• 제목/요약/키워드: intermetallic

검색결과 782건 처리시간 0.027초

반응 용탕단조한(AI203 . SIO2+Ni)/Al하이브리드 금속복합재료의 파괴거동 특성 (Fraccture Behavior of Recation Squeeze Cast ($AI_20_3{\cdot}SiO_2+Ni$)/Al Hybrid Metal Matrix Composites)

  • 김익우;김상석;박익민
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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    • pp.67-70
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    • 2000
  • Mechanical properties of (10%$AI_20_3{\cdot}SiO_2$+5%Ni)/Al hybrid composites fabricated by the reaction squeeze casting were compared with those of (15%$AI_20_3{\cdot}SiO_2$)/Al composites. Intermetallic compound formed by reaction between molten aluminum and reinforcing powder was uniformly distributed in the Al matrix. These intermetallic compounds were identified as $Al_3$NI using EDS and X-ray diffraction analysis. Microhardness and flexural strength of hybrid composites were higher than that of (15%$AI_20_3{\cdot}SiO_2$)/Al Composite. In-Situ fracture tests were Conducted on (15%$AI_20_3{\cdot}SiO_2$)/Al Composites and (10%$AI_20_3{\cdot}SiO_2$+5%Ni)/Al hybrid composites to identify the microfracture process. It was identified from the in-situ fracture test of (10%$AI_20_3{\cdot}SiO_2$+5%Ni)/Al composites, microcracks were initiated mainly at the short fiber / matrix interfaces. As the loading was continued, the crack propagated mainly along the separated interfacial regions and the well developed shear bands. It was identified from the in-situ fracture test of (10%$AI_20_3{\cdot}SiO_2$+5%Ni)/Al hybrid composites, microcracks were initiated mainly by the short fiber/matrix interfacial debonding. The crack proceeded mainly through the intermetallic compound clusters

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금속간 화합물 NiTi와 순금속 니켈 및 티타늄의 전기화학적 부식 특성 (Electrochemical Corrosion Characteristics of the Intermetallic Compound NiTi from Pure Metals)

  • 이규환;신명철
    • 분석과학
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    • 제5권1호
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    • pp.97-101
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    • 1992
  • 순수한 니켈과 티타늄이 같은 양 함유되어 있는 NiTi 금속간 화합물의 인공 생리식염수에서의 부식 특성을 순수한 니켈 및 티타늄과 함께 연구하였다. Tafel 외삽법과 선형 분극법 공히 유사한 결과를 보였으며, 부식 전류 Icorr와 부식 속도는 다음과 같은 순서로 증가하였다. NiTi

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분사주조한 과공정 Al-Si-Fe 합금의 기계적 및 열적 특성에 관한 고찰 (A Study on the Mechanical and Thermal Properties of Spray-cast Hypereutectic Al-Si-Fe Alloys)

  • 박재성;류민;윤의박;윤우영;김권희;김명호
    • 한국주조공학회지
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    • 제26권3호
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    • pp.123-128
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    • 2006
  • Mechanical and thermal properties of spray-cast hypereutectic Al-20wt.%Si-xwt.%Fe alloys (x=0, 1, 3, 5) were investigated. After the spray-casting, hot extrusion was performed at $400^{\circ}C$. Intermetallic compound (${\beta}-Al_5FeSi$) and primary Si are observed in the spray-cast aluminum alloys. The size of primary Si and intermetallic compound of the spray-aluminum alloys became finer and more uniformly distributed than that of the permanent mold cast ones. Ultimate tensile strength of the spray-cast aluminum alloys increased by increasing Fe contents, but that of the permanent mold cast aluminum alloys decreased by increasing Fe contents possibly due to increased amount of coarse intermatallic compound. The coefficient of thermal expansion (CTEs) of the aluminum alloys became lower with finer primary Si and intermetallic compound, and this is attributed to the increased amount of interfacial area between the aluminum matrix and the phases of finer Si and intermetallic compound.

BNi-2계 삽입금속에 의한 SUS304 스테인리스강 접합체의 강도와 조직에 미치는 브레이징 온도의 영향 : Ni기 삽입금속에 의한 브레이징 접합성의 기초적 검토(II) (Influence of Brazing Temperature on Strength and Structure of SUS304 Stainless Steel Brazed System with BNi-2 Filler Metal : Fundamental Study on Brazeability with Ni-Based Filler Metal(II))

  • 이용원;김종훈
    • 한국재료학회지
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    • 제17권3호
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    • pp.179-183
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    • 2007
  • A plate heat exchanger (PHE) normally uses vacuum brazing technology for connecting plates and fins. However, the reliability of high temperature brazing, especially with nickel-based filler metals containing boron the formation of brittle intermetallic compounds (IMCs) in brazed joints is of major concern. since they considerably degrade the mechanical properties. This research was examined the vacuum brazing of commercially SUS304 stainless steel with BNi-2 (Ni-Cr-B-Si) filler metal, and discussed to determine the influence of brazing temperatures on the microstructure and mechanical strength of brazed joints. In the metallographic analysis it is observed that considerable large area of Cr-B intermetallic compound phases at the brazing layer and the brazing tensile strength is related to removal of this brittle phase greatly. The mechanical properties of brazing layer could be stabilized through increasing the brazing temperature over $100^{\circ}C$ more than melting temperature of filler metals, and diffusing enough the brittle intermetallic compound formed in the brazing layer to the base metal.

직접질화법에 의한 (Ti,Al)N계 복합질화물의 합성(II) (Synthesis of (Ti,Al)N Powder by the Direct Nitridation(II))

  • 조영수;이영기;손용운;박경호;김석윤
    • 열처리공학회지
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    • 제9권3호
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    • pp.219-227
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    • 1996
  • The purpose of this research is to develop the technology for the synthesis of (Ti,Al)N powder, which shows simultaneously the excellent properties of TiN and AlN, from the Ti-Al intermetallic compounds by the direct nitriding method. The effects of variables such as temperature, Ti-Al intermetallic compounds ($TiAl_3$, TiAl and $Ti_3Al$) were investigated by TG, XRD and SEM. The (Ti,Al)N powder can be easily synthesized from the intermetallic compounds by the direct nitriding method. Among the intermetallic compounds, the nitriding behavior increased with TiAl> $Ti_3Al$ > $TiAl_3$, as the difference of diffusion coefficient for nitrogen in each materials. The ternary nitride such as $Ti_2AlN$ and $Ti_3Al_2N_2$ can be synthesized by the direct nitriding method, although the ternary nitride coexist with TiN and AlN. The ternary nitrides are stable below $1400^{\circ}C$, but these are gradually decomposed into TiN and AlN above $1400^{\circ}C$.

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보론/티타늄 나노박막다층 내 이종금속간 화학반응 전파특성 해석연구 (Computational Study of Intermetallic Reaction Propagation in Nanoscale Boron/Titanium Metallic Multilayers)

  • 김경진;박중윤
    • 한국추진공학회지
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    • 제21권3호
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    • pp.10-17
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    • 2017
  • 빠른 반응성 및 자체전파특성을 가지는 보론/티타늄 나노 다층박막구조를 대상으로 박막층 수평방향으로의 이종금속간 화학반응 및 화염 전파현상 해석 모델링을 수립하였다. 이종금속간 화학반응은 Arrhenius 반응식을 가정하여 모델링하였으며, 열 및 화학종 확산, 발열 화학반응에 따른 화염 자체전파 현상에 대하여 2차원적 전산해석을 수행하였다. 보론 및 티타늄 박막층의 두께 및 두께비 등 나노구조 형상의 영향을 비롯하여 접촉층 예혼합 정도가 화염 자체전파속도에 미치는 영향을 분석하였다.

고온자전합성과 확산 열처리를 이용한 V 이 첨가된 TiAl계 금속간화합물 복합판재의 제조 (Formation of a V-Added Ti Aluminide Multilayered Sheet by Self-Propagating High-Temperature Synthesis and Diffusion Annealing)

  • 김연욱
    • 한국재료학회지
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    • 제12권9호
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    • pp.696-700
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    • 2002
  • The Ti-aluminide intermetallic compound was formed from high purity elemental Ti and Al foils by self-propagating, high-temperature synthesis(SHS) in hot press. formation of $TiAl_3$ at the interface between Ti and Al foils was controlled by temperature, pressure, heating rate, and so on. According to the thermal analysis, it is known in this study that the heating rate is the most important factor to form the intermetallic compound by this SHS reaction. The V layer addition between Al and Ti foils increased SHS reaction temperatures. The fully dense, well-boned inter-metallic composite($TiA1/Ti_3$Al) sheets of 700 m thickness were formed by heat treatment at $1000^{\circ}C$ for 10 hours after the SHS reaction of alternatively layered 10 Ti and 9 Al foils with the V coating layer. The phases and microstructures of intermetallic composite sheets were confirmed by EPMA and XRD.

The Observation of Intermetallic Compound Microstructure Under Sn Whisker in Lead-free Finish

  • Yu, Chong-Hee
    • 마이크로전자및패키징학회지
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    • 제16권2호
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    • pp.27-31
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    • 2009
  • Sn whiskers can grow from the pure Sn and high Sn-based finish and cause the electrical shorts and failures. Even with the wealth of information on whiskers, we have neither the clear understanding of whisker growth nor methods for its prevention. In this study, the whisker grain roots which connected with intermetallic layer were analyzed by high-resolution transmission electron microscopy (HR-TEM). In the Sn-Cu plated leadframe (LF) that was stored at ambient condition for 540 days, filament-shaped whiskers were grown on the Sn-plated surface and ${\eta}'-Cu_6Sn_5$ precipitates were widely distributed along the grain boundaries at the Sn matrix. The measured of the lattice fringes at the ${\eta}'-Cu_6Sn_5$ was $4.71{\AA}$ at the coarse grain and $2.91{\AA}$ at the fine grain. The $Cu_3Sn$ which generates the tensile stresses was not observed. The formation of $Cu_6Sn_5$ precipitates and intermetallic layer were strongly related to whisker growth, but, the whisker growth tendency does not closely relate with the geometric morphology of irregularly grown intermetallic compound (lMC).

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Ni5Y 합금상이 형성된 Ni계 산화물 분산강화 아토마이징 분말의 밀링 거동 분석 (Analysis on Milling Behavior of Oxide Dispersion Strengthened Ni-based Atomizing Powder with Ni5Y Intermetallic Phase)

  • 박천웅;변종민;최원준;김영도
    • 한국분말재료학회지
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    • 제26권2호
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    • pp.101-106
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    • 2019
  • Ni-based oxide dispersion strengthened (ODS) alloys have a higher usable temperature and better high-temperature mechanical properties than conventional superalloys. They are therefore being explored for applications in various fields such as those of aerospace and gas turbines. In general, ODS alloys are manufactured from alloy powders by mechanical alloying of element powders. However, our research team produces alloy powders in which the $Ni_5Y$ intermetallic phase is formed by an atomizing process. In this study, mechanical alloying was performed using a planetary mill to analyze the milling behavior of Ni-based oxide dispersions strengthened alloy powder in which the $Ni_5Y$ is the intermetallic phase. As the milling time increased, the $Ni_5Y$ intermetallic phase was refined. These results are confirmed by SEM and EPMA analysis on microstructure. In addition, it is confirmed that as the milling increased, the mechanical properties of Ni-based ODS alloy powder improve due to grain refinement by plastic deformation.

The corrosion of aluminium alloy and release of intermetallic particles in nuclear reactor emergency core coolant: Implications for clogging of sump strainers

  • Huang, Junlin;Lister, Derek;Uchida, Shunsuke;Liu, Lihui
    • Nuclear Engineering and Technology
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    • 제51권5호
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    • pp.1345-1354
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    • 2019
  • Clogging of sump strainers that filter the recirculation water in containment after a loss-of-coolant accident (LOCA) seriously impedes the continued cooling of nuclear reactor cores. In experiments examining the corrosion of aluminium alloy 6061, a common material in containment equipment, in borated solutions simulating the water chemistry of sump water after a LOCA, we found that Fe-bearing intermetallic particles, which were initially buried in the Al matrix, were progressively exposed as corrosion continued. Their cathodic nature $vis-{\grave{a}}-vis$ the Al matrix provoked continuous trenching around them until they were finally released into the test solution. Such particles released from Al alloy components in a reactor containment after a LOCA will be transported to the sump entrance with the recirculation flow and trapped by the debris bed that typically forms on the strainer surface, potentially aggravating strainer clogging. These Fe-bearing intermetallic particles, many of which had a rod or thin strip-like geometry, were identified to be mainly the cubic phase ${\alpha}_c-Al(Fe,Mn)Si$ with an average size of about $2.15{\mu}m$; 11.5 g of particles with a volume of about $3.2cm^3$ would be released with the dissolution of every 1 kg 6061 aluminium alloy.