• Title/Summary/Keyword: Ti powder

Search Result 1,432, Processing Time 0.021 seconds

Processing of NiTi Shape Memory Alloy by Self- propagating High-temperature Synthesis (자전 고온 반응 합성법을 이용한 NiTi계 형상기억 합금의 제조에 관한 연구)

  • 윤종필
    • Journal of Powder Materials
    • /
    • v.2 no.2
    • /
    • pp.158-164
    • /
    • 1995
  • Synthesis of the NiTi shape memory alloy using the thermal explosion mode of the self-propagating high-temperature synthesis has been investigated. The significant fractions of intermetallics phases were found to form at the Ti/Ni powder interface during the heating to the ignition temperature and seemed to influence the relative fraction of phases in the final products. As the heating rate to the ignition temperature was increased, the combustion temperature and the fraction of NiTi in the final reaction products were increased. The synthesis reaction under 70 MPa compressive pressure yielded a reaction product with 98% theoretical density.

  • PDF

Formation Behaviour Al-Ti Intermetallic Compounds by Ball milling methods (볼 밀링에 의한 Al-Ti 계 금속간화합물 생성 거동)

  • 안인섭
    • Journal of Powder Materials
    • /
    • v.6 no.1
    • /
    • pp.42-48
    • /
    • 1999
  • Three mixtures of elemental powders of Al-25at.%Ti, 48at.%Ti and 70at.%Ti were offered to ball milling process for the formation of intermetallic compounds of $Al_3Ti$, AlTi and $Ti_3Al$. Ballmilling or attrition process were carried out at the condition of rotaing speed of 110 or 350 rpm at $10^{-3}$ torr vacuum or argon atmospheres. $Al_3Ti$phases were fully obtained by heat treatment for 1 hors at $600^{\circ}C$ with Al-25at.%Ti composition mixtures milled by 100 hours. The amorphous phase was completely formed at the composition of Al-48at.%Ti mixed powders by milling 100hours at the 50 to 1 weight ratio of ball to powder, and AlTi compounds were obtained by heat treament. In the case of Al-70at%Ti mixed powders milled for 100 hours, $Ti_3Al$ and $Al_3Ti$intermetallic compounds were formed by heat treatment for 1 hour at $600^{\circ}C$. By attrition milling of 350rpm for 10 hours, $Ti_3Al$ phase was formed completley after heat treatment for 1 hour at $600^{\circ}C$.

  • PDF

Photocatalysis Characteristics of Nano Cu/TiO2 Composite Powders Fabricated from Salt Solution (염용액으로부터 제조된 Cu/TiO2복합분말의 광촉매 특성)

  • 고봉석;안인섭;배승열;이상진
    • Journal of Powder Materials
    • /
    • v.10 no.2
    • /
    • pp.136-141
    • /
    • 2003
  • In the present study, $TiO_2$ imbedded copper matrix powders have been successfully prepared from the ($CuSO_4+TiO_2+Zn$) composite salt solution. The composite $Cu/TiO_2$ powders were formed by drying the solution at $200{\sim}~400^{\circ}C$ in the hydrogen atmosphere. Photocatalytic characteristics was evaluated by detecting TOC (total organic carbon) amount with TOC analyzer (model 5000A Shimadzu Co). Phase analysis of $Cu/TiO_2$ composite powders was carried out by XRD, DSC and powder size was measured with TEM. The mean particle size of composite powders was about 100 nm and a few zinc and copper oxide phases was included. The reduction ratio of TOC amount was 60% by the composite $Cu/TiO_2$ powders under the UV irradiation for 8 hours.

Pore Structure and Mechanic:11 Property of Porous TiNi Biomaterial Produced by Self-Propagating High-Temperature Synthesis (고온자전합성법으로 제조된 다공성 TiNi 생체재료의 기공구조 및 기계적 특성)

  • 김지순;강지훈;양석균;정순호;권영순
    • Journal of Powder Materials
    • /
    • v.10 no.1
    • /
    • pp.34-39
    • /
    • 2003
  • Porous TiNi bodies were produced by Self-propagating High-temperature Synthesis (SHS) method from a powder mixture of Ti and Ni. Porosity, pore size and structure, mechanical property, and transformation temperature of TiNi product were investigated. The average porosity and pore size of produced porous TiNi body are 63% and $216\mutextrm{m}$, respectively. XRD analysis showed that the major phase of produced TiNi body is B2 phase. Its average fracture strength and elastic modulus measured under dry condition were $22\pm2$ MPa and $0.18\pm0.01$GPa, respectively. It could be strained up to 7.3 %. The transformation temperatures determined by DSC showed the $M_s$ temperature of $67^{\circ}C$ and $A_f$ temperature of $99^{\circ}C$.

Fabrication of $MoSi_2$-TiC Composite Powders by Mechanical Alloying (기계적 압금화에 의한 $MoSi_2$-TiC 복합분말의 제조)

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

  • PDF