• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1995.11a
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• pp.17-17
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• 1995

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1995.11a
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• pp.15-15
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• 1995

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 1995.11a
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• pp.19-19
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• 1995

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1995.11a
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• pp.33-33
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• 1995

• Journal of Ocean Engineering and Technology
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• v.13 no.4 s.35
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• pp.37-44
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• 1999

Hardness characteristics and microstructures of $Nb/MoSi_2$ laminate composites were evaluated from the variation of fabricating conditions such as preparation temperature, applied pressure and pressure holding time. $Nb/MoSi_2$ laminate composites composed of $MoSi_2$ powder and Nb sheets were fabricated by the hot press. From experimental results, it was found that the lamination from Nb sheet and $MoSi_2$ powder was an excellent strategy to improve hardness characteristics of monolithic $MoSi_2$. However, interfacial reaction products like(Nb, Mo)$SiO_2\;and\;Nb2Si_3$ formed at the interface of $Nb/MoSi_2$ and increased with fabricating temperature.

• Journal of Powder Materials
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• v.5 no.4
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• pp.312-318
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• 1998

The effect of the mechanical alloying of elemental Mo and Si powders on the combustion densification behavior of MoSi$_2$ was investigated. The ignition temperature of the combustion reaction of the mechanically alloyed powder was measured to be significantly lower than that of the powder mixture prepared by the low energy ball milling process. The densification of the products after the combustion reaction under compressive pressure from the mechanically alloyed powders, however, was found to be poorer than that of the products from the ball milled powder.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.109-110
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• 2006

We have studied the effect of C/Ti atomic ratio of TiCx (x=0.5, 0.75 and 1.0) raw powder on the properties of the Ti-Mo-WTiC sintered hard alloy. The decrease of C/Ti atomic ratio accelerated the densification in the sintering process. The hardness was remarkably improved up to 1350HV with decreasing the C/Ti atomic ratio because of increase of TiCx phase volume content and its fine dispersion. From the results of electro-chemical tests in acid and 3% NaCl solutions, it was obvious that every alloy had excellent corrosion resistance, which meant about 200 times better than that of WC-Co cemented carbide.

• Journal of Powder Materials
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• v.3 no.3
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• pp.167-173
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• 1996

The effect of ball milling on the pressureless sintering of MoSi$_2$ was investigated. Ball milling was conducted at 70 rpm for 72 hours using different balls and vessels: one used tungsten carbide balls in a plastic vessel(referred as B-powder) and the other stainless steel ball in a stainless steel vessel(referred as C- powder). The powder was compacted with 173MPa and subsequently sintered at the temperature range of 1150 $^{\circ}C$ and 1450 $^{\circ}C$ in H$_2$, atmosphere. Sintered density was measured and scanning electron micrograph was observed. Over 90% of the theoretical density was attained at 1250 $^{\circ}C$ within 10 minutes for C-powders, while the similar densification required a sintering temperature of 1450 $^{\circ}C$ for B-powders. Such a difference in sinterability between B and C-powders was discussed in terms of the effect of particle size reduction and activated sintering caused by Ni and/or Fe introduced during ball milling.

• Journal of Powder Materials
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• v.6 no.2
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• pp.178-185
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• 1999

MoSi$_2$-TiC composite powders were fabricated by in-situ reaction through mechanical alloying. Also the monolithic MoSi$_2$ as well as TiC were synthesiced by mechanical alloying for comparison. An abrupt increase of vial surface temperature was detected due to a sudden reaction between elemental powders during milling. The reaction time for synthesis of composite powders decreased with increasing the content of (Ti+C) powder. It was found that a significant decrease of Ti grain size was observed with increasing the milling time. And the synthesis reaction of MoSi$_2$-TiC composite powders were largely dependent on the reaction between Ti and C powders.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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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.