Effect of Sintering Schedule on the Microstructure of Carbon Nanotubes Reinforced Alumina Fabricated by SPS Method

2009 ◽  
Vol 66 ◽  
pp. 288-291
Author(s):  
Li Wei Huang ◽  
Zheng Yi Fu ◽  
Jin Yong Zhang ◽  
Wei Min Wang ◽  
Hao Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Raman Spectrum ◽  
Sintering Temperature ◽  
Alumina Ceramics ◽  
Pure Alumina ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sintering Method

Carbon nanotubes reinforced alumina was fabricated by spark plasma sintering method. When adding 0.2wt% nanotubes, the fracture toughness of the composites prepared increases 19% compared with the pure alumina ceramics. The effect of sintering schedule on microstructure and mechanical properties is investigated systematically. Microstructure studies reveal that at high sintering temperature, the nanotubes tend to gather in the gaps surrounded by three or more grains in a flocculent state, which leads to poor mechanical properties. Raman spectrum indicates that long sintering duration may cause serious nanotubes destruction and lower the mechanical properties.

scholarly journals Improvement of the mechanical properties of spark plasma sintered hap bioceramics by decreasing the grain size and by adding multi-walled carbon nanotubes

2013 ◽  
Vol 45 (2) ◽  
pp. 233-243 ◽  
Author(s):  
Dj. Veljovic ◽  
G. Vukovic ◽  
I. Steins ◽  
E. Palcevskis ◽  
P.S. Uskokovic ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Grain Size ◽  
Sintering Temperature ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Multi Walled Carbon Nanotubes ◽  
Spark Plasma ◽  
Walled Carbon Nanotubes

Composites based on HAP and oxidized multi-walled carbon nanotubes (o-MWCNT) and monophase HAP materials were processed by spark plasma sintering. Starting from stoichiometric nano-sized HAP powder, monophase bioceramics were obtained with a density close to the theoretical one and with an average grain size of several hundred nanometers to micron dimensions. It was shown that decreasing the sintering temperature resulted in a decrease of the grain size, which affected an increase in the fracture toughness and hardness. The fracture toughness of an HAP/ o-MWCNT bioceramic processed at 900?C for only 5 min was 30 % higher than that of monophase HAP materials obtained under the same conditions. The addition of MWCNT during SPS processing of HAP materials caused a decrease in the grain size to the nano-dimension, which was one of the reasons for the improved mechanical properties.

Effects of Powder Microscopic Defects on Densification and Mechanical Properties of WC via Spark Plasma Sintering

2021 ◽  
Vol 1016 ◽  
pp. 1770-1777
Author(s):  
Liu Zhu ◽  
Jin Fang Wang ◽  
Zhi Biao Tu ◽  
Na Xue ◽  
Wei Wei Li
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Free Energy ◽  
Composite Powder ◽  
Sintering Temperature ◽  
Chemical Activation ◽  
Activation Technique ◽  
Specific Chemical ◽  
Plasma Sintering ◽  
Spark Plasma

The WC composite powder was synthesized by a new specific chemical activation technique. A large number of lattice defects such as surface humps, dislocations and stacking fault exist in the surface of the WC powder after chemical activation technique. By using such activated WC powder, the binderless WC cemented carbide with high density (15.54 g/cm3), super hardness (average 26.29 GPa) and excellent fracture toughness (8.9 MPa.m1/2) can be fabricated by SPS at 1700 °C and 50 MPa pressure. The improvement in density, hardness and fracture toughness are respectively 4.5%, 15.3% and 17.1% compared to when using the original WC powder. This improvement is because microscopic defects on the surface of the WC powder can greatly improve surface free energy of the powder, which improves the sintering activity and reduces the sintering temperature of the WC powder.

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.

scholarly journals Properties of TiC and TiN Reinforced Alumina–Zirconia Composites Sintered with Spark Plasma Technique

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1220 ◽  
Author(s):  
Magdalena Szutkowska ◽  
Sławomir Cygan ◽  
Marcin Podsiadło ◽  
Jolanta Laszkiewicz-Łukasik ◽  
Jolanta Cyboroń ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Vickers Hardness ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Plasma Sintering ◽  
Different Temperatures ◽  
Spark Plasma ◽  
New Type ◽  
Diffraction Patterns

In this paper, Al2O3–ZrO2 composites with an addition of 20 wt% TiN and 10 wt% TiC were modified. The addition of zirconia in a range from 2 to 5 wt% of the monoclinic phase and 10 wt% of Y2O3 stabilised ZrO2 affected the mechanical properties of the composites. A new type of sintering technique—the spark plasma sintering (SPS) method—within a temperature range from 1575 °C to 1675 °C, was used. Vickers hardness, apparent density, wear resistance and indentation fracture toughness KIC(HV) were evaluated at room temperature. An increase of the sintering temperature resulted in an improvement of Vickers hardness and an increase of the fracture toughness of the tested composites. The tribological properties of the samples were tested using the ball-on-disc method. The friction coefficient was in a range from 0.31 to 0.55, depending on the sintering temperature. An enhancement of the specific wear rate was dependent on the sintering temperature. The mechanical properties of the samples sintered by pressureless sintering (PS) were compared. X-ray diffraction patterns were presented in order to determine the phase composition. SEM microstructure of the tested composites sintered at different temperatures was observed.

scholarly journals Influence of Ti3C2Tx MXene and Surface-Modified Ti3C2Tx MXene Addition on Microstructure and Mechanical Properties of Silicon Carbide Composites Sintered via Spark Plasma Sintering Method

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3558
Author(s):  
Mateusz Petrus ◽  
Jarosław Woźniak ◽  
Tomasz Cygan ◽  
Artur Lachowski ◽  
Dorota Moszczyńska ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Silicon Carbide ◽  
Spark Plasma Sintering ◽  
Reference Sample ◽  
Plasma Sintering ◽  
New Findings ◽  
Spark Plasma ◽  
Surface Modified ◽  
Sintering Method

This article presents new findings related to the problem of the introduction of MXene phases into the silicon carbide matrix. The addition of MXene phases, as shown by the latest research, can significantly improve the mechanical properties of silicon carbide, including fracture toughness. Low fracture toughness is one of the main disadvantages that significantly limit its use. As a part of the experiment, two series of composites were produced with the addition of 2D-Ti3C2Tx MXene and 2D-Ti3C2Tx surface-modified MXene with the use of the sol-gel method with a mixture of Y2O3/Al2O3 oxides. The composites were obtained with the powder metallurgy technique and sintered with the Spark Plasma Sintering method at 1900 °C. The effect adding MXene phases had on the mechanical properties and microstructure of the produced sinters was investigated. Moreover, the influence of the performed surface modification on changes in the properties of the produced composites was determined. The analysis of the obtained results showed that during sintering, the MXene phases oxidize with the formation of carbon flakes playing the role of reinforcement. The influence of the Y2O3/Al2O3 layer on the structure of carbon flakes and the higher quality of the interface was also demonstrated. This was reflected in the higher mechanical properties of composites with the addition of modified Ti3C2Tx. Composites with 1 wt.% addition of Ti3C2Tx M are characterized with a fracture toughness of 5 MPa × m0.5, which is over 50% higher than in the case of the reference sample and over 15% higher than for the composite with 2.5 wt.% addition of Ti3C2Tx, which showed the highest fracture toughness in this series.

Effects of Carbon Nanotubes Incorporation on the Grain Growth and Properties of WC/Co Nanocomposites

2005 ◽  
Vol 475-479 ◽  
pp. 989-992 ◽  
Author(s):  
Fa Ming Zhang ◽  
Jian Fei Sun ◽  
Jun Shen
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Grain Growth ◽  
Binder Phase ◽  
Tubular Structures ◽  
Plasma Sintering ◽  
Mechanical And Physical Properties ◽  
The Matrix ◽  
Spark Plasma

Carbon nanotubes (CNTs) combining unique mechanical and physical properties could offer a kind of nanosized reinforcements for composite materials. Incorporating of CNTs to develop advance engineering composites has become an interesting concept, but the cermets based CNTs composites have been less focused. WC-Co-CNTs nanocomposites were consolidated by spark plasma sintering (SPS) to investigate the effects of CNTs incorporation on the grain growth and mechanical properties of WC-Co nanocomposites. Experimental results show that CNTs could preserve their tubular structures in high temperature SPS process, some CNTs are surviving in the WC-Co fracture surfaces featured bridging and pulling out manner. The interaction between the CNTs and the matrix has a retardation effect of grain growth of WC, but CNTs additions could be resulted in an increase of carbon content in the binder phase that causes enhanced tendency of grain growth, either of which plays the dominated role depending on the CNTs content. The WC-10Co-0.5wt%CNTs nanocomposites possess superior hardness to toughness combinations, which hardness is about 15% and fracture toughness is about 40% higher than that of the pure nano-WC-10Co cermets consolidated under the same process.

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.

Microstructure and Mechanical Properties of Magnesium Prepared by Spark Plasma Sintering

2010 ◽  
Vol 129-131 ◽  
pp. 764-768 ◽  
Author(s):  
Wan Nur Azrina Wan Muhammad ◽  
Yoshiharu Mutoh ◽  
Yukio Miyashita
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Pressureless Sintering ◽  
Microstructure And Mechanical Properties ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sintering Method

Magnesium powders were sintered by using spark plasma sintering (SPS) and conventional pressureless sintering (PLS) techniques at sintering temperatures ranged from 552°C to 605°C to investigate effect of sintering method on microstructure and mechanical properties of sintered magnesium. High densed magnesium could be obtained by using spark plasma sintering technique compared to conventional presureless sintering at the same sintering temperature. It was found that the ultimate tensile strength increased with increasing sintering temperature for both the materials sintered by PLS and SPS. The magnesium samples prepared by SPS showed better mechanical properties than those prepared by PLS. The microstructural observations revealed that the grain growth was not significant in SPS process compared to PLS, which would enhance the mechanical properties of the SPS sintered magnesium.

Mechanical Properties of ZrO2 (Y2O3)-Al2O3 Nanocomposites with Addition of Hydroxyapatite Prepared by Spark Plasma Sintering

2009 ◽  
Vol 631-632 ◽  
pp. 413-423 ◽  
Author(s):  
Shu Feng Li ◽  
Hiroshi Izui ◽  
Michiharu Okano ◽  
Wei Hua Zhang ◽  
Taku Watanabe
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Spark Plasma Sintering ◽  
Vickers Hardness ◽  
Volume Fraction ◽  
Sintering Temperature ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Hardness Values

TZP-3Y20A/HA composites with addition of different volume fraction of hydroxyapatite (HA) were fabricated successfully using spark plasma sintering (SPS). The densification behavior and mechanical properties of composites are investigated as a function of sintering temperature and HA content respectively. The density of TZP-3Y20A composite increases steadily with temperature and a maximum value of 97.8% is obtained after sintering at 1400°C. Sintering the TZP-3Y20A/HA composites at 1400°C led to the decomposition of HA in the samples. Flexural strength, fracture toughness and Vickers hardness values increase with increasing sintering temperature, show decrease trend with increasing of HA content at the same temperature. They compared well with densities obtained at different sintering temperature. The maximum flexural strength, fracture toughness and Vickers hardness of 967.1 MPa, 5.27 MPam1/2 and 13.26 GPa were achieved for TZP-3Y20A composite respectively. Flexural strength, fracture toughness and Vickers hardness values of TZP-3Y20A/HA composite fell within the value range of dense HA and of TZP-3Y20A composite.

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