• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.523-524
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• 2006

The $TiB_2$ dispersion strengthened copper alloy was attracted as thermal and electrical functional material for the high mechanical strength, high thermal stability and good conductivity of $TiB_2$. In the present study, the focus is on the synthesis of $TiB_2$ dispersed copper alloy by spark plasma sintering process using copper oxide and titanium diboride as raw materials. The mechanical, thermal and electrical properties of sintered bodies were discussed with the sintering parameters, and developed microstructure and phase of sintered bodies.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.221-222
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• 2006

This paper describes a Plasma Assisted Debinding and Sintering (PADS) equipment, which has been designed to process Metal Injection Molded (MIM) components. The use of a hybrid system combining a glow discharge with a conventional heating system makes debinding and sintering of MIM components, in the same heating cycle, a feasible industrial process. Characteristics as density, carbon content and mechanical properties are similar to traditionally processed MIM materials. The reduction of energy and gas consumption and shorter lead-times are economic advantages of PADS system. The clean environment of PADS is also an ecological advantage.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.350-351
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• 2006

A solid stage sinterizacion model of the WC-Co is applied on this work. These results are compaired with the experimental data obtained for nanometric and micrometric sinter powder in an electric furnace and micrometric in a plasma reactor (using Abnormal Glow Discharge AGD). The correlations obtained allow the prediction of the sintering behavior in AGD for nanometric powder. The activation of the solid state sintering is shown with the decraease of the WC size and the use of AGD

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.3
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• pp.128-132
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• 2007

[ $B_4C$ ] ceramics were fabricated by spark plasma sintering process and their sintering behavior, microstructure and mechanical properties were evaluated. Relative density of $B_4C$ ceramics were obtained by spark plasma sintering method reached as high as 99% at lower temperature than conventional sintering method, in addition, without any sintering additives. The mechanical properties of $B_4C$ ceramics was improved by a methanol washing process which can be removed $B_2O_3$ phase from a $B_4C$ powder surface. This improvement results ken the formation of homogeneous microstructure because the grain coarsening was suppressed by the elimination of $B_2O_3$ phase. Particularly, fracture toughness of the sintered specimen using a methanol washed powder improved over 30% compared with the specimen using an as-received commercial powder.

• Journal of Powder Materials
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• v.18 no.6
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• pp.562-567
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• 2011

This paper reports the effect of sintering processes and additives on the microstructures and mechanical properties of $ZrB_2$-SiC composite ceramics. We fabricated sintered bodies of $ZrB_2$-20 vol.% SiC with or without sintering additive, such as C or $B_4C$, densified by spark plasma sintering as well as hot pressing. While almost full densification was achieved regardless of sintering processes or sintering additives, significant grain growth was observed in the case of spark plasma sintering, especially with $B_4C$. With sintered bodies, mechanical properties, such as flexural strength and Vickers hardness, were also examined.

• Journal of Powder Materials
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• v.20 no.5
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• pp.338-344
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• 2013

Fe-TiC composite was fabricated from Fe and TiC powders by high-energy milling and subsequent spark-plasma sintering. The microstructure, particle size and phase of Fe-TiC composite powders were investigated by field emission scanning electron microscopy and X-ray diffraction to evaluate the effect of milling conditions on the size and distribution of TiC particles in Fe matrix. TiC particle size decreased with milling time. The average TiC particle size of 38 nm was obtained after 60 minutes of milling at 1000 rpm. Prepared Fe-TiC powder mixture was densified by spark-plasma sintering. Sintered Fe-TiC compacts showed a relative density of 91.7~96.2%. The average TiC particle size of 150 nm was observed from the FE-SEM image. The microstructure, densification behavior, Vickers hardness, and fracture toughness of Fe-TiC sintered compact were investigated.

• Journal of Powder Materials
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• v.19 no.4
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• pp.285-290
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• 2012

The present study was focused on the analysis of the electric and thermal properties of spark plasma sintered $Bi_{0.5}Sb_{1.5}Te_3$ thermoelectric material. The crystal structure, microstructure, electric and thermal properties of the sintered body were evaluated by measuring XRD, SEM, electric resistivity, Hall effect and thermal conductivity. The $Bi_{0.5}Sb_{1.5}Te_3$ sintered body showed anisotropic crystal structure. The c-axis of the $Bi_{0.5}Sb_{1.5}Te_3$ crystal aligned in a parallel direction with applied pressure during spark plasma sintering. The degree of the crystal alignment increased with increasing sintering temperature and sintering time. The electric resistivity and thermal conductivity of the $Bi_{0.5}Sb_{1.5}Te_3$ sintered body showed anisotropic characteristics result from crystal alignment.

• Journal of Powder Materials
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• v.14 no.5
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• pp.292-297
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• 2007

The present study was focused on the synthesis of a $TiB_2$ dispersed copper matrix composite material by the combination of the mechanical milling and plasma activated sintering processes. The $Cu/TiB_2$ mixed powder was prepared by the combination of the mechanical milling and reduction processes using the copper oxide and titanium diboride powder as the raw material. The synthesized $Cu/TiB_2$ mixed powder was sintered by the plasma activated sintering process. The hardness and electric conductivity of the sintered bodies were measured using micro vickers hardness and four probe method, respectively. The relative density of $Cu/TiB_2$ composite material sintered at $800^{\circ}C$ showed about 98% of theoretical density. The $Cu-1vol%TiB_2$ composite material has a hardness of about 130Hv and an electric conductivity of about 85% IACS. The hardness and electric conductivity of $Cu-3vol%TiB_2$ composite material were about 140 Hv and about 45% IACS, respectively.

• Korean Journal of Materials Research
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• v.17 no.2
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• pp.107-114
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• 2007

Porous Ti compacts were fabricated by spark plasma sintering (SPS) method and their in vitro and in vivo biocompatibilities were investigated. Alkaline phosphatase (ALP) activity representing the activity of osteoblast was increased when osteoblast-like MG-63 cells were cultured on the Ti powder surface. Some genes related to cell growth were over-expressed through microarray analysis. The porous Ti compact with 32.2% of porosity was implanted in the subcutaneous tissue of rats to confirm in vivo cytotoxicity. 12 weeks post-operation, outer surface and inside the porous body was fully filled with fibrous tissue and the formation of new blood vessels were observed. No inflammatory response was confirmed. To investigate the osteoinduction, porous Ti compact was implanted in the femur of NZW rabbits for 4 months. Active in-growth of new bone from the surrounded compact bone was observed around the porous body. From the results, The porous Ti compacts fabricated by spark plasma sintering might be available for the application of the stem part of artificial hip joint.

• Journal of Powder Materials
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• v.17 no.6
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• pp.494-498
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• 2010

The p-type thermoelectric compounds of $Bi_2Te_3$ based doped with 3wt% Te were fabricated by a combination of rapid solidification and spark plasma sintering (SPS) process. The effect of holding time during spark plasma sintering (SPS) on the microstructure and thermoelectric properties were investigated using scanning electron microscope (SEM), X-ray diffraction (XRD) and thermoelectric properties. The powders as solidified consisted of homogeneous thermoelectric phases. The thermoelectric figure of merit measured to be maximum ($3.41{\times}10^{-3}/K$) at the SPS temperature of $430^{\circ}C$.