• Journal of Welding and Joining
• /
• 제13권1호
• /
• pp.103-114
• /
• 1995

Plasma Transferred arc(PTA) hard facing process has been developed to obtain an overlay weld metal having excellent wear resistance. The effect of Ti, TiSi$_{2}$ and TiC powders addition on the surface of Aluminum alloy 5083 has been investigated with PTA process. This paper describes the result of test the performance of the overlay weld metal. The result can be summarized as follows 1. Intermetallic compound is formed on surface of base metal in Ti or TiSi$_{2}$ powder but the reaction with surface of base metal is little seen in TiC powder. 2. In formation of composite layer on aluminum alloy surface by plasma transferred arc welding process, high melting ceramics like TiC powder is excellent. 3. The multipass welding process is available for formation of high density of powder. But the more number of pass, the less effect of powder, it is considered, and limits of number of pass. 4. By increasing area fraction of TiC powder on Al alloy surface, in especially TiC powder the hardness increase more than 40% area fraction and 88% shows about Hv 700.

• 한국세라믹학회지
• /
• 제44권1호
• /
• pp.37-42
• /
• 2007

The preparation of $TiC_{0.7}N_{0.3}$ powder by SHS in the system of $Ti-TiH_2-C$ ($N_2$ atmosphere) was investigated in this study. In the preparation of $TiC_{0.7}N_{0.3}$ powder, the effect of gas pressure, compositions such as Ti, $TiH_2$, C, and additive in mixture on the reactivity were investigated. At 50 atm of the initial inert gas pressure in reactor, the optimum composition for the preparation of pure $TiC_{0.7}N_{0.3}$ was $0.75Ti+0.25TiH_2+0.7C+0.5NaCl$. The $TiC_{0.7}N_{0.3}$ powder synthesized in this condition was a single phase with irregular shape.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
• /
• pp.618-619
• /
• 2006

The binder phase for TiC reinforced steel matrix composite was added in the form of elemental powders and master alloy powders. The microstructures, binder phase variation with TiC content and mechanical properties were evaluated. The addition of a type of binder phase largely effects the microstructure and mechanical properties. The binder phase variation from starting composition was observed with increase in wt% TiC content and this variation was higher when the master alloy powders were used as a binder. The response to heat treatment was decreased with an increase in TiC content due to the shift of binder phase from the starting composition.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2003년도 춘계학술강연 및 발표대회
• /
• pp.40-41
• /
• 2003

• 한국분말재료학회지
• /
• 제14권3호
• /
• pp.208-214
• /
• 2007

The microstructure and hardness of (W,Ti)C cemented carbides with a different metallic binder composition of Ni and Co fabricated by powder technology were investigated. The densifications of the prepared materials were accomplished by using vacuum sintering at $1450^{\circ}C$. Nearly full dense (W,Ti)C cemented carbides were obtained with a relative density of up to 99.7% with 30 wt.% Co and 99.9% with 30 wt.% Ni as a metallic binder. The average grain size of the (W,Ti)C-Co and the (W,Ti)C-Ni was decreased by increasing the metallic binder content. The hardness of the dense (W,Ti)C-15 wt%Co and (W,Ti)C-15 wt%Ni, was greater than that of the other related cemented carbides; in addition, the cobalt-based cemented carbides had greater hardness values than the nickel-based cemented carbides.

• 한국재료학회지
• /
• 제12권1호
• /
• pp.48-53
• /
• 2002

$Al_2O_3-SiC$ and $Al_2O_3-SiC$-TiC composite powders were prepared by SHS process using $SiO_2,\;TiO_2$, Al and C as raw materials. Aluminum powder was used as reducing agent of $SiO_2,\;TiO_2$ and activated charcoal was used as carbon source. In the preparations of $Al_2O_3-SiC$, the effect of the molar ratio in raw materials, compaction pressure, preheating temperature and atmosphere were investigated. The most important variable affecting the synthesis of $Al_2O_3-SiC$ was the molar ratio of carbon. Unreactants remained in the product among all conditions without compaction. The optimum condition in this reaction was $SiO_2$: Al: C=3: 5: 5.5, 80MPa compaction pressure under Preheating of $400^{\circ}C$ with Ar atmosphere. However there remains cabon in the optimum condition. The effect of $TiO_2$ as additive was investigated in the preparations of $Al_2O_3-SiC$. As a result of $TiO_2$ addition, $Al_2O_3-SiC$-TiC composite powder was prepared. The $Al_2O_3$ powder showed an angular type with 8 to $15{\mu}m$, and the particle size of SiC powder were 5~$10{\mu}m$ and TiC powder were 2 to $5{\mu}m$.

• 한국분말재료학회지
• /
• 제16권2호
• /
• pp.98-103
• /
• 2009

The ultrafine titanium carbonitride particles ($TiC_{0.7}N_{0.3}$) below 100nm in mean size were successfully synthesized by Mg-thermal reduction process. The nanostructured sub-stoichiometric titanium carbide ($TiC_{0.7}$) particles were produced by the magnesium reduction at 1123K of gaseous $TiC_{l4}+xC_2Cl_4$ and the heat treatments in vacuum were performed for five hours to remove residual magnesium and magnesium chloride mixed with $TiC_{0.7}$. And final $TiC_{0.7}N_{0.3}$ phase was obtained by nitrification under normal $N_2$ gas at 1373K for 2 hrs. The purity of produced $TiC_{0.7}N_{0.3}$ particles was above 99.3% and the oxygen contents below 0.2 wt%. We investigated in particular the effects of the temperatures in vacuum treatment on the particle refinement of final product.

• 한국분말재료학회지
• /
• 제12권5호
• /
• pp.336-344
• /
• 2005

In the present study, the focus is on the effect of cobalt oxide powder in the carbothermal reduction of the titanium-cobalt-oxygen based oxide powder by solid carbon for the optimizing synthesis process of ultra fine TiC/Co composite powder. The titanium-cobalt-oxygen based oxide powder was prepared by the combination of the spray drying and desalting processes using the titanium dioxide powder and cobalt nitrate as the raw materials. The titanium-cobalt-oxygen based oxide powder was mixed with carbon black, and then this mixture was carbothermally reduced under flowing argon atmosphere. Changes in the phase structure and thermal gravity of the mixture during carbothermal reduction were analysed using XRD and TGA. Titanium-cobalt-oxygen based oxide powder desalted at $600^{\circ}C$ had a mixture of $TiO_2\;and\;Co_{3}O_4$. And the one desalted at $800^{\circ}C$ had a mixture of $TiO_2\;and\;CoTiO_3$. In the case of the former powder, the reduction of cobalt oxide powder in the titanium-cobalt-oxygen based oxide powder occurred at lower temperature than the latter one. However, the carbothermal reduction of titanium dioxide powder in the titanium-cobalt-oxygen based oxide powder with a mixture of $TiO_2\;and\;Co_{3}O_4$ occurred at higher temperature than the one with a mixture of $TiO_2\;and\;CoTiO_3$. And also, the former powder showed a lower TiC formation ability than the latter one.

• 한국분말재료학회지
• /
• 제24권1호
• /
• pp.29-33
• /
• 2017

Titanium carbide (TiC) powders are successfully synthesized by carburization of titanium hydride ($TiH_2$) powders. The $TiH_2$ powders with size lower than $45{\mu}m$ (-325 Mesh) are optimally produced by the hydrogenation process, and are mixed with graphite powder by ball milling. The mixtures are then heat-treated in an Ar atmosphere at $800-1200^{\circ}C$ for carburization to occur. It has been experimentally and thermodynamically determined that the de-hydrogenation, "$TiH_2=Ti+H_2$", and carburization, "Ti + C = TiC", occur simultaneously over the reaction temperature range. The unreacted graphite content (free carbon) in each product is precisely measured by acid dissolution and by the filtering method, and it is possible to conclude that the maximal carbon stoichiometry of $TiC_{0.94}$ is accomplished at $1200^{\circ}C$.

• 한국분말재료학회지
• /
• 제19권5호
• /
• pp.356-361
• /
• 2012

The ultra-fine and less agglomerated titanium carbonitride particles were successfully synthesized by magnesiothermic reduction with low feeding rate of $TiCl_4+1/4C_2Cl_4$ solution. The sub-stoichiometric titanium carbide ($TiC_{0.5{\sim}0.6}$) particles were produced by reduction of chlorine component by liquid magnesium at $800^{\circ}C$ of gaseous $TiCl_4+1/4C_2Cl_4$ and the heat treatments in vacuum were performed for 5 hours to remove the residual magnesium and magnesium chloride mixed with produced $TiC_{{\sim}0.5}$. The final $TiC_{{\sim}0.5}N_{0{\sim}0.5}$ particle with near 100 nm in mean size and high specific surface area of $65m^2/g$ was obtained by nitrification under nitrogen gas at $1,150^{\circ}C$ for 2 hrs.