References  M. Nygren, Z. Shen, On the preparation of bio-, nano- and structural ceramics and composites by spark plasma sintering Solid State Sciences 5 , 125-131 (2003).  J.R. Groza, A. Zavaliangos, Sintering activation by external electrical field, Mater. Sci. Eng. A287 , 171-177 (2000).  O. Zgalat- Lozynskyy, M. Herrmann, A. Ragulya, Spark plasma sintering of TiCN nanopowders in non-linear heating and loading regimes J. Europ. Ceram. Soc. 31 , 809-813 (2011).  V
O. Zgalat-Lozynskyy, M. Herrmann, A. Ragulya, M. Andrzejczuk and A. Polotai
properties of the steel composites prepared by spark plasma sintering, Materials Science and Technology, (2014) (in press).  CRC Materials Science and Engineering Handbook, Third Edition Edited by James F. Shackelford and William Alexander CRC Press, 509 (2001).
I. Sulima, G. Boczkal and P. Palka
References  M. Tokita, Trends in Advanced SPS Spark Plasma Sintering Systems and Technology, Journal of the Society of Powder Technology Japan 30, 11, 790-804 (1993).  X. Song, X. Liu, J. Zhang, Mechanism of conductive powder microstructure evolution in the process of SPS, Science in China Ser. E Engineering & Materials Science 48, 3, 258-269 (2005).  D.M. Hulber, A. Anders, J. Andersson, E.J. Lavernia, A.K. Mukherjee, A discussion on the absence of plasma in spark plasma sintering, Scripta Materialia
Y.-K. Jeong, Y.S. Kim and S.-T. Oh
An optimum route to fabricate the Cu-based SiC composites with homogeneous microstructure was investigated. Three methods for developing the densified composites with sound interface between Cu and SiC were compared on the basis of the resulting microstructures. Starting with three powder mixtures of elemental Cu and SiC, elemental Cu and PCS coated SiC or PCS and Cunitrate coated SiC was used to obtain Cu-based SiC composites. SEM analysis revealed that the composite fabricated by spark plasma sintering using elemental SiC and Cu powder mixture showed inhomogeneous microstructure. Conversely, dense microstructure with sound interface was observed in the sintered composites using powder mixture of pre-coated PCS and Cu-nitrate onto SiC. The relationship between powder processing and microstructure was discussed based on the role of coating layer for the wettability
M. Lis, A. Wrona, J. Mazur, C. Dupont, M. Kamińska, D. Kopyto and M. Kwarciński
The paper presents results of investigations of the obtained nanocomposite materials based on silver with addition of multiwall carbon nanotubes. The powder of carbon nanotubes content from 0.1 to 3 wt. % was produced by application of powder metallurgy methods, through mixing and high-energetic milling, and also chemical methods. Modification of carbon nanotubes included electroless deposition of silver particles on the carbon nanotube active surfaces and chemical reduction with strong reducing agent – sodium borohydride (NaBH4). The obtained powder mixtures were consolidated by SPS – Spark Plasma Sintering method. The formed composites were subjected to tests of relative density, electrical conductivity and electro-erosion properties. Detailed examinations of the structure with application of X-ray microanalysis, with consideration of carbon nanotubes distribution, were also carried out. The effect of manufacturing methods on properties of the obtained composites was observed.
P. Dharmaiah, H.-S. Kim, K.-H. Lee and S.-J. Hong
In this study, single phase polycrystalline Zn4Sb3 as well as 11 at.% Zn-rich Zn4Sb3 alloy having ε-Zn4Sb3 (majority phase) and Zn (minority phase) phases bulk samples produced by gas-atomization and subsequently consolidated by spark plasma sintering (SPS) process. The crystal structures were analyzed by X-ray diffraction (XRD) and cross-sectional microstructure were observed by the scanning electron microscopy (SEM). The internal grain microstructure of 11at.% Zn-rich Zn4Sb3 powders shows lamellar structure. Relative density, Vickers hardness and crack lengths were measured to investigate the effect of sintering temperature of Zn4Sb3 samples which are sintered at 653, 673 and 693 K. Relative density of the single phase bulk Zn4Sb3 sample reached to 99.2% of its theoretical density. The micro Vickers hardness of three different sintering temperatures were found around 2.17 – 2.236 GPa.
A. Mróz, D. Garbiec, A. Wielowiejska-Giertuga, T. Wiśniewski, M. Gierzyńska-Dolna and A. Martyła
The influence of spark plasma sintering parameters on the structural, mechanical and tribological characteristics of the Ti6Al4V alloy, which is used as implant material in biomedical engineering, was investigated. The experimental data confirm that full density and attractive mechanical properties can be obtained using the spark plasma sintering method. Tribological tests, performed in dry conditions, allowed the authors to indicate the most suitable sintering parameters. The material characterized by the highest wear resistance was selected for further tribological testing in articulation with UHMWPE in simulated body fluids. Although the weight of the polymeric material articulating against the sintered Ti6Al4V was slightly higher compared to the UHMWPE articulating against the reference material (Ti6Al4V rod), the friction coefficient was lower.
S.H. Park, D.B. Kim, R.G. Lee and I.J. Son
This study focuses on the fabrication of thermal management material for power electronics applications using graphite flake reinforced copper composites. The manufacturing route involved electroless plating of copper in the graphite flake and sintering process are optimized. The microstructures, interface, thermal properties, and relative density of graphite/Cu composites are investigated. The relative density of the composites shows 99.5% after sintering. Thermal conductivities and coefficients of thermal expansion of this composites were 400-480 Wm−1K−1 and 8 to 5 ppm k−1, respectively. Obtained graphite nanoplatelets-reinforced composites exhibit excellent thermo-physical properties to meet the heat dispersion and matching requirements of power electronic devices to the packaging materials.
D.H. Shim, S.S. Jung, H.S. Kim, H. Cho, J.K. Kim, T.G. Kim and S.J. Yoon
Zirconia matrix ZrO2/CNT composite materials reinforced with multiwall carbon nanotubes were fabricated using a spark plasma sintering technique. The effects of the amount of CNTs addition, sintering temperature and sintering pressure on the properties of the resulting ZrO2/CNT composites were examined. 0 to 9 vol. % CNTs were dispersed in zirconia powder, and the resulting mixture was sintered. The electrical conductivity, hardness, flexural strength, and density were measured to characterize the composites. The friction and wear properties of the composites were also tested. The flexural strength and friction coefficient of the composites were improved with up to 6 vol.% of CNT addition and the flexural strength showed a close relationship with the relative density of the composite. The electrical conductivity increased with increasing proportion of the CNTs, but the efficiency was reduced at more than 6 vol.% CNTs.
S.-M. Yoon, B. Madavali, Y.-N. Yoon and S.-J. Hong
In this work, p-type Bi0.5Sb1.5Te3 alloys were fabricated by high-energy ball milling (MA) and spark plasma sintering. Different revolutions per minute (RPM)s were used in the MA process, and their effect on microstructure, and thermoelectric properties of p-type Bi0.5Sb1.5Te3 were systematically investigated. The crystal structure of milled powders and sintered samples were characterized using X-ray diffraction. All the powders exhibited the same morphology albeit with slight differences find at 1100 RPM conditions. A slight grain size refinement was observed on the fracture surfaces from 500 to 1100 RPM specimens. The temperature dependence of Seebeck coefficient, electrical conductivity, and power factors were measured as a function of temperature with different RPM conditions. The power factor shows almost same (~3.5 W/mK2 at RT) for all samples due to unchanged Seebeck and electrical conductivity values. The peak ZT of 1.07 at 375K is obtained for 1100 RPM specimen due to low thermal conductivity.