Gas Analysis in Spark Plasma Sintering of Hydroxyapatite

In this paper, the effect of electric current on sintering of hydroxyapatite (HAp) in spark plasma sintering (SPS) process was investigated. The carbonate partially substituting hydroxyapatite was sintered up to 900 °C, and CO2 evolved from HAp powder were measured in situ by using mass spectroscopy apparatus in the same time. The same gas analysis was performed in thermal analysis as comparison. In the thermal analysis, CO2 gas was evolved at about 600 °C. On the other hand, in the SPS process, CO2 gas was detected at lower temperature than that of thermal analysis. This result indicates that the surface of hydroxyapatite particles would be heated up locally in SPS process due to electric current.

Download Full-text

Preparing Magnetocaloric LaFeSi Uniform Microstructures by Spark Plasma Sintering

Materials Science Forum ◽

10.4028/www.scientific.net/msf.802.491 ◽

2014 ◽

Vol 802 ◽

pp. 491-495

Author(s):

N. Vicente ◽

J. Ocanã ◽

H.N. Bez ◽

C.S. Teixeira ◽

Izabel Fernanda Machado ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Electric Current ◽

Spark Plasma Sintering ◽

Joule Effect ◽

Plasma Sintering ◽

Spark Plasma ◽

Vicker’S Microhardness ◽

Scanning Electron

Spark Plasma Sintering (SPS) of LaFeSi alloy powders was conducted to prepare magnetocaloric La-Fe-Si-based uniform microstructures. Two electrically insulating discs made of alumina were interposed between the punches and powder sample inhibiting the flow of electric current across the powder. This approaching aiming at improving the sample temperature distribution by deviating the electric current throughout the graphite die, since the electric current induces overheating byin situJoule effect on powder. The LaFeSi powder with particles under 150 µm was obtained by mechanical milling of particles from hydrogenated and decrypted casting ingot. The characterizations of sintered samples were performed by Scanning Electron Microscopy (SEM), Archimedes principle, Vicker’s hardness and microhardness. The uniformity of the microstructure was evaluated by checking the evidence of position on the Vicker’s microhardness by means of ANOVA statistics.

Download Full-text

Study on mechanical properties and wear behavior of in-situ synthesized CNTs/ CuCrZrY composites prepared by spark plasma sintering

Vacuum ◽

10.1016/j.vacuum.2021.110180 ◽

2021 ◽

pp. 110180

Author(s):

Honglei Zhou ◽

Xiaohong Chen ◽

Ping Liu ◽

Weidong Wang ◽

Wen Liu

Keyword(s):

Mechanical Properties ◽

Spark Plasma Sintering ◽

Wear Behavior ◽

Plasma Sintering ◽

Spark Plasma

Download Full-text

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

Journal of Advanced Ceramics ◽

10.1007/s40145-021-0459-0 ◽

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.

Download Full-text