• Title/Summary/Keyword: Titanium Hydride

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A Study on the Synthesis of Titanium Carbonitride by SHS(Self-propagating High-temperature Synthesis) Method (자체반응열 고온합성법을 이용한 Titanium Carbonitride의 합성에 관한 연구)

  • Ha, Ho;Hwang, Gyu-Min;Lee, Hee-Cheol
    • Journal of the Korean Ceramic Society
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    • v.31 no.6
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    • pp.637-642
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    • 1994
  • Using SHS(Self-propagating High-temperature Synthesis) method, the optimum synthetic condition of titanium carbonitride was established by controlling the parameters such as relative density of mixture (Ti+C), nitrogen pressure, additive amounts of titanium hydride(TiH1.924) and protecting heat loss. Under 1 atm nitrogen pressure, nitridation ratio with changing relative density of the sample compacts has a maximum (87.2%) at about 55%, and in the case of enveloping the pellet with a quartz tube, the highest nitridation ratio of 90% was obtained at about 68%. At relative density of 55%, nitridation ratio with the nitrogen pressure has a miximum (87.3%) at 7 atm. As the amounts of additive titanium hydride increased, nitridation ratio decreased at below 7 atm nitrogen pressure and, increased at above this pressure until percent of addition percent reached 15 wt% and decreased abruptly upon futher increases in titanium hydride. In the synthesis of TiCxNy by combustion reaction, heat transfer from combustion zone to preheating zone and nitrogen gas penetration into the compact were found to be important factors affecting the TiCxNy formation. It was difficult to obtain high nitridation ratio when the conbustion temperature was either too high or too low, and it seems that the retention of high temperature after a combustion wave sweeped through the reactant mixture pellet is critical to obtain a satisfactory nitridation ratio.

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Investigation of Thermal/hygrothermal Aging Effects on the Ignition Characteristics of Ti Metal-based Pyrotechnics and Construction of the Aging Models (열/수분노화로 인한 Ti 금속 기반의 파이로 물질의 점화 성능 변화와 노화 모델 제시)

  • Oh, Juyoung;Yoh, Jai-ick
    • Journal of the Korean Society of Propulsion Engineers
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    • v.25 no.3
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    • pp.26-41
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    • 2021
  • Titanium hydride potassium perchlorate (THPP) has played an important role as initiators of the propulsion system. However, the 'aging' may cause performance degradation and even give rise to a failure in the total system. In this study, various hygrothermal aging conditions were considered and the aging effects on thermodynamic and ignition characteristics of THPP are provided via thermal analysis and ignition measurements. Also, physical-chemical changes were identified by morphological analysis. In conclusion, thermal aging led to Eα decrease-high reactivity due to oxidizer decomposition whereas hygrothermal aging gave rise to an opposite tendency by fuel oxidation.

Synthesis of nano-size titanium hydride powder at room temperature with RMG (상온에서 RMG법에 의한 타이타늄 수소화분말의 제조)

  • Choi, Seung-Jun;Choi, Jeon;Cho, Sung-Wook;Park, Choon-Nyeon
    • Transactions of the Korean hydrogen and new energy society
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    • v.14 no.4
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    • pp.313-320
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    • 2003
  • 볼밀링법을 이용하여 타이타늄 스펀지와 칩 또는 스크랩으로부터 상온애서 직접 타이타늄 수소와 분말을 재조하는 실험을 행하였다. 실험결과 진공중에서 볼링을 행한 타이타늄 스펀지와 칩의 경우 24시간외 후 합금분말의 크기는 약 20 um 정도의 크기를 갖는 것을 확인하였다. 그러나 수소화 분위기에서 볼밀링을 행한 경우에 12시간 후 수소화분말의 입도는 0.1-0.2 um로 극히 미세한 합금 분말이 제조되었다. 수소분위기에서의 볼밀링에 의한 타이타늄 분말제조는 기존의 방법에 비해 열을 가하지 않고 타이타늄 수소화분말을 얻을 수 있다는 장점과 나노크기의 미세한 수소화 분말을 얻을 수 있음을 알 수 있었다.

Fabrication of TiC powder by carburization of TiH2 powder (타이타늄 하이드라이드 분말의 침탄에 의한 타이타늄 카바이드 분말 제조)

  • Lee, Hun-Seok;Seo, Hyang-Im;Lee, Young-Seon;Lee, Dong-Jun;Wang, Jei-Pil;Lee, Dong-Won
    • Journal of Powder Materials
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    • v.24 no.1
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    • pp.29-33
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    • 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 $1200^{\circ}C$.

Control of Cell Morphology of Al Foams fabricated by P/M Method and Induction Heating (P/M법과 유도가열법을 이용한 A1 Foam 재료의 기공제어)

  • Youn S. W.;Lee S. H.;Kang C. G.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.10a
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    • pp.289-292
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    • 2001
  • Aluminium foams, having a closed cell structure, fabricated by applying the powder compact method and an induction heating were studied. The powdered A6061 mixed with the powdered titanium hydride as a foaming agent was hot pressed into a foamable precursor. The resulting precursor was foamed by induction heating up to desired temperature. The effects of the titanium hydride content ($0.3{\~}1.5 wt.\%$), pressing pressure of the foamable precursor material (50-150kN), the forming temperature ($610{\~}690^{\circ}C$) and heating rate during foaming on the expansion behavior of the foam were investigated.

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