Spark plasma sintering and characterization of bulk nanostructured fully stabilized zirconia: Part II. Characterization studies

2004 ◽  
Vol 19 (11) ◽  
pp. 3263-3269 ◽  
Author(s):  
U. Anselmi-Tamburini ◽  
J.E. Garay ◽  
Z.A. Munir ◽  
A. Tacca ◽  
F. Maglia ◽  
...  

Dense fully stabilized cubic zirconia, sintered by the spark plasma sintering (SPS) method, was characterized through hardness, fracture toughness, and electrical impedance measurements. The effect of sintering temperature on hardness and fracture toughness was evaluated. Samples sintered at 1200 °C for 5 min, which had crystallite size of <100 nm, exhibited the highest hardness. Impedance measurements showed an increase in bulk contribution relative to grain boundaries as sintering temperature is increased. Calculation of the activation energy for conduction gave a value, 1.13 eV, in agreement with previously published results.

2014 ◽  
Vol 616 ◽  
pp. 194-198 ◽  
Author(s):  
Jian Feng Zhang ◽  
Rong Tu ◽  
Takashi Goto

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.


2005 ◽  
Vol 287 ◽  
pp. 335-339 ◽  
Author(s):  
Kyeong Sik Cho ◽  
Kwang Soon Lee

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.


2008 ◽  
Vol 368-372 ◽  
pp. 544-546
Author(s):  
Dong Choul Cho ◽  
Jae Seol Lee ◽  
Chul Ho Lim ◽  
Chi Hwan Lee

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.


2007 ◽  
Vol 534-536 ◽  
pp. 893-896 ◽  
Author(s):  
Swapan Kumar Sarkar ◽  
Min Ho Youn ◽  
Ik Hyun Oh ◽  
Byong Taek Lee

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.


2020 ◽  
Author(s):  
Jingzhe Fan ◽  
Weixia Shen ◽  
zhuangfei Zhang ◽  
Chao Fang ◽  
Yuewen Zhang ◽  
...  

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.


2009 ◽  
Vol 423 ◽  
pp. 67-72 ◽  
Author(s):  
A. Lara ◽  
R. Poyato ◽  
A. Muñoz ◽  
A.L. Ortiz ◽  
Arturo Domínguez-Rodríguez

Additive-free -SiC powders were sintered by means of Spark Plasma Sintering System. Experiments were performed in the temperature range from 1650°C to 2200°C, 3 to 10 min holding time and pressure from 50 until 150 MPa. In order to favour sinterization, the starting powder was mechanically activated: defect concentration was increased by centrifugal ball milling. Applied temperature, holding time and/or pressure were varied to analyze their effect on the densification and grain growth kinetics. The full sinterization of the material was obtained for temperatures as high as 1900°C and over. The relative density of the obtained material was high, up to 97.0  0.6 % the theoretical density for 2200°C sintering temperature. An intense grain growth took place while sintering. The final microstructure exhibited a grain size distribution range from 1.0 to 2.5 m, depending on the sintering conditions. Such grain growth strongly depends on the sintering time, not so much on the sintering temperature.


2009 ◽  
Vol 631-632 ◽  
pp. 413-423 ◽  
Author(s):  
Shu Feng Li ◽  
Hiroshi Izui ◽  
Michiharu Okano ◽  
Wei Hua Zhang ◽  
Taku Watanabe

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.


2017 ◽  
Vol 59 (11-12) ◽  
pp. 1033-1036 ◽  
Author(s):  
Sherzod Kurbanbekov ◽  
Mazhyn Skakov ◽  
Viktor Baklanov ◽  
Batyrzhan Karakozov

2020 ◽  
Vol 16 (4) ◽  
pp. 578-583
Author(s):  
Muhammad Asif Hussain ◽  
Adnan Maqbool ◽  
Abbas Saeed Hakeem ◽  
Fazal Ahmad Khalid ◽  
Muhammad Asif Rafiq ◽  
...  

Background: The development of new bioimplants with enhanced mechanical and biomedical properties have great impetus for researchers in the field of biomaterials. Metallic materials such as stainless steel 316L (SS316L), applied for bioimplants are compatible to the human osteoblast cells and bear good toughness. However, they suffer by corrosion and their elastic moduli are very high than the application where they need to be used. On the other hand, ceramics such as hydroxyapatite (HAP), is biocompatible as well as bioactive material and helps in bone grafting during the course of bone recovery, it has the inherent brittle nature and low fracture toughness. Therefore, to overcome these issues, a hybrid combination of HAP, SS316L and carbon nanotubes (CNTs) has been synthesized and characterized in the present investigation. Methods: CNTs were acid treated to functionalize their surface and cleaned prior their addition to the composites. The mixing of nano-hydroxyapatite (HAPn), SS316L and CNTs was carried out by nitrogen gas purging followed by the ball milling to insure the homogeneous mixing of the powders. In three compositions, monolithic HAPn, nanocomposites of CNTs reinforced HAPn, and hybrid nanocomposites of CNTs and SS316L reinforced HAPn has been fabricated by spark plasma sintering (SPS) technique. Results: SEM analysis of SPS samples showed enhanced sintering of HAP-CNT nanocomposites, which also showed significant sintering behavior when combined with SS316L. Good densification was achieved in the nanocomposites. No phase change was observed for HAP at relatively higher sintering temperatures (1100°C) of SPS and tricalcium phosphate phase was not detected by XRD analysis. This represents the characteristic advantage with enhanced sintering behavior by SPS technique. Fracture toughness was found to increase with the addition of CNTs and SS316L in HAPn, while hardness initially enhanced with the addition of nonreinforcement (CNTs) in HAPn and then decrease for HAPn-CNT-SS316L hybrid nanocomposites due to presence of SS316L. Conclusion: A homogeneous distribution of CNTs and SPS technique resulted in the improved mechanical properties for HAPn-CNT-SS316L hybrid nanocomposites than other composites and suggested their application as bioimplant materials.


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