• Journal of Welding and Joining
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• 제13권3호
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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.

• Journal of Welding and Joining
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• 제18권3호
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• pp.1-4
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• 2000

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1999년도 특별강연 및 춘계학술발표대회 개요집
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• pp.103-106
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• 1999

• Journal of Welding and Joining
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• 제30권6호
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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.

• 한국산학기술학회논문지
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• 제7권2호
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• pp.113-119
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• 2006

중수로형 핵연료 제조공정 중 연료봉 피복관에 간격체와 지지체 등의 부착물이 브레이징으로 접합된다. 본 연구에서는 베릴륨을 물리 증착법(PVD)으로 접합될 부착물의 표면에 증착한 것과 비정질 용가재[$Zr_{1-x}Be_{x}(0.3{\le}x{\le}0.5)$]를 사용하여 브레이징된 접합부의 미세조직과 경도 등의 특성을 비교하고 브레이징 온도가 접합부에 미치는 영향 조사하였다. 비정질 용가재에 의한 접합층의 두께는 PVD-Be의 경우와 비교하여 더 얇았고, Be 함량이 감소할수록 접합층의 두께는 감소하였으며 모재의 침식은 거의 없었다. PVD-Be의 경우 공정 반응, 액상 출현, 모세관 현상과 확산으로 브레이징 되나 비정질 합금은 용가재 만이 용융되어 액상 접합되는 것으로 사료된다. PVD-Be 접합부의 미세조직은 계면에서 수지상이 형성되어 내부로 성장하나, 비정질 합금에 의한 접합부는 석출된 제2상들이 구상으로 구성되며 브레이징 온도가 증가할수록 구상은 더욱 커졌다. 비정질 합금 접합부의 경도는 Be 함량이 감소할수록 경도는 증가하였다. 본 연구에 사용된 비정질 합금 중 $Zr_{0.7}Be_{0.3}$ 합금은 접합부에서 Be의 모재로의 확산이 적어 부드러운 계면과 모재의 침식이 없었고 높은 경도 때문에 핵연료 피복재 접합에 가장 적합한 용가재로 사료된다.

• 동력기계공학회지
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• 제7권3호
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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 $Al_2Si_5\;and\;SiO_2$.

• Journal of Welding and Joining
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• 제20권6호
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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.

• Journal of Welding and Joining
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• 제20권6호
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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.

• 한국재료학회지
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• 제26권7호
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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.

• 한국항공우주학회지
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• 제30권8호
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• pp.65-70
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• 2002

본 연구에서는 로켓엔진에 사용되고 있는 2상 스테인리스강의 브레이징 접합성에 관하여 접합 현상과 기계적 강도의 두가지 측면의 고찰을 통하여 검증하였다. UNS32550을 모재로, MBF-50을 인서트금속으로 사용하여 브레이징 접합온도를 1473K, 1498K로 변화시키고, 접합 시간은 0~1.8ks로 변화시키면서 각 조건에서의 접합현상을 고찰한 결과, 접합부에서는 모재와 인서트금속간의 반응으로 인해 다양한 상이 생성되었다. 접합 초기에는 접합계면 및 접합부 근방의 모재에서 BN가 생성되고, 접합계면에서는 Cr질화물이 생성되어 접합 시간이 증가함에 따라 BN과 Cr질화물의 양이 감소하였다. 전단시험 결과 500MPa의 우수한 전단강도를 얻었다.