• 제목/요약/키워드: Al/Cu

검색결과 2,084건 처리시간 0.025초

급속응고한 Al-Mg 합금의 미세조직 및 인장특성에 미치는 첨가원소의 영향 (Effects of Alloying Elements on the Microstructure and Tensile Properties of Rapidly Solidified Al-Mg Alloys)

  • 박현호;박종성;김명호
    • 한국주조공학회지
    • /
    • 제17권4호
    • /
    • pp.356-364
    • /
    • 1997
  • In order to study effects of Cu and Be on the microstructure and tensile properties of rapidly solidified Al-Mg alloys, Al-Mg-Cu-Be alloys have been rapidly solidified by inert gas atomization process. Microstructure of rapidly solidified Al-Mg-Cu-Be powders exhibited refinement and good dispersion of Be particles as increasing of solidification rate. Solidification rate of atomized powders was estimated to be about $5{\times}10^{3{\circ}}C/s$. Inert gas atomized Al-Mg-Cu-Be powders were hot-processed by vacuum hot pressing at $450^{\circ}C$ under 100 MPa and hot extruded with reduction ratio in area of 25: 1 at $450^{\circ}C$. The extruded Al-Mg-Cu-Be powders consisted of recrystallized fine Al grains and homogeneously dispersed fine Be particles, and exhibited improved tensile properties with increase in Cu content. $Al_2CuMg$ compounds precipitated in grain and grain boundaries of Al-Mg-Cu-Be alloys with aging heat treatment after solution treatment. Hardness and tensile properties were improved by increasing Cu content and Be addition. Compared with extruded Al-Mg-Cu powders, the extruded Al-Mg-Cu-Be powders exhibited finer recrystallized grains and improved tensile properties by dispersion hardening of Be and subgrain boundaries pinned by fine Be particles. After aging treatment, hardness and tensile properties were improved due to restricted precipitation by increasing of dislocation density around Be particles in matrix.

  • PDF

Effect of Cu Addition on Oxide Growth of Al-7 mass%Mg Alloy at High Temperature

  • Seong-Ho Ha;Abdul Wahid Shah;Bong-Hwan Kim;Young-Ok Yoon;Hyun-Kyu Lim;Shae K. Kim
    • Archives of Metallurgy and Materials
    • /
    • 제66권3호
    • /
    • pp.699-702
    • /
    • 2021
  • Effect of Cu addition on oxide growth of Al-7 mass%Mg alloy at high temperature was investigated. As-cast microstructures of Al-7 mass%Mg and Al-7 mass%Mg-1 mass%Cu alloys showed α-Al dendrites and area of secondary particles. The 1 mass%Cu addition into Al-7 mass%Mg alloy formed Mg32(Al, Cu)49 ternary phase with β-Al3Mg2. The total fraction of two Mg-containing phases in Cu-added alloy was higher than the β-Al3Mg2 fraction in Cu-free alloy. From measured weight gains depending on time at 500℃ under an air atmosphere, it was shown that all samples exhibited significant weight gains depending on time. Al-7mass%Mg-1mass%Cu alloy showed the relatively increased oxidation rate when compared with Cu-free alloy. All the oxidized cross-sections throughout the entire oxidation time showed coarse and dark areas regarded as oxides grown from the surface to inside, but bigger oxidized areas were formed in the Al-7mass%Mg-1mass%Cu alloy containing higher fraction of Mg-based phases in the as-cast microstructure. As a result of compositional analysis on the oxide clusters, it was found that the oxide clusters contained Mg-based oxides formed through internal oxidation during a long time exposure to oxidizing environments.

CU Oxide 분산 및 환원에 의한 Al2O3/Cu 나노복합재료의 제조공정 (Fabrication Process of Al2O3/Cu Nanocomposite by Dispersion and Reduction of Cu Oxide)

  • 고세진;민경호;강계명;김영도;문인형
    • 한국재료학회지
    • /
    • 제12권8호
    • /
    • pp.656-660
    • /
    • 2002
  • It was investigated that $Al_2$$O_3$/Cu nanocomposite powder could be optimally prepared by dispersion and reduction of Cu oxide, and suitably consolidated by employing pulse electric current sintering (PECS) process. $\alpha$-$Al_2$$O_3$ and CuO powders were used as elemental powders. In order to obtain $Al_2$O$_3$ embedded by finely and homogeneously dispersed CuO particles, the elemental powders were high energy ball milled at the rotating speed of 900 rpm, with the milling time varying up to 10 h. The milled powders were heat treated at $350^{\circ}C$ in H$_2$ atmosphere for 30 min to reduce CuO into Cu. The reduced powders were subsequently sintered by employing PECS process. The composites sintered at $1250^{\circ}C$ for 5 min showed the relative density of above 98%. The fracture toughness of the $Al_2$$O_3$/Cu nanocomposite was as high as 4.9MPa.$m^{1}$2//, being 1.3 times the value of pure $Al_2$$O_3$ sintered under the same condition.

업셋팅 을 이용한 냉간압접 에 대한 연구 (Study on the cold pressure welding by upsetting)

  • 안기원;김재도
    • Journal of Welding and Joining
    • /
    • 제3권2호
    • /
    • pp.27-34
    • /
    • 1985
  • The mechanical properties and bonding mechanism of aluminum, copper and mild steel have been determined in cold pressure welding. The brittle cover layer to be established by scratch-brushing plays an important role in bond strength and has an influence on the threshold of deformation. The cold pressure welding was achieved at 54% of height reduction in A1-A1, 75% in Cu-Cu, 56% in Al-Cu, and 74% in Cu-steel. The height reduction at which the bond strength of weld interface was the same as the tensile strength of base metal should be over 76% in Al-Al, 82% in Cu-Cu, and 78% in Al-Cu.

  • PDF

Al-Zn-Mg-Cu-(Sc) 합금의 석출특성 (Precipitation Behavior of Al-Zn-Mg-Cu-(Sc) Alloy)

  • 최갑송;문호정;우기도
    • 열처리공학회지
    • /
    • 제19권5호
    • /
    • pp.257-261
    • /
    • 2006
  • Scandium(Sc) in Al-Zn-Mg-Cu based Al alloy on precipitation phenomenon was compared to a 7001(Al-7.2%Zn-3.2%Mg-1.8%Cu) Al alloy. GP zone and ${\eta}^{\prime}$ phases were the main strengthening phases at low aging temperature under $100^{\circ}C$, but ${\eta}^{\prime}$ and $Al_3Sc$ phases were the main strengthening phases at high aging temperature above $1600^{\circ}C$ in Sc added 7000(Al-7.7%Zn-2.0%Mg-1.9%Cu-0.1%Zr) Al alloy. With the addition of 0.1%Sc in 7000 Al alloy, the activation energy for the GP zone, ${\eta}^{\prime}$ and ${\eta}$ phase decreased compared to the 7001 Al alloy. This result indicates that the Sc accelerated the precipitation for the GP zone, ${\eta}^{\prime}$ and ${\eta}$ phases in 7000 Al alloy. Al-7.7%Zn-2.0%Mg-1.9%Cu-0.1%Zr-0.1 Sc alloy has higher strength than 7001 Al alloy, which has high strength.

${\gamma}-Al_2O_3$$SiO_2$에 입혀진 산화 구리의 승온 환원 (Temperature-Programmed Reduction of Copper Oxide Supported on ${\gamma}-Al_2O_3$ and $SiO_2$)

  • 이화경;한종수;조민수;이계수;전학제
    • 대한화학회지
    • /
    • 제30권5호
    • /
    • pp.415-422
    • /
    • 1986
  • ${\gamma}-Al_2O_3$$SiO_2$에 입혀진 CuO계에서 지지체와 금속과의 상호 작용을 X선 회절법과 승온 환원법으로 연구했다. CuO/${\gamma}-Al_2O_3$계의 CuO X선 회절 피크는 구리의 농도가 약 5.0wt % 이상일 때 관찰될 수 있었으며 CuO/$SiO_2$계에서는 2.5wt%의 구리 함량에서도 볼 수 있었다. CuO/${\gamma}-Al_2O_3$의 수소에 의한 승온 환원 실험에서는 145${\circ}C$, 185${\circ}C$, 210${\circ}C$, 그리고 250${\circ}C$부근에서 네개의 주 피크가 나타났으며 CuO/$SiO_2$의 경우는 425${\circ}C$에서의 작은 피크와 함께 250${\circ}C$에서 큰 피크가 나타났었다. 1000${\circ}C$에서 소성시킨 CuO/${\gamma}-Al_2O_3$의 Cu$Al_2O_4$에 대한 승온 환원 피크들과 145${\circ}C$, 200${\circ}C$ (185${\circ}C$, 210${\circ}C$), 250${\circ}C$ 부근의 피크들을 비교해 보면 그들은 각각 ${\gamma}-Al_2O_3$와 상호작용하는 CuO격자에 있는 $Cu^+$이온, ${\gamma}-Al_2O_3$의 결함 자리들에 존재하는 $Cu^+$이온, 그리고 입자가 큰 CuO층에 있는 $Cu^{2+}$이온에 대응시킬 수 있었다. 이러한 결과들로 부터 CuO/${\gamma}-Al_2O_3$계에서는 지지체와 금속간에 상당한 상호작용이 있으며 이 상호 작용이 CuO/${\gamma}-Al_2O_3$계의 $Cu^{2+}$이온을 안정화 시킴을 알 수 있었다.

  • PDF

Al-Cu-Li-X(In,Be) 합금(合金)의 조직(組織)과 기계적성질(機械的性質)의 상호관계(相互關係) (Interrelationship between Structure and Mechanical Properties of Al-Cu-Li-X(In,Be) Alloy)

  • 이승호;이종수;김석원;우기도
    • 한국주조공학회지
    • /
    • 제15권4호
    • /
    • pp.351-359
    • /
    • 1995
  • The effects of In and Be additions on the aging behaviors and mechanical properties in the Al-Cu-Li alloy were investigated using the transmission electron microscope, the scanning electron microscope, hardness and tensile strength measurement. The aging is promoted and the double hardness peak is appeared by the addition of In and Be in the Al-Cu-Li alloy. The strength is increased, but the elongation and toughness are decreased by the addition of In in the Al-Cu-Li alloy. And the Al-Cu-Li-In-Be alloy has good combination with the strength, the elogation and toughness than Al-Cu-Li-In alloy.

  • PDF

Cu-Al-Ni계 금속간화합물의 연소합성 Coating에 미치는 Ball Mill처리의 영향 (The Effect of Ball-milling Energy on Combustion Synthesis Coating of Cu-Al-Ni Based Intermetallics)

  • 이한영
    • Tribology and Lubricants
    • /
    • 제27권1호
    • /
    • pp.1-6
    • /
    • 2011
  • The possibility of Cu-Al-Ni intermetallic coating on the mild steel through the combustion synthesis has been investigated. In particular, the effect of the ball milling energy on the microstructure of the coating layer was examined to obtain the best coating condition. Experimental results show that Cu-Al-Ni powder compact was explosively synthesized and successfully coated with the steel matrix. It was revealed that the formation of $Cu_9Al_4$ intermetallic decreased with increase in the ball milling energy. This result supports that the high energy ball milling would be effective for obtaining the most suitable microstructure for Cu-Al-Ni coating layer. However, the excessive ball milling energy seems to decrease the bonding strength between the coating layer and the matrix.

Effects of Al3+ precipitation onto primitive amorphous Cu-Zn precipitate on methanol synthesis over Cu/ZnO/Al2O3 catalyst

  • Jeong, Cheonwoo;Park, Jongha;Kim, Jinsung;Baik, Joon Hyun;Suh, Young-Woong
    • Korean Journal of Chemical Engineering
    • /
    • 제36권2호
    • /
    • pp.191-196
    • /
    • 2019
  • The phase of Cu,Zn,Al precursors strongly affects the activity of their final catalysts. Herein, the Cu,Zn,Al precursor was prepared by precipitation of $Al^{3+}$ onto primitive, amorphous Cu,Zn precipitate. This precursor turned out to be a phase mixture of zincian malachite and hydrotalcite in which the latter phase was less abundant compared to the co-precipitated precursor. The final catalyst derived from this precursor exhibited a little higher copper surface area and methanol synthesis activity than the co-precipitated counterpart. Therefore, the two precursor phases need to be mixed in an adequate proportion for the preparation of active $Cu/ZnO/Al_2O_3$ catalyst.

AlN 반도체와 Cu의 도핑 농도에 대한 자성 (Magnetic Properties of Cu-doped AlN Semiconductor)

  • 강병섭;이행기
    • 반도체디스플레이기술학회지
    • /
    • 제9권3호
    • /
    • pp.1-4
    • /
    • 2010
  • First-principles calculations based on spin density functional theory are performed to study the spin-resolved electronic properties of AlN doped with a Cu concentration of 6.25%-18.75%. The ferromagnetic state is more energetically favorable state than the antiferromagnetic state or the nonmagnetic state. For $Al_{0.9375}Cu_{0.0625}N$, a global magnetic moment of 1.26 mB per supercell, with a localized magnetic moment of 0.75 $m_B$ per Cu atom is found. The magnetic moment is reduced due to an increase in the number of Cu atoms occupying adjacent cation lattice position. For $Al_{0.8125}Cu_{0.1875}N$, the magnetism of the supercell disappears by the interaction of the neighboring Cu atoms. The nonmagnetic to ferromagnetic phase transition is found to occur at this Cu concentration. The range of concentrations that are spin-polarized should be restricted within very narrow.