of the composite ceramics, significantly improving their electrical properties: the electrical conductivity reached 114.9 S·cm−1 at 1800 °C when x = 20. Optimum mechanical properties were obtained for the B4C ceramics sintered with 20 wt% TiH2, which had a relative density of 99.9 ± 0.1%, Vickers hardness of 31.8 GPa and fracture toughness of 8.5 MPa·m1/2. The results indicated that the doping of fine Ti particles into the B4C matrix increased the conductivity and the fracture toughness of B4C.

Effect of Y2O3 on Microstructure and Properties of cBN/SiAlON Composite

2015 ◽  
Vol 655 ◽  
pp. 22-26
Author(s):  
Xiao Fei Shi ◽  
Zhi Xin Cai ◽  
Chao He ◽  
Jian Jun Wang ◽  
Xin Yan Yue ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Phase Composition ◽  
Bulk Density ◽  
Spark Plasma Sintering ◽  
Raw Materials ◽  
Experimental Results ◽  
Sintering Process ◽  
Maximum Hardness ◽  
Plasma Sintering ◽  
Spark Plasma

cBN/SiAlON composites were prepared by spark plasma sintering (SPS) method using Si3N4, AlN, Al2O3,cBN and Y2O3 powders as raw materials. The sintering process is at the temperature of 1500°C holding for 5 min. Effect of the Y2O3 content on phase composition, microstructure, bulk density, hardness and fracture toughness of the cBN/SiAlON composite was investigated. The experimental results showed that when the Y2O3 content was 0.2 wt. % the bulk density and fracture toughness of the composite had the maximum values of 3.0 g/cm3 and KIC = 5.7 MPa∙m1/2, respectively. The cBN/SiAlON composite with 0.8 wt. % Y2O3 addition got the maximum hardness of 16.4 GPa.

Dispersion of Carbon Nanotubes in Alumina Using a Novel Mixing Technique and Spark Plasma Sintering of the Nanocomposites with Improved Fracture Toughness

2014 ◽  
Vol 89 ◽  
pp. 76-81 ◽  
Author(s):  
Nabi Bakhsh ◽  
Fazal Ahmad Khalid ◽  
Abbas Saeed Hakeem ◽  
Tahar Laoui
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Spark Plasma Sintering ◽  
Alumina Powder ◽  
Alumina Matrix ◽  
Pull Out ◽  
Plasma Sintering ◽  
Structural Applications ◽  
Spark Plasma

The present study emphasizes on the fabrication of carbon nanotubes (CNTs) reinforced alumina nanocomposites for structural applications. A new technique for the mixing and dispersion of CNTs in alumina powder was employed. Spark plasma sintering (SPS) technique was used for the fabrication of nanocomposites with varying amounts of as-received CNTs (1, 2 and 3 weight %) in alumina matrix. Densification behavior, hardness and fracture toughness of the nanocomposites were studied. A comparison of mechanical properties of the desired nanocomposites was presented. An improvement in fracture toughness of approximately 14% at 1 wt% CNT-alumina nanocomposite over monolithic alumina compacts was observed due to better dispersion of CNTs in alumina matrix that ultimately helped in grain growth suppression to provide finer grain in the nanocomposites. The fractured surfaces also revealed the presence of CNTs bridging and pull out that aided in the improvement of mechanical properties. The synthesized samples were characterized using field emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy, densification, Vickers hardness testing and fracture toughness measurements.

Sign in / Sign up

Export Citation Format

Share Document