• 제목/요약/키워드: brazing joint

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Brazing of Aluminium Nitride(AlN) to Copper with Ag-based Active Filler Metals (은(Ag)계 활성금속을 사용한 질화 알미늄(AlN)과 Cu의 브레이징)

  • Huh, D.;Kim, D.H.;Chun, B.S.
    • Journal of Welding and Joining
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    • v.13 no.3
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    • pp.134-146
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    • 1995
  • Aluminium nitride(AlN) is currently under investigation as potential candidate for replacing alumium oxide(Al$_{2}$ $O_{3}$) as a substrate material for for electronic circuit packaging. Brazing of aluminium nitride(AlN) to Cu with Ag base active alloy containing Ti has been investigated in vacuum. Binary Ag$_{98}$ $Ti_{2}$(AT) and ternary At-1wt.%Al(ATA), AT-1wt.%Ni(ATN), AT-1wt.% Mn(ATM) alloys showed good wettability to AlN and led to the development of strong bond between brate alloy and AlN ceramic. The reaction between AlN and the melted brazing alloys resulted in the formation of continuous TiN layers at the AlN side iterface. This reaction layer was found to increase by increase by increasing brazing time and temperature for all filler metals. The bond strength, measured by 4-point bend test, was increased with bonding temperature and showed maximum value and then decreased with temperature. It might be concluded that optimum thickness of the reaction layer was existed for maximum bond strength. The joint brazed at 900.deg.C for 1800sec using binary AT alloy fractured at the maximum load of 35kgf which is the highest value measured in this work. The failure of this joint was initiated at the interface between AlN and TiN layer and then proceeded alternately through the interior of the reaction layer and AlN ceramic itself.

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Effect of Brazing Condition on Tensile Properties in Brazing Joints of Inconel-625/Ni-201 Using MBF-30 (MBF-30을 사용한 Inconel-625/Ni-201 브레이징 접합부의 인장성질에 미치는 접합조건의 영향)

  • Yu, Jeong-Woo;Park, Sang-Hyun;Kim, Chang-Su;Kang, Chung-Yun
    • Journal of Welding and Joining
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    • v.30 no.6
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    • pp.106-112
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    • 2012
  • This study was carried out to investigate the effect of bonding temperature and holding time on microstructure and mechanical properties in brazing joints of Ni-base superalloy using MBF-30 (Ni-4.5Si-3.2B [wt.%]). The heating rate was $20^{\circ}C$/min to the bonding temperatures $1050^{\circ}C$, $1070^{\circ}C$, $1090^{\circ}C$ under high vacuum condition. The holding times were 100s, 400s, 900s and 1600s. $Ni_3B$ phases and proeutectic Ni were observed in the interlayer of Ni-201. Then, Ni3B and Ni3Si were found in the middle region of brazing joint. Cr-boride phase appeared in the interlayer of Inconel-625. Tensile strength and elongation were decreased at $1050^{\circ}C$-1600s, $1070^{\circ}C$-900s and $1090^{\circ}C$-400s. After observation the fracture specimens, There was Ni3B which is very brittle phase in the grain boundary of Ni201.

A Study on the Comparison of Brazed Joint of Zircaloy-4 with PVD-Be and Zr-Be Amorphous alloys as Filler Metals (PVD-Be와 비정질 Zr-Be 합금을 용가재로 사용한 Zircaloy-4의 브레이징 접합부의 비교 연구)

  • Hwang, Yong-Hwa;Kim, Jae-Yong;Lee, Hyung-Kwon;Koh, Jin-Hyun;Oh, Se-Yong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.2
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    • pp.113-119
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    • 2006
  • Brazing is an important manufacturing process in the fabrication of Heavy Water Reactor fuel rods, in which bearing and spacer pads are joined to Zircaloy-4 cladding tubes. The physical vapor deposition(PVD) technique is currently used to deposit metallic Be on the surfaces of pads as a filler metal. Amorphous Zr-Be binary alloys which are manufactured by rapid solidification process are under developing to substitute the conventional PVD-Be coating. In the present study, brazed joint with PVD and amorphous alloys of $Zr_{1-x}Be_{x}(0.3{\le}x{\le}0.5)$ as filler metals are compared by mechanism, microstructure and hardness. The thickness of brazed joint with amorphous alloys became much smaller than that of PVD-Be. The erosion of base metal did not occur in the brazed joint with amorphous alloys. The brazing mechanism for PVD-Be seems to be Be diffusion into Zr-4 with capillary action resulting from eutectic reaction while that for amorphous alloys are associated with the liquid phase formation in the brazed joint. The brazed joint microstructure with PVD-Be consists of dendrite while that with amorphous alloys is globular. The $Zr_{0.7}Be_{0.3}$ alloy shows the smooth interface with little erosion in the base metal and is recommended a most suitable brazing filler metal for Zircaloy-4.

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A study on Brazing Interfacial Properties of $Al_2O_3/Al$ 6061 ($Al_2O_3/Al$ 6061의 접합부 계면특성에 관한 연구)

  • Seo, S.Y.;An, B.G.;Lee, K.Y.
    • Journal of Power System Engineering
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    • v.7 no.3
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    • pp.74-79
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    • 2003
  • Alumina($Al_2O_3$) and Al 6061 were brazed by using Al-12wt% Si filler metal in a high vacuum environment. The interfacial microstructure and mechanical properties of the joints were investigated. The results obtained were as follows. (1) The maximum tensile strength of 54Mpa was acquired at the processing conditions of high vacuum ($3{\times}10^{-6}Torr$), $620^{\circ}C$ and 10min, but this condition will not be used in the industrial area due to high evaporation of Al alloy composition. (2) Reaction products for holding time and brazing temperature worked as stress relieve layer and the fractures after the mechanical properties test were occurred to the ceramic side or reaction layer. (3) The glancing angle X-ray diffraction analysis for the reaction product of $Al_2O_3/Al$ 6061 were processed. the joint strengths were low due to existed $Al_2Si_5\;and\;SiO_2$.

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Variations of Micro-Structures and Mechanical Properties of Ti/STS321L Joint Using Brazing Method (브레이징을 이용한 Ti/STS321L 접합체의 미세조직과 기계적 특성의 변화)

  • 구자명;정우주;한범석;권상철;정승부
    • Journal of Welding and Joining
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    • v.20 no.6
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    • pp.106-106
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    • 2002
  • This study investigated variations of micro-structures and mechanical properties of Ti / STS321L joint with various bonding temperature and time using brazing method. According to increasing bonding temperature and time, it was observed that the thickness of their reaction layer increased due So increasing diffusion rate and time. From the EPMA results, Ti diffused to the STS321L substrate according to increasing bending time to 30min. Hardness of bonded interface increased with increasing bonding temperature and time due to increasing their oxides and intermetallic compounds. XRD data indicated that Ag, Ag-Ti intermetallic compounds, TiAg and Ti₃Ag and titanium oxide, TiO₂were formed in interface. In tensile test, it was found that the tensile strength had a maximum value at the bonding temperature of 900℃ and time of 5min, and tensile strength decreased over bonding time of 5min. The critical thickness of intermetallic compounds was observed to about 30㎛, because of brittleness from their excessive intermetallic compounds and titanium oxide, and weakness from void.

Variations of Micro-Structures and Mechanical Properties of Ti/STS321L Joint Using Brazing Method (브레이징을 이용한 Ti/STS321L 접합체의 미세조직과 기계적 특성의 변화)

  • 구자명;정우주;한범석;권상철;정승부
    • Journal of Welding and Joining
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    • v.20 no.6
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    • pp.830-837
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    • 2002
  • This study investigated variations of micro-structures and mechanical properties of Ti / STS321L joint with various bonding temperature and time using brazing method. According to increasing bonding temperature and time, it was observed that the thickness of their reaction layer increased due So increasing diffusion rate and time. From the EPMA results, Ti diffused to the STS321L substrate according to increasing bending time to 30min. Hardness of bonded interface increased with increasing bonding temperature and time due to increasing their oxides and intermetallic compounds. XRD data indicated that Ag, Ag-Ti intermetallic compounds, TiAg and $Ti_3Ag$ and titanium oxide, $TiO_2$ were formed in interface. In tensile test, it was found that the tensile strength had a maximum value at the bonding temperature of $900^{\circ}C$ and time of 5min, and tensile strength decreased over bonding time of 5min. The critical thickness of intermetallic compounds was observed to about $30\mu\textrm{m}$, because of brittleness from their excessive intermetallic compounds and titanium oxide, and weakness from void.

Effect of Tin Addition on the Melting Temperatures and Mechanical Properties of Al-Si-Cu Brazing Filler Metals (저온 브레이징용 Al-Si-Cu 합금의 Sn 첨가에 따른 융점 및 기계적 특성 변화 연구)

  • Kim, Min Sang;Park, Chun Woong;Byun, Jong Min;Kim, Young Do
    • Korean Journal of Materials Research
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    • v.26 no.7
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    • pp.376-381
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    • 2016
  • For the development of a low-melting point filler metal for brazing aluminum alloy, we analyzed change of melting point and wettability with addition of Sn into Al-20Cu-10Si filler metal. DSC results showed that the addition of 5 wt% Sn into the Al-20Cu-10Si filler metal caused its liquidus temperature to decrease by about 30 oC. In the wettability test, spread area of melted Al-Cu-Si-Sn alloy is increased through the addition of Sn from 1 to 5 wt%. For the measuring of the mechanical properties of the joint region, Al 3003 plate is brazed by Al-20Cu-10Si-5Sn filler metal and the mechanical property is measured by tensile test. The results showed that the tensile strength of the joint region is higher than the tensile strength of Al 3003. Thus, failure occurred in the Al 3003 plate.

A Study on the Brazed Joint of Duplex Stainless Steel with Ni Base Insert Metal (Ni기 인서트금속을 이용한 2상 스테인리스강의 브레이징 접합부에 관한 연구)

  • Rhee, Byong-Ho;Ma, Chang-Ik;Kim, Dae-Up
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.30 no.8
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    • pp.65-70
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    • 2002
  • The brazing of duplex stainless steels which is an essential process for rocket engine manufacturing has been investigated on bonding phenomena and shear strength. The UNS32550 was used for base metal, and the MBF-50 was used for insert metal. Brazing was carried out under the various conditions (brazing temperature : 1473K, 1498K, holding time : 0, 0.3, 0.9, 1.8 ks). There were various phases in the joint because of reaction between liquid insert metal and base metal, In the early stage, BN is formed in the bonded interlayer and base metal near the bonded layer. Cr nitride is formed in the bonded interlayer. The amount of BN and Cr nitride decrease with the increase of holding time. Superior shear strength of 550MPa is obtained by restraining the formation of nitride.