• 한국세라믹학회지
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• 제26권4호
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• pp.583-587
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• 1989

Various $\alpha$-silicon carbied and colloidal graphite particles were sintered at 155$0^{\circ}C$ in vacuum atmosphere by reaction bonding sintering method, and the physical properties and microstructural analysis of specimen were investigated. With decreasing particle size, sintered density and 3-point bending strength of materials were increased and 3.2${\mu}{\textrm}{m}$ specimen showed high density and strength, 3.05g/㎤, 40kg/$\textrm{mm}^2$, respectively. The results of X-ray diffractometer and optical micrographs analysis showed that graphite and silicon melt reacted to convert to fine $\beta$-SiC particle and the body was changed to dense material.

• 한국세라믹학회지
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• 제34권8호
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• pp.834-842
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• 1997

Controlled Ca impurity implanted inner crack-like pore in the high purity alumina single crystal, sapphire, had been created by micro-fabrication technique, which includes ion implantation, photo-lithography, Ar ion milling, and hot press technique. The morphological change and the healing of cracklike pore in Ca doped high purity single crystal alumina, sapphire, during high temperature heat treatment in vacuum were observed using optical microscopy. The dot-like surface roughening was developed and hexagon like crystal appeared on inner surface of crack-like pore after heat treatment. Bar type crystals, probably CaO.6Al2O3, were observed on the inner surface after 1 hour heat treatment at 1, 50$0^{\circ}C$, but this bar type crystal disappeared after 1 hour heat treatment at 1, $600^{\circ}C$. This disappearance means that there should be a little increase of Ca solubility limit to alumina at this temperatures.

• 한국세라믹학회지
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• 제31권4호
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• pp.399-406
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• 1994

The SiC/MoSi2 composite material was prepared by infiltration with the mixture of metal Si and MoSi2 into the preform of $\alpha$-SiC and graphite under the vacuum atmosphere of 10-1 torr. The mechanical properties, phases and microstructural characteristics have been investigated by employing an universal testing machine, scanning electron microscope and X-ray diffractometer. With the increase of MoSi2/Si mixing content, the quantity of the residual silicon phase was decreased and the hardness and fracture toughness of composite materials were increased. Also, as the infiltration temperature increased, a lot of fine-grained $\beta$-SiC phases, which were produced from the reaction of graphite and liquid silicon melt, were transformed to $\alpha$-SiC phases.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.21-23
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• 1993

In this study PLZT was selected which has the excellent quadratic electro-optic property and slim-loop. It was fabricated by the methods of vacuum hot-pressing and sintering. The electrode of color filter was evaporated using the interdigital type masks. Through XRD have we investigated the molecular structure composition formular. Hysteresis and transmission characteristics were measured, The transmission of RGB was envestigated. We are going to study the correlation of coercive field and the nontransmited field.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.640-641
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• 2006

To improve the mechanical properties of WC-Co cemented carbides, the dual composite was studied. The compositions of granule and matrix were nano-sized WC-6 wt% Co(granule) and normal sized WC-20 wt% Co(matrix), respectively. The granules were grouped 50, 100 and $150\;{\mu}m$ and mixed with WC and Co powders as the volume fractions of granule to matrix were 50 to 50, 40 to 60 and 30 to 70. These compacts were sintered at $1380^{\circ}C$ for 10 minutes in vacuum. The microstructure, transverse rupture strength and wear resistance were investigated.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.627-628
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• 2006

The present work is a study on the argon gas pressure effects of Sinter/HIP sintering on microstructure and strength of different grades of TiC-NiMo cermets. Titanium carbide in the composition of different grades of TiC-NiMo cermets was ranged from 40 to 80 wt.% and the ratio of nickel to molybdenum in the initial powder composition was 1:1, 2:1 and 4:1 respectively. On the sintered alloys, the main strength characteristic, transverse rupture strength (TRS) was measured. Furthermore, the microstructure parameters of some alloys were measured and the pressure effect on pore elimination was evaluated. All the results were compared with common, vacuum sintered alloys. The TRS values of TiC-NiMo cermets could be considerably improved by using Sinter/HIP technique, for high-carbide fraction alloys and for alloys sintered at elevated temperatures.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.507-508
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• 2006

In this communication the development of a new metal injection moulding (MIM) system for duplex stainless steels is presented. The metal powders were prepared by premixing 316L and 430L stainless steels gas atomised powders in a ratio of 50:50. The binder used to prepare the feedstock was composed by HDPE and paraffin wax. Torque measurements of the mixture indicated that the maximum amount of metal was 68 vol%. The polymeric part was driven off by thermal debinding and the sintering was performed in low vacuum. The final densities were close to the theoretical ones.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.583-584
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• 2006

This work presents mechanical properties and corrosion resistance of duplex stainless steels obtained through powder metallurgy starting from austenitic, martensitic powders by controlled addition of alloying elements in the right quantity to obtain the chemical composition of the structure similar to biphasic one. In the mixes preparations the Schaffler's diagram was taken into consideration. Prepared mixes of powders have been sintered in a vacuum furnace with argon backfilling. After sintering rapid cooling was applied using nitrogen. Corrosion properties have been studied through electrochemical methods in 1M NaCl.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.555-557
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• 1993

In this study PLZT was selected which has the excel lent quadratic electro-optic property and slim-loop. It was fabricated by the methods of vacuum hot-pressing and sintering. The electrode of color filter was evaporated using the interdigital type masks. Through XRD have we investigated the molecular structure composition formular. Hysteresis and transmission characteristics were measured. The transmission of RGB was envestigated. We are going to study the correlation of coercive field and the nontransmited field.

• 대한의용생체공학회:의공학회지
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• 제15권2호
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• pp.195-200
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• 1994

To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that consists consisted of calcium phosphate and collagen according to the natural bone's main composition. The crystallinity of the synthesized apatite was shown to depend on the synthesis temperature. Carbonate apatite synthesized at $58{\circ}C$ demonstrated crystallinity very similar to that of the natural bone. By sintering the apatite over $700{\circ}C$ in vacuum, porous carbonate apatite could be obtained, and the pore extent was controllable according to the additive hydrogenperoxide volume.